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Sample records for surfactant-enhanced aquifer remediation

  1. Surfactant-enhanced aquifer remediation at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Jackson, R.E.; Londergan, J.T.; Pickens, J.

    1995-01-01

    Many DOE facilities are situated in areas of sand and gravel which have become polluted with dense, non-aqueous phase liquids or DNAPLs, such as chlorinated solvents, from the various industrial operations at these facilities. The presence of such DNAPLs in sand and gravel aquifers is now recognized as the principal factor in the failure of standard ground-water remediation methods, i.e., open-quotes pump-and-treatclose quotes operations, to decontaminate such systems. The principal objective of this study is to demonstrate that multi-component DNAPLs can be readily solubilized in sand and gravel aquifers by dilute surfactant solutions

  2. Field pilot test of surfactant-enhanced remediation of trichloroethane DNAPL in a sand aquifer

    International Nuclear Information System (INIS)

    Jackson, R.E.; Butler, G.W.; Londergan, J.T.; Mariner, P.E.; Pickens, J.F.; Fountain, J.C.

    1994-01-01

    The sequence of lacustrine and outwash deposits beneath a vapor degreasing operation at the Paducah Gaseous Division Plant, Kentucky, is contaminated with trichloroethane due to leakage from a sewer/sump line. A plume of dissolved trichloroethane (TCE) extends throughout an area of approximately 3 km 2 in the Regional Gravel Aquifer (RGA) which is located between 20 and 30 meters below ground surface. It is suspected that some 40,000 liters of TCE might have escaped into the subsurface at Paducah, most of which is still present in the lacustrine deposits and the underlying RGA as DNAPL. A field test to confirm the presence of TCE DNAPL in the sandy, upper portion of the RGA around a monitoring well and to test the efficiency of the surfactant for TCE solubilization is described. The aqueous concentrations of TCE in this well have consistently been measured at 300--550 mg TCE/L over a period of three years. The use of Capillary and Bond numbers to estimate the improbability of mobilization of DNAPL due to the lowering of the interfacial tension is described. The multiphase, multicomponent simulator UTCHEM was used to simulate both the injection and extraction of the surfactant solution and the solubilization of the TCE by the surfactant micelles

  3. Correlation between DNAPL distribution area and dissolved concentration in surfactant enhanced aquifer remediation effluent: a two-dimensional flow cell study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Bin; Li, Huiying; Du, Xiaoming; Zhong, Lirong; Yang, Bin; Du, Ping; Gu, Qingbao; Li, Fasheng

    2016-02-01

    During the process of surfactant enhanced aquifer remediation (SEAR), free phase dense non-aqueous phase liquid (DNAPL) may be mobilized and spread. The understanding of the impact of DNAPL spreading on the SEAR remediation is not sufficient with its positive effect infrequently mentioned. To evaluate the correlation between DNAPL spreading and remediation efficiency, a two-dimensional sandbox apparatus was used to simulate the migration and dissolution process of 1,2-DCA (1,2-dichloroethane) DNAPL in SEAR. Distribution area of DNAPL in the sandbox was determined by digital image analysis and correlated with effluent DNAPL concentration. The results showed that the effluent DNAPL concentration has significant positive linear correlation with the DNAPL distribution area, indicating the mobilization of DNAPL could improve remediation efficiency by enlarging total NAPL-water interfacial area for mass transfer. Meanwhile, the vertical migration of 1,2-DCA was limited within the boundary of aquifer in all experiments, implying that by manipulating injection parameters in SEAR, optimal remediation efficiency can be reached while the risk of DNAPL vertical migration is minimized. This study provides a convenient visible and quantitative method for the optimization of parameters for SEAR project, and an approach of rapid predicting the extent of DNAPL contaminant distribution based on the dissolved DNAPL concentration in the extraction well.

  4. Multi-Objective Optimization of the Setup of a Surfactant-Enhanced DNAPL Remediation

    NARCIS (Netherlands)

    Schaerlaekens, J.; Carmeliet, J.; Feyen, J.

    2005-01-01

    Surfactant-enhanced aquifer remediation (SEAR) is widely considered a promising technique to remediate dense nonaqueous phase liquid (DNAPL) contaminations in-situ. The costs of a SEAR remediation are important and depend mostly on the setup of the remediation. Costs can be associated with the

  5. A multi-objective optimization framework for surfactant-enhanced remediation of DNAPL contaminations

    NARCIS (Netherlands)

    Schaerlaekens, J.; Mertens, J.; Van Linden, J.; Vermeiren, G.; Carmeliet, J.; Feyen, J.

    2006-01-01

    The occurrence of Dense Non-Aqueous Phase Liquid (DNAPL) contaminations in the subsurface is a threat for drinkwater resources in the western world. Surfactant-Enhanced Aquifer Remediation (SEAR) is widely considered as one of the most promising techniques to remediate DNAPL contaminations in-situ,

  6. Effect of increased groundwater viscosity on the remedial performance of surfactant-enhanced air sparging

    Science.gov (United States)

    Choi, Jae-Kyeong; Kim, Heonki; Kwon, Hobin; Annable, Michael D.

    2018-03-01

    The effect of groundwater viscosity control on the performance of surfactant-enhanced air sparging (SEAS) was investigated using 1- and 2-dimensional (1-D and 2-D) bench-scale physical models. The viscosity of groundwater was controlled by a thickener, sodium carboxymethylcellulose (SCMC), while an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), was used to control the surface tension of groundwater. When resident DI water was displaced with a SCMC solution (500 mg/L), a SDBS solution (200 mg/L), and a solution with both SCMC (500 mg/L) and SDBS (200 mg/L), the air saturation for sand-packed columns achieved by air sparging increased by 9.5%, 128%, and 154%, respectively, (compared to that of the DI water-saturated column). When the resident water contained SCMC, the minimum air pressure necessary for air sparging processes increased, which is considered to be responsible for the increased air saturation. The extent of the sparging influence zone achieved during the air sparging process using the 2-D model was also affected by viscosity control. Larger sparging influence zones (de-saturated zone due to air injection) were observed for the air sparging processes using the 2-D model initially saturated with high-viscosity solutions, than those without a thickener in the aqueous solution. The enhanced air saturations using SCMC for the 1-D air sparging experiment improved the degradative performance of gaseous oxidation agent (ozone) during air sparging, as measured by the disappearance of fluorescence (fluorescein sodium salt). Based on the experimental evidence generated in this study, the addition of a thickener in the aqueous solution prior to air sparging increased the degree of air saturation and the sparging influence zone, and enhanced the remedial potential of SEAS for contaminated aquifers.

  7. Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

    Science.gov (United States)

    Yan, Jingchun; Gao, Weiguo; Qian, Linbo; Han, Lu; Chen, Yun; Chen, Mengfang

    2015-01-01

    The combination of surfactant enhanced soil washing and degradation of nitrobenzene (NB) in effluent with persulfate was investigated to remediate NB contaminated soil. Aqueous solution of sodium dodecylbenzenesulfonate (SDBS, 24.0 mmol L-1) was used at a given mass ratio of solution to soil (20:1) to extract NB contaminated soil (47.3 mg kg-1), resulting in NB desorption removal efficient of 76.8%. The washing effluent was treated in Fe2+/persulfate and Fe2+/H2O2 systems successively. The degradation removal of NB was 97.9%, being much higher than that of SDBS (51.6%) with addition of 40.0 mmol L-1 Fe2+ and 40.0 mmol L-1 persulfate after 15 min reaction. The preferential degradation was related to the lone pair electron of generated SO4•−, which preferably removes electrons from aromatic parts of NB over long alkyl chains of SDBS through hydrogen abstraction reactions. No preferential degradation was observed in •OH based oxidation because of its hydrogen abstraction or addition mechanism. The sustained SDBS could be reused for washing the contaminated soil. The combination of the effective surfactant-enhanced washing and the preferential degradation of NB with Fe2+/persulfate provide a useful option to remediate NB contaminated soil. PMID:26266532

  8. Geotechnical behaviour of low-permeability soils in surfactant-enhanced electrokinetic remediation.

    Science.gov (United States)

    López-Vizcaíno, Rubén; Navarro, Vicente; Alonso, Juan; Yustres, Ángel; Cañizares, Pablo; Rodrigo, Manuel A; Sáez, Cristina

    2016-01-01

    Electrokinetic processes provide the basis of a range of very interesting techniques for the remediation of polluted soils. These techniques consist of the application of a current field in the soil that develops different transport mechanisms capable of mobilizing several types of pollutants. However, the use of these techniques could generate nondesirable effects related to the geomechanical behavior of the soil, reducing the effectiveness of the processes. In the case of the remediation of polluted soils with plasticity index higher than 35, an excessive shrinkage can be observed in remediation test. For this reason, the continued evaporation that takes place in the sample top can lead to the development of cracks, distorting the electrokinetic transport regime, and consequently, the development of the operation. On the other hand, when analyzing silty soils, in the surroundings of injection surfactant wells, high seepages can be generated that give rise to the development of piping processes. In this article methods are described to allow a reduction, or to even eliminate, both problems.

  9. Drivers and applications of integrated clean-up technologies for surfactant-enhanced remediation of environments contaminated with polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Liang, Xujun; Guo, Chuling; Liao, Changjun; Liu, Shasha; Wick, Lukas Y; Peng, Dan; Yi, Xiaoyun; Lu, Guining; Yin, Hua; Lin, Zhang; Dang, Zhi

    2017-06-01

    Surfactant-enhanced remediation (SER) is considered as a promising and efficient remediation approach. This review summarizes and discusses main drivers on the application of SER in removing polycyclic aromatic hydrocarbons (PAHs) from contaminated soil and water. The effect of PAH-PAH interactions on SER efficiency is, for the first time, illustrated in an SER review. Interactions between mixed PAHs could enhance, decrease, or have no impact on surfactants' solubilization power towards PAHs, thus affecting the optimal usage of surfactants for SER. Although SER can transfer PAHs from soil/non-aqueous phase liquids to the aqueous phase, the harmful impact of PAHs still exists. To decrease the level of PAHs in SER solutions, a series of SER-based integrated cleanup technologies have been developed including surfactant-enhanced bioremediation (SEBR), surfactant-enhanced phytoremediation (SEPR) and SER-advanced oxidation processes (SER-AOPs). In this review, the general considerations and corresponding applications of the integrated cleanup technologies are summarized and discussed. Compared with SER-AOPs, SEBR and SEPR need less operation cost, yet require more treatment time. To successfully achieve the field application of surfactant-based technologies, massive production of the cost-effective green surfactants (i.e. biosurfactants) and comprehensive evaluation of the drivers and the global cost of SER-based cleanup technologies need to be performed in the future. Copyright © 2017. Published by Elsevier Ltd.

  10. Steam Injection For Soil And Aquifer Remediation

    Science.gov (United States)

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

  11. Remediation of a contaminated thin aquifer by horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  12. Bio-remediation of aquifers polluted by chlorinated solvents

    International Nuclear Information System (INIS)

    Fayolle, F.

    1996-01-01

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

  13. GROUND WATER ISSUE: STEAM INJECTION FOR SOIL AND AQUIFER REMEDIATION

    Science.gov (United States)

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

  14. Groundwater Remediation in a Floodplain Aquifer at Shiprock, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dave [Navarro Research and Engineering; Miller, David [Navarro Research and Engineering; Kautsky, Mark [U. S. Department of Energy, Office of Legacy Management; Dander, David [Navarro Research and Engineering; Nofchissey, Joni [Navajo Nation Division of Natural Resources

    2016-03-06

    A uranium- and vanadium-ore-processing mill operated from 1954 to 1968 within the Navajo Nation near Shiprock, New Mexico. By September 1986, all tailings and structures on the former mill property were encapsulated in a disposal cell built on top of two existing tailings piles on the Shiprock site (the site) [1]. Local groundwater was contaminated by multiple inorganic constituents as a result of the milling operations. The U.S. Department of Energy (DOE) took over management of the site in 1978 as part of the Uranium Mill Tailings Remedial Action (UMTRA) Project. The DOE Office of Legacy Management currently manages ongoing activities at the former mill facility, including groundwater remediation. Remediation activities are designed primarily to reduce the concentrations and total plume mass of the mill-related contaminants sulfate, uranium, and nitrate. In addition to contaminating groundwater in alluvial and bedrock sediments directly below the mill site, ore processing led to contamination of a nearby floodplain bordering the San Juan River. Groundwater in a shallow alluvial aquifer beneath the floodplain is strongly influenced by the morphology of the river channel as well as changing flows in the river, which provides drainage for regional runoff from the San Juan Mountains of Colorado. As part of a recent study of the floodplain hydrology, a revised conceptual model was developed for the alluvial aquifer along with an updated status of contaminant plumes that have been impacted by more than 10 years of groundwater pumping for site remediation purposes. Several findings from the recent study will be discussed here.

  15. Using simulation-optimization techniques to improve multiphase aquifer remediation

    Energy Technology Data Exchange (ETDEWEB)

    Finsterle, S.; Pruess, K. [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1995-03-01

    The T2VOC computer model for simulating the transport of organic chemical contaminants in non-isothermal multiphase systems has been coupled to the ITOUGH2 code which solves parameter optimization problems. This allows one to use linear programming and simulated annealing techniques to solve groundwater management problems, i.e. the optimization of operations for multiphase aquifer remediation. A cost function has to be defined, containing the actual and hypothetical expenses of a cleanup operation which depend - directly or indirectly - on the state variables calculated by T2VOC. Subsequently, the code iteratively determines a remediation strategy (e.g. pumping schedule) which minimizes, for instance, pumping and energy costs, the time for cleanup, and residual contamination. We discuss an illustrative sample problem to discuss potential applications of the code. The study shows that the techniques developed for estimating model parameters can be successfully applied to the solution of remediation management problems. The resulting optimum pumping scheme depends, however, on the formulation of the remediation goals and the relative weighting between individual terms of the cost function.

  16. Surfactant enhanced non-classical extraction

    International Nuclear Information System (INIS)

    Szymanowski, J.

    2000-01-01

    Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilisation abilities are also discussed. (author)

  17. Surfactant enhanced non-classical extraction

    International Nuclear Information System (INIS)

    Szymanowski, J.

    1999-01-01

    Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilization abilities are also discussed. (author)

  18. A comparative research of different ensemble surrogate models based on set pair analysis for the DNAPL-contaminated aquifer remediation strategy optimization

    Science.gov (United States)

    Hou, Zeyu; Lu, Wenxi; Xue, Haibo; Lin, Jin

    2017-08-01

    Surrogate-based simulation-optimization technique is an effective approach for optimizing the surfactant enhanced aquifer remediation (SEAR) strategy for clearing DNAPLs. The performance of the surrogate model, which is used to replace the simulation model for the aim of reducing computation burden, is the key of corresponding researches. However, previous researches are generally based on a stand-alone surrogate model, and rarely make efforts to improve the approximation accuracy of the surrogate model to the simulation model sufficiently by combining various methods. In this regard, we present set pair analysis (SPA) as a new method to build ensemble surrogate (ES) model, and conducted a comparative research to select a better ES modeling pattern for the SEAR strategy optimization problems. Surrogate models were developed using radial basis function artificial neural network (RBFANN), support vector regression (SVR), and Kriging. One ES model is assembling RBFANN model, SVR model, and Kriging model using set pair weights according their performance, and the other is assembling several Kriging (the best surrogate modeling method of three) models built with different training sample datasets. Finally, an optimization model, in which the ES model was embedded, was established to obtain the optimal remediation strategy. The results showed the residuals of the outputs between the best ES model and simulation model for 100 testing samples were lower than 1.5%. Using an ES model instead of the simulation model was critical for considerably reducing the computation time of simulation-optimization process and maintaining high computation accuracy simultaneously.

  19. Groundwater re-injection at Fernald: Its role in accelerating the aquifer remedy

    International Nuclear Information System (INIS)

    Broberg, Kenneth A.; Janke, Robert

    2000-01-01

    A successful field-scale demonstration of the use of groundwater re-injection at the Fernald Environmental Management Project (FEMP) was recently completed, bringing the U.S. Department of Energy one step closer to achieving an accelerated site remediation. The demonstration marks the end of a several-year effort to evaluate (a) whether re-injection could be conducted efficiently at Fernald and (b) whether the approved aquifer remedy at Fernald would benefit from incorporating re-injection

  20. Pump-and-treat is not the only solution to aquifer remediation

    International Nuclear Information System (INIS)

    Odermatt, J.R.

    1994-01-01

    The Environmental Protection Agency (EPA) recently surveyed remediation technologies used at petroleum-contaminated sites in 22 states. About 96 percent of underground storage tank (UST) corrective action sites used some form of pump-and-treat technology to remediate contaminated groundwater. However, using only pump-and-treat technology is not a cost-effective approach to aquifer remediation. Pump-and-treat may be more appropriate for containing plumes or for use in initial emergency response actions at sites and massive NAPL releases to groundwater. As of 1990, 68 percent of Superfund records of decision selected pump-and-treat as the final remedy for aquifer remediation. However, of 13 sites where the remedial alternative objective was to restore the aquifer to health-based levels, only one pump-and-treat method has succeeded. Except in cases where human health and the environment are threatened, long-term active technologies, such as pump-and-treat, may not be warranted. Groundwater monitoring and possible wellhead treatment may be perceived as time-consuming processes; however, at many sites, this long-term approach may be far less costly and just as effective as other long-term strategies based on exclusive use of pump-and-treat technology

  1. Advances in hydrocarbons spill remediation in Barreal-Belen: proposed measures for the protection of aquifers

    International Nuclear Information System (INIS)

    Vargas Fallas, Luis Carlos

    2011-01-01

    The advances accomplished with regard to hydrocarbons spill remediation, through 2009 are shown and the costs made in the process are listed. In the Central Valley have been located about 160 gas stations on major aquifers at risk of contamination, in light of the case of hydrocarbons spill happened in Barreal-Belen in 2004, discovered by chance during the inspection to a nearby well. The study instruments of the vulnerability to contamination of aquifers are analyzed. A proposal of measures is presented, which should be taken to ensure control over the risk of further spillage and for proper management of waters. (author) [es

  2. Surfactant-enhanced electrokinetic remediation of soil contaminated with hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.W.; Park, J.Y.; Lee, H.H.; Cho, H.J. [Dept. of Chemical Engineering, Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2001-07-01

    Removal of hydrophobic organic contaminants (HOCs) using electrokinetic method was studied in a model system. Kaolinite and phenanthrene were selected as the model clay soil and representative HOC. Three different types of surfactants, APG (alkyl polyglucoside), Brij30 (polyoxyethylene 4 lauryl ether), and SDS (sodium dodecyl sulfate), were used to enhance the solubility of HOCs. Electrokinetic (EK) column experiments were performed using water, surfactant solution, and acetate buffer solution under a constant current condition. Voltage and flow through the soil system were interpreted with time. Electrolyte pH at the anode and cathode compartments was observed for operation time. Removal efficiency of phenanthrene was examined after the end of EK operation during 2, 4, and 6 weeks. (orig.)

  3. Aquifer characterization and groundwater modeling in support of remedial actions at the Weldon Spring Site

    International Nuclear Information System (INIS)

    Durham, L.A.; Carman, J.D.

    1993-01-01

    Aquifer characterization studies were performed to develop a hydrogeologic understanding of an unconfined shallow aquifer at the Weldon Spring site west of St. Louis, Missouri. The 88-ha site became contaminated because of uranium and thorium processing and disposal activities that took place from the 1940s through the 1960s. Slug and pumping tests provided valuable information on the lateral distribution of hydraulic conductivities, and packer tests and lithologic information were used to determine zones of contrasting hydrologic properties within the aquifer. A three-dimensional, finite- element groundwater flow model was developed and used to simulate the shallow groundwater flow system at the site. The results of this study show that groundwater flow through the system is predominantly controlled by a zone of fracturing and weathering in the upper portion of the limestone aquifer. The groundwater flow model, developed and calibrated from field investigations, improved the understanding of the hydrogeology and supported decisions regarding remedial actions at the site. The results of this study illustrate the value, in support of remedial actions, of combining field investigations with numerical modeling to develop an improved understanding of the hydrogeology at the site

  4. Lab-scale investigation on remediation of diesel-contaminated aquifer using microwave energy.

    Science.gov (United States)

    Falciglia, Pietro P; Maddalena, Riccardo; Mancuso, Giuseppe; Messina, Valeria; Vagliasindi, Federico G A

    2016-02-01

    Aquifer contamination with diesel fuel is a worldwide environmental problem, and related available remediation technologies may not be adequately efficient, especially for the simultaneous treatment of both solid and water phases. In this paper, a lab-scale 2.45 GHz microwave (MW) treatment of an artificially diesel-contaminated aquifer was applied to investigate the effects of operating power (160, 350 and 500 W) and time on temperature profiles and contaminant removal from both solid and water phases. Results suggest that in diesel-contaminated aquifer MW remediation, power significantly influences the final reachable temperature and, consequently, contaminant removal kinetics. A maximum temperature of about 120 °C was reached at 500 W. Observed temperature values depended on the simultaneous irradiation of both aquifer grains and groundwater. In this case, solid phase heating is limited by the maximum temperature that interstitial water can reach before evaporation. A minimal residual diesel concentration of about 100 mg kg(-1) or 100 mg L(-1) was achieved by applying a power of 500 W for a time of 60 min for the solid or water phase, respectively. Measured residual TPH fractions showed that MW heating resulted in preferential effects of the removal of different TPH molecular weight fractions and that the evaporation-stripping phenomena plays a major role in final contaminant removal processes. The power low kinetic equation shows an excellent fit (r(2) > 0.993) with the solid phase residual concentration observed for all the powers investigated. A maximum diesel removal of 88 or 80% was observed for the MW treatment of the solid or water phase, respectively, highlighting the possibility to successfully and simultaneously remediate both the aquifer phases. Consequently, MW, compared to other biological or chemical-physical treatments, appears to be a better choice for the fast remediation of diesel-contaminated aquifers. Copyright © 2015 Elsevier

  5. Electrokinetically Enhanced Delivery for ERD Remediation of Chlorinated Ethenes in a Fractured Limestone Aquifer

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Hyldegaard, Bente Højlund; With Nedergaard, Lærke

    causing very long remediation timeframes. Electrokinetics (EK) offers some unique transport processes, which can potentially overcome the diffusion limitations in the matrix. A novel technology combines ERD and EK for enhanced delivery. The combined technology (EK-BIO) has shown promising results in clay....... Experimental work on EK-BIO in limestone was conducted in a laboratory setup with limestone cores. EK was demonstrated to be promising in establishing enhanced contact between the donor lactate, bacteria, and cis-DCE within the limestone matrix. Complete dechlorination is expected to take place in the matrix......, since back diffusion limitations in the limestone matrix are overcome. This is essential for the overall time perspective of a remediation in limestone aquifers....

  6. Application of Fe-Cu/Biochar System for Chlorobenzene Remediation of Groundwater in Inhomogeneous Aquifers

    Directory of Open Access Journals (Sweden)

    Xu Zhang

    2017-12-01

    Full Text Available Chlorobenzene (CB, as a typical Volatile Organic Contaminants (VOC, is toxic, highly persistent and easily migrates in water, posing a significant risk to human health and subsurface ecosystems. Therefore, exploring effective approaches to remediate groundwater contaminated by CB is essential. As an enhanced micro-electrolysis system for CB-contaminated groundwater remediation, this study attempted to couple the iron-copper bimetal with biochar. Two series of columns using sands with different grain diameters were used, consisting of iron, copper and biochar fillings as the permeable reactive barriers (PRBs, to simulate the remediation of CB-contaminated groundwater in homogeneous and heterogeneous aquifers. Regardless of the presence of homogeneous or heterogeneous porous media, the CB concentrations in the effluent from the PRB columns were significantly lower than the natural sandy columns, suggesting that the iron and copper powders coupled with biochar particles could have a significant removal effect compared to the natural sand porous media in the first columns. CB was transported relatively quickly in the heterogeneous porous media, likely due to the fact that the contaminant residence time is proportional to the infiltration velocities in the different types of porous media. The average effluent CB concentrations from the heterogeneous porous media were lower than those from homogeneous porous media. The heterogeneity retarded the vertical infiltration of CB, leading to its extended lateral distribution. During the treatment process, benzene and phenol were observed as the products of CB degradation. The ultimate CB removal efficiency was 61.4% and 68.1%, demonstrating that the simulated PRB system with the mixture of iron, copper and biochar was effective at removing CB from homogeneous and heterogeneous aquifers.

  7. Air Sparging Versus Gas Saturated Water Injection for Remediation of Volatile LNAPL in the Borden Aquifer

    Science.gov (United States)

    Barker, J.; Nelson, L.; Doughty, C.; Thomson, N.; Lambert, J.

    2009-05-01

    In the shallow, rather homogeneous, unconfined Borden sand aquifer, field trials of air sparging (Tomlinson et al., 2003) and pulsed air sparging (Lambert et al., 2009) have been conducted, the latter to remediate a residual gasoline source emplaced below the water table. As well, a supersaturated (with CO2) water injection (SWI) technology, using the inVentures inFusion system, has been trialed in two phases: 1. in the uncontaminated sand aquifer to evaluate the radius of influence, extent of lateral gas movement and gas saturation below the water table, and 2. in a sheet pile cell in the Borden aquifer to evaluate the recovery of volatile hydrocarbon components (pentane and hexane) of an LNAPL emplaced below the water table (Nelson et al., 2008). The SWI injects water supersaturated with CO2. The supersaturated injected water moves laterally away from the sparge point, releasing CO2 over a wider area than does gas sparging from a single well screen. This presentation compares these two techniques in terms of their potential for remediating volatile NAPL components occurring below the water table in a rather homogeneous sand aquifer. Air sparging created a significantly greater air saturation in the vicinity of the sparge well than did the CO2 system (60 percent versus 16 percent) in the uncontaminated Borden aquifer. However, SWI pushed water, still supersaturated with CO2, up to about 2.5 m from the injection well. This would seem to provide a considerable advantage over air sparging from a point, in that gas bubbles are generated at a much larger radius from the point of injection with SWI and so should involve additional gas pathways through a residual NAPL. Overall, air sparging created a greater area of influence, defined by measurable air saturation in the aquifer, but air sparging also injected about 12 times more gas than was injected in the SWI trials. The pulsed air sparging at Borden (Lambert et al.) removed about 20 percent (4.6 kg) of gasoline

  8. Numerical modeling of Etla Valley aquifer, Oax., Mexico: Evolution and remediation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Marquez, E. L; Martinez-Serrano, R. G; Chavez, R. E; Crusillo, Y [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico); Jimenez, G [Facultad de Ingenieria, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Camops-Enriquez, O [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico)

    2008-01-15

    Short-term evolution (for 2001, 2005 and 2015) for the shallow aquifer of Etla Valley, Oaxaca, southern Mexico, was simulated based in a 3D hydrological model elaborated from the available geological, geophysical, geochemical, and hydrologic parameters. The numerical simulations were based on Visual MODFLOW code. These simulations indicate that, if the actual extraction regime is maintained, the drawdown of the potentiometric surface will get worse to the SE of the study area (i. e. beneath Oaxaca city). The prevailing aquifer flow direction favors the ground water pollution by fertilizers and leakage from the sewage network (dumped to the Atoyac river). According to the numerical simulation, remediation of this situation is possible if the wells located in the neighborhood of Oaxaca City are relocated at the recharge zones (i. e. at the feet from Sierra de Juarez). This remediation scenario will allow a recovery of the drawdown of the potentiometric surface. [Spanish] Se presenta un modelo geohidrologico evolutivo 3D a corto plazo (para los anos 2001, 2005 y 2015) del acuifero somero del Valle de Etla, Oaxaca, sureste de Mexico, basado en los parametros disponibles de geologia, geofisica, geoquimica e hidrologia. Las simulaciones numericas fueron realizadas en Visual MODFLOW. Estas simulaciones indican que, si el actual regimen de extraccion es mantenido, el abatimiento de la superficie potenciometrica puede ser mayor en el SE del area de estudio (i. e. cerca de la ciudad de Oaxaca). La contaminacion por fertilizantes y por las fugas de drenaje es favorecida por la direccion de flujo imperante en el acuifero (vaciandose en el rio Atoyac). De acuerdo a las simulaciones numericas, existe una posible remediacion de este proceso, relocalizando los pozos situados en la ciudad de Oaxaca en las zonas de recarga (i. e. en las faldas de la Sierra de Juarez). Este escenario de remediacion permitiria una recuperacion en el nivel de la superficie potenciometrica.

  9. In-Situ Anaerobic Biosurfactant Production Process For Remediation Of DNAPL Contamination In Subsurface Aquifers

    Science.gov (United States)

    Albino, J. D.; Nambi, I. M.

    2009-12-01

    Microbial Enhanced Oil Recovery (MEOR) and remediation of aquifers contaminated with hydrophobic contaminants require insitu production of biosurfactants for mobilization of entrapped hydrophobic liquids. Most of the biosurfactant producing microorganisms produce them under aerobic condition and hence surfactant production is limited in subsurface condition due to lack of oxygen. Currently bioremediation involves expensive air sparging or excavation followed by exsitu biodegradation. Use of microorganisms which can produce biosurfactants under anaerobic conditions can cost effectively expedite the process of insitu bioremediation or mobilization. In this work, the feasibility of anaerobic biosurfactant production in three mixed anaerobic cultures prepared from groundwater and soil contaminated with chlorinated compounds and municipal sewage sludge was investigated. The cultures were previously enriched under complete anaerobic conditions in the presence of Tetrachloroethylene (PCE) for more than a year before they were studied for biosurfactant production. Biosurfactant production under anaerobic conditions was simulated using two methods: i) induction of starvation in the microbial cultures and ii) addition of complex fermentable substrates. Positive result for biosurfactant production was not observed when the cultures were induced with starvation by adding PCE as blobs which served as the only terminal electron acceptor. However, slight reduction in interfacial tension was noticed which was caused by the adherence of microbes to water-PCE interface. Biosurfactant production was observed in all the three cultures when they were fed with complex fermentable substrates and surface tension of the liquid medium was lowered below 35 mN/m. Among the fermentable substrates tested, vegetable oil yielded highest amount of biosurfactant in all the cultures. Complete biodegradation of PCE to ethylene at a faster rate was also observed when vegetable oil was amended to the

  10. Aquifers

    Data.gov (United States)

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

  11. Transport of poly(acrylic acid) coated 2-line ferrihydrite nanoparticles in saturated aquifer sediments for environmental remediation

    Science.gov (United States)

    Xiang, Aishuang; Zhou, Sheng; Koel, Bruce E.; Jaffé, Peter R.

    2014-04-01

    Groundwater remediation using iron oxide and zero-valent iron nanoparticles (NPs) can be effective, but is limited in many applications due to the NP strong retention in groundwater-saturated porous media after injection, the passivation of the porous surface, and the high cost of nanomaterials versus macro scale iron. In this study, we investigated transport of bare and polymer-coated 2-line ferrihydrite NPs (30-300 nm) in saturated aquifer sediments. The influence of poly(acrylic acid) (PAA) polymer coatings was studied on the colloidal stability and transport in sediments packed column tests simulating groundwater flow in saturated sediments. In addition, the influence of calcium cations was investigated by transport measurements using sediments with calcium concentrations in the aqueous phase ranging from 0.5 (typical for most sediments) to 2 mM. Measurements were also made of zeta potential, hydrodynamic diameter, polymer adsorption and desorption properties, and bio-availability of PAA-coated NPs. We found that NP transport through the saturated aquifer sediments was improved by PAA coating and that the transport properties could be tuned by adjusting the polymer concentration. We further discovered that PAA coatings enhanced NP transport, compared to bare NPs, in all calcium-containing experiments tested, however, the presence of calcium always exhibited a negative effect on NP transport. In tests of bioavailability, the iron reduction rate of the coated and bare NPs by Geobacter sulfurreducens was the same, which shows that the PAA coating does not significantly reduce NP Fe(III) bioavailability. Our results demonstrate that much improved transport of iron oxide NP can be achieved in saturated aquifer sediments by introducing negatively charged polyelectrolytes and optimizing polymer concentrations, and furthermore, these coated NPs retain their bioavailability that is needed for applications in bio-environmental remediation.

  12. An economic decision framework using modeling for improving aquifer remediation design

    International Nuclear Information System (INIS)

    James, B.R.; Gwo, J.P.; Toran, L.E.

    1995-11-01

    Reducing cost is a critical challenge facing environmental remediation today. One of the most effective ways of reducing costs is to improve decision-making. This can range from choosing more cost- effective remediation alternatives (for example, determining whether a groundwater contamination plume should be remediated or not) to improving data collection (for example, determining when data collection should stoop). Uncertainty in site conditions presents a major challenge for effective decision-making. We present a framework for increasing the effectiveness of remedial design decision-making at groundwater contamination sites where there is uncertainty in many parameters that affect remediation design. The objective is to provide an easy-to-use economic framework for making remediation decisions. The presented framework is used to 1) select the best remedial design from a suite of possible ones, 2) estimate if additional data collection is cost-effective, and 3) determine the most important parameters to be sampled. The framework is developed by combining elements from Latin-Hypercube simulation of contaminant transport, economic risk-cost-benefit analysis, and Regional Sensitivity Analysis (RSA)

  13. Application of Fe-Cu/Biochar System for Chlorobenzene Remediation of Groundwater in Inhomogeneous Aquifers

    OpenAIRE

    Xu Zhang; Yanqing Wu; Pingping Zhao; Xin Shu; Qiong Zhou; Zichen Dong

    2017-01-01

    Chlorobenzene (CB), as a typical Volatile Organic Contaminants (VOC), is toxic, highly persistent and easily migrates in water, posing a significant risk to human health and subsurface ecosystems. Therefore, exploring effective approaches to remediate groundwater contaminated by CB is essential. As an enhanced micro-electrolysis system for CB-contaminated groundwater remediation, this study attempted to couple the iron-copper bimetal with biochar. Two series of columns using sands with differ...

  14. Surfactant-enhanced flushing enhances colloid transport and alters macroporosity in diesel-contaminated soil.

    Science.gov (United States)

    Guan, Zhuo; Tang, Xiang-Yu; Nishimura, Taku; Katou, Hidetaka; Liu, Hui-Yun; Qing, Jing

    2018-02-01

    Soil contamination by diesel has been often reported as a result of accidental spillage, leakage and inappropriate use. Surfactant-enhanced soil flushing is a common remediation technique for soils contaminated by hydrophobic organic chemicals. In this study, soil flushing with linear alkylbenzene sulfonates (LAS, an anionic surfactant) was conducted for intact columns (15cm in diameter and 12cm in length) of diesel-contaminated farmland purple soil aged for one year in the field. Dynamics of colloid concentration in column outflow during flushing, diesel removal rate and resulting soil macroporosity change by flushing were analyzed. Removal rate of n-alkanes (representing the diesel) varied with the depth of the topsoil in the range of 14%-96% while the n-alkanes present at low concentrations in the subsoil were completely removed by LAS-enhanced flushing. Much higher colloid concentrations and larger colloid sizes were observed during LAS flushing in column outflow compared to water flushing. The X-ray micro-computed tomography analysis of flushed and unflushed soil cores showed that the proportion of fine macropores (30-250μm in diameter) was reduced significantly by LAS flushing treatment. This phenomenon can be attributed to enhanced clogging of fine macropores by colloids which exhibited higher concentration due to better dispersion by LAS. It can be inferred from this study that the application of LAS-enhanced flushing technique in the purple soil region should be cautious regarding the possibility of rapid colloid-associated contaminant transport via preferential pathways in the subsurface and the clogging of water-conducting soil pores. Copyright © 2017. Published by Elsevier B.V.

  15. Analysis and Remediation of the Salinized, Damour Coastal (Dolomitic) Limestone Aquifer in Lebanon

    NARCIS (Netherlands)

    Khadra, W.M.

    2017-01-01

    Coastal aquifer management has recently emerged as a main scope in groundwater hydrology, especially in arid and semi-arid zones. About two thirds of the human population are currently gathered close to shorelines relying on coastal groundwater resources. Worldwide, these systems are subject to

  16. Use of high performance computing to examine the effectiveness of aquifer remediation

    International Nuclear Information System (INIS)

    Tompson, A.F.B.; Ashby, S.F.; Falgout, R.D.; Smith, S.G.; Fogwell, T.W.; Loosmore, G.A.

    1994-06-01

    Large-scale simulation of fluid flow and chemical migration is being used to study the effectiveness of pump-and-treat restoration of a contaminated, saturated aquifer. A three-element approach focusing on geostatistical representations of heterogeneous aquifers, high-performance computing strategies for simulating flow, migration, and reaction processes in large three-dimensional systems, and highly-resolved simulations of flow and chemical migration in porous formations will be discussed. Results from a preliminary application of this approach to examine pumping behavior at a real, heterogeneous field site will be presented. Future activities will emphasize parallel computations in larger, dynamic, and nonlinear (two-phase) flow problems as well as improved interpretive methods for defining detailed material property distributions

  17. The use of horizontal wells for subsurface soil and aquifer remediation

    International Nuclear Information System (INIS)

    May, D.W.

    1994-01-01

    The use of directionally controlled horizontal drilling for environmental restoration had its genesis in 1988 when two horizontal remediation wells were drilled at the Savannah River Nuclear Facility near Aiken, South Carolina. Since that time, horizontal remediation wells have been drilled at several Department of Energy and Department of Defense sites as well as on several commercial sites across the country. Directional drilling technology applied to ''Near Surface Horizontal Environmental Drilling'' comes from the oil and gas industry, the utility/pipeline river crossing industry and to a lesser extent the mining industry. Rig designs vary from very small track or wheel mounted rigs using 10 feet (3 meters) drill pipe and having less than 2,500 ft. lb. (3,400 N-m) of torque and 15,000 lb. (67 kN) of push/pull force to extremely large trailer mounted rigs with torques exceeding 60,000 ft. lb. (81,400 N-m) and over 500,000 lb. (2,200 kN) of pull. Vertical depths of horizontal wells drilled to-date have exceeded 250 feet (75 m), but the great majority of contaminant plumes are located at depths of less than 50 feet (15 m). Horizontal well displacements have exceeded 1000 feet (300 m) but most of the projects cover less than 400 feet (120 m). Wells can be drilled ''blind'' (terminate in the earth) or exit back up the earth on the other side of the plume from the drill rig

  18. Surfactant-enhanced alkaline flooding for light oil recovery. Annual report, 1992--1993

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, D.T.

    1994-08-01

    In this report, the authors present the results of experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties.

  19. Chance-constrained multi-objective optimization of groundwater remediation design at DNAPLs-contaminated sites using a multi-algorithm genetically adaptive method.

    Science.gov (United States)

    Ouyang, Qi; Lu, Wenxi; Hou, Zeyu; Zhang, Yu; Li, Shuai; Luo, Jiannan

    2017-05-01

    In this paper, a multi-algorithm genetically adaptive multi-objective (AMALGAM) method is proposed as a multi-objective optimization solver. It was implemented in the multi-objective optimization of a groundwater remediation design at sites contaminated by dense non-aqueous phase liquids. In this study, there were two objectives: minimization of the total remediation cost, and minimization of the remediation time. A non-dominated sorting genetic algorithm II (NSGA-II) was adopted to compare with the proposed method. For efficiency, the time-consuming surfactant-enhanced aquifer remediation simulation model was replaced by a surrogate model constructed by a multi-gene genetic programming (MGGP) technique. Similarly, two other surrogate modeling methods-support vector regression (SVR) and Kriging (KRG)-were employed to make comparisons with MGGP. In addition, the surrogate-modeling uncertainty was incorporated in the optimization model by chance-constrained programming (CCP). The results showed that, for the problem considered in this study, (1) the solutions obtained by AMALGAM incurred less remediation cost and required less time than those of NSGA-II, indicating that AMALGAM outperformed NSGA-II. It was additionally shown that (2) the MGGP surrogate model was more accurate than SVR and KRG; and (3) the remediation cost and time increased with the confidence level, which can enable decision makers to make a suitable choice by considering the given budget, remediation time, and reliability. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Chance-constrained multi-objective optimization of groundwater remediation design at DNAPLs-contaminated sites using a multi-algorithm genetically adaptive method

    Science.gov (United States)

    Ouyang, Qi; Lu, Wenxi; Hou, Zeyu; Zhang, Yu; Li, Shuai; Luo, Jiannan

    2017-05-01

    In this paper, a multi-algorithm genetically adaptive multi-objective (AMALGAM) method is proposed as a multi-objective optimization solver. It was implemented in the multi-objective optimization of a groundwater remediation design at sites contaminated by dense non-aqueous phase liquids. In this study, there were two objectives: minimization of the total remediation cost, and minimization of the remediation time. A non-dominated sorting genetic algorithm II (NSGA-II) was adopted to compare with the proposed method. For efficiency, the time-consuming surfactant-enhanced aquifer remediation simulation model was replaced by a surrogate model constructed by a multi-gene genetic programming (MGGP) technique. Similarly, two other surrogate modeling methods-support vector regression (SVR) and Kriging (KRG)-were employed to make comparisons with MGGP. In addition, the surrogate-modeling uncertainty was incorporated in the optimization model by chance-constrained programming (CCP). The results showed that, for the problem considered in this study, (1) the solutions obtained by AMALGAM incurred less remediation cost and required less time than those of NSGA-II, indicating that AMALGAM outperformed NSGA-II. It was additionally shown that (2) the MGGP surrogate model was more accurate than SVR and KRG; and (3) the remediation cost and time increased with the confidence level, which can enable decision makers to make a suitable choice by considering the given budget, remediation time, and reliability.

  1. Risk-Based Management of Contaminated Groundwater: The Role of Geologic Heterogeneity, Exposure and Cancer Risk in Determining the Performance of Aquifer Remediation

    International Nuclear Information System (INIS)

    Maxwell, R.M.; Carle, S.F.; Tompson, A.F.B.

    2000-01-01

    The effectiveness of aquifer remediation is typically expressed in terms of a reduction in contaminant concentrations relative to a regulated maximum contaminant level (MCL), and is usually confined by sparse monitoring data and/or simple model calculations. Here, the effectiveness of remediation is examined from a risk-based perspective that goes beyond the traditional MCL concept. A methodology is employed to evaluate the health risk to individuals exposed to contaminated household water that is produced from groundwater. This approach explicitly accounts for differences in risk arising from variability in individual physiology and water use, the uncertainty in estimating chemical carcinogenesis for different individuals, and the uncertainties and variability in contaminant concentrations within groundwater. A hypothetical contamination scenario is developed as a case study in a saturated, alluvial aquifer underlying a real Superfund site. A baseline (unremediated) human exposure and health risk scenario, as induced by contaminated groundwater pumped from this site, is predicted and compared with a similar estimate based upon pump-and-treat exposure intervention. The predicted reduction in risk in the remediation scenario is not an equitable one-that is, it is not uniform to all individuals within a population and varies according to the level of uncertainty in prediction. The importance of understanding the detailed hydrogeologic connections that are established in the heterogeneous geologic regime between the contaminated source, municipal receptors, and remediation wells, and its relationship to this uncertainty is demonstrated. Using two alternative pumping rates, we develop cost-benefit curves based upon reduced exposure and risk to different individuals within the population, under the presence of uncertainty

  2. Laboratory-scale column study for remediation of TCE-contaminated aquifers using three-section controlled-release potassium permanganate barriers.

    Science.gov (United States)

    Yuan, Baoling; Li, Fei; Chen, Yanmei; Fu, Ming-Lai

    2013-05-01

    A laboratory-scale study with a sand column was designed to simulate trichloroethylene (TCE) pollution in the aquifer environment with three-section controlled-release potassium permanganate (CRP) barriers. The main objective of this study was to evaluate the feasibility of CRP barriers in remediation of TCE in aquifers in a long-term and controlled manner. CRP particles with a 1:3 molar ratio of KMnO4 to stearic acid showed the best controlled-release properties in pure water, and the theoretical release time was 138.5 days. The results of TCE removal in the test column indicated that complete removal efficiency of TCE in a sand column by three-section CRP barriers could be reached within 15 days. The molar ratio of KMnO4 to TCE in the three-section CRP barriers was 16:1, which was much lower than 82:1 as required when KMnO4 solution is used directly to achieve complete destruction of TCE. This result revealed that the efficiency of CRP for remediation of TCE was highly improved after encapsulation.

  3. Surfactant-enhanced alkaline flooding for light oil recovery. Final report 1994--1995

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, D.T.

    1995-12-01

    In this report, the authors present the results of their experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are summarized.

  4. Surfactant-enhanced alkaline flooding for light oil recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wasan, D.T.

    1996-05-01

    In this report, we present the results of our experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12. 0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, we have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are discussed.

  5. BENCH-SCALE VISUALIZATION OF DNAPL REMEDIATION PROCESSES IN ANALOG HETEROGENEOUS AQUIFERS: SURFACTANT FLOODS, AND IN SITU OXIDATION USING PERMANGANATE

    Science.gov (United States)

    We have conducted well-controlled DNAPL remediation experiments using surfactants (Aerosol MA and Tween 80) to increase solubility and an oxidant (permanganate) to chemically degrade the DNAPL. Photographs and digital image analysis illustrate previously unobserved interactions b...

  6. Development and validation of a model of bio-barriers for remediation of Cr(VI) contaminated aquifers using laboratory column experiments.

    Science.gov (United States)

    Shashidhar, T; Bhallamudi, S Murty; Philip, Ligy

    2007-07-16

    Bench scale transport and biotransformation experiments and mathematical model simulations were carried out to study the effectiveness of bio-barriers for the containment of hexavalent chromium in contaminated confined aquifers. Experimental results showed that a 10cm thick bio-barrier with an initial biomass concentration of 0.205mg/g of soil was able to completely contain a Cr(VI) plume of 25mg/L concentration. It was also observed that pore water velocity and initial biomass concentration are the most significant parameters in the containment of Cr(VI). The mathematical model developed is based on one-dimensional advection-dispersion reaction equations for Cr(VI) and molasses in saturated, homogeneous porous medium. The transport of Cr(VI) and molasses is coupled with adsorption and Monod's inhibition kinetics for immobile bacteria. It was found that, in general, the model was able to simulate the experimental results satisfactorily. However, there was disparity between the numerically simulated and experimental breakthrough curves for Cr(VI) and molasses in cases where there was high clay content and high microbial activity. The mathematical model could contribute towards improved designs of future bio-barriers for the remediation of Cr(VI) contaminated aquifers.

  7. Surfactant-enhanced solubilization of residual dodecane in soil columns. 2. Mathematical modeling

    International Nuclear Information System (INIS)

    Abriola, L.M.; Dekker, T.J.; Pennell, K.D.

    1993-01-01

    A mathematical model is developed to describe surfactant-enhanced solubilization of nonaqueous-phase liquids (NAPLs) in porous media. The model incorporates aqueous-phase transport equations for organic and surfactant components as well as a mass balance for the organic phase. Rate-limited solubilization and surfactant sorption are represented by a linear driving force expression and a Langmuir isotherm, respectively. The model is implemented in a one-dimensional Galerkin finite element simulator which idealizes the entrapped residual organic as a collection of spherical globules. Soil column data for the solubilization of residual dodecane by an aqueous solution of polyoxyethylene (20) sorbitan monooleate are used to evaluate the conceptual model. Input parameters were obtained, where possible, from independent batch experiments. Calibrated model simulations exhibit good agreement with measured effluent concentrations, supporting the utility of the conceptual modeling approach. Sensitivity analyses explore the influence of surfactant concentration and flushing strategy on NAPL recovery. 45 refs., 6 figs., 3 tabs

  8. CHROTRAN 1.0: A mathematical and computational model for in situ heavy metal remediation in heterogeneous aquifers

    Science.gov (United States)

    Hansen, Scott K.; Pandey, Sachin; Karra, Satish; Vesselinov, Velimir V.

    2017-12-01

    Groundwater contamination by heavy metals is a critical environmental problem for which in situ remediation is frequently the only viable treatment option. For such interventions, a multi-dimensional reactive transport model of relevant biogeochemical processes is invaluable. To this end, we developed a model, chrotran, for in situ treatment, which includes full dynamics for five species: a heavy metal to be remediated, an electron donor, biomass, a nontoxic conservative bio-inhibitor, and a biocide. Direct abiotic reduction by donor-metal interaction as well as donor-driven biomass growth and bio-reduction are modeled, along with crucial processes such as donor sorption, bio-fouling, and biomass death. Our software implementation handles heterogeneous flow fields, as well as arbitrarily many chemical species and amendment injection points, and features full coupling between flow and reactive transport. We describe installation and usage and present two example simulations demonstrating its unique capabilities. One simulation suggests an unorthodox approach to remediation of Cr(VI) contamination.

  9. CHROTRAN 1.0. A mathematical and computational model for in situ heavy metal remediation in heterogeneous aquifers

    International Nuclear Information System (INIS)

    Hansen, Scott K.; Pandey, Sachin; Karra, Satish; Vesselinov, Velimir V.

    2017-01-01

    Groundwater contamination by heavy metals is a critical environmental problem for which in situ remediation is frequently the only viable treatment option. For such interventions, a multi-dimensional reactive transport model of relevant biogeochemical processes is invaluable. To this end, we developed a model, chrotran, for in situ treatment, which includes full dynamics for five species: a heavy metal to be remediated, an electron donor, biomass, a nontoxic conservative bio-inhibitor, and a biocide. Direct abiotic reduction by donor-metal interaction as well as donor-driven biomass growth and bio-reduction are modeled, along with crucial processes such as donor sorption, bio-fouling, and biomass death. Our software implementation handles heterogeneous flow fields, as well as arbitrarily many chemical species and amendment injection points, and features full coupling between flow and reactive transport. We describe installation and usage and present two example simulations demonstrating its unique capabilities. One simulation suggests an unorthodox approach to remediation of Cr(VI) contamination.

  10. CHROTRAN 1.0: A mathematical and computational model for in situ heavy metal remediation in heterogeneous aquifers

    Directory of Open Access Journals (Sweden)

    S. K. Hansen

    2017-12-01

    Full Text Available Groundwater contamination by heavy metals is a critical environmental problem for which in situ remediation is frequently the only viable treatment option. For such interventions, a multi-dimensional reactive transport model of relevant biogeochemical processes is invaluable. To this end, we developed a model, chrotran, for in situ treatment, which includes full dynamics for five species: a heavy metal to be remediated, an electron donor, biomass, a nontoxic conservative bio-inhibitor, and a biocide. Direct abiotic reduction by donor–metal interaction as well as donor-driven biomass growth and bio-reduction are modeled, along with crucial processes such as donor sorption, bio-fouling, and biomass death. Our software implementation handles heterogeneous flow fields, as well as arbitrarily many chemical species and amendment injection points, and features full coupling between flow and reactive transport. We describe installation and usage and present two example simulations demonstrating its unique capabilities. One simulation suggests an unorthodox approach to remediation of Cr(VI contamination.

  11. CHROTRAN 1.0. A mathematical and computational model for in situ heavy metal remediation in heterogeneous aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Scott K.; Pandey, Sachin; Karra, Satish; Vesselinov, Velimir V. [Los Alamos National Laboratory, Los Alamos, NM (United States). Computational Earth Science Group (EES-16)

    2017-07-01

    Groundwater contamination by heavy metals is a critical environmental problem for which in situ remediation is frequently the only viable treatment option. For such interventions, a multi-dimensional reactive transport model of relevant biogeochemical processes is invaluable. To this end, we developed a model, chrotran, for in situ treatment, which includes full dynamics for five species: a heavy metal to be remediated, an electron donor, biomass, a nontoxic conservative bio-inhibitor, and a biocide. Direct abiotic reduction by donor-metal interaction as well as donor-driven biomass growth and bio-reduction are modeled, along with crucial processes such as donor sorption, bio-fouling, and biomass death. Our software implementation handles heterogeneous flow fields, as well as arbitrarily many chemical species and amendment injection points, and features full coupling between flow and reactive transport. We describe installation and usage and present two example simulations demonstrating its unique capabilities. One simulation suggests an unorthodox approach to remediation of Cr(VI) contamination.

  12. Remediation of a marine shore tailings deposit and the importance of water-rock interaction on element cycling in the coastal aquifer.

    Science.gov (United States)

    Dold, Bernhard; Diaby, Nouhou; Spangenberg, Jorge E

    2011-06-01

    We present the study of the geochemical processes associated with the first successful remediation of a marine shore tailings deposit in a coastal desert environment (Bahía de Ite, in the Atacama Desert of Peru). The remediation approach implemented a wetland on top of the oxidized tailings. The site is characterized by a high hydraulic gradient produced by agricultural irrigation on upstream gravel terraces that pushed river water (∼500 mg/L SO(4)) toward the sea and through the tailings deposit. The geochemical and isotopic (δ(2)H(water) and δ(18)O(water), δ(34)S(sulfate), δ(18)O(sulfate)) approach applied here revealed that evaporite horizons (anhydrite and halite) in the gravel terraces are the source of increased concentrations of SO(4), Cl, and Na up to ∼1500 mg/L in the springs at the base of the gravel terraces. Deeper groundwater interacting with underlying marine sequences increased the concentrations of SO(4), Cl, and Na up to 6000 mg/L and increased the alkalinity up to 923 mg/L CaCO(3) eq. in the coastal aquifer. These waters infiltrated into the tailings deposit at the shelf-tailings interface. Nonremediated tailings had a low-pH oxidation zone (pH 1-4) with significant accumulations of efflorescent salts (10-20 cm thick) at the surface because of upward capillary transport of metal cations in the arid climate. Remediated tailings were characterized by neutral pH and reducing conditions (pH ∼7, Eh ∼100 mV). As a result, most bivalent metals such as Cu, Zn, and Ni had very low concentrations (around 0.01 mg/L or below detection limit) because of reduction and sorption processes. In contrast, these reducing conditions increased the mobility of iron from two sources in this system: (1) The originally Fe(III)-rich oxidation zone, where Fe(III) was reduced during the remediation process and formed an Fe(II) plume, and (2) reductive dissolution of Fe(III) oxides present in the original shelf lithology formed an Fe-Mn plume at 10-m depth. These

  13. The application of a mulch biofilm barrier for surfactant enhanced polycyclic aromatic hydrocarbon bioremediation

    International Nuclear Information System (INIS)

    Seo, Youngwoo; Lee, Woo-Hyung; Sorial, George; Bishop, Paul L.

    2009-01-01

    Lab scale mulch biofilm barriers were constructed and tested to evaluate their performance for preventing the migration of aqueous and surfactant solubilized PAHs. The spatial distribution of viable PAH degrader populations and resultant biofilm formation were also monitored to evaluate the performance of the biobarrier and the prolonged surfactant effect on the PAH degrading microorganism consortia in the biobarrier. Sorption and biodegradation of PAHs resulted in stable operation of the system for dissolved phenanthrene and pyrene during 150 days of experimentation. The nonionic surfactant could increase the solubility of phenanthrene and pyrene significantly. However, the biobarrier itself couldn't totally prevent the migration of micellar solubilized phenanthrene and pyrene. The presence of surfactant and the resultant highly increased phenanthrene or pyrene concentration didn't appear to cause toxic effects on the attached biofilm in the biobarrier. However, the presence of surfactant did change the structural composition of the biofilm. - Mulch biofilm barrier showed potential for surfactant enhanced bioremediation, and the presence of surfactant changed the structural composition of the biofilm

  14. Practical Considerations and Challenges Involved in Surfactant Enhanced Bioremediation of Oil

    Directory of Open Access Journals (Sweden)

    Sagarika Mohanty

    2013-01-01

    Full Text Available Surfactant enhanced bioremediation (SEB of oil is an approach adopted to overcome the bioavailability constraints encountered in biotransformation of nonaqueous phase liquid (NAPL pollutants. Fuel oils contain n-alkanes and other aliphatic hydrocarbons, monoaromatics, and polynuclear aromatic hydrocarbons (PAHs. Although hydrocarbon degrading cultures are abundant in nature, complete biodegradation of oil is rarely achieved even under favorable environmental conditions due to the structural complexity of oil and culture specificities. Moreover, the interaction among cultures in a consortium, substrate interaction effects during the degradation and ability of specific cultures to alter the bioavailability of oil invariably affect the process. Although SEB has the potential to increase the degradation rate of oil and its constituents, there are numerous challenges in the successful application of this technology. Success is dependent on the choice of appropriate surfactant type and dose since the surfactant-hydrocarbon-microorganism interaction may be unique to each scenario. Surfactants not only enhance the uptake of constituents through micellar solubilization and emulsification but can also alter microbial cell surface characteristics. Moreover, hydrocarbons partitioned in micelles may not be readily bioavailable depending on the microorganism-surfactant interactions. Surfactant toxicity and inherent biodegradability of surfactants may pose additional challenges as discussed in this review.

  15. Surfactant-enhanced recovery of dissolved hydrocarbons at petroleum production facilities

    International Nuclear Information System (INIS)

    Freeman, J.T.; Mayes, M.; Wassmuth, F.; Taylor, K.; Rae, W.; Kuipers, F.

    1997-01-01

    The feasibility and cost effectiveness of surfactant-enhanced pumping to reduce source concentrations of petroleum hydrocarbons from contaminated soils was discussed. Light non-aqueous phase liquids (LNAPL) hydrocarbons are present beneath many petroleum production processing facilities in western Canada. Complete removal of LNAPLs from geologic materials is difficult and expensive. Treatment technologies include costly ex-situ methods such as excavation and in-situ methods such as physical extraction by soil venting and pumping, bioremediation, and combination methods such as bioventing, bioslurping or air sparging. Surfactant-aided pumping can reduce source hydrocarbon concentrations when used in conjunction with traditional pump and treat, or deep well injection. This study involved the selection of an appropriate surfactant from a wide variety of commercially available products. A site contaminated by hydrocarbons in Turner Valley, Alberta, was used for field scale testing. One of the major problems was quantifying the increase in the dissolved hydrocarbon concentrations in the recovered water once a surfactant was added. From the 30 surfactants screened in a series of washing and oil solubilization tests, two surfactants, Brij 97 and Tween 80, were selected for further evaluation. Increased hydrocarbon recovery was observed within 10 days of the introduction of the first surfactant. 2 refs., 7 figs

  16. Surfactant-Enhanced Size-Excluded Transport of Bacteria Through Unsaturated Porous Media.

    Science.gov (United States)

    Zhu, J.

    2017-12-01

    US domestic waste water is rich in surfactants because of the intensive usage of surfactants-containing household product. It results in a surfactants presence environment when this untreated waste water released into subsurface. It was reported that surfactants enhance the colloidal transport in porous media, which have significant effect on issues such as subsurface pathogens contamination and biodegradation. In this study, soil column experiments were conducted. The soil column was remained unsaturated and with a steady flow passing through it. Escherichia coli K-12 transported in the soil column and its breakthrough data was collected in presence of surfactant anionic surfactant linear alkylbenzene sulfonate (LAS) concentration range over 0, 0.25, 0.5, 0.75, 1, and 2 times Critical Micelle Concentration (CMC). It was found that the increase in LAS concentration greatly increases breakthrough concentration C/C0 and decreases breakthrough time tb until LAS concentration reaches 1 xCMC. Numerical models were built simulating and investigating this phenomenon. The goodness of model fitting was greatly improved by adding exclusion factor into the model, which indicated that the presence of surfactant might enhance the exclusion effect. The relationships between LAS concentration and the two coefficients, deposition rate coefficient k and exclusion effect coefficient θim, were found can be fitted by a quasi-Langmuir equation. And the model validation with observed data showed that the model has an acceptable reliability.

  17. Practical Considerations and Challenges Involved in Surfactant Enhanced Bioremediation of Oil

    Science.gov (United States)

    Mohanty, Sagarika; Jasmine, Jublee

    2013-01-01

    Surfactant enhanced bioremediation (SEB) of oil is an approach adopted to overcome the bioavailability constraints encountered in biotransformation of nonaqueous phase liquid (NAPL) pollutants. Fuel oils contain n-alkanes and other aliphatic hydrocarbons, monoaromatics, and polynuclear aromatic hydrocarbons (PAHs). Although hydrocarbon degrading cultures are abundant in nature, complete biodegradation of oil is rarely achieved even under favorable environmental conditions due to the structural complexity of oil and culture specificities. Moreover, the interaction among cultures in a consortium, substrate interaction effects during the degradation and ability of specific cultures to alter the bioavailability of oil invariably affect the process. Although SEB has the potential to increase the degradation rate of oil and its constituents, there are numerous challenges in the successful application of this technology. Success is dependent on the choice of appropriate surfactant type and dose since the surfactant-hydrocarbon-microorganism interaction may be unique to each scenario. Surfactants not only enhance the uptake of constituents through micellar solubilization and emulsification but can also alter microbial cell surface characteristics. Moreover, hydrocarbons partitioned in micelles may not be readily bioavailable depending on the microorganism-surfactant interactions. Surfactant toxicity and inherent biodegradability of surfactants may pose additional challenges as discussed in this review. PMID:24350261

  18. Application of surfactant enhanced permanganate oxidation and bidegradation of trichloroethylene in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, T.T.; Kao, C.M. [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Yeh, T.Y. [Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung, Taiwan (China)], E-mail: tyyeh@nuk.edu.tw; Liang, S.H.; Chien, H.Y. [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan (China)

    2009-01-15

    The industrial solvent trichloroethylene (TCE) is among the most ubiquitous chlorinated solvents found in groundwater contamination. The main objectives of this study were to evaluate the feasibility of using non-ionic surfactant Simple Green{sup TM} (SG) to enhance the oxidative dechlorination of TCE by potassium permanganate (KMnO{sub 4}) employing a continuous stir batch reactor system (CSBR) and column experiments. The effect of using surfactant SG to enhance the biodegradation of TCE via aerobic cometabolism was also examined. Results from CSBR experiments revealed that combination of KMnO{sub 4} with surfactant SG significantly enhanced contaminant removal, particularly when the surfactant SG concentrated at its CMC. TCE degradation rates ranged from 74.1% to 85.7% without addition of surfactant SG while TCE degradation rates increased to ranging from 83.8% to 96.3% with presence of 0.1 wt% SG. Furthermore, results from column experiments showed that TCE was degraded from 38.1 {mu}M to 6.2 {mu}M in equivalent to 83.7% of TCE oxidation during first 560 min reaction. This study has also demonstrated that the addition of surfactant SG is a feasible method to enhance bioremediation efficiency for TCE contaminated groundwater. The complete TCE degradation was detected after 75 days of incubation with both 0.01 and 0.1 wt% of surfactant SG addition. Results revealed that surfactant enhanced chemical oxidation and bioremediation technology is one of feasible approaches to clean up TCE contaminated groundwater.

  19. Aquifer Characteristics Data Report for the Weldon Spring Site chemical plant/raffinate pits and vicinity properties for the Weldon Spring Site Remedial Action Project, Weldon Spring, Missouri

    International Nuclear Information System (INIS)

    1990-11-01

    This report describes the procedures and methods used, and presents the results of physical testing performed, to characterize the hydraulic properties of the shallow Mississippian-Devonian aquifer beneath the Weldon Spring chemical plant, raffinate pits, and vicinity properties. The aquifer of concern is composed of saturated rocks of the Burlington-Keokuk Limestone which constitutes the upper portion of the Mississippian-Devonian aquifer. This aquifer is a heterogeneous anisotropic medium which can be described in terms of diffuse Darcian flow overlain by high porosity discrete flow zones and conduits. Average hydraulic conductivity for all wells tested is 9.6E-02 meters/day (3.1E-01 feet/day). High hydraulic conductivity values are representative of discrete flow in the fractured and weathered zones in the upper Burlington-Keokuk Limestone. They indicate heterogeneities within the Mississippian-Devonian aquifer. Aquifer heterogeneity in the horizontal plane is believed to be randomly distributed and is a function of fracture spacing, solution voids, and preglacial weathering phenomena. Relatively high hydraulic conductivities in deeper portions of the aquifer are though to be due to the presence of widely spaced fractures. 44 refs., 27 figs., 9 tabs

  20. Shifts in microbial community structure during in situ surfactant-enhanced bioremediation of polycyclic aromatic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wang, Lingwen; Li, Feng; Zhan, Yu; Zhu, Lizhong

    2016-07-01

    This study aims to reveal the microbial mechanism of in situ surfactant-enhanced bioremediation (SEBR). Various concentrations of rhamnolipids, Tween 80, and sodium dodecyl benzenesulfonate (SDBS) were separately sprayed onto soils contaminated with polycyclic aromatic hydrocarbons (PAHs) for years. Within 90 days, the highest level of degradation (95 %) was observed in the soil treated with rhamnolipids (10 mg/kg), followed by 92 % degradation with Tween 80 (50 mg/kg) and 90 % degradation with SDBS (50 mg/kg). The results of the microbial phospholipid fatty acids (PLFAs) suggest that bacteria dominated the enhanced PAH biodegradation (94 % of the maximum contribution). The shift of bacterial community structure during the surfactant treatment was analyzed by using the 16S rRNA gene high-throughput sequencing. In the presence of surfactants, the number of the operational taxonomic units (OTUs) associated with Bacillus, Pseudomonas, and Sphingomonas increased from 2-3 to 15-30 % at the end of the experiment (two to three times of control). Gene prediction with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) shows that the PAH-degrading genes, such as 1-hydroxy-2-naphthoate dioxygenase and PAH dioxygenase large subunit, significantly increased after the surfactant applications (p bioremediation.

  1. Alluvial Aquifer

    Data.gov (United States)

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

  2. Carbonate aquifers

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

    Sreekanth, J.; Datta, Bithin

    2011-07-01

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

  4. Ozark Aquifer

    Data.gov (United States)

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

  5. Risk assessment and management of an oil contaminated aquifer

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  6. Guarani aquifer

    International Nuclear Information System (INIS)

    2007-01-01

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

  7. Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe3O4 nanoparticles

    Science.gov (United States)

    Manafi, Mohammad Hanif; Allahyari, Mehdi; Pourghazi, Kamyar; Amoli-Diva, Mitra; Taherimaslak, Zohreh

    2015-07-01

    The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100 mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL-1 with low detection limit of 0.03 ng mL-1 were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method.

  8. Methyl Salicylate-Based Vortex-Assisted Surfactant-Enhanced Emulsification Microextraction and HPLC for Determination of Fungicides in Honey Samples.

    Science.gov (United States)

    Santaladchaiyakit, Yanawath; Bunchamnan, Jutamas; Tongsa, Darunee; Srijaranai, Supalax

    2017-12-01

    Methyl salicylate based vortex-assisted surfactant-enhanced emulsification microextraction (MeSA-VASEME) has been developed and applied for rapid preconcentration of fungicides (i.e., carbendazim, thiabendazole, and fluberidazole) in honey samples followed by high performance liquid chromatographic analysis. MeSA was used as an extraction solvent, while surfactant was used to enhance the extraction performance under the dispersion by vortex agitation. The optimum MeSA-VASEME conditions were 100 μL MeSA, 2.0 mmol L‒1 sodium dodecyl sulfate, and vortex agitation at 1200 rpm for 90 s. Preconcentration factors were obtained in the range of 32-40. The limit of detection in the studied honey samples was 0.5 μg L‒1. The recovery of the spiked target fungicides at 20, 50, and 100 μg L‒1 were 81.5-116.8 % with the relative standard deviation below 11%. The proposed method is simple, sensitive, less organic solvent consuming, inexpensive, and a rapid procedure for the residue analysis of fungicides in honey samples.

  9. Improved surfactants formulation for remediation of oil sludge recovery

    International Nuclear Information System (INIS)

    Syed Hakimi Sakuma Syed Ahmad; Shahidan Radiman

    2000-01-01

    Surfactant enhanced remediation based on mobilisation of the residual NAPLs (oil sludge) which is radioactive depends on the tendency of the surfactants to lower interfacial tension. Mobilisation has greater potential than solubilisation to increase the rate of remediation. Optimised surfactants formulation was determined with concentration of Aqua 2000 and D Bond of 1% wt respectively, sodium chloride concentration of 2 gmL -1 and addition of 3% wt butanol as cosolvent. The formulation was of benefit not only able to decrease further the interfacial tension of aqueous solution containing oil emulsion, but also to make possible to be more mobile and destruction of mixed liquid crystals that formed. Formation of liquid crystals can hinders significantly recovery efficiency of aqueous solution containing oil emulsion in field remediation work. In a 100 litres soil column experiment conducted containing oil emulsion in field sludge soil and using the surfactants formulation for flushing, miniemulsion formed sizes maintained at average size between 125 nm and 280 nm before and after remediation. Total oil and grease concentration removed from the soil were significant due to the decreased in oil emulsion sizes, increase mobility and solubility. (Author)

  10. Determination of melamine in soil samples using surfactant-enhanced hollow fiber liquid phase microextraction followed by HPLC–UV using experimental design

    Directory of Open Access Journals (Sweden)

    Ali Sarafraz Yazdi

    2015-11-01

    Full Text Available Surfactant-enhanced hollow fiber liquid phase (SE-HF-LPME microextraction was applied for the extraction of melamine in conjunction with high performance liquid chromatography with UV detection (HPLC–UV. Sodium dodecyl sulfate (SDS was added firstly to the sample solution at pH 1.9 to form hydrophobic ion-pair with protonated melamine. Then the protonated melamine–dodecyl sulfate ion-pair (Mel–DS was extracted from aqueous phase into organic phase immobilized in the pores and lumen of the hollow fiber. After extraction, the analyte-enriched 1-octanol was withdrawn into the syringe and injected into the HPLC. Preliminary, one variable at a time method was applied to select the type of extraction solvent. Then, in screening step, the other variables that may affect the extraction efficiency of the analyte were studied using a fractional factorial design. In the next step, a central composite design was applied for optimization of the significant factors having positive effects on extraction efficiency. The optimum operational conditions included: sample volume, 5 mL; surfactant concentration, 1.5 mM; pH 1.9; stirring rate, 1500 rpm and extraction time, 60 min. Using the optimum conditions, the method was analytically evaluated. The detection limit, relative standard deviation and linear range were 0.005 μg mL−1, 4.0% (3 μg mL−1, n = 5 and 0.01–8 μg mL−1, respectively. The performance of the procedure in extraction of melamine from the soil samples was good according to its relative recoveries in different spiking levels (95–109%.

  11. Application of Optimized Vortex-Assisted Surfactant-Enhanced DLLME for Preconcentration of Thymol and Carvacrol, and Their Determination by HPLC-UV: Response Surface Methodology.

    Science.gov (United States)

    Ghaedi, Mehrorang; Roosta, Mostafa; Khodadoust, Saeid; Daneshfar, Ali

    2015-08-01

    A novel vortex-assisted surfactant-enhanced dispersive liquid-liquid microextraction combined with high-performance liquid chromatography (VASEDLLME-HPLC) was developed for the determination of thymol and carvacrol (phenolic compound). In this method, the extraction solvent (CHCl3) was dispersed into the aqueous samples via a vortex agitator and addition of the surfactant (Triton X-100). The preliminary experiments were undertaken to select the best extraction solvent and surfactant. The influences of effective variables were investigated using a Plackett-Burman 2(7-4) screening design and then, the significant variables were optimized by using a central composite design combined with desirability function. Working under optimum conditions specified as: 140 µL CHCl3, 0.08% (w/v, Triton X-100), 3 min extraction time, 6 min centrifugation at 4,500 rpm, pH 7, 0.0% (w/v) NaCl permit achievement of high and reasonable linear range over 0.005-4.0 mg L(-1) with R(2) = 0.9998 (n = 10). The separation of thymol and carvacrol was achieved in <14 min using a C18 column and an isocratic binary mobile phase acetonitrile-water (55:45, v/v) with a flow rate of 1.0 mL min(-1). The VASEDLLME is applied for successful determination of carvacrol and thymol in different thyme and pharmaceutical samples with relative standard deviation <4.7% (n = 5). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Groundwater remediation in the Straz leaching operation

    International Nuclear Information System (INIS)

    Novak, J.

    2001-01-01

    The locality affected by consequences of the chemical mining of the uranium during underground leaching 'in situ' is found in the area of the Czech Republic in the northeastern part of the Ceska Lipa district. In the contribution the complex groundwater remediation project is discussed. First, the risks of the current state are expressed. Then the alternatives of remediation of the both Cenomanian and Turonian aquifers are presented. Evaluation of the remediation alternatives with the view to the time-consumption, economy, ecology and the elimination of unacceptable risks for the population and environment is done. Finally, the present progress of remediation and the conception of remediation of chemical mining on deposit of Straz pod Ralskem are presented. (orig.)

  13. Alternative Remedies

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Alternative Remedies Font ... medical treatment prescribed by their healthcare provider. Using this type of alternative therapy along with traditional treatments is ...

  14. Genealogy Remediated

    DEFF Research Database (Denmark)

    Marselis, Randi

    2007-01-01

    Genealogical websites are becoming an increasingly popular genre on the Web. This chapter will examine how remediation is used creatively in the construction of family history. While remediation of different kinds of old memory materials is essential in genealogy, digital technology opens new...... possibilities. Genealogists use their private websites to negotiate family identity and hereby create a sense of belonging in an increasingly complex society. Digital technologies enhance the possibilities of coorporation between genealogists. Therefore, the websites are also used to present archival...

  15. Recovery of energetically overexploited urban aquifers using surface water

    Science.gov (United States)

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

    2015-12-01

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

  16. Dual Pump Recovery (DPR System to Extract Freshwater in Coastal Aquifers

    Directory of Open Access Journals (Sweden)

    C. Otto

    2002-06-01

    Full Text Available The paper describes the hydraulic theory of recovering a dense plume using a newly devised dual pump recover system (DPR and its feasibility to half the remediation time of a contaminated unconfined aquifer in a coastal urban environment. Although the DPR system was successfully applied to clean up the polluted aquifer, the hydraulic principles and techniques are also applicable to extract fresh groundwater from coastal aquifers without the risk of saltwater incursion.

  17. 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...

  18. Understanding Uranium Behavior in a Reduced Aquifer

    Science.gov (United States)

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

    2012-12-01

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

  19. DEMONSTRATION BULLETIN STEAM ENHANCED REMEDIATION STEAM TECH ENVIRONMENTAL SERVICES, INC.

    Science.gov (United States)

    Steam Enhanced Remediation is a process in which steam is injected into the subsurface to recover volatile and semivolatile organic contaminants. It has been applied successfully to recover contaminants from soil and aquifers and at a fractured granite site. This SITE demonstra...

  20. Laboratory evidence of MTBE biodegradation in Borden aquifer material

    Science.gov (United States)

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

    2003-02-01

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

  1. Fifth national outdoor action conference on aquifer restoration, ground water monitoring, and geophysical methods

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This book presents papers on technology in ground water sampling, monitoring, and remediation and geophysical techniques. The section on monitoring and remediation covers monitoring case studies, monitoring waste disposal sites, petroleum recovery, techniques in aquifer remediation, mathematical analysis of remedial techniques, vacuum extraction, bioremediation, and monitoring techniques. The section on sampling covers measurement variability, microbial sampling, vadose zone sampling, sampling with hydraulic probes, unusual sampling problems and equipment, and data management. A section on geophysics covers geophysics and site characterization, and geophysics and mining. The focus is on hazardous organic compounds. Individual articles are abstracted separately

  2. EPA Sole Source Aquifers

    Data.gov (United States)

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

  3. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl

    1995-01-01

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

  4. Ogallala Aquifer Mapping Program

    International Nuclear Information System (INIS)

    1984-10-01

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

  5. Perched aquifers - their potential impact on contaminant transport in the southern High Plains, Texas

    International Nuclear Information System (INIS)

    Mullican, W.F. III; Fryar, A.E.; Johns, N.D.

    1993-01-01

    Understanding the hydrogeology and hydrochemistry of perched aquifers at potential and known contaminated waste sites has become increasingly important because of the impact these aquifers may have on contaminant transport independent of regional aquifer processes. Investigations of a perched aquifer above the Ogallala aquifer are being conducted in the region of the U.S. Department of Energy's Pantex Plant, a proposed Superfund site, located approximately 20 mi northeast of Amarillo, Texas. Since the early 1950s, a small playa basin located on the Pantex Plant has been used as a waste-water discharge pond with daily discharge rates ranging from 400,000 to 1 million gal. The focus of this investigation is an unconfined, perched aquifer that overlies a thick silty clay sequence within the upper, mostly unsaturated part of the Ogallala Formation (Neogene). In the area of the Pantex Plant, measured depths to the perched aquifer range from 200 to 300 ft below land surface, whereas depth to the regional Ogallala aquifer ranges from 375 to 500 ft. The potentiometric surface of the perched aquifer typically represents groundwater mounds proximal to the playas and thins into trough in the interplaya areas. Hydrologic gradients of the primary mound under investigation are relatively high, ranging from 28 to 45 ft/mi. Calculated transmissivities have a geometric mean of 54 ft 2 /day, with saturated thicknesses ranging from 4 to 1000 ft. Modeling of the perched aquifer was designed to determine how much, if any, discharge to the small playa basin has enhanced recharge to the perched aquifers and increased the vertical and lateral extent of the perched aquifer. Preliminary results indicate that measurements of vertical conductance through the perching silty-clay sequence and recharge rates through playas are critical for calibrating the model. Accurate delineation of rates and flow directions in the perched aquifer is critical to any successful remediation effort

  6. Ultrasound-assisted surfactant-enhanced emulsification microextraction with solidification of floating organic droplet followed by high performance liquid chromatography for the determination of strobilurin fungicides in fruit juice samples.

    Science.gov (United States)

    Liang, Pei; Liu, Guojiao; Wang, Fang; Wang, Wanting

    2013-05-01

    A novel method, ultrasound-assisted surfactant-enhanced emulsification microextraction with solidification of floating organic droplet (UASEME-SFOD), has been developed for the extraction of four strobilurin fungicides (kresoxim-methyl, picoxystrobin, pyraclostrobin and trifloxystrobin) in fruit juices. In the UASEME-SFOD technique, Tween 80 was used as emulsifier, and 1-undecanol was used as extraction solvent without using any organic dispersive solvent. Several parameters that affect the extraction efficiency, such as the kind and volume of extraction solvent, the type and concentration of the surfactant, extraction time, extraction temperature and salt addition were investigated and optimized. Under the optimum extraction condition, the method yields a linear calibration curve in the concentration range from 5 to 10,000 ng mL(-1) for the targeted analytes with the correlation coefficient ranging from 0.9991 to 0.9998. The enrichment factors were in the range between 95 and 135, and the limits of detection of the method were 2-4 ng mL(-1). The fruit juice samples were successfully analyzed using the proposed method, and the relative recoveries at fortified levels of 50 and 100 ng mL(-1) were in the range of 82.6-97.5%. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Mold: Cleanup and Remediation

    Science.gov (United States)

    ... National Center for Environmental Health (NCEH) Cleanup and Remediation Recommend on Facebook Tweet Share Compartir On This ... CDC and EPA on mold cleanup, removal and remediation. Cleanup information for you and your family Homeowner’s ...

  8. Colloid remediation in groundwater by polyelectrolyte capture

    International Nuclear Information System (INIS)

    Nuttall, H.E.; Rao, S.; Jain, R.

    1992-01-01

    This paper describes an ongoing study to characterize groundwater colloids, to understand the geochemical factors affecting colloid transport in groundwater, and to develop an in-situ colloid remediation process. The colloids and suspended particulate matter used in this study were collected from a perched aquifer site that has radiation levels several hundred times the natural background and where previous researchers have measured and reported the presence of radiocolloids containing plutonium and americium. At this site, radionuclides have spread over several kilometers. Inorganic colloids collected from water samples are characterized with respect to concentration, mineralogy, size distribution, electrophoretic mobility (zeta potential), and radioactivity levels. Presented are the methods used to investigate the physiochemical factors affecting colloid transport and the preliminary analytical results. Included below are a description of a colloid transport model and the corresponding computational code, water analyses, characterization of the inorganic colloids, and a conceptual description of a process for in-situ colloid remediation using the phenomenon of polyelectrolyte capture

  9. Topical Day on Site Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, H [ed.

    1996-09-18

    Ongoing activities at the Belgian Nuclear Research Centre relating to site remediation and restoration are summarized. Special attention has been paid to the different phases of remediation including characterization, impact assessment, evaluation of remediation actions, and execution of remediation actions.

  10. Effects of microarrangement of solid particles on PCE migration and its remediation in porous media

    Science.gov (United States)

    Wu, Ming; Wu, Jianfeng; Wu, Jichun; Hu, Bill X.

    2018-02-01

    Groundwater can be stored abundantly in granula-composed aquifers with high permeability. The microstructure of granular materials has important effect on the permeability of aquifers and the contaminant migration and remediation in aquifers is also influenced by the characteristics of porous media. In this study, two different microscale arrangements of sand particles are compared to reveal the effects of microstructure on the contaminant migration and remediation. With the help of fractal theory, the mathematical expressions of permeability and entry pressure are conducted to delineate granular materials with regular triangle arrangement (RTA) and square pitch arrangement (SPA) at microscale. Using a sequential Gaussian simulation (SGS) method, a synthetic heterogeneous site contaminated by perchloroethylene (PCE) is then used to investigate the migration and remediation affected by the two different microscale arrangements. PCE is released from an underground storage tank into the aquifer and the surfactant is used to clean up the subsurface contamination. Results suggest that RTA can not only cause more groundwater contamination, but also make remediation become more difficult. The PCE remediation efficiency of 60.01-99.78 % with a mean of 92.52 and 65.53-99.74 % with a mean of 95.83 % is achieved for 200 individual heterogeneous realizations based on the RTA and SPA, respectively, indicating that the cleanup of PCE in aquifer with SPA is significantly easier. This study leads to a new understanding of the microstructures of porous media and demonstrates how microscale arrangements control contaminant migration in aquifers, which is helpful to design successful remediation scheme for underground storage tank spill.

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

    International Nuclear Information System (INIS)

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

    1993-04-01

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

  12. A Mathematical View of Water Table Fluctuations in a Shallow Aquifer in Brazil

    NARCIS (Netherlands)

    Neto, Dagmar C.; Chang, Hung K.; van Genuchten, Martinus Th

    Detailed monitoring of the groundwater table can provide important data about both short- and long-term aquifer processes, including information useful for estimating recharge and facilitating groundwater modeling and remediation efforts. In this paper, we presents results of 4years (2002 to 2005)

  13. Almost remediation of saltwater spills at E and P sites

    International Nuclear Information System (INIS)

    Carty, D.J.

    1995-01-01

    At exploration and production (E and P) sites crude spills restricted to topsoil are often self-remediating, but salt spills rarely are. Most soils naturally biodegrade crude. Without appropriate human intervention, brine spills can result in decades of barren land and seriously degrade surface water and aquifers. Servicing the E and P industry are remediation practitioners with a limited array of often expensive remediation concepts and materials which they hope will work, and sometimes do. Unfortunately, many remediation practitioners are unfamiliar with, or disregard, the natural physical, chemical, and biotic complexity of the soil and aquatic media. All too often this results in exacerbating injury to an already damaged ecosystem. Likewise, important cultural factors such as public relations, environmental regulations, property rights, and water rights are also overlooked until after implementation of an ill-advised or illegal remediation design has been initiated. A major issue is determining what constitutes ''successful'' remediation of a brine spill. Environmental managers have long sought one or two universally applicable fast and cheap amendment/treatment protocols for all their diverse multi-state salt affected spill scenarios. This presentation describes aspects of common spill-affected ecosystems which must be considered to achieve ''successful'' remediation

  14. Remedial design of the Fultz Landfill Site, Byesville, Ohio

    International Nuclear Information System (INIS)

    Rajaram, V.; Riesing, R.; Bloom, T.

    1994-01-01

    The Fultz Landfill Superfund (Fultz) site is a 30-acre hazardous waste landfill located near Byesville, Ohio. The site is approximately 75 miles east of Columbus and 3 miles southwest of Cambridge, the largest city in Guernsey County, Ohio. The landfill is situated on the north slope of a ridge that overlies abandoned coal mines in the Upper Freeport Coal seam. The north half of the landfill lies in an unreclaimed strip mine in the Upper Freeport Coal seam, where saturated portions of surface mine spoils and natural soils form the ''shallow aquifer''. The south half of the landfill lies 40 to 50 feet (ft.) above an abandoned, flooded deep mine in the same coal seam. The flooded deep mine forms an aquifer referred to as the ''coal mine aquifer''. This paper presents the results of design studies completed by PRC Environmental Management, Inc. (PRC), during 1993, and the remedial design (RD) of the components specified by the US Environmental Protection Agency (EPA) Record of Decision (ROD) for the Fultz site (EPA 1991). The remedy specified in the ROD includes a multilayer landfill cap that is compliant with Resource Conservation and Recovery Act (RCRA) Subtitle C guidelines, a leachate collection and groundwater extraction and treatment system, and stabilizing mine voids underlying the southern portion of the site. Vinyl chloride is the only contaminant exceeding a maximum contaminant limit (MCL) in the coal mine aquifer

  15. 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.)

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

    Science.gov (United States)

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

    1999-01-01

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

  17. Groundwater flow to a horizontal or slanted well in an unconfined aquifer

    Science.gov (United States)

    Zhan, Hongbin; Zlotnik, Vitaly A.

    2002-07-01

    New semianalytical solutions for evaluation of the drawdown near horizontal and slanted wells with finite length screens in unconfined aquifers are presented. These fully three-dimensional solutions consider instantaneous drainage or delayed yield and aquifer anisotropy. As a basis, solution for the drawdown created by a point source in a uniform anisotropic unconfined aquifer is derived in Laplace domain. Using superposition, the point source solution is extended to the cases of the horizontal and slanted wells. The previous solutions for vertical wells can be described as a special case of the new solutions. Numerical Laplace inversion allows effective evaluation of the drawdown in real time. Examples illustrate the effects of well geometry and the aquifer parameters on drawdown. Results can be used to generate type curves from observations in piezometers and partially or fully penetrating observation wells. The proposed solutions and software are useful for the parameter identification, design of remediation systems, drainage, and mine dewatering.

  18. Electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Karlsmose, Bodil; Ottosen, Lisbeth M.; Hansen, Lene

    1999-01-01

    The paper gives an overview of how heavy metals can be found in the soil and the theory of electrodialytic remediation. Basically electrodialytic remediation works by passing electric current through the soil, and the heavy metals in ionic form will carry some of the current. Ion-exchange membranes...... prevents the protons and the hydroxides ions from the electrode processes to enter the soil. The heavy metals are collected in a concentration compartment, which is separated from the soil by ion-exchange membranes. Examples from remediation experiments are shown, and it is demonstrated that it is possible...... to remediate soil polluted with heavy metals be this method. When adding desorbing agents or complexing agents, chosing the right current density, electrolyte and membranes, the proces can be optimised for a given remediation situation. Also electroosmosis is influencing the system, and if extra water...

  19. Arsenic levels in groundwater aquifer

    African Journals Online (AJOL)

    Miodrag Jelic

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

  20. EPA Region 1 Sole Source Aquifers

    Data.gov (United States)

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

  1. Multi-phase flow modeling of soil contamination and soil remediation

    NARCIS (Netherlands)

    Dijke, van M.I.J.

    1997-01-01


    In this thesis multi-phase flow models are used to study the flow behavior of liquid contaminants in aquifers and of gases that are injected below the groundwater table for remediation purposes. Considered problems are redistribution of a lens of light nonaqueous phase

  2. Degradation of petroleum hydrocarbons in a laboratory aquifer column

    International Nuclear Information System (INIS)

    Billowits, M.; Whyte, L.; Greer, C.; Ramsay, J.

    1998-01-01

    One of the primary mechanisms for eliminating hydrocarbon pollutants from the environment is degradation of hydrocarbons by indigenous microorganisms. This report describes a study in which samples from a petroleum polluted shallow aquifer in the Yukon were used which contained a hundred times greater concentration of psychrotropic bacteria than mesophilic bacteria. Results showed a maximum degradation of 47 per cent of the total petroleum hydrocarbon in columns which simulated the aquifer conditions and to which nutrients were added. It was concluded that although in this case bioaugmentation of the columns with a psychrotropic hydrocarbon-degrading consortium increased microbial numbers, total petroleum hydrocarbon degradation was not much greater than could be achieved by remediation with nutrients alone

  3. 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.

  4. Post monitoring of a cyclodextrin remeditated chlorinated solvent contaminated aquifer

    Science.gov (United States)

    Blanford, W. J.

    2006-12-01

    Hydroxypropyl-â-cyclodextrin (HPâCD) has been tested successfully in the laboratory and in the field for enhanced flushing of low-polarity contaminants from aquifers. The cyclodextrin molecule forms a toroidal structure, which has a hydrophobic cavity. Within this cavity, organic compounds of appropriate shape and size can form inclusion complexes, which is the basis for the use of cyclodextrin in groundwater remediation. The hydrophilic exterior of the molecule makes cyclodextrin highly water-soluble. The solubility of cyclodextrins can be further enhanced by adding functional groups, such as hydroxypropyl groups, to the cyclodextrin core. The aqueous solubility of HPâCD exceeds 950 g/L. These high solubilities are advantageous for field applications because they permit relatively high concentrations of the flushing agent. In order for cyclodextrin to become a feasible remediative alternative, it must be demonstrate a short term resistance to biodegradation during field application, but ultimately biodegrade so as not to pose a long term presence in the aquifer. The potential for degradation of cyclodextrin as well as changes in the chlorinated solvents and groundwater geochemistry were examined during the post monitoring of a field demonstration in a shallow aquifer at Little Creek Naval Amphibious Base in Virginia. It was found that a portion of the cyclodextrin remaining in the aquifer after the cessation of field activities biodegraded during the 425 days of post monitoring. This degradation also led to the degradation of the chlorinated solvents trichloroethylene and 1,1-trichloroethane through both biological and chemical processes. The aquifer remained anaerobic with average dissolved oxygen levels below 0.5 mg/L. Dissolved nitrate and sulfate concentrations within the cyclodextrin plume decreased due their being used as terminal electron acceptors during the degradation of the cyclodextrin. The concentrations of total iron at the field site showed no

  5. AQUIFER IN AJAOKUTA, SOUTHWESTERN NIGERIA

    African Journals Online (AJOL)

    2005-03-08

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

  6. Superfund Green Remediation

    Science.gov (United States)

    Green remediation is the practice of considering all environmental effects of site cleanup and incorporating options – like the use of renewable energy resources – to maximize the environmental benefits of cleanups.

  7. MGP site remediation: Working toward presumptive remedies

    International Nuclear Information System (INIS)

    Larsen, B.R.

    1996-01-01

    Manufactured Gas Plants (MGPs) were prevalent in the United States during the 19th and first half of the 20th centuries. MGPs produced large quantities of waste by-products, which varied depending on the process used to manufacture the gas, but most commonly were tars and polynuclear aromatic hydrocarbons. There are an estimated 3,000 to 5,000 abandoned MGP sites across the United States. Because these sites are not concentrated in one geographic location and at least three different manufacturing processes were used, the waste characteristics are very heterogeneous. The question of site remediation becomes how to implement a cost-effective remediation with the variety of cleanup technologies available for these sites. Because of the significant expenditure required for characterization and cleanup of MGP sites, owners and regulatory agencies are beginning to look at standardizing cleanup technologies for these sites. This paper discusses applicable cleanup technologies and the attitude of state regulatory agencies towards the use of presumptive remedies, which can reduce the amount of characterization and detailed analysis necessary for any particular site. Additionally, this paper outlines the process of screening and evaluating candidate technologies, and the progress being made to match the technology to the site

  8. Papers of the remediation technologies symposium 2005. CD-ROM ed.

    International Nuclear Information System (INIS)

    2005-01-01

    This conference was attended by over 500 delegates and provided an opportunity for industry, practitioners, researchers and regulators to discuss technical issues in environmental remediation research and recent innovations in soil and groundwater remediation. Sessions included presentations on in-situ, groundwater and surface water remediation. Issues concerning phytoremediation, natural attenuation, extraction and commercial redevelopment were examined. The aim of the conference was also to provide a forum for innovators in remediation to present new work. Topics included hydrocarbon and salt contamination; engineered soil cover for management of salt impacted sites; remediation and revegetation of tar sands composite tailings containing naphthenic acids; sorption of oil sands naphthenic acid mixtures; denitrification as a natural attenuation mechanism; sampling methodologies; variability assessments; stabilization treatment technologies; remediation of coal wastes; bioreactor landfills; well blowouts in Alberta; soil remediation in coarse gravelly soils; diesel-contaminated aquifers; gasoline spill remediation; soil vapour extraction systems; technological solutions for erosion control and water clarification; and cost-effective in-situ remediation strategies. Fifty-two technical presentations were given, of which 27 have been catalogued separately for inclusion in this database

  9. Papers of the remediation technologies symposium 2005. CD-ROM ed.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This conference was attended by over 500 delegates and provided an opportunity for industry, practitioners, researchers and regulators to discuss technical issues in environmental remediation research and recent innovations in soil and groundwater remediation. Sessions included presentations on in-situ, groundwater and surface water remediation. Issues concerning phytoremediation, natural attenuation, extraction and commercial redevelopment were examined. The aim of the conference was also to provide a forum for innovators in remediation to present new work. Topics included hydrocarbon and salt contamination; engineered soil cover for management of salt impacted sites; remediation and revegetation of tar sands composite tailings containing naphthenic acids; sorption of oil sands naphthenic acid mixtures; denitrification as a natural attenuation mechanism; sampling methodologies; variability assessments; stabilization treatment technologies; remediation of coal wastes; bioreactor landfills; well blowouts in Alberta; soil remediation in coarse gravelly soils; diesel-contaminated aquifers; gasoline spill remediation; soil vapour extraction systems; technological solutions for erosion control and water clarification; and cost-effective in-situ remediation strategies. Fifty-two technical presentations were given, of which 27 have been catalogued separately for inclusion in this database. tabs., figs.

  10. To fail is human: remediating remediation in medical education.

    Science.gov (United States)

    Kalet, Adina; Chou, Calvin L; Ellaway, Rachel H

    2017-12-01

    Remediating failing medical learners has traditionally been a craft activity responding to individual learner and remediator circumstances. Although there have been moves towards more systematic approaches to remediation (at least at the institutional level), these changes have tended to focus on due process and defensibility rather than on educational principles. As remediation practice evolves, there is a growing need for common theoretical and systems-based perspectives to guide this work. This paper steps back from the practicalities of remediation practice to take a critical systems perspective on remediation in contemporary medical education. In doing so, the authors acknowledge the complex interactions between institutional, professional, and societal forces that are both facilitators of and barriers to effective remediation practices. The authors propose a model that situates remediation within the contexts of society as a whole, the medical profession, and medical education institutions. They also outline a number of recommendations to constructively align remediation principles and practices, support a continuum of remediation practices, destigmatize remediation, and develop institutional communities of practice in remediation. Medical educators must embrace a responsible and accountable systems-level approach to remediation if they are to meet their obligations to provide a safe and effective physician workforce.

  11. Demonstration of risk-based decision analysis in remedial alternative selection and design

    International Nuclear Information System (INIS)

    Evans, E.K.; Duffield, G.M.; Massmann, J.W.; Freeze, R.A.; Stephenson, D.E.

    1993-01-01

    This study demonstrates the use of risk-based decision analysis (Massmann and Freeze 1987a, 1987b) in the selection and design of an engineering alternative for groundwater remediation at a waste site at the Savannah River Site, a US Department of Energy facility in South Carolina. The investigation focuses on the remediation and closure of the H-Area Seepage Basins, an inactive disposal site that formerly received effluent water from a nearby production facility. A previous study by Duffield et al. (1992), which used risk-based decision analysis to screen a number of ground-water remediation alternatives under consideration for this site, indicated that the most attractive remedial option is ground-water extraction by wells coupled with surface water discharge of treated effluent. The aim of the present study is to demonstrate the iterative use of risk-based decision analysis throughout the design of a particular remedial alternative. In this study, we consider the interaction between two episodes of aquifer testing over a 6-year period and the refinement of a remedial extraction well system design. Using a three-dimensional ground-water flow model, this study employs (1) geostatistics and Monte Carlo techniques to simulate hydraulic conductivity as a stochastic process and (2) Bayesian updating and conditional simulation to investigate multiple phases of aquifer testing. In our evaluation of a remedial alternative, we compute probabilistic costs associated with the failure of an alternative to completely capture a simulated contaminant plume. The results of this study demonstrate the utility of risk-based decision analysis as a tool for improving the design of a remedial alternative through the course of phased data collection at a remedial site

  12. aquifer in ajaokuta, southwestern nigeria

    African Journals Online (AJOL)

    2005-03-08

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

  13. Remediating a design tool

    DEFF Research Database (Denmark)

    Jensen, Mads Møller; Rädle, Roman; Klokmose, Clemens N.

    2018-01-01

    digital sticky notes setup. The paper contributes with a nuanced understanding of what happens when remediating a physical design tool into digital space, by emphasizing focus shifts and breakdowns caused by the technology, but also benefits and promises inherent in the digital media. Despite users......' preference for creating physical notes, handling digital notes on boards was easier and the potential of proper documentation make the digital setup a possible alternative. While the analogy in our remediation supported a transfer of learned handling, the users' experiences across technological setups impact......Sticky notes are ubiquitous in design processes because of their tangibility and ease of use. Yet, they have well-known limitations in professional design processes, as documentation and distribution are cumbersome at best. This paper compares the use of sticky notes in ideation with a remediated...

  14. Thermal soil remediation

    International Nuclear Information System (INIS)

    Nelson, D.

    1999-01-01

    The environmental properties and business aspects of thermal soil remediation are described. Thermal soil remediation is considered as being the best option in cleaning contaminated soil for reuse. The thermal desorption process can remove hydrocarbons such as gasoline, kerosene and crude oil, from contaminated soil. Nelson Environmental Remediation (NER) Ltd. uses a mobile thermal desorption unit (TDU) with high temperature capabilities. NER has successfully applied the technology to target heavy end hydrocarbon removal from Alberta's gumbo clay in all seasons. The TDU consist of a feed system, a counter flow rotary drum kiln, a baghouse particulate removal system, and a secondary combustion chamber known as an afterburner. The technology has proven to be cost effective and more efficient than bioremediation and landfarming

  15. Electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Ottosen, Lisbeth M.; Hansen, Lene

    1997-01-01

    It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective......It is not possible for all heavy metal polluted soils to remediate it by an applied electric field alone. A desorbing agent must in different cases be added to the soil in order to make the process possible or to make it cost effective...

  16. The Effects of Surfactants on the Desorption of Organic Contaminants from Aquifer Materials

    Science.gov (United States)

    1989-08-01

    costs for remediating a contaminated aquifer can be reduced by 50-80 percent using this system. A preflush of 0.1-1.0 percent concentration potassium ...use of polymers such as polyacrylic acid and polyacrylamide as sacrificial adsorbates to decrease the adsorption of a mixed nonionic and anionic...cribed by Chapman (1965) in Methods of Soils Analysis was used to determine the masses of extractable sodium, potassium , calcium and mag- nesium

  17. Applicability of petroleum horizontal drilling technology to hazardous waste site characterization and remediation

    International Nuclear Information System (INIS)

    Goranson, C.

    1992-09-01

    Horizontal wells have the potential to become an important tool for use in characterization, remediation and monitoring operations at hazardous waste disposal, chemical manufacturing, refining and other sites where subsurface pollution may develop from operations or spills. Subsurface pollution of groundwater aquifers can occur at these sites by leakage of surface disposal ponds, surface storage tanks, underground storage tanks (UST), subsurface pipelines or leakage from surface operations. Characterization and remediation of aquifers at or near these sites requires drilling operations that are typically shallow, less than 500-feet in depth. Due to the shallow nature of polluted aquifers, waste site subsurface geologic formations frequently consist of unconsolidated materials. Fractured, jointed and/or layered high compressive strength formations or compacted caliche type formations can also be encountered. Some formations are unsaturated and have pore spaces that are only partially filled with water. Completely saturated underpressured aquifers may be encountered in areas where the static ground water levels are well below the ground surface. Each of these subsurface conditions can complicate the drilling and completion of wells needed for monitoring, characterization and remediation activities. This report describes some of the equipment that is available from petroleum drilling operations that has direct application to groundwater characterization and remediation activities. A brief discussion of petroleum directional and horizontal well drilling methodologies is given to allow the reader to gain an understanding of the equipment needed to drill and complete horizontal wells. Equipment used in river crossing drilling technology is also discussed. The final portion of this report is a description of the drilling equipment available and how it can be applied to groundwater characterization and remediation activities

  18. EPA Region 1 Sole Source Aquifers

    Science.gov (United States)

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

  19. Some new hydraulic and tracer measurement techniques for heterogeneous aquifer formations

    International Nuclear Information System (INIS)

    Ptak, T.; Teutsch, G.

    1990-01-01

    Groundwater contamination assessment and remediation activities demand reliable techniques for the determination of the governing aquifer parameters and their spatial distribution. In order to define guidelines and recommendations, some existing underground investigation techniques were tested and new methods have been developed as a part of the research program at the Horkheimer Insel experimental field site. In this paper, some new developed field and laboratory techniques are introduced and the results compared for two example monitoring wells located in the northern part of the field site. It is shown that highly conductive and highly heterogeneous aquifers demand high resolution investigation techniques. For transport predictions, new methods are needed that are able to detect preferential flow paths. Results from multilevel tracer tests show that simple analytical interpretations are not valid for this type of aquifer. (Author) (8 refs., 12 figs., tab.)

  20. Contamination in fractured-rock aquifers: Research at the former Naval Air Warfare Center, West Trenton, New Jersey

    Science.gov (United States)

    Goode, Daniel J.; Tiedeman, Claire; Lacombe, Pierre J.; Imbrigiotta, Thomas E.; Shapiro, Allen M.; Chapelle, Francis H.

    2007-01-01

    The U.S. Geological Survey and cooperators are studying chlorinated solvents in a fractured sedimentary rock aquifer underlying the former Naval Air Warfare Center (NAWC), West Trenton, New Jersey. Fractured-rock aquifers are common in many parts of the United States and are highly susceptible to contamination, particularly at industrial sites. Compared to 'unconsolidated' aquifers, there can be much more uncertainty about the direction and rate of contaminant migration and about the processes and factors that control chemical and microbial transformations of contaminants. Research at the NAWC is improving understanding of the transport and fate of chlorinated solvents in fractured-rock aquifers and will compare the effectiveness of different strategies for contaminant remediation.

  1. Benzene dynamics and biodegradation in alluvial aquifers affected by river fluctuations.

    Science.gov (United States)

    Batlle-Aguilar, J; Morasch, B; Hunkeler, D; Brouyère, S

    2014-01-01

    The spatial distribution and temporal dynamics of a benzene plume in an alluvial aquifer strongly affected by river fluctuations was studied. Benzene concentrations, aquifer geochemistry datasets, past river morphology, and benzene degradation rates estimated in situ using stable carbon isotope enrichment were analyzed in concert with aquifer heterogeneity and river fluctuations. Geochemistry data demonstrated that benzene biodegradation was on-going under sulfate reducing conditions. Long-term monitoring of hydraulic heads and characterization of the alluvial aquifer formed the basis of a detailed modeled image of aquifer heterogeneity. Hydraulic conductivity was found to strongly correlate with benzene degradation, indicating that low hydraulic conductivity areas are capable of sustaining benzene anaerobic biodegradation provided the electron acceptor (SO4 (2-) ) does not become rate limiting. Modeling results demonstrated that the groundwater flux direction is reversed on annual basis when the river level rises up to 2 m, thereby forcing the infiltration of oxygenated surface water into the aquifer. The mobilization state of metal trace elements such as Zn, Cd, and As present in the aquifer predominantly depended on the strong potential gradient within the plume. However, infiltration of oxygenated water was found to trigger a change from strongly reducing to oxic conditions near the river, causing mobilization of previously immobile metal species and vice versa. MNA appears to be an appropriate remediation strategy in this type of dynamic environment provided that aquifer characterization and targeted monitoring of redox conditions are adequate and electron acceptors remain available until concentrations of toxic compounds reduce to acceptable levels. © 2013, National Ground Water Association.

  2. A Review of the Multilevel Slug Test for Characterizing Aquifer Heterogeneity

    Directory of Open Access Journals (Sweden)

    Chia-Shyun Chen

    2012-01-01

    Full Text Available All aquifers are heterogeneous to a certain degree. The spatial distribution of hydraulic conductivity K(x, y, z, or aquifer heterogeneity, significantly influences the groundwater flow movement and associated solute transport. Of particular importance in designing an in-situ remediation plan is a knowledge of low-K layers because they are less accessible to remedial agents and form a bottleneck in remediation. The characterization of aquifer heterogeneity is essential to the solution of many practical and scientific groundwater problems. This article reviews the field technique using the multilevel slug test (MLST, which determines a series of K estimates at depths of interest in a well by making use of a double-packer system. The K(z obtained manifests the vertical variation of hydraulic conductivity in the vicinity of the test well, and the combination of K(z from different wells gives rise to a three-dimensional description of K(x, y, z. The MLST response is rather sensitive to hydraulic conductivity variation; e.g., it is oscillatory for highly permeable conditions (K > 5 × 10-4 m s-1 and a nonoscillatory for K < 5 × 10-4 m s-1. In this article we discuss the instrumentation of the double-packer system, the implementation of the depth-specific slug test, the data analysis methods for a spectrum of response characteristics usually observed in the field, and field applications of the MLST.

  3. Modeling contaminant plumes in fractured limestone aquifers

    DEFF Research Database (Denmark)

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

    Determining the fate and transport of contaminant plumes from contaminated sites in limestone aquifers is important because they are a major drinking water resource. This is challenging because they are often heavily fractured and contain chert layers and nodules, resulting in a complex transport...... model. The paper concludes with recommendations on how to identify and employ suitable models to advance the conceptual understanding and as decision support tools for risk assessment and the planning of remedial actions....... behavior. Improved conceptual models are needed for this type of site. Here conceptual models are developed by combining numerical models with field data. Several types of fracture flow and transport models are available for the modeling of contaminant transport in fractured media. These include...... the established approaches of the equivalent porous medium, discrete fracture and dual continuum models. However, these modeling concepts are not well tested for contaminant plume migration in limestone geologies. Our goal was to develop and evaluate approaches for modeling the transport of dissolved contaminant...

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  6. Trade Remedies: A Primer

    National Research Council Canada - National Science Library

    Jones, Vivian C

    2006-01-01

    The United States and many of its trading partners use laws known as trade remedies to mitigate the adverse impact of various trade practices on domestic industries and workers. U.S. antidumping laws (19 U.S.C. 1673 et seq...

  7. Modularizing Remedial Mathematics

    Science.gov (United States)

    Wong, Aaron

    2013-01-01

    As remedial mathematics education has become an increasingly important topic of conversation in higher education. Mathematics departments have been put under increased pressure to change their programs to increase the student success rate. A number of models have been introduced over the last decade that represent a wide range of new ideas and…

  8. Trade Remedies: A Primer

    National Research Council Canada - National Science Library

    Jones, Vivian C

    2007-01-01

    The United States and many of its trading partners use laws known as trade remedies to mitigate the adverse impact of various trade practices on domestic industries and workers. U.S. antidumping (AD) laws (19 U.S.C. 1673 et seq...

  9. Trade Remedies: A Primer

    National Research Council Canada - National Science Library

    Jones, Vivian C

    2008-01-01

    The United States and many of its trading partners use laws known as trade remedies to mitigate the adverse impact of various trade practices on domestic industries and workers. U.S. antidumping (AD) laws (19 U.S.C. 1673 et seq...

  10. Catalysts for Environmental Remediation

    DEFF Research Database (Denmark)

    Abrams, B. L.; Vesborg, Peter Christian Kjærgaard

    2013-01-01

    The properties of catalysts used in environmental remediation are described here through specific examples in heterogeneous catalysis and photocatalysis. In the area of heterogeneous catalysis, selective catalytic reduction (SCR) of NOx was used as an example reaction with vanadia and tungsta...

  11. 2014 Ohio Remediation Report

    Science.gov (United States)

    Ohio Board of Regents, 2014

    2014-01-01

    In fulfillment of Ohio Revised Code 3333.041 (A) (1) the Chancellor has published a listing by school district of the number of the 2013 high school graduates who attended a state institution of higher education in academic year 2013-2014 and the percentage of each district's graduates required by the institution to enroll in a remedial course in…

  12. The Remediation of Nosferatu

    DEFF Research Database (Denmark)

    Ghellal, Sabiha; Morrison, Ann; Hassenzahl, Marc

    2014-01-01

    In this paper we present The Remediation of Nosferatu, a location based augmented reality horror adventure. Using the theory of fictional universe elements, we work with diverse material from Nosferatu’s horror genre and vampire themes as a case study. In this interdisciplinary research we...

  13. Surfactant flushing remediation of o-dichlorobenzene and p-dichlorobenzene contaminated soil.

    Science.gov (United States)

    Pei, Guangpeng; Zhu, Yuen; Cai, Xiatong; Shi, Weiyu; Li, Hua

    2017-10-01

    Surfactant-enhanced remediation is used to treat dichlorobenzene (DCB) contaminated soil. In this study, soil column experiments were conducted to investigate the removal efficiencies of o-dichlorobenzene (o-DCB) and p-dichlorobenzene (p-DCB) from contaminated soil using micellar solutions of biosurfactants (saponin, alkyl polyglycoside) compare to a chemically synthetic surfactant (Tween 80). Leachate was collected and analyzed for o-DCB and p-DCB content. In addition, soil was analyzed to explore the effect of surfactants on soil enzyme activities. Results showed that the removal efficiency of o-DCB and p-DCB was highest for saponin followed by alkyl polyglycoside and Tween 80. The maximum o-DCB and p-DCB removal efficiencies of 76.34% and 80.43%, respectively, were achieved with 4 g L -1 saponin solution. However, an opposite result was observed in the cumulative mass of o-DCB and p-DCB in leachate. The cumulative extent of o-DCB and p-DCB removal by the biosurfactants saponin and alkyl polyglycoside was lower than that of the chemically synthetic surfactant Tween 80 in leachate. Soil was also analyzed to explore the effect of surfactants on soil enzyme activities. The results indicated that surfactants were potentially effective in facilitating soil enzyme activities. Thus, it was confirmed that the biosurfactants saponin and alkyl polyglycoside could be used for remediation of o-DCB and p-DCB contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    African Journals Online (AJOL)

    user

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

  15. A new risk and stochastic analysis of monitoring and remediation in subsurface contamination

    Science.gov (United States)

    Papapetridis, K.; Paleologos, E.

    2012-04-01

    Sanitary landfills constitute the most widely used management approach for the disposal of solid wastes because of their simplicity and cost effectiveness. However, historical records indicate that landfills exhibit a high failure rate of groundwater contamination. Successful detection of aquifer contamination via monitoring wells is a complicated problem with many factors, such as the heterogeneity of the geologic environment, the dispersion of contamination into the geologic medium, the quantity and nature of the contaminants, the number and location of the monitoring wells, and the frequency of sampling, all contributing to the uncertainty of early detection. Detection of contaminants, of course, is of value if remedial actions follow as soon as possible, so that the volume of contaminated groundwater to be treated is minimized. Practically, there is always a time lag between contaminant detection and remedial action response. Administrative decisions and arrangements with local contractors initiate remedial procedures introduces a time lag between detection and remediation time. During this time lag a plume continues to move into an aquifer contaminating larger groundwater volumes. In the present study these issues are addressed by investigating the case of instantaneous leakage from a landfill facility into a heterogeneous aquifer. The stochastic Monte Carlo framework was used to address, in two dimensions, the problem of evaluating the effectiveness of contaminant detection in heterogeneous aquifers by linear networks of monitoring wells. Numerical experiments based on the random-walk tracking-particle method were conducted to determine the detection probabilities and to calculate contaminated areas at different time steps. Several cases were studied assuming different levels of geologic heterogeneity, contamination dispersion, detectable contamination limits and monitoring wells' sampling frequencies. A new perspective is introduced for the correction of

  16. Innovative mathematical modeling in environmental remediation

    International Nuclear Information System (INIS)

    Yeh, Gour T.; Gwo, Jin Ping; Siegel, Malcolm D.; Li, Ming-Hsu; Fang, Yilin; Zhang, Fan; Luo, Wensui; Yabusaki, Steven B.

    2013-01-01

    There are two different ways to model reactive transport: ad hoc and innovative reaction-based approaches. The former, such as the Kd simplification of adsorption, has been widely employed by practitioners, while the latter has been mainly used in scientific communities for elucidating mechanisms of biogeochemical transport processes. It is believed that innovative mechanistic-based models could serve as protocols for environmental remediation as well. This paper reviews the development of a mechanistically coupled fluid flow, thermal transport, hydrologic transport, and reactive biogeochemical model and example-applications to environmental remediation problems. Theoretical bases are sufficiently described. Four example problems previously carried out are used to demonstrate how numerical experimentation can be used to evaluate the feasibility of different remediation approaches. The first one involved the application of a 56-species uranium tailing problem to the Melton Branch Subwatershed at Oak Ridge National Laboratory (ORNL) using the parallel version of the model. Simulations were made to demonstrate the potential mobilization of uranium and other chelating agents in the proposed waste disposal site. The second problem simulated laboratory-scale system to investigate the role of natural attenuation in potential off-site migration of uranium from uranium mill tailings after restoration. It showed inadequacy of using a single Kd even for a homogeneous medium. The third example simulated laboratory experiments involving extremely high concentrations of uranium, technetium, aluminum, nitrate, and toxic metals (e.g.,Ni, Cr, Co). The fourth example modeled microbially-mediated immobilization of uranium in an unconfined aquifer using acetate amendment in a field-scale experiment. The purposes of these modeling studies were to simulate various mechanisms of mobilization and immobilization of radioactive wastes and to illustrate how to apply reactive transport models

  17. Innovative mathematical modeling in environmental remediation

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Gour T. [Taiwan Typhoon and Flood Research Institute (Taiwan); National Central Univ. (Taiwan); Univ. of Central Florida (United States); Gwo, Jin Ping [Nuclear Regulatory Commission (NRC), Rockville, MD (United States); Siegel, Malcolm D. [Sandia National Laboratories, Albuquerque, NM (United States); Li, Ming-Hsu [National Central Univ. (Taiwan); ; Fang, Yilin [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Zhang, Fan [Inst. of Tibetan Plateau Research, Chinese Academy of Sciences (China); Luo, Wensui [Inst. of Tibetan Plateau Research, Chinese Academy of Sciences (China); Yabusaki, Steven B. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2013-05-01

    There are two different ways to model reactive transport: ad hoc and innovative reaction-based approaches. The former, such as the Kd simplification of adsorption, has been widely employed by practitioners, while the latter has been mainly used in scientific communities for elucidating mechanisms of biogeochemical transport processes. It is believed that innovative mechanistic-based models could serve as protocols for environmental remediation as well. This paper reviews the development of a mechanistically coupled fluid flow, thermal transport, hydrologic transport, and reactive biogeochemical model and example-applications to environmental remediation problems. Theoretical bases are sufficiently described. Four example problems previously carried out are used to demonstrate how numerical experimentation can be used to evaluate the feasibility of different remediation approaches. The first one involved the application of a 56-species uranium tailing problem to the Melton Branch Subwatershed at Oak Ridge National Laboratory (ORNL) using the parallel version of the model. Simulations were made to demonstrate the potential mobilization of uranium and other chelating agents in the proposed waste disposal site. The second problem simulated laboratory-scale system to investigate the role of natural attenuation in potential off-site migration of uranium from uranium mill tailings after restoration. It showed inadequacy of using a single Kd even for a homogeneous medium. The third example simulated laboratory experiments involving extremely high concentrations of uranium, technetium, aluminum, nitrate, and toxic metals (e.g.,Ni, Cr, Co).The fourth example modeled microbially-mediated immobilization of uranium in an unconfined aquifer using acetate amendment in a field-scale experiment. The purposes of these modeling studies were to simulate various mechanisms of mobilization and immobilization of radioactive wastes and to illustrate how to apply reactive transport models

  18. Simulant composition for the Mixed Waste Management Facility (MWMF) groundwater remediation project

    International Nuclear Information System (INIS)

    Siler, J.L.

    1992-01-01

    A project has been initiated at the request of ER to study and remediate the groundwater contamination at the Mixed Waste Management Facility (MWMF). This water contains a wide variety of both inorganics (e.g., sodium) and organics (e.g., benzene, trichloroethylene). Most compounds are present in the ppB range, and certain components (e.g., trichloroethylene, silver) are present at concentrations that exceed the primary drinking water standards (PDWS). These compounds must be reduced to acceptable levels as per RCRA and CERCLA orders. This report gives a listing of the important constituents which are to be included in a simulant to model the MWMF aquifer. This simulant will be used to evaluate the feasibility of various state of the art separation/destruction processes for remediating the aquifer

  19. Remediation Technology Collaboration Development

    Science.gov (United States)

    Mahoney, John; Olsen, Wade

    2010-01-01

    This slide presentation reviews programs at NASA aimed at development at Remediation Technology development for removal of environmental pollutants from NASA sites. This is challenging because there are many sites with different environments, and various jurisdictions and regulations. There are also multiple contaminants. There must be different approaches based on location and type of contamination. There are other challenges: such as costs, increased need for resources and the amount of resources available, and a regulatory environment that is increasing.

  20. Application of a numerical model in the interpretation of a leaky aquifer test

    International Nuclear Information System (INIS)

    Schroth, B.; Narasimhan, T.N.

    1997-01-01

    The potential use of numerical models in aquifer analysis is by no means a new concept; yet relatively few engineers and scientists are taking advantage of this powerful tool that is more convenient to use now than ever before. In this technical note the authors present an example of using a numerical model in an integrated analysis of data from a three-layer leaky aquifer system involving well-bore storage, skin effects, variable discharge, and observation wells in the pumped aquifer and in an unpumped aquifer. The modeling detail may differ for other cases. The intent is to show that interpretation can be achieved with reduced bias by reducing assumptions in regard to system geometry, flow rate, and other details. A multiwell aquifer test was carried out at a site on the western part of the Lawrence Livermore National Laboratory (LLNL), located about 60 kilometers east of San Francisco. The test was conducted to hydraulically characterize one part of the site and thus help develop remediation strategies to alleviate the ground-water contamination

  1. Remediating MGP brownfields

    International Nuclear Information System (INIS)

    Larsen, B.R.

    1997-01-01

    Before natural gas pipelines became widespread in this country, gas fuel was produced locally in more than 5,000 manufactured gas plants (MGPs). The toxic wastes from these processes often were disposed onsite and have since seeped into the surrounding soil and groundwater. Although the MGPs--commonly called gas plants, gas-works or town gas plants--have closed and most have been demolished, they have left a legacy of environmental contamination. At many MGP sites, underground storage tanks were constructed of wood or brick, with process piping and equipment which frequently leaked. Waste materials often were disposed onsite. Releases of coal tars, oils and condensates produced within the plants contributed to a wide range of contamination from polycyclic aromatic hydrocarbons, phenols, benzene and cyanide. Remediation of selected MGP sites has been sporadic. Unless the site has been identified as a Comprehensive Environmental Response, Compensation and Liability Information System (CERCLIS) Superfund site, the regulatory initiative to remediate often remains with the state in which the MGP is located. A number of factors are working to change that picture and to create a renewed interest in MGP site remediation. The recent Brownfield Initiative by the US Environmental Protection Agency (EPA) is such an example

  2. CENTRAL PLATEAU REMEDIATION

    International Nuclear Information System (INIS)

    ROMINE, L.D.

    2006-01-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress

  3. Post-Remediation Evaluation of EVO Treatment: How Can We Improve Performance

    Science.gov (United States)

    2017-11-15

    QA/QC Quality Assurance/ Quality Control RAOs Remedial Action Objectives Resolutions Resolutions Consultants SA17 Study Area 17 viii SAP...upper 30 feet of the unconfined aquifer consists of fine sand with multiple discontinuous layers of silty sand , ranging from 1 to over 5 ft thick...Beneath the lower silty sand is a layer of fine to coarse grained sand that extends from 30 to 50 ft bgs. The confining unit of the Hawthorne Group

  4. Hydrocarbons spill remediation in the case Barreal-Belen, Costa Rica

    International Nuclear Information System (INIS)

    Vargas Fallas, Luis Carlos

    2009-01-01

    The advance in the attention of the hydrocarbon spill case occurred in Barreal-Belen, Costa Rica, is presented. The leakage consists about 30,000 liters of gasoline and diesel compounds, which are contained in an aquifer hanging located a depth of 20 to 22 meters. In this aquifer lies beneath it a layer of calcined tuff has worked as a seal and prevented the collimated flow to aquifers that underlie and are used to supply populations. The strategy to achieve the remediation work established is presented by the Interagency Committee in 2005. The measures adopted to separate hydrocarbons from waters have established a prognosis in years of operation, according to two cleanup scenarios, presented to two months of initiated. (author) [es

  5. Uniroyal Chemical`s remediation project meets or exceeds expectations

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    1997-11-01

    Recent remedial actions taken by Uniroyal Chemical Ltd at their Elmira, Ontario, plant have been considered. The company has been manufacturing a wide range of organic chemicals at this plant for use in agriculture and in the plastics and rubber industries since 1942. Historically, wastes were disposed of on-site, which while common practice at the time, caused soil and water contamination by N-nitrosodimethylamine (NDMA), volatile organic compounds such as benzene, toluene, and chlorobenzene, aniline, mercaptobenzothiazole and basic compounds such as ammonia. The local hydrogeology is fairly complex and consists of several aquifers and aquitards of which the Upper Aquifer (UA) and the Municipal Aquifer (MA) have been the primary concern. They have supplied all or part of the drinking water for the Kitchener-Waterloo area and the town of Elmira. After an extensive feasibility study, the decision was made to install shallow extension wells, and a system to treat the groundwater to acceptable criteria to discharge the treated water to the river system. Development of the system, which besides ten extraction wells includes a tertiary treatment process for UV oxidation, was described. The system has been in operation since January 1997. It affords 95 to 98 per cent of containment efficiency, 99 per cent ammonia removal, and 99.97 per cent of NDMA removal. Effluent requirements have been consistently met for all 18 primary contaminants, and no groundwater is being discharged into the river system.

  6. Field Test of Enhanced Remedial Amendment Delivery Using a Shear-Thinning Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Vermeul, Vincent R.; Adamson, David; Oostrom, Martinus; Zhong, Lirong; Mackley, Rob D.; Fritz, Brad G.; Horner, Jacob A.; Johnson, Timothy C.; Thomle, Jonathan N.; Newcomer, Darrell R.; Johnson, Christian D.; Rysz, Michal; Wietsma, Thomas W.; Newell, Charles J.

    2015-03-01

    Heterogeneity of hydraulic properties in aquifers may lead to contaminants residing in lower-permeability zones where it is difficult to deliver remediation amendments using conventional injection processes. The focus of this effort is to examine use of a shear-thinning fluid (STF) to improve the uniformity of remedial amendment distribution within a heterogeneous aquifer. Previous studies have demonstrated the significant potential of STFs for improving remedial amendment delivery in heterogeneous aquifers, but quantitative evaluation of these improvements from field applications are lacking. A field-scale test was conducted that compares data from successive injection of a tracer in water followed by injection of a tracer in a STF to evaluate the impact of the STF on tracer distribution uniformity in the presence of permeability contrasts within the targeted injection zone. Data from tracer breakthrough at multiple depth-discrete monitoring intervals and electrical resistivity tomography showed that inclusion of STF in the injection solution slowed movement in high-permeability pathways, improved delivery of amendment to low-permeability materials, and resulted in better uniformity in injected fluid distribution within the targeted treatment zone.

  7. Aquifer thermal energy stores in Germany

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  8. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    Energy Technology Data Exchange (ETDEWEB)

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  9. DOE'S remedial action assurance program

    International Nuclear Information System (INIS)

    Welty, C.G. Jr.; Needels, T.S.; Denham, D.H.

    1984-10-01

    The formulation and initial implementation of DOE's Assurance Program for Remedial Action are described. It was initiated in FY 84 and is expected to be further implemented in FY 85 as the activities of DOE's Remedial Action programs continue to expand. Further APRA implementation will include additional document reviews, site inspections, and program office appraisals with emphasis on Uranium Mill Tailings Remedial Action Program and Surplus Facilities Management Program

  10. [Cognitive remediation and nursing care].

    Science.gov (United States)

    Schenin-King, Palmyre; Thomas, Fanny; Braha-Zeitoun, Sonia; Bouaziz, Noomane; Januel, Dominique

    2016-01-01

    Therapies based on cognitive remediation integrate psychiatric care. Cognitive remediation helps to ease cognitive disorders and enable patients to improve their day-to-day lives. It is essential to complete nurses' training in this field. This article presents the example of a patient with schizophrenia who followed the Cognitive Remediation Therapy programme, enabling him to access mainstream employment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Shallow Aquifer Methane Gas Source Assessment

    Science.gov (United States)

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

    2014-12-01

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

  12. Kinetics and Efficiency of H2O2 Activation by Iron-Containing Minerals and Aquifer Materials

    Science.gov (United States)

    Pham, Anh Le-Tuan; Doyle, Fiona M.; Sedlak, David L.

    2014-01-01

    To gain insight into factors that control H2O2 persistence and ˙OH yield in H2O2-based in situ chemical oxidation systems, the decomposition of H2O2 and transformation of phenol were investigated in the presence of iron-containing minerals and aquifer materials. Under conditions expected during remediation of soil and groundwater, the stoichiometric efficiency, defined as the amount of phenol transformed per mole of H2O2 decomposed, varied from 0.005 to 0.28%. Among the iron-containing minerals, iron oxides were 2 to 10 times less efficient in transforming phenol than iron-containing clays and synthetic iron-containing catalysts. In both iron-containing mineral and aquifer materials systems, the stoichiometric efficiency was inversely correlated with the rate of H2O2 decomposition. In aquifer materials systems, the stoichiometric efficiency was also inversely correlated with the Mn content, consistent with the fact that the decomposition of H2O2 on manganese oxides does not produce ˙OH. Removal of iron and manganese oxide coatings from the surface of aquifer materials by extraction with citrate-bicarbonate-dithionite slowed the rate of H2O2 decomposition on aquifer materials and increased the stoichiometric efficiency. In addition, the presence of 2 mM of dissolved SiO2 slowed the rate of H2O2 decomposition on aquifer materials by over 80% without affecting the stoichiometric efficiency. PMID:23047055

  13. Remediating Remediation: From Basic Writing to Writing across the Curriculum

    Science.gov (United States)

    Faulkner, Melissa

    2013-01-01

    This article challenges faculty members and administrators to rethink current definitions of remediation. First year college students are increasingly placed into basic writing courses due to a perceived inability to use English grammar correctly, but it must be acknowledged that all students will encounter the need for remediation as they attempt…

  14. Remedial action technology - arid

    International Nuclear Information System (INIS)

    Hakonson, T.E.; DePoorter, G.L.; Nyhan, J.W.; Perkins, B.A.; Lane, L.J.

    1982-01-01

    A summary is presented of the low-level waste remedial action program at Los Alamos. The experimental design and progress is described for the experiments on second generation intrusion barriers, subsidence effects on SLB components, moisture cycling effects on chemical transport, and erosion control methodologies. The soil moisture data from the bio-intrusion and moisture cycling experiments both demonstrate the overwhelming importance of vegetation in minimizing infiltration of water through trench covers and backfill. Evaporation, as a water loss component in trench covers, is only effective in reducing soil moisture within 40 cm of the trench cover surface. Moisture infiltrating past the zone of evaporation in unvegetated or poorly vegetated trench covers is in storage and accumulates until drainage out of the soil profile occurs. Judicious selection of vegetation species for revegetating a low-level waste site may prevent infiltration of moisture into the trench and, when coupled with other design features (i.e. trench cover slope, tilling and seeding practice), may greatly reduce problems with erosion. Standard US Department of Agriculture erosion plots, when coupled with a state-of-the-art water balance and erosion model (CREAMS) promises to be highly useful in screening proposed remedial action cover designs for low-level waste sites. The erosion plot configuration allows for complete accounting of the water balance in a soil profile. This feature enables the user to optimize cover designs to minimize erosion and infiltration of water into the trench

  15. Lasagna trademark soil remediation

    International Nuclear Information System (INIS)

    1996-04-01

    Lasagna trademark is an integrated, in situ remediation technology being developed which remediates soils and soil pore water contaminated with soluble organic compounds. Lasagna trademark is especially suited to sites with low permeability soils where electroosmosis can move water faster and more uniformly than hydraulic methods, with very low power consumption. The process uses electrokinetics to move contaminants in soil pore water into treatment zones where the contaminants can be captured and decomposed. Initial focus is on trichloroethylene (TCE), a major contaminant at many DOE and industrial sites. Both vertical and horizontal configurations have been conceptualized, but fieldwork to date is more advanced for the vertical configuration. Major features of the technology are electrodes energized by direct current, which causes water and soluble contaminants to move into or through the treatment layers and also heats the soil; treatment zones containing reagents that decompose the soluble organic contaminants or adsorb contaminants for immobilization or subsequent removal and disposal; and a water management system that recycles the water that accumulates at the cathode (high pH) back to the anode (low pH) for acid-base neutralization. Alternatively, electrode polarity can be reversed periodically to reverse electroosmotic flow and neutralize pH

  16. Visualization of residual organic liquid trapped in aquifers

    International Nuclear Information System (INIS)

    Conrad, S.H.; Wilson, J.L.; Mason, W.R.; Peplinski, W.J.

    1992-01-01

    Organic liquids that are essentially immiscible with water migrate through the subsurface under the influence of capillary, viscous, and buoyancy forces. These liquids originate from the improper disposal of hazardous wastes, and the spills and leaks of petroleum hydrocarbons and solvents. The flow visualization experiments described in this study examined the migration of organic liquids through the saturated zone of aquifers, with a primary focus on the behavior of the residual organic liquid saturation, referring to that portion of the organic liquid that is trapped by capillary forces. Etched glass micromodels were used to visually observe dynamic multiphase displacement processes in pore networks. The resulting fluid distributions were photographed. Pore and blob casts were produced by a technique in which an organic liquid was solidified in place within a sand column at the conclusion of a displacement. The columns were sectioned and examined under optical and scanning electron microscopes. Photomicrographs of these sections show the morphology of the organic phase and its location within the sand matrix. The photographs from both experimental techniques reveal that in the saturated zone large amounts of residual organic liquid are trapped as isolated blobs of microscopic size. The size, shape, and spatial distribution of these blobs of residual organic liquid affect the dissolution of organic liquid into the water phase and the biotransformation of organic components. These processes are of concern for the prediction of pollution migration and the design of aquifer remediation schemes

  17. Remediation of BTEX contaminated groundwater: best technology assessment between pump&treat and bioremediation by oxygen injection

    Directory of Open Access Journals (Sweden)

    Daniele Baldi

    2012-06-01

    Full Text Available The presence of benzene, toluene, ethylbenzene and xylene (BTEX dissolved in the groundwater and migrated from a light non-aqueous phase liquid (LNAPL source in an alluvial aquifer required a remedial action to be taken by the responsible party as established by the Italian regulation (Legislative Decree 152/06 and subsequent amendments. For such purpose, field investigations were conducted on site in order to define the site conceptual model and to identify the appropriate remediation technology to be applied. The remediation design was developed by means of a flow and reactive transport mathematical model, applied to saturated media, using the numerical codes MODFLOW and RT3D. Groundwater field observations showed evidence of occurring BTEX biodegradation processes by bacteria naturally present in the aquifer. Since such specific bacterial activity would be significantly enhanced by the injection of free oxygen in the aquifer, the performance of traditional pump and treat systems (P&T was assessed and compared with cost/efficiency of reactive oxygen bio-barrier technology (OD. The results showed a clear advantage in terms of cost/efficiency with the application of the OD. This presents an overall cost of about 30% of the P&T installation and maintenance, and it reaches remedial target in a shorter timeframe. Moreover, the system is also applicable as a bioremediation technology in case of Environmental Emergency Measures (MISE. The site examined is part of an industrial plant located in Central Italy.

  18. Hanford well remediation and decommissioning plan

    International Nuclear Information System (INIS)

    Ledgerwood, R.K.

    1993-01-01

    Protection of Hanford Site groundwater resources and assessment of the effects of their use or contamination upon public safety are required by federal and state regulations and U.S. Department of Energy (DOE) policy, (DOE, 1989). Compliance with constraints applicable to the use of existing wells requires assessment as to the suitability for use and needs for rehabilitation, remediation or decommissioning of existing groundwater wells and other boreholes potentially affecting aquifers beneath the Hanford Site. Approximately 3,500 groundwater wells and vadose zone boreholes had been drilled on the Hanford Site prior to 1989, over 2,900 still exist. Most of these boreholes were drilled prior to 1987 and do not conform to presently accepted construction standards intended to protect groundwater resources. Approximately 260 wells have been installed since 1987. These wells were constructed to current standards for well construction which mandate seals between the permanent casing and the formation to prevent potential migration of contaminated liquid. Several programs presently construct and/or utilize existing and newly drilled wells to provide characterization and groundwater monitoring data. The programs are summarized

  19. Herbal remedies and supplements for weight loss

    Science.gov (United States)

    Weight loss - herbal remedies and supplements; Obesity - herbal remedies; Overweight - herbal remedies ... health care provider. Nearly all over-the-counter supplements with claims of weight-loss properties contain some ...

  20. Electrodialytic remediation of solid waste

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Ottosen, Lisbeth M.; Karlsmose, Bodil

    1996-01-01

    Electrodialytic remediation of heavy metal polluted solid waste is a method that combines the technique of electrodialysis with the electromigration of ions in the solid waste. Results of laboratory scale remediation experiments of soil are presented and considerations are given on how to secure...

  1. Arsenic, microbes and contaminated aquifers

    Science.gov (United States)

    Oremland, Ronald S.; Stolz, John F.

    2005-01-01

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

  2. Site remediation: The naked truth

    International Nuclear Information System (INIS)

    Calloway, J.M.

    1991-01-01

    The objective of any company faced with an environmental site remediation project is to perform the cleanup effectively at the lowest possible cost. Today, there are a variety of techniques being applied in the remediation of sites involving soils and sludges. The most popular include: stabilization, incineration, bioremediation and off-site treatment. Dewatering may also play an integral role in a number of these approaches. Selecting the most cost-effective technique for remediation of soils and sludges can be a formidable undertaking, namely because it is often difficult to quantify certain expenses in advance of the project. In addition to providing general cost guidelines for various aspects of soil and sludge remediation, this paper will show how some significant cost factors can be affected by conditions related to specific remediation projects and the cleanup technology being applied

  3. Aquifer thermal-energy-storage modeling

    Science.gov (United States)

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

    1982-09-01

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

  4. Field Investigation of Natural Attenuation of a Petroleum Hydrocarbon Contaminated Aquifer, Gyeonggi Province, Korea

    Science.gov (United States)

    Yang, J.; Lee, K.; Bae, G.

    2004-12-01

    In remediation of a petroleum hydrocarbon contaminated aquifer, natural attenuation may be significant as a remedial alternative. Therefore, natural attenuation should be investigated in the field in order to effectively design and evaluate the remediation strategy at the contaminated site. This study focused on evaluating the natural attenuation for benzene, toluene, ethylbenzene, and xylene (BTEX) at a contaminated site in South Korea. At the study site, the aquifer is composed of a high permeable gravel layer and relatively low permeable sandy-silt layers. Groundwater level vertically fluctuated between 1m and 2m throughout the year (April, 2003~June, 2004) and showed direct response to rainfall events. Chemical analyses of sampled groundwater were performed to investigate the concentrations of various chemical species which are associated with the natural attenuation processes. To evaluate the degree of the biodegradation, the expressed biodegradation capacity (EBC) analysis was done using aerobic respiration, nitrate reduction, manganese reduction, ferric iron reduction, and sulfate reduction as an indicator. High EBC value of sulfate indicate that anaerobic biodegradation by sulfate reduction was a dominant process of mineralization of BTEX at this site. The EBC values decrease sensitively when heavy rainfall occurs due to the dilution and inflow of electron acceptors through a gravel layer. The first-order biodegradation rates of BTEX were estimated by means of the Buscheck and Alcantar method (1995). Results show that the natural attenuation rate of benzene was the highest among the BTEX.

  5. Cognitive Remediation in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Joana Vieira

    2014-06-01

    Full Text Available Several reviews of the literature support the idea that cognitive deficits observed in a large percentage of patients with schizophrenia are responsible for the cognitive performance deficit and functional disability associated with the disease. The grow- ing importance of neurocognition in Psychiatry, especially with regard to planning strategies and rehabilitative therapies to improve the prognosis of patients contrib- utes to the interest of achieving this literature review on cognitive rehabilitation in schizophrenia. In this work, drawn from research in the areas of schizophrenia, cog- nition, cognitive rehabilitation and cognitive remediation (2000-2012 through PubMed and The Cochrane Collaboration, it is intended, to describe the types of psychological and behavioral therapies recommended in the treatment of cognitive disabilities in patients diagnosed with schizophrenia. This review will also highlight the clinical and scientific evidence of each of these therapies, as their effect on cognitive performance, symptoms and functionality in patients with schizophrenia.

  6. Hydrochemistry of New Zealand's aquifers

    International Nuclear Information System (INIS)

    Rosen, M.R.

    2001-01-01

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

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

    International Nuclear Information System (INIS)

    Jensen, E.J.

    1987-10-01

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

  8. Aquifer Characterization and Groundwater Potential Assessment

    African Journals Online (AJOL)

    Timothy Ademakinwa

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

  9. Object reasoning for waste remediation

    International Nuclear Information System (INIS)

    Pennock, K.A.; Bohn, S.J.; Franklin, A.L.

    1991-08-01

    A large number of contaminated waste sites across the United States await size remediation efforts. These sites can be physically complex, composed of multiple, possibly interacting, contaminants distributed throughout one or more media. The Remedial Action Assessment System (RAAS) is being designed and developed to support decisions concerning the selection of remediation alternatives. The goal of this system is to broaden the consideration of remediation alternatives, while reducing the time and cost of making these considerations. The Remedial Action Assessment System is a hybrid system, designed and constructed using object-oriented, knowledge- based systems, and structured programming techniques. RAAS uses a combination of quantitative and qualitative reasoning to consider and suggest remediation alternatives. The reasoning process that drives this application is centered around an object-oriented organization of remediation technology information. This paper describes the information structure and organization used to support this reasoning process. In addition, the paper describes the level of detail of the technology related information used in RAAS, discusses required assumptions and procedural implications of these assumptions, and provides rationale for structuring RAAS in this manner. 3 refs., 3 figs

  10. Evaluation of modeling approaches to simulate contaminant transport in a fractured limestone aquifer

    DEFF Research Database (Denmark)

    Mosthaf, Klaus; Fjordbøge, Annika Sidelmann; Broholm, Mette Martina

    in fractured limestone aquifers. The model comparison is conducted for a contaminated site in Denmark, where a plume of dissolved PCE has migrated through a fractured limestone aquifer. Field data includes information on spill history, distribution of the contaminant (multilevel sampling), geology...... and hydrogeology. To describe the geology and fracture system, data from borehole logs and cores was combined with an analysis of heterogeneities and fractures from a nearby excavation and pump test data. We present how field data is integrated into the different model concepts. A challenge in the use of field...... and remediation strategies. Each model is compared with field data, considering both model fit and model suitability. Results show a considerable difference between the approaches, and that it is important to select the right one for the actual modeling purpose. The comparison with data showed how much...

  11. Sustainable Technologies and Social Costs for Eliminating Contamination of an Aquifer

    Directory of Open Access Journals (Sweden)

    Mario Schirmer

    2010-07-01

    Full Text Available This case study deals with long-term contamination of the Leuna aquifer, which is intended to be restored using sustainable technologies financed by the state. The contamination can only be solved using active rather than passive intervention, because the aquifer has an extraordinarily low natural attenuation capacity for the specific pollutants. Due to the longevity of the contamination source, the groundwater treatment technology that was chosen for the site must operate for a minimum of 20 years but probably much longer. Since the polluter-pay principle cannot be applied, the estimated dynamic primary remediation costs must be accepted as a political or social cost, which must be paid by current and future generations.

  12. French uranium mining sites remediation

    International Nuclear Information System (INIS)

    Roche, M.

    2002-01-01

    Following a presentation of the COGEMA's general policy for the remediation of uranium mining sites and the regulatory requirements, the current phases of site remediation operations are described. Specific operations for underground mines, open pits, milling facilities and confining the milled residues to meet long term public health concerns are detailed and discussed in relation to the communication strategies to show and explain the actions of COGEMA. A brief review of the current remediation situation at the various French facilities is finally presented. (author)

  13. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Gunnison, Colorado

    International Nuclear Information System (INIS)

    1992-10-01

    To achieve compliance with the proposed US Environmental Protection Agency (EPA) groundwater protection standards the US Department of Energy (DOE) proposes to meet background concentrations or the EPA maximum concentration limits (MCLS) for hazardous constituents in groundwater in the uppermost aquifer at the point of compliance (POC) at the Gunnison Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site near Gunnison, Colorado. The proposed remedial action will ensure protection of human health and the environment. A summary of the principal features of the water resources protection strategy for the Gunnison disposal site is included in this report

  14. Chaos and remedial investigations

    International Nuclear Information System (INIS)

    Galbraith, R.M.

    1991-01-01

    Current research into the nature of chaos indicates that even for systems that are well known and easily modeled, slight changes in the scale used to measure the input have unpredictable results in the model output. The conduct of a remedial investigation (RI) is dictated by well-established rules of investigation and management, yet small changes in project orientation, regulatory environment, or site conditions have unpredictable consequences to the project. The consequences can lead to either brilliant success or utter failure. The chaotic effect of a change in scale is most often illustrated by an exercise in measuring the length of the coast of Great Britain. If a straight ruler 10-kilometers long is used, the sum of the 10-kilometer increments gives the length of the coast. If the ruler is changed to five kilometers long and the exercise is repeated, the sum of the five-kilometer increments will not be the same as the sum of the 10-kilometer increments. Nor is there a way to predict what the length of the coast will be using any other scale. Several examples from the Fernald Project RI are used to illustrate open-quotes changes in scaleclose quotes in both technical and management situations. Given that there is no way to predict the outcome of scale changes in a RI, technical and project management must be alert to the fact that a scale has changed and the investigation is no longer on the path it was thought to be on. The key to success, therefore, is to develop specific units of measure for a number of activities, in addition to cost and schedule, and track them regularly. An example for tracking a portion of the field investigation is presented. The determination of effective units of measure is perhaps the most difficult aspect of any project. Changes in scale sometimes go unnoticed until suddenly the budget is expended and only a portion of the work is completed. Remedial investigations on large facilities provide new and complex challenges

  15. Identification of abiotic and biotic reductive dechlorination in a chlorinated ethene plume after thermal source remediation by means of isotopic and molecular biology tools

    DEFF Research Database (Denmark)

    Badin, Alice; Broholm, Mette Martina; Jacobsen, Carsten S.

    2016-01-01

    Thermal tetrachloroethene (PCE) remediation by steam injection in a sandy aquifer led to the release of dissolved organic carbon (DOC) from aquifer sediments resulting in more reduced redox conditions, accelerated PCE biodegradation, and changes in microbial populations. These changes were...... documented by comparing data collected prior to the remediation event and eight years later. Based on the premise that dual C-Cl isotope slopes reflect ongoing degradation pathways, the slopes associated with PCE and TCE suggest the predominance of biotic reductive dechlorination near the source area. PCE...... is supported by the relative lack of Dhc in the downgradient part of the plume. The results of this study show that thermal remediation can enhance the biodegradation of chlorinated ethenes, and that this effect can be traced to the mobilisation of DOC due to steam injection. This, in turn, results in more...

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

    Science.gov (United States)

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

    2018-05-01

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

  17. ICDF Complex Remedial Action Report

    Energy Technology Data Exchange (ETDEWEB)

    W. M. Heileson

    2007-09-26

    This Idaho CERCLA Disposal Facility (ICDF) Remedial Action Report has been prepared in accordance with the requirements of Section 6.2 of the INEEL CERCLA Disposal Facility Remedial Action Work Plan. The agency prefinal inspection of the ICDF Staging, Storage, Sizing, and Treatment Facility (SSSTF) was completed in June of 2005. Accordingly, this report has been developed to describe the construction activities completed at the ICDF along with a description of any modifications to the design originally approved for the facility. In addition, this report provides a summary of the major documents prepared for the design and construction of the ICDF, a discussion of relevant requirements and remedial action objectives, the total costs associated with the development and operation of the facility to date, and identification of necessary changes to the Agency-approved INEEL CERCLA Disposal Facility Remedial Action Work Plan and the ICDF Complex Operations and Maintenance Plan.

  18. Approaches for assessing sustainable remediation

    DEFF Research Database (Denmark)

    Søndergaard, Gitte Lemming; Binning, Philip John; Bjerg, Poul Løgstrup

    Sustainable remediation seeks to reduce direct contaminant point source impacts on the environment, while minimizing the indirect cost of remediation to the environment, society and economy. This paper presents an overview of available approaches for assessing the sustainability of alternative...... remediation strategies for a contaminated site. Most approaches use multi-criteria assessment methods (MCA) to structure a decision support process. Different combinations of environmental, social and economic criteria are employed, and are assessed either in qualitative or quantitative forms with various...... tools such as life cycle assessment and cost benefit analysis. Stakeholder involvement, which is a key component of sustainable remediation, is conducted in various ways. Some approaches involve stakeholders directly in the evaluation or weighting of criteria, whereas other approaches only indirectly...

  19. Plant-based remediation processes

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Dharmendra Kumar (ed.) [Belgian Nuclear Research Centre (SCK.CEN), Mol (Belgium). Radiological Impact and Performance Assessment Division

    2013-11-01

    A valuable source of information for scientists in the field of environmental pollution and remediation. Describes the latest biotechnological methods for the treatment of contaminated soils. Includes case studies and protocols. Phytoremediation is an emerging technology that employs higher plants for the clean-up of contaminated environments. Basic and applied research have unequivocally demonstrated that selected plant species possess the genetic potential to accumulate, degrade, metabolize and immobilize a wide range of contaminants. The main focus of this volume is on the recent advances of technologies using green plants for remediation of various metals and metalloids. Topics include biomonitoring of heavy metal pollution, amendments of higher uptake of toxic metals, transport of heavy metals in plants, and toxicity mechanisms. Further chapters discuss agro-technological methods for minimizing pollution while improving soil quality, transgenic approaches to heavy metal remediation and present protocols for metal remediation via in vitro root cultures.

  20. A responsible remediation strategy

    International Nuclear Information System (INIS)

    Knowles, C.R.

    1992-01-01

    This paper deals with an approach to cleaning up the residue of 150 years of intense urban and industrial development in the United States. The discussion focuses on several choices and strategies that business can adopt given the existing environmental laws and the socio-economic trends of the 1990's. The thesis of this paper is that the best business strategy for dealing with environmental liabilities is to act affirmatively and aggressively. An aggressive, pro-active approach to environmental remediation liabilities makes good business sense. It allows a company to learn the true size of the problem early. Early assessment and prioritization allows one to control the course and conduct of the cleanup. Early voluntary action is always viewed favorably by agencies. It gives one control over spending patterns which has value in and of itself. Voluntary cleanups are certainly faster and invariably more efficient. And they attain clearly acceptable standards. The volunteering company that takes the lead in a multi-party site finds that the courts are supportive in helping the volunteer collect from recalcitrant polluters. All of these pluses have a direct and positive impact on the bottom line and that means that the aggressive approach is the right thing to do for both stockholders and the communities where a business exists

  1. Opium the Best Remedy

    Directory of Open Access Journals (Sweden)

    Harold Merskey

    2004-01-01

    Full Text Available Sydenham was the leading English physician of the 17th century and probably to the present time. He was using a well tried remedy. It had been known by then for about 4000 years, frequently mentioned by Hippocrates, and recognized in use in medieval Europe where it probably came through Arabic traders and was well established in use in Paris by the 12th century (2. Professional concerns up to the time of Sydenham were not about addiction. As can be seen from his text, they were about whether the drug was available in adequate preparations, whether there was any difference between opium and other narcotics, particularly comparing the natural juice with "its artificial preparations" (1 (all of which he thought to be about equal in effect, whether it was stimulant or restorative and invigorating, and whether it was being properly used for all the conditions in which it could be helpful. Addiction, dependence and insanity are not mentioned, although the fact that it could occasionally promote excitement ("frenzy" was known.

  2. Techniques for Source Zone and Plume Characterization of Tetrachloroethene in Fractured Limestone Aquifers

    DEFF Research Database (Denmark)

    Fjordbøge, Annika Sidelmann; Mosthaf, Klaus; Janniche, Gry S.

    Characterization of chlorinated solvents in fractured limestone aquifers is essential for proper development of site specific conceptual models and subsequent risk assessment and remediation. High resolution characterization is challenged by the difficulties involved in collection of intact core...... an improved conceptual understanding of contaminant transport. At both sites limestone cores were collected with significant core losses. The discrete quantification of chlorinated solvents in the retrieved limestone cores was compared to different FLUTe technologies at the DNAPL site and passive and active...... distribution compared to the data obtained by quantification of chlorinated solvents in the limestone cores....

  3. Geohydrology of the Cerro Prieto geothermal aquifer

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-01-01

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

  4. Estimating Aquifer Properties Using Sinusoidal Pumping Tests

    Science.gov (United States)

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

    2001-12-01

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

  5. Geochemistry of the Arbuckle-Simpson Aquifer

    Science.gov (United States)

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

    2009-01-01

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

  6. Laboratory and pilot field-scale testing of surfactants for environmental restoration of chlorinated solvent DNAPLs

    International Nuclear Information System (INIS)

    Jackson, R.E.; Fountain, J.C.

    1994-01-01

    This project is composed of two phases and has the objective of demonstrating surfactant-enhanced aquifer remediation (SEAR) as a practical remediation technology at DOE sites with ground water contaminated by dense, non-aqueous phase liquids (DNAPLs), in particular, chlorinated solvents. The first phase of this project, Laboratory and Pilot Field Scale Testing, which is the subject of the work so far, involves (1) laboratory experiments to examine the solubilization of multiple component DNAPLs, e.g., solvents such as perchloroethylene (PCE) and trichloroethylene (TCE), by dilute surfactant solutions, and (2) a field test to demonstrate SEAR technology on a small scale and in an existing well

  7. Economics of Managed Aquifer Recharge

    Directory of Open Access Journals (Sweden)

    Robert G. Maliva

    2014-05-01

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

  8. The Role of Attached and Free-Living Bacteria in Biodegradation in Karst Aquifers

    Directory of Open Access Journals (Sweden)

    Ahmad Kheder

    2011-12-01

    Full Text Available Natural attenuation of groundwater contamination occurs at some level for all aquifers impacted with organic contaminants. The issues regarding natural attenuation are whether it takes place at a sufficient rate to be protective of human health and the environment. Implementation of a Monitored Natural Attenuation (MNA remedial alternative for groundwater requires parties responsible for the contamination to demonstrate to regulators and the public that MNA is protective at a given site. Analysis of MNA for remediation of karst aquifers is hampered by a lack of understanding of biodegradation in karst environments. The lack of studies examining biodegradation in karst aquifers may in large part be due to the widespread perception that contaminants are rapidly flushed out of karst aquifers resulting in insufficient residence times for contaminants to biodegrade. In highly developed and well-connected conduit systems, the rate of contaminant migration is perceived to be much faster than the rate of biodegradation. This perception of contaminant transport is largely incorrect. Tracer studies for karst aquifers often indicate that these aquifers are characterized by diverse flow regimes and storage capabilities. Additionally, it is also believed that if bioremediation in bedrock aquifers is dependent upon contact between surface-attached bacteria and contaminants, then bioremediation would be limited by the low surface-area-to-volume ratio (SA/V of karst aquifers. A quantitative basis, however, for accepting or rejecting the assumption that attached bacteria dominate the biodegradation process in karst conduits has not been shown. The objective of this research was to determine if free-living karst bacteria from contributed as much to toluene biodegradation as attached bacteria. This is an important area of research. Research indicates bacteria are both attached and free-living in karst aquifers and it is unrealistic to think that only the attached

  9. Integrated Assessment to Evaluate the Artificial Recharge in a Small Portion of the Aquifer of Puebla, Mexico

    Science.gov (United States)

    Arango-Galván, C.; Flores-Marquez, L. E.; Martínez-Serrano, R.

    2009-12-01

    New policies on the use of water resources in Mexico have led to implement some alternative measures to optimize water management. In particular, water regulation entities have recommended some tools to preserve and protect the groundwater supplies. One of these tools is the artificial recharge by injecting water directly into the aquifer. The main goal of this study is to assess if it is suitable to inject rainwater and surface water in a small portion of the aquifer of the city of Puebla, in central Mexico. Artificial aquifer recharging was evaluated using a numeric model, which simulated the physical properties of the system. The model setup was inferred from an integrated study taking into account hydraulic, geological and geophysical data. The geoelectrical model was computed using electric resistivity tomography (ERT) and time domain electromagnetic data (TDEM). The aquifer geological structure inferred from geophysics depicts the presence of a shallower layer composed of sand and clay deposits with low saturation and permeability. This layer contains silt lenses that can be controlling the persistence of small water bodies on surface. Some water surficial bodies seem to be isolated from the main aquifer system. The intermediate layer shows lower electrical resistivity and higher permeability. Underlying this horizon, it is a deeper layer that reaches 200 m depth, according to information obtained from borehole in the zone. This layer shows an electrical resistivity even lower than intermediate layer but low permeability, caused by the higher content of silts. Both of these layers are the shallower aquifer exploited in the area. Once the numeric model was built we proceeded to simulate scenarios that include the continued extraction and recharge of water in wells located in strategic areas of the study zone. The results suggest that the effect of infiltration is beneficial on aquifer recharge and reduces the cone of depression caused by the extraction

  10. Foam-Delivery of Remedial Amendments for Enhanced Vadose Zone Metals and Radionuclides Remediation

    International Nuclear Information System (INIS)

    Zhong, L.; Szecsody, J.E.; Dresel, P.E.; Zhang, Z.F.; Qafoku, N.P.

    2009-01-01

    The remediation of metals and radionuclides contamination, such as Cr(VI), Tc-99, and Sr-90 in the U.S. DOE Hanford Site vadose zone is a critical need. Water-based remedial amendments delivery to the deep vadose zone is facing significant technical challenges. Water-based delivery will easily leach out the highly mobile pollutants therefore contaminate the underlying aquifer. Preferential flow of the amendment-laden solution in the vadose zone due to the formation heterogeneity is difficult to overcome, resulting in bypassing of the less permeable zones. Foam has unique transport properties in the vadose zone that enable mitigation on the mobilization of mobile contaminants and enhance the sweeping over heterogeneous systems. Calcium polysulfide (CPS) is a remedial amendment that can be used to reduce and immobilize hexavalent chromium [Cr(VI)] and other redox-sensitive radionuclides/metals in the vadose zone. The delivery of CPS to the vadose zone using foam and the immobilization of Cr(VI) via reduction by the foam-delivered CPS was investigated in this study. Batch tests were conducted to select the foam-generating CPS-surfactant solutions, to determine the solution foamability and the reducing potential of CPS-containing foams, and to study the influence of foam quality, surfactant concentration, and CPS concentration on foam stability. Column experiments were performed to test the foam delivery of CPS to sediments under conditions similar to field vadose zone, to study the foam transport and interaction with sediments, and to determine the extent of Cr(VI) immobilization using this novel delivery approach. CPS-containing foams with high reducing potential were prepared based on the batch tests. Sediment reduction by foam-delivered CPS was observed in the column studies. Significant mobilization of Cr(VI) from sediments occurred when CPS was delivered in aqueous solution. The Cr(VI) mobilization was minimized when CPS was delivered by foams, resulting in

  11. Characterization of Uranium Contamination, Transport, and Remediation at Rocky Flats - Across Remediation into Post-Closure

    Science.gov (United States)

    Janecky, D. R.; Boylan, J.; Murrell, M. T.

    2009-12-01

    The Rocky Flats Site is a former nuclear weapons production facility approximately 16 miles northwest of Denver, Colorado. Built in 1952 and operated by the Atomic Energy Commission and then Department of Energy, the Site was remediated and closed in 2005, and is currently undergoing long-term surveillance and monitoring by the DOE Office of Legacy Management. Areas of contamination resulted from roughly fifty years of operation. Of greatest interest, surface soils were contaminated with plutonium, americium, and uranium; groundwater was contaminated with chlorinated solvents, uranium, and nitrates; and surface waters, as recipients of runoff and shallow groundwater discharge, have been contaminated by transport from both regimes. A region of economic mineralization that has been referred to as the Colorado Mineral Belt is nearby, and the Schwartzwalder uranium mine is approximately five miles upgradient of the Site. Background uranium concentrations are therefore elevated in many areas. Weapons-related activities included work with enriched and depleted uranium, contributing anthropogenic content to the environment. Using high-resolution isotopic analyses, Site-related contamination can be distinguished from natural uranium in water samples. This has been instrumental in defining remedy components, and long-term monitoring and surveillance strategies. Rocky Flats hydrology interlinks surface waters and shallow groundwater (which is very limited in volume and vertical and horizontal extent). Surface water transport pathways include several streams, constructed ponds, and facility surfaces. Shallow groundwater has no demonstrated connection to deep aquifers, and includes natural preferential pathways resulting primarily from porosity in the Rocky Flats alluvium, weathered bedrock, and discontinuous sandstones. In addition, building footings, drains, trenches, and remedial systems provide pathways for transport at the site. Removal of impermeable surfaces (buildings

  12. In-situ arsenic remediation in Carson Valley, Douglas County, west-central Nevada

    Science.gov (United States)

    Paul, Angela P.; Maurer, Douglas K.; Stollenwerk, Kenneth G.; Welch, Alan H.

    2010-01-01

    Conventional arsenic remediation strategies primarily involve above-ground treatment that include costs involved in the disposal of sludge material. The primary advantages of in-situ remediation are that building and maintaining a large treatment facility are not necessary and that costs associated with the disposal of sludge are eliminated. A two-phase study was implemented to address the feasibility of in-situ arsenic remediation in Douglas County, Nevada. Arsenic concentrations in groundwater within Douglas County range from 1 to 85 micrograms per liter. The primary arsenic species in groundwater at greater than 250 ft from land surface is arsenite; however, in the upper 150 ft of the aquifer arsenate predominates. Where arsenite is the primary form of arsenic, the oxidation of arsenite to arsenate is necessary. The results of the first phase of this investigation indicated that arsenic concentrations can be remediated to below the drinking-water standard using aeration, chlorination, iron, and pH adjustment. Arsenic concentrations were remediated to less than 10 micrograms per liter in groundwater from the shallow and deep aquifer when iron concentrations of 3-6 milligrams per liter and pH adjustments to less than 6 were used. Because of the rapid depletion of dissolved oxygen, the secondary drinking-water standards for iron (300 micrograms per liter) and manganese (100 micrograms per liter) were exceeded during treatment. Treatment was more effective in the shallow well as indicated by a greater recovery of water meeting the arsenic standard. Laboratory and field tests were included in the second phase of this study. Laboratory column experiments using aquifer material indicated the treatment process followed during the first phase of this study will continue to work, without exceeding secondary drinking-water standards, provided that groundwater was pre-aerated and an adequate number of pore volumes treated. During the 147-day laboratory experiment, no

  13. Implementation of a funnel-and-gate remediation system

    International Nuclear Information System (INIS)

    O'Brien, K.; Keyes, G.; Sherman, N.

    1997-01-01

    A funnel-and-gate trademark system incorporating activated carbon was deemed the most attractive remediation method for an active lumber mill in the western United States. Petroleum hydrocarbons, chlorinated solvents, pentachlorophenol, and tetrachlorophenol were detected in on-site groundwater samples. The shallow aquifer consists of a heterogeneous mixture of marine deposits and artificial fill, underlain by low-permeability siltstones and mudstone. In the funnel-and-gate trademark system, a low-permeability cutoff wall was installed to funnel groundwater flow to a smaller area (a open-quotes gateclose quotes) where a passive below-grade treatment system treats the plume as it flows through the gate. Groundwater flow modeling focused on the inhomogeneities of the aquifer and the spatial relationship between gate(s) and barrier walls. The gate design incorporates several factors, including contaminant concentration, flow rate, and time between carbon changeouts. To minimize back pressure and maximize residence time, each gate was designed using 1.25-meter (4-foot) diameter corrugated metal pipe filled with a 1.25-meter (4-foot) thick bed of activated carbon. The configuration will allow water to flow through the treatment gates without pumps. The installed system is 190 meters (625 feet) long and treats approximately 76 L/min (20 gpm) during the winter months

  14. Intrinsic remediation of JP-4 fuel in soil and ground water

    International Nuclear Information System (INIS)

    Schmithorst, W.L. Jr.; Vardy, J.A.

    1995-01-01

    Intrinsic remediation methods were employed to remediate soil and ground water contaminated by JP-4 fuel at the United States Coast Guard (USCG) Support Center facility in Elizabeth City, North Carolina. By the time the release was discovered, non-aqueous phase JP-4 fuel was detected in ground water over an area of approximately 8,000 square feet. In addition, concentrations of dissolved BTEX in ground water exceeded 5,000 microg/L. Tight clays present in the upper two meters of the aquifer, underlain by highly transmissive sands, prevented remediation of the JP-4 by conventional treatment methods. Therefore, a system of air injection and air extraction wells were installed that simultaneously depressed the water table and extracted hydrocarbon vapors. The conceptual idea, developed by the EPA RS Kerr Environmental Laboratory (RSKERL) in Ada, Oklahoma, is to stimulate rapid intrinsic biodegradation of the JP-4 fuel compounds. Subsequent biorespiration measurements indicated that the fuel compounds were being rapidly biodegraded. Upon removal of the non aqueous JP-4 compounds, an investigation was conducted to determine if the aquifer had an adequate assimilative capacity to support natural aerobic and anaerobic biodegradation of the contaminants. Analysis of ground water samples collected using a cone penetrometer and a direct-push sampling device indicate a sufficient concentration of electron acceptors to support natural biodegradation of the JP-4 compounds

  15. Foam - novel delivery technology for remediation of vadose zone environments - 59019

    International Nuclear Information System (INIS)

    Jansik, Danielle; Wellman, Dawn M.; Mattigod, Shas V.; Zhong, Lirong; Zhang, Fred; Foote, Martin; Wu, Yuxin; Hubbard, Susan

    2012-01-01

    Deep vadose zone environments can be a primary source and pathway for contaminant migration to groundwater. These environments present unique characterization and remediation challenges that necessitate scrutiny and research. The thickness, depth, and intricacies of the deep vadose zone, combined with a lack of understanding of the key subsurface processes (e.g., biogeochemical and hydrologic) affecting contaminant migration, make it difficult to create validated conceptual and predictive models of subsurface flow dynamics and contaminant behavior across multiple scales. These factors also make it difficult to design and deploy sustainable remedial approaches and monitor long-term contaminant behavior after remedial actions. Functionally, methods for addressing contamination must remove and/or reduce transport of contaminants. This problem is particularly challenging in the arid western United States where the vadose zone is hundreds of feet thick, rendering transitional excavation methods exceedingly costly and ineffective. Delivery of remedial amendments is one of the most challenging and critical aspects for all remedy-based approaches. The conventional approach for delivery is through injection of aqueous remedial solutions. However, heterogeneous deep vadose zone environments present hydrologic and geochemical challenges that limit the effectiveness. Because the flow of solution infiltration is dominantly controlled by gravity and suction, injected liquid preferentially percolates through highly permeable pathways, by-passing low-permeability zones that frequently contain the majority of contamination. Moreover, the wetting front can readily mobilize and enhance contaminant transport to the underlying aquifer prior to stabilization. Development of innovative in-situ technologies may be the only means to meet remedial action objectives and long-term stewardship goals. Surfactants can be used to lower the liquid surface tension and create stabile foams, which

  16. Radon remediation in irish schools

    International Nuclear Information System (INIS)

    Synnott, H.

    2006-01-01

    Full text: Commencing in 1998, the Radiological Protection Institute of Ireland carried out radon measurements in 3826 schools in the Republic of I reland on behalf of the Irish Department of Education and Science (D.E.S.). This represents approximately 97% of all schools in the country. Approximately 25% (984) schools had radon concentrations above the Irish national schools Reference Level for radon of 200 Bq/m 3 and required remedial work. The number of individual rooms with radon concentrations above 200 Bq/m 3 was 3020. Remedial work in schools commenced in early 2000. In general schools with maximum radon concentrations in the range 200 -400 Bq/m 3 in one or more rooms were remediated through the installation of passive systems such as an increase in permanent background ventilation mainly wall vents and trickle vents in windows. Schools with maximum radon concentrations greater than 400 Bq/m 3 were usually remediated through the provision of active systems mainly fan assisted sub -slab de pressurization or where this was not possible fan assisted under floor ventilation. The cost of the remedial programme was funded by central Government. Active systems were installed by specialized remedial contractors working to the specifications of a radon remedial expert appointed by the D.E.S. to design remedial systems for affected schools. Schools requiring increased ventilation were granted aided 190 pounds per affected room and had to organize the work themselves. In most schools radon remediation was successful in reducing existing radon concentrations to below the Reference Level. Average radon concentration reduction factors for sub-slab de pressurization systems and fan assisted fan assisted under floor ventilation ranged from 5 to 40 with greater reduction rates found at higher original radon concentrations. Increasing ventilation in locations with moderately elevated radon concentrations (200 - 400 Bq/m 3 ) while not as effective as active systems produced on

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

    Science.gov (United States)

    Gordon, Debbie W.; Gonthier, Gerard

    2017-04-24

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

  18. HANFORD GROUNDWATER REMEDIATION

    Energy Technology Data Exchange (ETDEWEB)

    CHARBONEAU, B; THOMPSON, M; WILDE, R.; FORD, B.; GERBER, M.S.

    2006-02-01

    geographically dispersed community is united in its desire to protect the Columbia River and have a voice in Hanford's future. This paper presents the challenges, and then discusses the progress and efforts underway to reduce the risk posed by contaminated groundwater at Hanford. While Hanford groundwater is not a source of drinking water on or off the Site, there are possible near-shore impacts where it flows into the Columbia River. Therefore, this remediation is critical to the overall efforts to clean up the Site, as well as protect a natural resource.

  19. The benefits from environmental remediation

    International Nuclear Information System (INIS)

    Falck, W.E.

    2002-01-01

    Environmental remediation projects inevitably take place against a backdrop of overall social goals and values. These goals can include, for example, full employment, preservation of the cultural, economic and archaeological resources, traditional patterns of land use, spiritual values, quality of life factors, biological diversity, environmental and socio-economic sustainability, protection of public health. Different countries will have different priorities, linked to the overall set of societal goals and the availability of resources, including funding, man-power and skills. These issues are embedded within both a national and local socio-cultural context, and will shape the way in which the remediation process is structured in any one country. The context will shape both the overall objectives of a remediation activity within the framework of competing societal goals, as well as generate constraints on the decision making process. Hence, the overall benefit of a remediation project is determined by its overall efficiency and effectiveness within the given legal, institutional, and governance framework, under the prevailing socio-economic boundary conditions, and balancing technology performance and risk reduction with fixed or limited budgetary resources, and is not simply the result of the technical remediation operation itself. (author)

  20. Funnel-and-gate remediation systems augmented with passive filter wells.

    Science.gov (United States)

    Hudak, Paul F

    2010-09-01

    The objective of this study was to evaluate the ability of funnel-and-gate structures augmented with passive wells containing filter cartridges to capture contaminated groundwater in hypothetical, homogeneous and heterogeneous, unconfined aquifers. Perpendicular to groundwater flow, linear structures were 15 m wide, 1 m thick, and keyed into the base of the aquifer. Gates occupied 4 m of the total width of each simulated structure; one gate was 5 m from a contaminant plume's leading tip, while others occupied cross-gradient margins of the plume. Results suggest a modest reduction in remediation timeframes, up to 425 d per well added in these simulations; however, incremental benefits are highly variable and case specific.

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

    OpenAIRE

    Höyng, Dominik

    2014-01-01

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

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

    Science.gov (United States)

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

    1985-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-09-01

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

  4. Caresoil: A multidisciplinar Project to characterize, remediate, monitor and evaluate the risk of contaminated soils in Madrid (Spain)

    Science.gov (United States)

    Muñoz-Martín, Alfonso; Antón, Loreto; Granja, Jose Luis; Villarroya, Fermín; Montero, Esperanza; Rodríguez, Vanesa

    2016-04-01

    Soil contamination can come from diffuse sources (air deposition, agriculture, etc.) or local sources, these last being related to anthropogenic activities that are potentially soil contaminating activities. According to data from the EU, in Spain, and particularly for the Autonomous Community of Madrid, it can be considered that heavy metals, toxic organic compounds (including Non Aqueous Phases Liquids, NAPLs) and combinations of both are the main problem of point sources of soil contamination in our community. The five aspects that will be applied in Caresoil Program (S2013/MAE-2739) in the analysis and remediation of a local soil contamination are: 1) the location of the source of contamination and characterization of soil and aquifer concerned, 2) evaluation of the dispersion of the plume, 3) application of effective remediation techniques, 4) monitoring the evolution of the contaminated soil and 5) risk analysis throughout this process. These aspects involve advanced technologies (hydrogeology, geophysics, geochemistry,...) that require new developing of knowledge, being necessary the contribution of several researching groups specialized in the fields previously cited, as they are those integrating CARESOIL Program. Actually two cases concerning hydrocarbon spills, as representative examples of soil local contamination in Madrid area, are being studied. The first is being remediated and we are monitoring this process to evaluate its effectiveness. In the second location we are defining the extent of contamination in soil and aquifer to define the most effective remediation technique.

  5. A remedial alternative prioritization method

    International Nuclear Information System (INIS)

    Richter, S.A.; Travis, C.C.

    1987-01-01

    This study develops and tests a technique for evaluating and prioritizing alternative remedial actions for hazardous waste sites. The method is based on criteria involving risk, benefit and cost, and identifies the most cost-effective solution to a given remedial problem. Four sites on the Department of Energy's Oak Ridge National Laboratory (ORNL) property in Oak Ridge, Tennessee, were used in a case study to develop and test the method. Results of the case study indicate that even if the cap providing in situ containment must be replaced every 10 years, it is a superior alternative to total excavation of the waste sites

  6. Bioelectrical Perchlorate Remediation

    Science.gov (United States)

    Thrash, C.; Achenbach, L. A.; Coates, J. D.

    2007-12-01

    low-level perchlorate (100 μg.L-1) influent as well as mixed-waste influents more typically found in the environment containing both nitrate and perchlorate. Through extended periods of operation (>70 days), no loss in treatment efficiency was noted and no measurable growth in biomass was observed. Gas phase analysis indicated that low levels of H2 produced at the cathode surface through electrolysis can provide enough reducing equivalents to mediate this metabolism. The results of these studies demonstrate that perchlorate remediation can be facilitated through the use of a cathode as the primary electron donor, and that continuous treatment in such a system approaches current industry standards. This has important implications for the continuous treatment of this critical contaminant in industrial waste streams and drinking water. Such a process has the advantage of long-term, low-maintenance operation with ease of online monitoring and control while limiting the injection of additional chemicals into the water treatment process and outgrowth of the microbial populations. This would negate the need for the continual removal and disposal of biomass produced during treatment and also the downstream issues associated with corrosion and biofouling of distribution systems and the production of toxic disinfection byproducts.

  7. Remediation Technologies Eliminate Contaminants

    Science.gov (United States)

    2012-01-01

    groundwater tainted by chlorinated solvents once used to clean rocket engine components. The award-winning innovation (Spinoff 2010) is now NASA s most licensed technology to date. PCBs in paint presented a new challenge. Removing the launch stand for recycling proved a difficult operation; the toxic paint had to be fully stripped from the steel structure, a lengthy and costly process that required the stripped paint to be treated before disposal. Noting the lack of efficient, environmentally friendly options for dealing with PCBs, Quinn and her colleagues developed the Activated Metal Treatment System (AMTS). AMTS is a paste consisting of a solvent solution containing microscale particles of activated zero-valent metal. When applied to a painted surface, the paste extracts and degrades the PCBs into benign byproducts while leaving the paint on the structure. This provides a superior alternative to other methods for PCB remediation, such as stripping the paint or incinerating the structure, which prevents reuse and can release volatized PCBs into the air. Since its development, AMTS has proven to be a valuable solution for removing PCBs from paint, caulking, and various insulation and filler materials in older buildings, naval ships, and former munitions facilities where the presence of PCBs interferes with methods for removing trace explosive materials. Miles of potentially toxic caulking join sections of runways at airports. Any of these materials installed before 1979 potentially contain PCBs, Quinn says. "This is not just a NASA problem," she says. "It s a global problem."

  8. 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.

  9. Hydrophysical logging: A new wellbore technology for hydrogeologic and contaminant characterization of aquifers

    International Nuclear Information System (INIS)

    Pedler, W.H.; Williams, L.L.; Head, C.L.

    1992-01-01

    In the continuing search for improved groundwater characterization technologies, a new wellbore fluid logging method has recently been developed to provide accurate and cost effective hydrogeologic and contaminant characterization of bedrock aquifers. This new technique, termed hydrophysical logging, provides critical information for contaminated site characterization and water supply studies and, in addition, offers advantages compared to existing industry standards for aquifer characterization. Hydrophysical logging is based on measuring induced electrical conductivity changes in the fluid column of a wellbore by employing advanced downhole water quality instrumentation specifically developed for the dynamic borehole environment. Hydrophysical logging contemporaneously identifies the locations of water bearing intervals, the interval-specific inflow rate during pumping, and in-situ hydrochemistry of the formation waters associated with each producing interval. In addition, by employing a discrete point downhole fluid sampler during hydrophysical logging, this technique provides evaluation of contaminant concentrations and migration of contaminants vertically within the borehole. Recently, hydrophysical logging was applied in a deep bedrock wellbore at an industrial site in New Hampshire contaminated with dense nonaqueous phase liquids (DNAPLs). The results of the hydrophysical logging, conducted as part of a hydrogeologic site investigation and feasibility study, facilitated investigation of the site by providing information which indicated that the contamination had not penetrated into deeper bedrock fractures at concentrations of concern. This information was used to focus the pending Remedial Action Plan and to provide a more cost-effective remedial design

  10. Changing the scale of hydrogeophysical aquifer heterogeneity characterization

    Science.gov (United States)

    Paradis, Daniel; Tremblay, Laurie; Ruggeri, Paolo; Brunet, Patrick; Fabien-Ouellet, Gabriel; Gloaguen, Erwan; Holliger, Klaus; Irving, James; Molson, John; Lefebvre, Rene

    2015-04-01

    Contaminant remediation and management require the quantitative predictive capabilities of groundwater flow and mass transport numerical models. Such models have to encompass source zones and receptors, and thus typically cover several square kilometers. To predict the path and fate of contaminant plumes, these models have to represent the heterogeneous distribution of hydraulic conductivity (K). However, hydrogeophysics has generally been used to image relatively restricted areas of the subsurface (small fractions of km2), so there is a need for approaches defining heterogeneity at larger scales and providing data to constrain conceptual and numerical models of aquifer systems. This communication describes a workflow defining aquifer heterogeneity that was applied over a 12 km2 sub-watershed surrounding a decommissioned landfill emitting landfill leachate. The aquifer is a shallow, 10 to 20 m thick, highly heterogeneous and anisotropic assemblage of littoral sand and silt. Field work involved the acquisition of a broad range of data: geological, hydraulic, geophysical, and geochemical. The emphasis was put on high resolution and continuous hydrogeophysical data, the use of direct-push fully-screened wells and the acquisition of targeted high-resolution hydraulic data covering the range of observed aquifer materials. The main methods were: 1) surface geophysics (ground-penetrating radar and electrical resistivity); 2) direct-push operations with a geotechnical drilling rig (cone penetration tests with soil moisture resistivity CPT/SMR; full-screen well installation); and 3) borehole operations, including high-resolution hydraulic tests and geochemical sampling. New methods were developed to acquire high vertical resolution hydraulic data in direct-push wells, including both vertical and horizontal K (Kv and Kh). Various data integration approaches were used to represent aquifer properties in 1D, 2D and 3D. Using relevant vector machines (RVM), the mechanical and

  11. Hydrogeologic characterization of devonian aquifers in Uruguay

    International Nuclear Information System (INIS)

    Massa, E.

    1988-01-01

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

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

    African Journals Online (AJOL)

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

  13. Consensus implementation of a groundwater remediation project at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Hastings, K.R.; Carlson, D.S.

    1996-01-01

    Because of significant characterization uncertainties existing when the Record of Decision was signed and the unfavorable national reputation of groundwater pump and treat remediation projects, the Test Area North (TAN) groundwater ROD includes the evaluation of five emerging technologies that show potential for treating the organic contamination in situ or reducing the toxicity of contaminants above ground. Treatability studies will be conducted to ascertain whether any may be suitable for implementation at TAN to yield more timely or cost effective restoration of the aquifer. The implementation approach established for the TAN groundwater project is a consensus approach, maximizing a partnership relation with stakeholders in constant, iterative implementation decision making

  14. Abstracts of Remediation Case Studies, Volume 9

    Science.gov (United States)

    This report, published by the Federal Remediation Technologies Roundtable (FRTR), is a collection of recently published abstracts summarizing 13 cost and performance case studies on the use of remediation technologies at contaminated sites.

  15. Key Principles of Superfund Remedy Selection

    Science.gov (United States)

    Guidance on the primary considerations of remedy selection which are universally applicable at Superfund sites. Key guidance here include: Rules of Thumb for Superfund Remedy Selection and Role of the Baseline Risk Assessment.

  16. Electrokinetic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrián; Ottosen, Lisbeth M.

    2007-01-01

    Important process parameters to optimize in electrokinetic soil remediation are those influencing remediation time and power consumption since these directly affect the cost of a remediation action. This work shows how the electrokinetic remediation (EKR) process could be improved by implementing...... bipolar electrodes in the porous material. The bipolar electrodes in EKR meant two improvements: (1) a shorter migration pathway for the contaminant, and (2) an increased electrical conductivity in the remediation system. All together the remediation proceeded faster with lower electrical resistance than...... in similar experiments but without the bipolar electrodes. The new electrokinetic remediation design was tested on copper mine tailings with different applied electric fields, remediation times and pre-treatment. The results showed that the copper removal was increased from 8% (applying 20V for 8 days...

  17. Chlorine isotope investigation of natural attenuation of trichloroethene in an aerobic aquifer

    International Nuclear Information System (INIS)

    Sturchio, N.C.; Heraty, L.J.; Huang, L.; Holt, B.D.; Abrajano, T.A. Jr.; Clausen, J.L.

    1998-01-01

    Natural attenuation of chlorinated aliphatic hydrocarbons (CAHs) can be an important mechanism for groundwater remediation. It is difficult to determine the effectiveness of natural CAH attenuation from chemical analyses of groundwater samples because mixing, dispersion, and secondary reactions can mask the chemical evidence of attenuation. In this paper, the authors explore the application of stable chlorine isotope ratio measurements as a new tool for evaluating natural attenuation of CAHs. They report stable isotope ratios of chlorine in both trichloroethene (TCE) and inorganic chloride in groundwater from an aerobic aquifer beneath an extensively contaminated industrial site, the Paducah Gaseous Diffusion Plant in western Kentucky. Variations in the concentrations and chlorine isotope ratios of TCE and chloride in the groundwater are consistent with those expected from natural attenuation. These data support a model in which partial TCE degradation occurred in relatively impermeable, clay-rich sediments above the aquifer, and little or no further degradation of TCE occurred within the aquifer. A record of changing conditions within the TCE source area can be inferred from the spatial variation of chlorine isotope ratios for TCE and chloride within the plume

  18. Thermally enhanced bioremediation of a gasoline-contaminated aquifer using toluene oxidizing bacteria

    International Nuclear Information System (INIS)

    Deeb, R.; Alvarez-Cohen, L.

    1994-01-01

    The combined application of steam injection and vacuum extraction has proved to be very effective for the in situ remediation of a gasoline contaminated aquifer. It is expected that the steam treated zone with its near-sterile nature, increased temperature, and decreased level of contaminant concentration will provide a superior environment for enhanced bioremediation, and will favor the survival of an introduced microbial culture for the destruction of residual gasoline hydrocarbons and especially BTEX compounds (Benzene, Toluene, Ethyl benzene, and Xylene). A mixed microbial culture seeded from the pre-steamed aquifer material was enriched in a laboratory chemostat on toluene, a major gasoline aromatic. Studies were conducted to determine the optimal conditions for microbial growth and activity. Growth rate studies conducted at different temperatures revealed that cell growth was optimal at 35 C, a temperature at which the aquifer can be maintained using the existing steam injection wells. The enriched culture was shown to degrade all BTEX compounds successfully both individually and in mixtures. Substrate toxicity was observed for some of the gasoline aromatics but at concentration levels well above those found in groundwater. When cells were exposed to mixtures of BTEX compounds, the biodegradation of xylene, the most recalcitrant aromatic among BTEX compounds, was stimulated. When cells were exposed to gasoline, BTEX degradation proceeded with no apparent inhibition by gasoline aliphatics; little aliphatic degradation took place, however, suggesting the absence of monooxygenase enzymes in the mixed culture. In mixtures of both toluene and propane enriched cultures, only dioxygenase activity was observed

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

    Science.gov (United States)

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

    2014-05-01

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

  20. Electrodialytic Remediation of Copper Mine Tailings

    DEFF Research Database (Denmark)

    Hansen, H.K.; Rojo, A.; Ottosen, L.M.

    2012-01-01

    This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields.......This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields....

  1. Green Chemistry and Environmental Remediation

    Science.gov (United States)

    Abstract: Nutrient remediation and recovery is a growing concern for two key reasons: (i) the prevention of harmful algal bloom proliferation, and (ii) the recycling of nutrients (e.g., phosphates) as they are non-renewable resources which are quickly being depleted. A wide range...

  2. Academic Intervention: Acceleration and Remediation

    Science.gov (United States)

    Franklin, Barbara Gail

    2016-01-01

    Eighth grade math students must pass a standards based test to be promoted to the next grade. Students who were at risk of failing the state's annual test faced impending retention. The purpose of this quasi-experimental study was to see if an intensive nine-week (55 min per day) remedial Math Connection (MC) class for 67 suburban, eighth grade…

  3. Surfactants enhance recovery of poorly soluble drugs during microdialysis sampling

    DEFF Research Database (Denmark)

    Koplin, Sebastian; Kumpugdee-Vollrath, Mont; Bauer-Brandl, Annette

    2017-01-01

    Aim of this project was to investigate the applicability of a recently developed in vitro microdialysis-sampling approach in connection with a dissolution-/permeation (D/P) system, especially the impact of surfactants within the perfusion fluid. The D/P-system is based on side-by-side chambers...... drug-dissolution (-release) and drug permeation. Furthermore, it should allow quantification of the unbound (free) drug concentration. In the first step, it was assessed, if the addition of the anionic surfactant sodium dodecyl sulphate (SDS) to the perfusate of the microdialysis system affects...... celecoxib, i.e. the fraction of drug, which is not associated with taurocholate surfactant micelles. In buffer, the measured concentrations matched the overall CXB concentrations. By the use of SDS-containing perfusates microdialysis sampling enabled reliable quantification of minute amounts of free CXB...

  4. Surfactant-Enhanced Benard Convection on an Evaporating Drop

    Science.gov (United States)

    Nguyen, Van X.; Stebe, Kathleen J.

    2001-11-01

    Surfactant effects on an evaporating drop are studied experimentally. Using a fluorescent probe, the distribution and surface phase of the surfactant is directly imaged throughout the evaporation process. From these experiments, we identify conditions in which surfactants promote surface tension-driven Benard instabilities in aqueous systems. The drops under study contain finely divided particles, which act as tracers in the flow, and form well-defined patterns after the drop evaporates. Two flow fields have been reported in this system. The first occurs because the contact line becomes pinned by solid particles at the contact line region. In order for the contact line to remain fixed, an outward flow toward the ring results, driving further accumulation at the contact ring. A ‘coffee ring’ of particles is left as residue after the drop evaporates[1]. The second flow is Benard convection, driven by surface tension gradients on the drop[2,3]. In our experiments, an insoluble monolayer of pentadecanoic acid is spread at the interface of a pendant drop. The surface tension is recorded, and the drop is deposited on a well-defined solid substrate. Fluorescent images of the surface phase of the surfactant are recorded as the drop evaporates. The surfactant monolayer assumes a variety of surface states as a function of the area per molecule at the interface: surface gaseous, surface liquid expanded, and surface liquid condensed phases[4]. Depending upon the surface state of the surfactant as the drop evaporates, transitions of residue patterns left by the particles occur, from the coffee ring pattern to Benard cells to irregular patterns, suggesting a strong resistance to outward flow are observed. The occurrence of Benard cells on a surfactant-rich interface occurs when the interface is in LE-LC coexistence. Prior research concerning surfactant effects on this instability predict that surfactants are strongly stabilizing[5]. The mechanisms for this change in behavior are discussed. References: [1]R. D. Deegan,, PRE 61,475 (2000). [2]M. Maillard et al., J. Phys. Chem. B 104, 11871 (2000). [3]H. Wang et al. Langmuir 15, 957 (2001). [4]B. G. Moore et al., J. Phys. Chem. 94, 4588 (1990). [5]J. C. Berg & A. Acrivos, Chem. Eng. Sci. 20,737 (1965).

  5. Surfactant-enhanced control of track-etch pore morphology

    International Nuclear Information System (INIS)

    Apel', P.Yu.; Blonskaya, I.V.; Didyk, A.Yu.; Dmitriev, S.N.; Orelovich, O.L.; Samojlova, L.I.; Vutsadakis, V.A.; Root, D.

    2000-01-01

    The influence of surfactants on the process of chemical development of ion tracks in polymers is studied. Based on the experimental data, a mechanism of the surfactant effect on the track-etch pore morphology is proposed. In the beginning of etching the surfactant is adsorbed on the surface and creates a layer that is quasi-solid and partially protects the surface from the etching agent. However, some etchant molecules diffuse through the barrier and react with the polymer surface. This results in the formation of a small hole at the entrance to the ion track. After the hole has attained a few annometers in diameter, the surfactant molecules penetrate into the track and cover its walls. Further diffusion of the surfactant into the growing pore is hindered. The adsorbed surfactant layer is not permeable for large molecules. In contrast, small alkali molecules and water molecules diffuse into the track and provide the etching process enlarging the pore. At this stage the transport of the surfactant into the pore channel can proceed only due to the lateral diffusion in the adsorbed layer. The volume inside the pore is free of surfactant molecules and grows at a higher rate than pore entrance. After a more prolonged etching the bottle-like (or 'cigar-like') pore channels are formed. The bottle-like shape of the pore channels depends on the etching conditions such as alkali and surfactant concentration, temperature, and type of the surfactant. The use of surfactants enables one to produce track-etch membranes with improved flow rate characteristics compared with those having cylindrical pores with the same nominal pore diameters

  6. Baseline mapping study of the Steed Pond aquifer and vadose zone beneath A/M Area, Savannah River Site, Aiken, South Carolina

    International Nuclear Information System (INIS)

    Jackson, D.G. Jr.

    2000-01-01

    This report presents the second phase of a baseline mapping project conducted for the Environmental Restoration Department (ERD) at Savannah River Site. The purpose of this second phase is to map the structure and distribution of mud (clay and silt-sized sediment) within the vadose zone beneath A/M Area. The results presented in this report will assist future characterization and remediation activities in the vadose zone and upper aquifer zones in A/M Area

  7. Enhancing aquifer cleanup with reinjection

    International Nuclear Information System (INIS)

    Isherwood, W.F.; Ziagos, J.; Rice, D. Jr.; Krauter, P.; Nichols, E.

    1992-09-01

    Injection of water or steam, with or without chemical surfactants, is a common petroleum industry technique to enhance product recovery. In the geothermal industry, reinjection (reinjection is used to mean the injection of ground water that was previously injected) of heat- depleted subsurface fluids is commonly used to maintain reservoir pressure, thus prolonging field productivity. The use reinjection in ground-water remediation projects allows for the application of both traditional production field management and a variety of additional enhancements to the cleanup process. Development of the ideas in this paper was stimulated by an initial suggestion by Dr. Jacob Bear (personal discussions, 1990--1991) that reinjected water might be heated to aid the desorption process

  8. Integrated remediation of soil and groundwater

    International Nuclear Information System (INIS)

    Dykes, R.S.; Howles, A.C.

    1992-01-01

    Remediation of sites contaminated with petroleum hydrocarbons and other organic chemicals frequently focuses on a single phase of the chemical in question. This paper describes an integrated approach to remediation involving selection of complimentary technologies designed to create a remedial system which achieves cleanup goals in affected media in the shortest possible time consistent with overall environmental protection

  9. 32 CFR 310.47 - Civil remedies.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Civil remedies. 310.47 Section 310.47 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) PRIVACY PROGRAM DOD PRIVACY PROGRAM Privacy Act Violations § 310.47 Civil remedies. In addition to specific remedial...

  10. New Mexico English Remediation Taskforce Report

    Science.gov (United States)

    New Mexico Higher Education Department, 2016

    2016-01-01

    In March, 2016, the state of New Mexico established a Remediation Task Force to examine remediation reform efforts across the state's higher education institutions. On March 11, the Task Force met for the "New Mexico Corequisite Remediation at Scale Policy Institute" in order to learn about the results of the latest national reform…

  11. Remediation: Higher Education's Bridge to Nowhere

    Science.gov (United States)

    Complete College America, 2012

    2012-01-01

    The intentions were noble. It was hoped that remediation programs would be an academic bridge from poor high school preparation to college readiness. Sadly, remediation has become instead higher education's "Bridge to Nowhere." This broken remedial bridge is travelled by some 1.7 million beginning students each year, most of whom will…

  12. A two-dimensional analytical model for groundwater flow in a leaky aquifer extending finite distance under the estuary

    Science.gov (United States)

    Chuang, Mo-Hsiung; Hung, Chi-Tung; -Yen Lin, Wen; Ma, Kuo-chen

    2017-04-01

    In recent years, cities and industries in the vicinity of the estuarine region have developed rapidly, resulting in a sharp increase in the population concerned. The increasing demand for human activities, agriculture irrigation, and aquaculture relies on massive pumping of water in estuarine area. Since the 1950s, numerous studies have focused on the effects of tidal fluctuations on groundwater flow in the estuarine area. Tide-induced head fluctuation in a two-dimensional estuarine aquifer system is complicated and rather important in dealing with many groundwater management or remediation problems. The conceptual model of the aquifer system considered is multi-layered with estuarine bank and the leaky aquifer extend finite distance under the estuary. The solution of the model describing the groundwater head distribution in such an estuarine aquifer system and subject to the tidal fluctuation effects from estuarine river is developed based on the method of separation of variables along with river boundary. The solutions by Sun (Sun H. A two-dimensional analytical solution of groundwater response to tidal loading in an estuary, Water Resour. Res. 1997; 33:1429-35) as well as Tang and Jiao (Tang Z. and J. J. Jiao, A two-dimensional analytical solution for groundwater flow in a leaky confined aquifer system near open tidal water, Hydrological Processes, 2001; 15: 573-585) can be shown to be special cases of the present solution. On the basis of the analytical solution, the groundwater head distribution in response to estuarine boundary is examined and the influences of leakage, hydraulic parameters, and loading effect on the groundwater head fluctuation due to tide are investigated and discussed. KEYWORDS: analytical model, estuarine river, groundwater fluctuation, leaky aquifer.

  13. Analysis of Aquifer Response, Groundwater Flow, and PlumeEvolution at Site OU 1, Former Fort Ord, California

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Preston D.; Oldenburg, Curtis M.; Su, Grace W.

    2005-02-24

    This report presents a continuation from Oldenburg et al. (2002) of analysis of the hydrogeology, In-Situ Permeable Flow Sensor (ISPFS) results, aquifer response, and changes in the trichloroethylene (TCE) groundwater plume at Operational Unit 1 (OU 1) adjacent to the former Fritzsche Army Airfield at the former Fort Ord Army Base, located on Monterey Bay in northern Monterey County. Fuels and solvents were burned on a portion of OU 1 called the Fire Drill Area (FDA) during airport fire suppression training between 1962 and 1985. This activity resulted in soil and groundwater contamination in the unconfined A-aquifer. In the late 1980's, soil excavation and bioremediation were successful in remediating soil contamination at the site. Shortly thereafter, a groundwater pump, treat, and recharge system commenced operation. This system has been largely successful at remediating groundwater contamination at the head of the groundwater plume. However, a trichloroethylene (TCE) groundwater plume extends approximately 3000 ft (900 m) to the northwest away from the FDA. In the analyses presented here, we augment our prior work (Oldenburg et al., 2002) with new information including treatment-system totalizer data, recent water-level and chemistry data, and data collected from new wells to discern trends in contaminant migration and groundwater flow that may be useful for ongoing remediation efforts. Some conclusions from the prior study have been modified based on these new analyses, and these are pointed out clearly in this report.

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

    International Nuclear Information System (INIS)

    2009-01-01

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

  15. Aquifer response to earth tides

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  16. Use of Cometabolic Air Sparging to Remediate Chloroethene-Contaminated Groundwater Aquifers

    National Research Council Canada - National Science Library

    Magar, Victor

    2001-01-01

    ...) process at the McClellan National Test Site, California. The purpose of the demonstration was to evaluate the effectiveness of and costs associated with CAS for removal of chlorinated aromatic hydrocarbons (CAHs) from groundwater...

  17. Cost and Performance Report - Use of Cometabolic Air Sparging to Remediate Chloroethene-Contaminated Groundwater Aquifers

    National Research Council Canada - National Science Library

    Magar, Victor

    2001-01-01

    ...) process at the McClellan National Test Site, California. The purpose of the demonstration was to evaluate the effectiveness of and costs associated with CAS for removal of chlorinated aromatic hydrocarbons (CAHs) from groundwater...

  18. Treatment trains for the remediation of aquifers polluted with MTBE and other xenobiotic compounds

    DEFF Research Database (Denmark)

    Tsitonaki, Aikaterini

    2008-01-01

    Komplekse blandinger af forureningsstoffer, høje koncentrationer og heterogene geologiske forhold kan vanskeliggøre oprensning af forurenede grunde. Anvendelse af en aggressiv og måske dyr afværgeteknologi efterfulgt af en biologisk metode har været foreslået. Ved kombinationen af to afværgetekno...

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

    Reese, Ronald S.

    2006-01-01

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

  1. Groundwater flow in the Venice lagoon and remediation of the Porto Marghera industrial area (Italy)

    Science.gov (United States)

    Beretta, Giovanni Pietro; Terrenghi, Jacopo

    2017-05-01

    This study aims to determine the groundwater flow in a large area of the Venice (northeast Italy) lagoon that is under great anthropogenic pressure, which is influencing the regional flow in the surficial aquifer (about 30 m depth). The area presents several elements that condition the groundwater flow: extraction by means of drainage pumps and wells; tidal fluctuation; impermeable barriers that define part of the coastline, rivers and artificial channels; precipitation; recharge, etc. All the elements were studied separately, and then they were brought together in a numerical groundwater flow model to estimate the impact of each one. Identification of the impact of each element will help to optimise the characteristics of the Porto Marghera remediation systems. Longstanding industrial activity has had a strong impact on the soil and groundwater quality, and expensive and complex emergency remediation measures in problematic locations have been undertaken to ensure the continuity of industrial and maritime activities. The land reclamation and remediation works withdraw 56-74% of the water budget, while recharge from the river accounts for about 21-48% of the input. Only 21-42% of groundwater in the modelled area is derived from natural recharge sources, untouched by human activity. The drop of the piezometric level due to the realization of the upgradient impermeable barrier can be counteracted with the reduction of the pumping rate of the remediation systems.

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

    Science.gov (United States)

    Hamutoko, J. T.; Wanke, H.

    2017-12-01

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

  3. Development of a sitewide groundwater remediation strategy at the Hanford Site, Washington

    International Nuclear Information System (INIS)

    Goswami, D.

    1996-01-01

    Over 440 km 2 (170 mi 2 ) of groundwater beneath the Hanford Site are contaminated by hazardous and radioactive waste, out of which almost half is over state and federal drinking water standards. In addition to the complicated nature of these plumes, remediation is further obscured by limited application of available technologies and hydrogeologic information. This paper briefly describes the processes used by the Washington State Department of Ecology (Ecology), U.S. Environmental Protection Agency, and U.S. Department of Energy (USDOE) in developing a sitewide groundwater remediation strategy for Hanford and its outcome. As an initial approach to sitewide groundwater remediation, the strategy is to remediate the major plumes found in the reactor areas (100 Area) adjacent to the Columbia River and contain the major plumes found in the Central Plateau region (200 Area). This approach was based mainly on the qualitative risk, stakeholder's and tribe's values, and available technical feasibility. The strategy emphasizes the use of existing treatment and extraction technology for the remediation of groundwater in combination with proposed and existing site infrastructure. This work is being performed in parallel with ongoing risk and other feasibility activities. Under this strategy, innovative technologies being developed are in the areas of dense nonaqueous phase liquid identification and recovery, and problems associated with strontium-90, cesium-137, and plutonium in the vadose zone and groundwater. The final remediation strategy alternatives remain a product of risk assessment, technical feasibility, site use scenario, and cost consideration. In order to develop a strategy for the final cleanup, several issues such as aquifer restoration, natural attenuation, potential contamination of groundwater from the tank farms and from the existing contamination source in the vadose zone must be looked in detail in conjuction with public and stakeholder's values

  4. Transient well flow in vertically heterogeneous aquifers

    Science.gov (United States)

    Hemker, C. J.

    1999-11-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  6. Remediation using trace element humate surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  7. Cost considerations in remediation and disposal

    International Nuclear Information System (INIS)

    Dance, J.T.; Huddleston, R.D.

    1999-01-01

    Opportunities for assessing the costs associated with the reclamation and remediation of sites contaminated by oilfield wastes are discussed. The savings can be maximized by paying close attention to five different aspects of the overall site remediation and disposal process. These are: (1) highly focused site assessment, (2) cost control of treatment and disposal options, (3) value added cost benefits, (4) opportunities to control outside influences during the remedial process, and (5) opportunities for managing long-term liabilities and residual risk remaining after the remedial program is completed. It is claimed that addressing these aspects of the process will ultimately lower the overall cost of site remediation and waste disposal

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

    Science.gov (United States)

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

    2014-12-01

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

  9. Use of Geophysical and Remote Sensing Data for Assessment of Aquifer Depletion and Related Land Deformation

    Science.gov (United States)

    Othman, Abdullah; Sultan, Mohamed; Becker, Richard; Alsefry, Saleh; Alharbi, Talal; Gebremichael, Esayas; Alharbi, Hassan; Abdelmohsen, Karem

    2018-01-01

    An integrated approach [field, Interferometric Synthetic Aperture Radar (InSAR), hydrogeology, geodesy, and spatial analysis] was adopted to identify the nature, intensity, and spatial distribution of deformational features (sinkholes, fissures, differential settling) reported over fossil aquifers in arid lands, their controlling factors, and possible remedies. The Lower Mega Aquifer System (area 2 × 106 km2) in central and northern Arabia was used as a test site. Findings suggest that excessive groundwater extraction from the fossil aquifer is the main cause of deformation: (1) deformational features correlated spatially and/or temporally with increased agricultural development and groundwater extraction, and with a decline in water levels and groundwater storage (- 3.7 ± 0.6 km3/year); (2) earthquake events (years 1985-2016; magnitude 1-5) are largely (65% of reported earthquakes) shallow (1-5 km) and increased from 1 event/year in the early 1980s (extraction 1 km3/year), up to 13 events/year in the 1990s (average annual extraction > 6.4 km3). Results indicate that faults played a role in localizing deformation given that deformational sites and InSAR-based high subsidence rates (- 4 to - 15 mm/year) were largely found within, but not outside of, NW-SE-trending grabens bound by the Kahf fault system. Findings from the analysis of Gravity Recovery and Climate Experiment solutions indicate that sustainable extraction could be attained if groundwater extraction was reduced by 3.5-4 km3/year. This study provides replicable and cost-effective methodologies for optimum utilization of fossil aquifers and for minimizing deformation associated with their use.

  10. Evaluation of select trade-offs between ground-water remediation and waste minimization for petroleum refining industry

    International Nuclear Information System (INIS)

    Andrews, C.D.; McTernan, W.F.; Willett, K.K.

    1996-01-01

    An investigation comparing environmental remediation alternatives and attendant costs for a hypothetical refinery site located in the Arkansas River alluvium was completed. Transport from the land's surface to and through the ground water of three spill sizes was simulated, representing a base case and two possible levels of waste minimization. Remediation costs were calculated for five alternative remediation options, for three possible regulatory levels and alternative site locations, for four levels of technology improvement, and for eight different years. It is appropriate from environmental and economic perspectives to initiate significant efforts and expenditures that are necessary to minimize the amount and type of waste produced and disposed during refinery operations; or conversely, given expected improvements in technology, is it better to wait until remediation technologies improve, allowing greater environmental compliance at lower costs? The present work used deterministic models to track a light nonaqueous phase liquid (LNAPL) spill through the unsaturated zone to the top of the water table. Benzene leaching from LNAPL to the ground water was further routed through the alluvial aquifer. Contaminant plumes were simulated over 50 yr of transport and remediation costs assigned for each of the five treatment options for each of these years. The results of these efforts show that active remediation is most cost effective after a set point or geochemical quasi-equilibrium is reached, where long-term improvements in technology greatly tilt the recommended option toward remediation. Finally, the impacts associated with increasingly rigorous regulatory levels present potentially significant penalties for the remediation option, but their likelihood of occurrence is difficult to define

  11. Groundwater vulnerability mapping of Qatar aquifers

    Science.gov (United States)

    Baalousha, Husam Musa

    2016-12-01

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

  12. New IAEA guidelines on environmental remediation

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, Sergey [International Atomic Energy Agency, A2444, Seibersdorf (Austria); Howard, Brenda [Centre for Ecology and Hydrology, Lancaster Environment Centre, LA1 4AP, Lancaster (United Kingdom); Kashparov, Valery [Ukrainian Institute of Agricultural Radiology, 08162, 7, Mashinobudivnykiv str., Chabany, Kyivo-Svyatoshin region, Kyiv (Ukraine); Sanzharova, Natalie [Russian Institute of Agricultural Radiology and Agroecology, Russian Federation, 249032, Obninsk (Russian Federation); Vidal, Miquel [Analytical Chemistry Department-Universitat de Barcelona, Barcelona, 08028 Barcelona (Spain)

    2014-07-01

    In response to the needs of its Member States, the International Atomic Energy Agency (IAEA) has published many documents covering different aspects of remediation of contaminated environments. These documents range from safety fundamentals and safety requirements to technical documents describing remedial technologies. Almost all the documents on environmental remediation are related to uranium mining areas and decommissioning of nuclear facilities. IAEA radiation safety standards on remediation of contaminated environments are largely based on these two types of remediation. The exception is a document related to accidents, namely the IAEA TRS No. 363 'Guidelines for Agricultural Countermeasures Following an Accidental Release of Radionuclides'. Since the publication of TRS 363, there has been a considerable increase in relevant information. In response, the IAEA initiated the development of a new document, which incorporated new knowledge obtained during last 20 years, lessons learned and subsequent changes in the regulatory framework. The new document covers all aspects related to the environmental remediation from site characterisation to a description of individual remedial actions and decision making frameworks, covering urban, agricultural, forest and freshwater environments. Decisions taken to commence remediation need to be based on an accurate assessment of the amount and extent of contamination in relevant environmental compartments and how they vary with time. Major aspects of site characterisation intended for remediation are described together with recommendations on effective sampling programmes and data compilation for decision making. Approaches for evaluation of remedial actions are given in the document alongside the factors and processes which affect their implementation for different environments. Lessons learned following severe radiation accidents indicate that remediation should be considered with respect to many different

  13. Automated sample analysis and remediation

    International Nuclear Information System (INIS)

    Hollen, R.; Settle, F.

    1995-01-01

    The Contaminant Analysis Automation Project is developing an automated chemical analysis system to address the current needs of the US Department of Energy (DOE). These needs focus on the remediation of large amounts of radioactive and chemically hazardous wastes stored, buried and still being processed at numerous DOE sites. This paper outlines the advantages of the system under development, and details the hardware and software design. A prototype system for characterizing polychlorinated biphenyls in soils is also described

  14. Hanford Sitewide Groundwater Remediation Strategy

    International Nuclear Information System (INIS)

    Knepp, A.J.; Isaacs, J.D.

    1997-09-01

    This document fulfills the requirements of the Hanford Federal Facility Agreement and Consent Order, Milestone M-13-81, to develop a concise statement of strategy that describe show the Hanford Site groundwater remediation will be accomplished. The strategy addresses objectives and goals, prioritization of activities, and technical approaches for groundwater cleanup. The strategy establishes that the overall goal of groundwater remediation on the Hanford Site is to restore groundwater to its beneficial uses in terms of protecting human health and the environment, and its use as a natural resource. The Hanford Future Site Uses Working Group established two categories for groundwater commensurate with various proposed landuses: (1) restricted use or access to groundwater in the Central Plateau and in a buffer zone surrounding it and (2) unrestricted use or access to groundwater for all other areas. In recognition of the Hanford Future Site Uses Working Group and public values, the strategy establishes that the sitewide approach to groundwater cleanup is to remediate the major plumes found in the reactor areas that enter the Columbia River and to contain the spread and reduce the mass of the major plumes found in the Central Plateau

  15. Strategic planning for remediation projects

    International Nuclear Information System (INIS)

    Tapp, J.W.

    1995-01-01

    Remediation projects may range from a single leaking storage tank to an entire plant complex or producing oil and gas field. Strategic planning comes into play when the contamination of soil and groundwater is extensive. If adjacent landowners have been impacted or the community at large is concerned about the quality of drinking water, then strategic planning is even more important. (1) To manage highly complex interrelated issues--for example, the efforts expended on community relations can alter public opinion, which can impact regulatory agency decisions that affect cleanup standards, which can...and so on. (2) To ensure that all potential liabilities are managed--for example, preparation for the defense of future lawsuits is essential during site investigation and remediation. (3) To communicate with senior management--when the remediation team provides a strategic plan that includes both technical and business issues, senior management has the opportunity to become more involved and make sound policy decisions. The following discusses the elements of a strategic plan, who should participate in it, and the issues that should be considered

  16. Status report: Fernald site remediation

    International Nuclear Information System (INIS)

    Craig, J.R. Jr.; Saric, J.A.; Schneider, T.; Yates, M.K.

    1995-01-01

    The Fernald site is rapidly transitioning from a Remedial Investigation/ Feasibility Study (RI/FS) site to one where design and construction of the remedies dominates. Fernald is one of the first sites in the Department of Energy (DOE) complex to accomplish this task and real physical progress is being made in moving the five operable units through the CERCLA process. Two of the required Records of Decision (ROD) are in hand and all five operable units will have received their RODs (IROD for OU3) by the end of 1995. Pre-design investigations, design work or construction are now in progress on the operable units. The lessons learned from the work done to date include implementing innovations in the RI and FS process as well as effective use of Removal Actions to begin the actual site remediation. Also, forging close working relationships with the Federal and State Regulators, citizens action groups and the Fernald Citizens Task Force has helped move the program forward. The Fernald successes have been achieved by close coordination and cooperation among all groups working on the projects and by application of innovative technologies within the decision making process

  17. 40 CFR 147.502 - Aquifer exemptions. [Reserved

    Science.gov (United States)

    2010-07-01

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

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

    Indian Academy of Sciences (India)

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

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

  19. Superfund Record of Decision (EPA region 5): Fultz Landfill, Byesville, OH. (First remedial action), September 1991. Final report

    International Nuclear Information System (INIS)

    1991-01-01

    The 30-acre Fultz Landfill site is a privately owned inactive sanitary landfill on the north slope of a ridge that overlies abandoned coal mines in Jackson Township, Guernsey County, Ohio. The site lies within the drainage basin of Wills Creek, which flows north adjacent to the site and is used by the city of Cambridge as the municipal water supply. The northern half of the landfill lies in an unreclaimed strip mine where surface mine spoil and natural soil form a shallow aquifer. During the 1970's, the landfill operator was cited for various violations. Investigations in 1988 by EPA indicated that ground water and leachate contaminants emanating from the site have contaminated the shallow aquifer and, to a lesser extent, the deep mine aquifer. The Record of Decision (ROD) addresses all contaminated media, and provides a final remedy for the site. The primary contaminants of concern affecting the soil, sediment, debris, ground water, and surface water are VOCs including benzene, PCE, TCE, toluene, and xylenes; other organics including PAHs and phenols; metals including arsenic, chromium, and lead; and other inorganics. The selected remedial action for this site is included

  20. Ground Water movement in crystalline rock aquifers

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  1. Environmental Remediation Data Management Tools

    International Nuclear Information System (INIS)

    Wierowski, J. V.; Henry, L. G.; Dooley, D. A.

    2002-01-01

    Computer software tools for data management can improve site characterization, planning and execution of remediation projects. This paper discusses the use of two such products that have primarily been used within the nuclear power industry to enhance the capabilities of radiation protection department operations. Advances in digital imaging, web application development and programming technologies have made development of these tools possible. The Interactive Visual Tour System (IVTS) allows the user to easily create and maintain a comprehensive catalog containing digital pictures of the remediation site. Pictures can be cataloged in groups (termed ''tours'') that can be organized either chronologically or spatially. Spatial organization enables the user to ''walk around'' the site and view desired areas or components instantly. Each photo is linked to a map (floor plan, topographical map, elevation drawing, etc.) with graphics displaying the location on the map and any available tour/component links. Chronological organization enables the user to view the physical results of the remediation efforts over time. Local and remote management teams can view these pictures at any time and from any location. The Visual Survey Data System (VSDS) allows users to record survey and sample data directly on photos and/or maps of areas and/or components. As survey information is collected for each area, survey data trends can be reviewed for any repetitively measured location or component. All data is stored in a Quality Assurance (Q/A) records database with reference to its physical sampling point on the site as well as other information to support the final closeout report for the site. The ease of use of these web-based products has allowed nuclear power plant clients to plan outage work from their desktop and realize significant savings with respect to dose and cost. These same tools are invaluable for remediation and decommissioning planning of any scale and for recording

  2. Salmon Site Remedial Investigation Report

    International Nuclear Information System (INIS)

    1999-01-01

    This Salmon Site Remedial Investigation Report provides the results of activities initiated by the U.S. Department of Energy (DOE) to determine if contamination at the Salmon Site poses a current or future risk to human health and the environment. These results were used to develop and evaluate a range of risk-based remedial alternatives. Located in Lamar County, Mississippi, the Salmon Site was used by the U.S. Atomic Energy Commission (predecessor to the DOE) between 1964 and 1970 for two nuclear and two gas explosions conducted deep underground in a salt dome. The testing resulted in the release of radionuclides into the salt dome. During reentry drilling and other site activities, liquid and solid wastes containing radioactivity were generated resulting in surface soil and groundwater contamination. Most of the waste and contaminated soil and water were disposed of in 1993 during site restoration either in the cavities left by the tests or in an injection well. Other radioactive wastes were transported to the Nevada Test Site for disposal. Nonradioactive wastes were disposed of in pits at the site and capped with clean soil and graded. The preliminary investigation showed residual contamination in the Surface Ground Zero mud pits below the water table. Remedial investigations results concluded the contaminant concentrations detected present no significant risk to existing and/or future land users, if surface institutional controls and subsurface restrictions are maintained. Recent sampling results determined no significant contamination in the surface or shallow subsurface. The test cavity resulting from the experiments is contaminated and cannot be economically remediated with existing technologies. The ecological sampling did not detect biological uptake of contaminants in the plants or animals sampled. Based on the current use of the Salmon Site, the following remedial actions were identified to protect both human health and the environment: (1) the

  3. Unconsolidated Aquifers in Tompkins County, New York

    Science.gov (United States)

    Miller, Todd S.

    2000-01-01

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

  4. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

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

  5. Remediation plans in family medicine residency

    Science.gov (United States)

    Audétat, Marie-Claude; Voirol, Christian; Béland, Normand; Fernandez, Nicolas; Sanche, Gilbert

    2015-01-01

    Abstract Objective To assess use of the remediation instrument that has been implemented in training sites at the University of Montreal in Quebec to support faculty in diagnosing and remediating resident academic difficulties, to examine whether and how this particular remediation instrument improves the remediation process, and to determine its effects on the residents’ subsequent rotation assessments. Design A multimethods approach in which data were collected from different sources: remediation plans developed by faculty, program statistics for the corresponding academic years, and students’ academic records and rotation assessment results. Setting Family medicine residency program at the University of Montreal. Participants Family medicine residents in academic difficulty. Main outcome measures Assessment of the content, process, and quality of remediation plans, and students’ academic and rotation assessment results (successful, below expectations, or failure) both before and after the remediation period. Results The framework that was developed for assessing remediation plans was used to analyze 23 plans produced by 10 teaching sites for 21 residents. All plans documented cognitive problems and implemented numerous remediation measures. Although only 48% of the plans were of good quality, implementation of a remediation plan was positively associated with the resident’s success in rotations following the remediation period. Conclusion The use of remediation plans is well embedded in training sites at the University of Montreal. The residents’ difficulties were mainly cognitive in nature, but this generally related to deficits in clinical reasoning rather than knowledge gaps. The reflection and analysis required to produce a remediation plan helps to correct many academic difficulties and normalize the academic career of most residents in difficulty. Further effort is still needed to improve the quality of plans and to support teachers.

  6. Modelling contaminant transport in saturated aquifers

    International Nuclear Information System (INIS)

    Lakshminarayana, V.; Nayak, T.R.

    1990-01-01

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

  7. Comparison of groundwater flow in Southern California coastal aquifers

    Science.gov (United States)

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

    2009-01-01

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

  8. Air sparging for subsurface remediation: Numerical analysis using T2VOC

    Energy Technology Data Exchange (ETDEWEB)

    McCray, J.E.; Falta, R.W. [Clemson Univ. SC (United States)

    1995-03-01

    Air sparging is under active investigation as a promising remediation technology for aquifers contaminated with folatile organic dense nonaqueous phase liquids (DNAPLs). A theoretical study for the removal of DNAPLs from the subsurface using this technology is presented. T2VOC is used to conduct multiphase numerical simulations of DNAPL removal utilizing a model aquifer with a radially-symmetric geometry. Both homogeneous and macroscale heterogeneous systems are considered. These simulations suggest that DNAPLs are efficiently removed in a zone of contaminant cleanup at relatively low gas saturations within the injected air plume. The zone of effective removal may be referred to as the radius of influence (ROI). The sparging-induced pressure increase below the water table, which may be measured in the field, is recommended as the best method for determining the ROI. Multiphase numerical simulations are used to support this recommendation, to relate the injected gas ROI to the zone of NAPL cleanup, and to illustrate the transient and steady-state aquifer behavior.

  9. Modeling the Effects of Storm Surge from Hurricane Jeanne on Saltwater Intrusion into the Surficial Aquifer, East-Central Florida (USA)

    Science.gov (United States)

    Xiao, H.; Wang, D.; Hagen, S. C.; Medeiros, S. C.; Hall, C. R.

    2017-12-01

    Saltwater intrusion (SWI) that has been widely recognized as a detrimental issue causing the deterioration of coastal aquifer water quality and degradation of coastal ecosystems. While it is widely recognized that SWI is exacerbated worldwide due to global sea-level rise, we show that increased SWI from tropical cyclones under climate change is also a concern. In the Cape Canaveral Barrier Island Complex (CCBIC) located in east-central Florida, the salinity level of the surficial aquifer is of great importance to maintain a bio-diverse ecosystem and to support the survival of various vegetation species. Climate change induced SWI into the surficial aquifer can lead to reduction of freshwater storage and alteration of the distribution and productivity of vegetation communities. In this study, a three-dimensional variable-density SEAWAT model is developed and calibrated to investigate the spatial and temporal variation of salinity level in the surficial aquifer of CCBIC. We link the SEAWAT model to surge model data to examine the effects of storm surge from Hurricane Jeanne. Simulation results indicate that the surficial aquifer salinity level increases significantly right after the occurrence of storm surge because of high aquifer permeability and rapid infiltration and diffusion of the overtopping saltwater, while the surficial aquifer salinity level begins to decrease after the fresh groundwater recharge from the storm's rainfall. The tropical storm precipitation generates an effective hydraulic barrier further impeding SWI and providing seaward freshwater discharge for saltwater dilution and flushing. To counteract the catastrophic effects of storm surge, this natural remediation process may take at least 15-20 years or even several decades. These simulation results contribute to ongoing research focusing on forecasting regional vegetation community responses to climate change, and are expected to provide a useful reference for climate change adaptation planning

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

    Science.gov (United States)

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

    2010-01-01

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

  11. Innovative approaches to remediation for VOC sites using recirculating wells

    International Nuclear Information System (INIS)

    Dawson, G.W.

    1996-01-01

    In-well air stripping with approaches such as the patented NoVOCs system offer both cost and operational advantages over pump and treat, and in situ air sparging technologies. With in-well stripping, the water is treated in the well and discharged without being brought to the surface. Discharged water is circulated through the saturated zone acting as a carrier to continually flush contaminants from the aquifer matrix and transport them to the well for treatment. With pumping rates up to four times those of comparable extraction wells, large radii of influence can be maintained and remediation is achieved faster and more efficiently. In-well stripping is applicable to any strippable contaminant including chlorinated solvents (i.e., TCE and PCE) and hydrocarbons such as the aromatic components in petroleum fuels. Growing costs associated with water discharge, NPDES permits, water rights and, in some areas, salt water intrusion have provided economic incentives to retrofit existing pump and treat systems with NoVOCs units. A large number of wells are amenable to retrofitting depending on their diameter, location and length of screens, and back fill. Even with the new initiatives for intrinsic remediation for petroleum fuel releases, there is a role for the NoVOCs technology. Free product removal wells based on the NoVOCs design eliminate the need to treat and permit water discharges produced when generating a cone of depression for collecting the floating fuel. Additionally, the stripping action and introduction of dissolved oxygen reduce soluble hydrocarbon concentrations to risk levels that can be easily addressed through intrinsic bioremediation

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Data.gov (United States)

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

  16. Electrodialytic remediation of suspended mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrian; Pino, Denisse

    2008-01-01

    This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings...... efficiency from 1% to 80% compared to experiments with no stirring but with the same operational conditions. This showed the crucial importance of having the solids in suspension and not settled during the remediation....

  17. Air-Based Remediation Workshop - Section 8 Air-Based Remediation Technology Selection Logic

    Science.gov (United States)

    Pursuant to the EPA-AIT Implementing Arrangement 7 for Technical Environmental Collaboration, Activity 11 "Remediation of Contaminated Sites," the USEPA Office of International Affairs Organized a Forced Air Remediation Workshop in Taipei to deliver expert training to the Environ...

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

    Science.gov (United States)

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

    2018-03-01

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

  19. Nuclear facility decommissioning and site remedial actions

    International Nuclear Information System (INIS)

    Knox, N.P.; Webb, J.R.; Ferguson, S.D.; Goins, L.F.; Owen, P.T.

    1990-09-01

    The 394 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eleventh in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types -- technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions -- have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Programs, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Grand Junction Remedial Action Program, (7) Uranium Mill Tailings Management, (8) Technical Measurements Center, (9) Remedial Action Program, and (10) Environmental Restoration Program. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and keywords. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects and analyzes information on remedial actions and relevant radioactive waste management technologies

  20. Assessing sustainable remediation frameworks using sustainability principles.

    Science.gov (United States)

    Ridsdale, D Reanne; Noble, Bram F

    2016-12-15

    The remediation industry has grown exponentially in recent decades. International organizations of practitioners and remediation experts have developed several frameworks for integrating sustainability into remediation projects; however, there has been limited attention to how sustainability is approached and operationalized in sustainable remediation frameworks and practices - or whether sustainability plays any meaningful role at all in sustainable remediation. This paper examines how sustainability is represented in remediation frameworks and the guidance provided for practical application. Seven broad sustainability principles and review criteria are proposed and applied to a sample of six international remediation frameworks. Not all review criteria were equally satisfied and none of the frameworks fully met all criteria; however, the best performing frameworks were those identified as sustainability remediation frameworks. Intra-generational equity was addressed by all frameworks. Integrating social, economic and biophysical components beyond triple-bottom-line indicators was explicitly addressed only by the sustainable remediation frameworks. No frameworks provided principle- or rule-based guidance for dealing with trade-offs in sustainability decisions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Green PCB Remediation from Sediment Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — An ongoing problem facing the global environmental community including NASA centers is the removal and remediation of polychlorinated biphenyls (PCBs). PCBs were...

  2. Nuclear facility decommissioning and site remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Knox, N.P.; Webb, J.R.; Ferguson, S.D.; Goins, L.F.; Owen, P.T.

    1990-09-01

    The 394 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eleventh in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types -- technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions -- have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Programs, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Grand Junction Remedial Action Program, (7) Uranium Mill Tailings Management, (8) Technical Measurements Center, (9) Remedial Action Program, and (10) Environmental Restoration Program. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and keywords. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects and analyzes information on remedial actions and relevant radioactive waste management technologies.

  3. DECHEM: A remedial planning tool for metallic contaminants in soil at UMTRA Project sites

    International Nuclear Information System (INIS)

    1989-03-01

    The DECHEM (DEcontamination of CHEMicals) method was developed for the Uranium Mill Tailings Remedial Action (UMTRA) Project to guide characterization and remedial planning for metals contamination in soils. This is necessary because non-radiological hazardous constituents may be more mobile than radium-226 (Ra-226), and hence may migrate more deeply into subpile soils (beneath tailings that are to be relocated) or into adjacent contaminated soils at UMTRA Project sites. The result is that remedial action to the Ra-226 excavation limit, as specified in the US Environmental Protection Agency (EPA) standards, may not adequately remove hazardous non-radiological contamination. Unmitigated, these contaminants in soil may cause health risks because of their presence in resuspended particles, their uptake by crops or fodder their seepage into aquifers used for drinking water or other possible exposure pathways. The DECHEM method was developed in response to the need for advanced planning for the remediation of chemical contaminants at UMTRA Project sites, and includes the following elements: Establishment of acceptable exposure rates for humans to chemicals, based on EPA guidelines or other toxicological literature. Modeling of chemical migration through environmental pathways from a remediated UMTRA Project site to humans. Determination of allowable residual concentrations (i.e., cleanup guidelines) for chemicals in soils that results in doses to humans that are below established acceptable exposure rates. The initial development and application of the DECHEM method has focused upon hazardous metallic contaminants such as arsenic, lead, molybdenum, and selenium, which are known to occur in elevated concentrations at some UMTRA Project sites

  4. Groundwater sustainability assessment in coastal aquifers

    Indian Academy of Sciences (India)

    The present work investigates the response of shallow, coastal unconfined aquifers to anticipated overdraft conditions and climate change effect using numerical simulation. The groundwater flow model MODFLOW and variable density groundwater model SEAWAT are used for this investigation. The transmissivity and ...

  5. Biogeochemical aspects of aquifer thermal energy storage

    NARCIS (Netherlands)

    Brons, H.J.

    1992-01-01

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

  6. Hydrochemical characterization of groundwater aquifer using ...

    African Journals Online (AJOL)

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

  7. Transient well flow in vertically heterogeneous aquifers.

    NARCIS (Netherlands)

    Hemker, C.J.

    1999-01-01

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

  8. Aquifer restoration: state of the art

    National Research Council Canada - National Science Library

    Knox, Robert C; Knox, R. C

    1986-01-01

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

  9. Sedimentological analysis of a contaminated groundwater aquifer

    International Nuclear Information System (INIS)

    Towse, D.

    1991-01-01

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

  10. VULNERABILITY AND RISK OF CONTAMINATION KARSTIC AQUIFERS

    Directory of Open Access Journals (Sweden)

    Yameli Aguilar

    2013-08-01

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

  11. isotopic characteristics of aquifers in sinai

    International Nuclear Information System (INIS)

    Al-Gamal, S.A.

    2004-01-01

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

  12. Horizontal wells in subsurface remediation

    International Nuclear Information System (INIS)

    Losonsky, G.; Beljin, M.S.

    1992-01-01

    This paper reports on horizontal wells which offer an effective alternative to vertical wells in various environmental remediation technologies. Hydrogeological advantages of horizontal wells over vertical wells include a larger zone of influence, greater screen length, higher specific capacity and lower groundwater screen entrance velocity. Because of these advantages, horizontal wells can reduce treatment time and costs of groundwater recovery (pump-and-treat), in situ groundwater aeration (sparging) and soil gas extraction (vacuum extraction). Horizontal wells are also more effective than vertical wells in landfill leachate collection (under-drains), bioremediation, and horizontal grout injection

  13. Tank Waste Remediation System Guide

    International Nuclear Information System (INIS)

    Robershotte, M.A.; Dirks, L.L.; Seaver, D.A.; Bothers, A.J.; Madden, M.S.

    1995-06-01

    The scope, number and complexity of Tank Waste Remediation System (TWRS) decisions require an integrated, consistent, and logical approach to decision making. TWRS has adopted a seven-step decision process applicable to all decisions. Not all decisions, however, require the same degree of rigor/detail. The decision impact will dictate the appropriate required detail. In the entire process, values, both from the public as well as from the decision makers, play a key role. This document concludes with a general discussion of the implementation process that includes the roles of concerned parties

  14. Numerical Validation of Chemical Compositional Model for Wettability Alteration Processes

    Science.gov (United States)

    Bekbauov, Bakhbergen; Berdyshev, Abdumauvlen; Baishemirov, Zharasbek; Bau, Domenico

    2017-12-01

    Chemical compositional simulation of enhanced oil recovery and surfactant enhanced aquifer remediation processes is a complex task that involves solving dozens of equations for all grid blocks representing a reservoir. In the present work, we perform a numerical validation of the newly developed mathematical formulation which satisfies the conservation laws of mass and energy and allows applying a sequential solution approach to solve the governing equations separately and implicitly. Through its application to the numerical experiment using a wettability alteration model and comparisons with existing chemical compositional model's numerical results, the new model has proven to be practical, reliable and stable.

  15. Some Similarities and Differences Between Compositions Written by Remedial and Non-Remedial College Freshmen.

    Science.gov (United States)

    House, Elizabeth B.; House, William J.

    The essays composed by 84 remedial and 77 nonremedial college freshmen were analyzed for some features proposed by Mina Shaughnessy as being characteristic of basic writers. The students were enrolled in either a beginning remedial class (098), a class at the next level of remediation (099), or a regular English class (101). The essays were…

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

    Data.gov (United States)

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

  17. Arsenic release during managed aquifer recharge (MAR)

    Science.gov (United States)

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

    2013-12-01

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

  18. Electrokinetic remediation of contaminated soils

    International Nuclear Information System (INIS)

    Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

    1991-01-01

    Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques. 23 refs., 7 figs

  19. Soil remediation process and system

    International Nuclear Information System (INIS)

    Monlux, K.J.

    1992-01-01

    This patent describes a process for remediation of soil containing up to about 30,000 ppm hydrocarbon contaminants. It comprises: providing hydrocarbon-contaminated soil in a divided condition of minus 1 1/2 double-prime to a first confined zone where it is exposed to an open flame; heating while agitating the contaminated soil in an oxidizing atmosphere in the first zone to a temperature below soil ignition within a range of from about 375 degrees F. to about 750 degrees F. for a time sufficient to drive off as vapors a substantial percentage of the hydrocarbon contaminates from the soil; passing hot gases containing the hydrocarbon contaminates from the soil; passing hot gases containing the hydrocarbon vapors from the first zone to a second zone; recovering heat from the hot gases in the second zone to condense a substantial percentage of the hydrocarbon vapors as liquid hydrocarbons; recovering the liquid hydrocarbons; and removing the soil from the first zone as remediated soil having below about 1000 ppm hydrocarbon contaminants

  20. Solar One demolition and remediation

    International Nuclear Information System (INIS)

    Wallace, G.L.

    1995-01-01

    Solar One was designed to demonstrate the feasibility of generating electrical energy from solar power using a central receiver concept. An array of heliostats focused sunlight onto a central receiver, which superheated water to produce steam. Although Solar One was successful, the oil-based Thermal Storage System (TSS), used to store heat energy for power generation at night, was not efficient. When the TSS was demolished for the installation of a more efficient molten salt system, a major effort was made to salvage or recycle all of its equipment and materials. During TSS demolition, approximately 7 tons of aluminum shielding and 205 tons of steel were salvaged as scrap metal; 200 tons of concrete was used for erosion protection along the Mohave River banks; 150,000 gallons of oil was recycled and 100 tons of equipment was salvaged for use at other facilities. During remediation, approximately 9,000 tons of oil contaminated sand, gravel and soil was recycled into approximately 10,000 tons of asphalt concrete and used to pave a nearby 5-acre parking lot at Barstow College. This not only reduced project remediation costs, but also met environmental requirements and provided a much needed community service. Of the estimated 11,864 tons of equipment and material from the TSS, less than 1% was disposed of at a landfill

  1. Electrokinetic remediation of contaminated soils

    International Nuclear Information System (INIS)

    Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

    1991-01-01

    Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by-weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques

  2. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xianjun, E-mail: xjxie@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Wang, Yanxin, E-mail: yx.wang@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Pi, Kunfu [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Liu, Chongxuan [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China)

    2015-09-15

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO{sub 4} and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na{sub 2}HAsO{sub 4}) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles

  3. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study

    International Nuclear Information System (INIS)

    Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Liu, Chongxuan; Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu

    2015-01-01

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO 4 and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na 2 HAsO 4 ) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles. - Highlights:

  4. S/O modeling technique for optimal containment of light hydrocarbons in contaminated unconfined aquifers

    International Nuclear Information System (INIS)

    Cooper, G.S. Jr.; Kaluarachchi, J.J.; Peralta, R.C.

    1993-01-01

    An innovative approach is presented to minimize pumping for immobilizing a floating plume of a light non-aqueous phase liquid (LNAPL). The best pumping strategy is determined to contain the free oil product and provide for gradient control of the water table. This approach combined detailed simulation, statistical analysis, and optimization. This modeling technique uses regression equations that describe system response to variable pumping stimuli. The regression equations were developed from analysis of systematically performed simulations of multiphase flow in an areal region of an unconfined aquifer. Simulations were performed using ARMOS, a finite element model. ARMOS can be used to simulate a spill, leakage from subsurface storage facilities and recovery of hydrocarbons from trenches or pumping wells to design remediation schemes

  5. In situ aquifer bioremediation of organics including cyanide and carbon disulfide

    International Nuclear Information System (INIS)

    Abou-Rizk, J.A.M.; Leavitt, M.E.; Graves, D.A.

    1995-01-01

    Low levels (< 1 mg/L) of acetone, cyanide, phenol, naphthalene, 2-methylnaphthalene, and carbon disulfide from an inactive industrial landfill were found above background levels in a shallow aquifer at an eastern coastal site. In situ biodegradation was evaluated for treatment of these contaminants. Two soil samples and three groundwater samples were taken from the site for a laboratory bioassessment and a biotreatability test. The positive results of the bioassessment suggested moving forward with biotreatability testing. Biotreatability test results indicated suitable site conditions for bioremediation and that all the contaminants of concern at the site could be biodegraded to nondetect or very low levels (< 50 microg/L) with oxygen only; i.e., addition of nutrients was not required. Pilot-scale testing was undertaken on site to provide information for full-scale design, including oxygen requirements and air injection well spacing. This report describes the approach, the results, and their impact on the full-scale remediation system

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

    Science.gov (United States)

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

    2013-12-01

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

  7. Biogeochemical aspects of uranium mineralization, mining, milling, and remediation

    Science.gov (United States)

    Campbell, Kate M.; Gallegos, Tanya J.; Landa, Edward R.

    2015-01-01

    Natural uranium (U) occurs as a mixture of three radioactive isotopes: 238U, 235U, and 234U. Only 235U is fissionable and makes up about 0.7% of natural U, while 238U is overwhelmingly the most abundant at greater than 99% of the total mass of U. Prior to the 1940s, U was predominantly used as a coloring agent, and U-bearing ores were mined mainly for their radium (Ra) and/or vanadium (V) content; the bulk of the U was discarded with the tailings (Finch et al., 1972). Once nuclear fission was discovered, the economic importance of U increased greatly. The mining and milling of U-bearing ores is the first step in the nuclear fuel cycle, and the contact of residual waste with natural water is a potential source of contamination of U and associated elements to the environment. Uranium is mined by three basic methods: surface (open pit), underground, and solution mining (in situ leaching or in situ recovery), depending on the deposit grade, size, location, geology and economic considerations (Abdelouas, 2006). Solid wastes at U mill tailings (UMT) sites can include both standard tailings (i.e., leached ore rock residues) and solids generated on site by waste treatment processes. The latter can include sludge or “mud” from neutralization of acidic mine/mill effluents, containing Fe and a range of coprecipitated constituents, or barium sulfate precipitates that selectively remove Ra (e.g., Carvalho et al., 2007). In this chapter, we review the hydrometallurgical processes by which U is extracted from ore, the biogeochemical processes that can affect the fate and transport of U and associated elements in the environment, and possible remediation strategies for site closure and aquifer restoration.This paper represents the fourth in a series of review papers from the U.S. Geological Survey (USGS) on geochemical aspects of UMT management that span more than three decades. The first paper (Landa, 1980) in this series is a primer on the nature of tailings and radionuclide

  8. Remediation of uranium in-situ leaching area at Straz Pod Ralskem, Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Vokal, Vojtech; Muzak, Jiri; Ekert, Vladimir [DIAMO, s. e., TUU, Pod Vinici 84, Straz pod Ralskem, 471 27 (Czech Republic)

    2013-07-01

    A large-scale development in exploration and production of uranium ores in the Czech Republic was done in the 2nd half of the 20. century. Many uranium deposits were discovered in the territory of the Czech Republic. One of the most considerable deposits in the Czech Republic is the site Hamr na Jezere - Straz pod Ralskem where both mining methods - the underground mining and the acidic in-situ leaching - were used. The extensive production of uranium led to widespread environmental impacts and contamination of ground waters. Over the period of 'chemical' leaching of uranium (ca. 32 years), a total of more than 4 million tons of sulphuric acid and other chemicals have been injected into the ground. Most of the products (approx. 99.5 %) of the acids reactions with the rocks are located in the Cenomanian aquifer. The contamination of Cenomanian aquifer covers the area larger then 27 km{sup 2}. The influenced volume of groundwater is more than 380 million m{sup 3}. The total amount of dissolved SO{sub 4}{sup 2-} is about 3.6 million tons. After 1990 a large-scale environmental program was established and the Czech government decided to liquidate the ISL Mine and start the remediation in 1996. The remediation consists of contaminated groundwater pumping, removing of the contaminants and discharging or reinjection of treated water. Nowadays four main remedial technological installations with sufficient capacity for reaching of the target values of remedial parameters in 2037 are used - the 'Station for Acid Solutions Liquidation No. One', the 'Mother liquor reprocessing' station, the 'Neutralization and Decontamination Station NDS 6' and the 'Neutralization and Decontamination Station NDS 10'. It is expected that the amount of withdrawn contaminants will vary from 80 000 to 120 000 tons per year. Total costs of all remediation activities are expected to be in excess of 2 billion EUR. (authors)

  9. Tackling the Challenge of Deep Vadose Zone Remediation at the Hanford Site

    Science.gov (United States)

    Morse, J. G.; Wellman, D. M.; Gephart, R.

    2010-12-01

    The Central Plateau of the Hanford Site in Washington State contains some 800 waste disposal sites where 1.7 trillion liters of contaminated water was once discharged into the subsurface. Most of these sites received liquids from the chemical reprocessing of spent uranium fuel to recover plutonium. In addition, 67 single shell tanks have leaked or are suspected to have leaked 3.8 million liters of high alkali and aluminate rich cesium-contaminated liquids into the sediment. Today, this inventory of subsurface contamination contains an estimated 550,000 curies of radioactivity and 150 million kg (165,000 tons) of metals and hazardous chemicals. Radionuclides range from mobile 99Tc to more immobilized 137Cs, 241Am, uranium, and plutonium. A significant fraction of these contaminants likely remain within the deep vadose zone. Plumes of groundwater containing tritium, nitrate, 129I and other contaminants have migrated through the vadose zone and now extend outward from the Central Plateau to the Columbia River. During most of Hanford Site history, subsurface studies focused on groundwater monitoring and characterization to support waste management decisions. Deep vadose zone studies were not a priority because waste practices relied upon that zone to buffer contaminant releases into the underlying aquifer. Remediation of the deep vadose zone is now central to Hanford Site cleanup because these sediments can provide an ongoing source of contamination to the aquifer and therefore to the Columbia River. However, characterization and remediation of the deep vadose zone pose some unique challenges. These include sediment thickness; contaminant depth; coupled geohydrologic, geochemical, and microbial processes controlling contaminant spread; limited availability and effectiveness of traditional characterization tools and cleanup remedies; and predicting contaminant behavior and remediation performance over long time periods and across molecular to field scales. The U

  10. 300-FF-1 remedial design report/remedial action work plan

    International Nuclear Information System (INIS)

    Gustafson, F.W.

    1997-02-01

    The 300 Area has been divided into three operable units 300-FF-1, 300-FF-2, and 300-FF-5 all of which are in various stages of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) process. The 300-FF-1 Operable Unit, the subject of this report, includes liquid waste disposal sites, landfills, and a burial ground. This Remedial Design Report/Remedial Action Work Plan (RDR/RAWP) provides a summary description of each waste site included in the 300-FF-1 Operable Unit, the basis for remedial actions to be taken, and the remedial action approach and management process for implementing these actions. The remedial action approach and management sections provide a description of the remedial action process description, the project schedule, the project team, required planning documentation, the remedial action change process, the process for verifying attainment of the remedial action goals, and the required CERCLA and RCRA closeout documentation. Appendix A provides additional details on each waste site. In addition to remediation of the waste sites, waste generated during the remedial investigation/feasibility study portions of the project will also be disposed at the Environmental Restoration Disposal Facility (ERDF). Appendix B provides a summary of the modeling performed in the 300-FF-1 Phase 3 FS and a description of the modeling effort to be used to show attainment of the remedial action goals. Appendix C provides the sampling and analysis plan (SAP) for all sampling and field-screening activities performed during remediation and for verification of attainment with the remedial action goals. Appendix D provides the public involvement plan, prepared to ensure information is provided to the public during remedial design and remedial action processes

  11. 300-FF-1 remedial design report/remedial action work plan

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, F.W.

    1997-02-01

    The 300 Area has been divided into three operable units 300-FF-1, 300-FF-2, and 300-FF-5 all of which are in various stages of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) process. The 300-FF-1 Operable Unit, the subject of this report, includes liquid waste disposal sites, landfills, and a burial ground. This Remedial Design Report/Remedial Action Work Plan (RDR/RAWP) provides a summary description of each waste site included in the 300-FF-1 Operable Unit, the basis for remedial actions to be taken, and the remedial action approach and management process for implementing these actions. The remedial action approach and management sections provide a description of the remedial action process description, the project schedule, the project team, required planning documentation, the remedial action change process, the process for verifying attainment of the remedial action goals, and the required CERCLA and RCRA closeout documentation. Appendix A provides additional details on each waste site. In addition to remediation of the waste sites, waste generated during the remedial investigation/feasibility study portions of the project will also be disposed at the Environmental Restoration Disposal Facility (ERDF). Appendix B provides a summary of the modeling performed in the 300-FF-1 Phase 3 FS and a description of the modeling effort to be used to show attainment of the remedial action goals. Appendix C provides the sampling and analysis plan (SAP) for all sampling and field-screening activities performed during remediation and for verification of attainment with the remedial action goals. Appendix D provides the public involvement plan, prepared to ensure information is provided to the public during remedial design and remedial action processes.

  12. Ferrier Groundwater Remediation Project: A proactive response to public concerns

    International Nuclear Information System (INIS)

    Boulton, B.D.

    1993-01-01

    The Ferrier gas plant in Alberta is owned by Pembina Resources and produces ca 10 m 3 /d of oil, 8,000 l/d of natural gas liquids, and sales gas. In late 1992, contamination from benzene, toluene, ethylbenzene, and xylene was detected in a residential water well south of the plant. A site investigation found that a drain line from the plant's dehydrator still column to the flare was leaking, and that a well in the process building had free condensate on the water. Within the first three weeks of the initial report of contamination, the source of contamination had been identified, soil gas surveys had been conducted, integrity of pipelines was tested, piezometers were installed, and the first of many public meetings was held to inform residents of progress in tackling the problem. An action plan was developed and alternative water supplies were installed for affected residents. Newsletters were mailed to local residents concerning progress on remediation and plans to control the source and to capture the contamination plume were shared with the community at all times. Recovery wells to capture the plume were drilled and the captured water was treated and returned to the aquifer. Control of the source (the free condensate floating on the water table) was tackled by installing a recovery trench with drain lines. Meetings with the local residents' committee will continue to maintain trust with the community

  13. San Pedro River Aquifer Binational Report

    Science.gov (United States)

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

    2016-01-01

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

  14. Selected remedy at the Queen City Farms superfund site: A risk management approach

    International Nuclear Information System (INIS)

    Weber, E.F.; Wilson, J.; Kirk, M.; Tochko, S.

    1994-01-01

    A risk management approach at a former industrial waste disposal site in western Washington resulted in a selected remedy that is cost-effective and that meets the CERCLA threshold criterion of protecting human health and the environment. The proposed remedy, which addresses contamination in soil and groundwater, does not require an ARARs waiver and received state and community acceptance. By analyzing the current and potential risk at the site, a proposed remedy was chosen that would control the source and naturally attenuate the groundwater plume. Source control will include removal and treatment of some light nonaqueous phase liquid (LNAPL) and some soil, followed by isolation of the remaining soil and LNAPL within a slurry wall and beneath a multilayer cap. A contingent groundwater extraction and treatment system was included to address uncertainty in the risk characterization. Implementing source control is predicted to result in a steady decline in volatile organic compound levels in the drinking water aquifer through adsorption, degradation, and dispersion. Exposure to groundwater during the period of natural attenuation will be controlled by monitoring, institutional controls, and a thorough characterization of the plume and receptors. 7 figs., 1 tab

  15. Use of in-situ Dual Vacuum Extraction trademark for remediation of soil and ground water

    International Nuclear Information System (INIS)

    Dodson, M.E.; Trowbridge, B.E.; Ott, D.

    1994-01-01

    Dual Vacuum Extraction trademark provides a rapid and cost-effective method of remediating soil and ground water contaminated with volatile organic compounds. The system involves the removal of both water and vapors through the same borehole by use of entrainment. This technology provides for the remediation of the vadose zone, capillary fringe, smear zone, and existing water table. The effectiveness of this technology is shown in a case study. A release from an underground storage tank was responsible for a hydrocarbon plume spreading over approximately 50,000 ft 2 . The release produced vadose-zone contamination in the silty and sandy clays from 10 to 30 ft below ground surface (bgs) with total petroleum hydrocarbon (TPH) concentrations up to 1,400 mg/kg. In addition, a layer of free-floating liquid hydrocarbon was present on a shallow aquifer located at 25 ft bgs in thicknesses ranging from 0.5 to 3.0 ft. An in-situ dual-extraction system was installed to remediate the soils and ground water to levels as required by the Los Angeles Regional Water Quality Control Board (RWQCB). The system operated 24 hr a day, with an operating efficiency of over 99%. After 196 days (28 weeks), over 17,000 lb of hydrocarbons had been extracted from the soils. Seven confirmatory soil borings in the area of highest initial hydrocarbon concentrations indicated that TPH and benzene, toluene, ethylbenzene, xylene (BTEX) concentrations had decreased over 99% from initial soil concentrations

  16. An Expert support model for ex situ soil remediation

    NARCIS (Netherlands)

    Okx, J.P.; Frankhuizen, E.M.; Wit, de J.C.; Pijls, C.G.J.M.; Stein, A.

    2000-01-01

    This paper presents an expert support model recombining knowledge and experience obtained during ex situ soil remediation. To solve soil remediation problems, an inter-disciplinary approach is required. Responsibilities during the soil remediation process, however, are increasingly decentralised,

  17. Remediation of the Maxey Flats Site

    International Nuclear Information System (INIS)

    1990-01-01

    This report describes issues associated with remedial action of Maxey Flats, a low-level radioactive waste disposal site from 1963-1977, located in Fleming County, Kentucky. Present remedial action alternatives being considered are discussed along with emergency plans, ground water monitoring plans, and budgets

  18. Foreword Special Issue on Electrokinetic remediation

    NARCIS (Netherlands)

    Loch, J.P.G.; Lima, A.T.

    2012-01-01

    Since the first symposium on Electro-remediation (EREM) in 1997 at the École des Mines d’Albi, in Albi, France, much international attention, interest and progress have been generated in the science and technology of electro-remediation of contaminated soils, sediments and construction

  19. Remedial principles and meaningful engagement in education ...

    African Journals Online (AJOL)

    This article evaluates the meaningful engagement doctrine in the education rights jurisprudence of the Constitutional Court in the light of a set of normative principles developed by Susan Sturm for evaluating participatory public law remedies. It commences by identifying four principles for evaluating participatory remedies ...

  20. Laboratory Experiment on Electrokinetic Remediation of Soil

    Science.gov (United States)

    Elsayed-Ali, Alya H.; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E.

    2011-01-01

    Electrokinetic remediation is a method of decontaminating soil containing heavy metals and polar organic contaminants by passing a direct current through the soil. An undergraduate chemistry laboratory is described to demonstrate electrokinetic remediation of soil contaminated with copper. A 30 cm electrokinetic cell with an applied voltage of 30…

  1. 14 CFR 1212.800 - Civil remedies.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Civil remedies. 1212.800 Section 1212.800... Comply With Requirements of This Part § 1212.800 Civil remedies. Failure to comply with the requirements of the Privacy Act and this part could subject NASA to civil suit under the provisions of 5 U.S.C...

  2. 10 CFR 1008.15 - Civil remedies.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Civil remedies. 1008.15 Section 1008.15 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) RECORDS MAINTAINED ON INDIVIDUALS (PRIVACY ACT) Requests for Access or Amendment § 1008.15 Civil remedies. Subsection (g) of the Act provides that an individual may bring suit...

  3. Steam and electroheating remediation of tight soils

    Energy Technology Data Exchange (ETDEWEB)

    Balshaw-Biddle, K.; Oubre, C.L.; Ward, C.H. [eds.; Dablow, J.F. III; Pearce, J.A.; Johnson, P.C.

    2000-07-01

    In the past few decades the need for soil remediation has become urgent, even more necessary--innovative, cost effective methods. Steam and Electroheating Remediation of Tight Soils presents the results of a field study testing the cleanup of semi-volatile fuels from tight soils using combination of hydraulic fracturing and soil heating technologies.

  4. 40 CFR 85.1803 - Remedial Plan.

    Science.gov (United States)

    2010-07-01

    ... POLLUTION FROM MOBILE SOURCES Recall Regulations § 85.1803 Remedial Plan. (a) When any manufacturer is... the total parts requirement of each person who is to perform the repair under the remedial plan to be...: (i) The recall campaign number; and (ii) A code designating the campaign facility at which the repair...

  5. US Department of Energy Grand Junction Projects Office Remedial Action Project, final report of the decontamination and decommissioning of Building 36 at the Grand Junction Projects Office Facility

    International Nuclear Information System (INIS)

    Widdop, M.R.

    1996-08-01

    The U.S. Department of Energy (DOE) Grand Junction Projects Office (GJPO) occupies a 61.7-acre facility along the Gunnison River near Grand Junction, Colorado. This site was contaminated with uranium ore and mill tailings during uranium refining activities of the Manhattan Engineer District and during pilot milling experiments conducted for the U.S. Atomic Energy Commission's domestic uranium procurement program. The DOE Defense Decontamination and Decommissioning Program established the GJPO Remedial Action Project to clean up and restore the facility lands, improvements, and the underlying aquifer. The site contractor for the facility, Rust Geotech, also is the remedial action contractor. Building 36 was found to be radiologically contaminated and was demolished in 1996. The soil beneath the building was remediated in accordance with identified standards and can be released for unlimited exposure and unrestricted use. This document was prepared in response to a DOE request for an individual final report for each contaminated GJPO building

  6. Site remediation techniques in India: a review

    International Nuclear Information System (INIS)

    Anomitra Banerjee; Miller Jothi

    2013-01-01

    India is one of the developing countries operating site remediation techniques for the entire nuclear fuel cycle waste for the last three decades. In this paper we intend to provide an overview of remediation methods currently utilized at various hazardous waste sites in India, their advantages and disadvantages. Over the years the site remediation techniques have been well characterized and different processes for treatment, conditioning and disposal are being practiced. Remediation Methods categorized as biological, chemical or physical are summarized for contaminated soils and environmental waters. This paper covers the site remediation techniques implemented for treatment and conditioning of wastelands arising from the operation of nuclear power plant, research reactors and fuel reprocessing units. (authors)

  7. Proceedings of the remediation technologies symposium 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This conference provided an opportunity for industry, practitioners, researchers and regulators to discuss technical issues in environmental remediation research and the latest innovations in soil and groundwater remediation. Cost effective in-situ and ex-situ soil reclamation strategies were presented along with groundwater and surface water remediation strategies in 13 sessions entitled: hydrocarbon contamination; salt management; liability management; chemical oxidation; light non-aqueous phase liquids (LNAPL); Montreal Center of Excellence in Brownfields Rehabilitation; Alberta government updates; phytoremediation; natural attenuation; Lake Wabamun; ex-situ remediation; in-situ remediation; and, miscellaneous issues. Technological solutions for erosion control and water clarification were highlighted. The conference featured 52 presentations, of which 17 have been catalogued separately for inclusion in this database. tabs., figs.

  8. Electrodialytic remediation of heavy metal polluted soil

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Jensen, Pernille Erland; Kirkelund, Gunvor Marie

    2012-01-01

    Electrodialytic soil remediation is a method for removal of heavy metals. Good results have previously been obtained with both treatment of a stationary, water saturated soil matrix and with remediation of a stirred suspension of soil in water. The two different setups have different uses....... The first as in-situ or on-site treatment when there is no requirement for fast remediation, as the removal rate of the heavy metals are dependent on the distance between the electrodes (everything else equal) and in such application the electrode spacing must have a certain distance (often meters......). In the stirred setup it is possible to shorten the transport route to few mm and to have a faster and continuous process. The present paper for the first time reports a direct comparison of the two options. The remediation of the stirred suspension showed faster than remediation of the water saturated soil even...

  9. Remediation of spent block in Uvanas deposit

    International Nuclear Information System (INIS)

    Nurgaziev, M.A.; Iskakov, M.M.

    2012-01-01

    In 2007 by 'Kazatomprom' and 'Mining company' board decision, the branch of 'Mining company', 'Steppe ore management body' is reorganized in structure subdivision, the basic activity of which is organization and carrying out remediation works on spent blocks of PSV uranium deposit. In 2002 works are completed on OVOS for operating deposits Uvanas, Kanjugan, Northern Karamurun and Eastern Minkuduk. The results of present work were reported in IAEA conference. The working project 'Remediation of spent blocks of PSV uranium deposit PV-17 polygon of Steppe ore management body' approved in 2005 was developed for carrying out the remediation works. Works funding were carried out from liquidation fund of the current deposit established in accordance with the Republic of Kazakhstan law 'About interior and interior use'. Deposits remediation is the part of deposit operation life cycle which obliges to operate deposits with minimum expenditures for remediation.

  10. LCA of Soil and Groundwater Remediation

    DEFF Research Database (Denmark)

    Søndergaard, Gitte Lemming; Owsianiak, Mikolaj

    2018-01-01

    Today, there is increasing interest in applying LCA to support decision-makers in contaminated site management. In this chapter, we introduce remediation technologies and associated environmental impacts, present an overview of literature findings on LCA applied to remediation technologies...... and present methodological issues to consider when conducting LCAs within the area. Within the field of contaminated site remediation , a terminology distinguishing three types of environmental impacts: primary, secondary and tertiary, is often applied. Primary impacts are the site-related impacts due...... and efficiency of remediation, which are important for assessment or primary impacts; (ii) robust assessment of primary impacts using site-specific fate and exposure models; (iii) weighting of primary and secondary (or tertiary) impacts to evaluate trade-offs between life cycle impacts from remediation...

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

    Science.gov (United States)

    Schaap, Bryan D.

    2000-01-01

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

  12. Colloidal behavior of goethite nanoparticles modified with humic acid and implications for aquifer reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Tiraferri, Alberto; Saldarriaga Hernandez, Laura Andrea; Bianco, Carlo; Tosco, Tiziana; Sethi, Rajandrea, E-mail: rajandrea.sethi@polito.it [Politecnico di Torino, Department of Land, Environment, and Infrastructure Engineering (DIATI) (Italy)

    2017-03-15

    Nanosized colloids of iron oxide adsorb heavy metals, enhance the biodegradation of contaminants, and represent a promising technology to clean up contaminated aquifers. Goethite particles for aquifer reclamation were recently synthesized with a coating of humic acids to reduce aggregation. This study investigates the stability and the mobility in porous media of this material as a function of aqueous chemistry, and it identifies the best practices to maximize the efficacy of the related remediation. Humic acid-coated nanogoethite (hydrodynamic diameter ∼90 nm) displays high stability in solutions of NaCl, consistent with effective electrosteric stabilization. However, particle aggregation is fast when calcium is present and, to a lesser extent, also in the presence of magnesium. This result is rationalized with complexation phenomena related to the interaction of divalent cations with humic acid, inducing rapid flocculation and sedimentation of the suspensions. The calcium dose, i.e., the amount of calcium ions with respect to solids in the dispersion, is the parameter governing stability. Therefore, more concentrated slurries may be more stable and mobile in the subsurface than dispersions of low particle concentration. Particle concentration during field injection should be thus chosen based on concentration and proportion of divalent cations in groundwater.

  13. Enhancing emerging organic compound degradation: applying chaotic flow to managed aquifer recharge

    Science.gov (United States)

    Rodríguez-Escales, Paula; Fernandez-Garcia, Daniel; Drechsel, Johannes; Folch, Albert; Sanchez-Vila, Xavier

    2017-04-01

    The coupling of Managed Aquifer Recharge with soil aquifer remediation treatment, by placing a reactive layer containing organic matter at the bottom of the infiltration pond, is a promising technology to improve the rate of degradation of EOCs. Its success is based on assuming that recharged water and groundwater get well mixed, which is not always true. It has been demonstrated that mixing can be enhanced by inducing chaotic advection through extraction-injection engineering. In this work we analyze how chaotic advection might enhance the spreading of redox conditions with the final aim of improving degradation of a mix of benzotriazoles: benzotriazole, 5-methyl-benzotriazole, and 5-chloro-benzotriazole. The first two compounds are better degraded under aerobic conditions whereas the third one under nitrate reducing conditions. We developed a reactive transport model that describes how a recharged water rich in organic matter mixes with groundwater, how this organic matter is oxidized by different electron acceptors, and how the benzotriazoles are degraded attending for the redox state. The model was tested in different scenarios of recharge, both in homogenous and in heterogenous media. It was found that chaotic flow increases the spreading of the plume of recharged water. Consequently, different redox conditions coexist at a given time within the area affected by recharge, facilitating the degradation of EOCs.

  14. High-resolution Electrical Resistivity Tomography monitoring of a tracer test in a confined aquifer

    Science.gov (United States)

    Wilkinson, P. B.; Meldrum, P. I.; Kuras, O.; Chambers, J. E.; Holyoake, S. J.; Ogilvy, R. D.

    2010-04-01

    A permanent geoelectrical subsurface imaging system has been installed at a contaminated land site to monitor changes in groundwater quality after the completion of a remediation programme. Since the resistivities of earth materials are sensitive to the presence of contaminants and their break-down products, 4-dimensional resistivity imaging can act as a surrogate monitoring technology for tracking and visualising changes in contaminant concentrations at much higher spatial and temporal resolution than manual intrusive investigations. The test site, a municipal car park built on a former gasworks, had been polluted by a range of polycyclic aromatic hydrocarbons and dissolved phase contaminants. It was designated statutory contaminated land under Part IIA of the UK Environmental Protection Act due to the risk of polluting an underlying minor aquifer. Resistivity monitoring zones were established on the boundaries of the site by installing vertical electrode arrays in purpose-drilled boreholes. After a year of monitoring data had been collected, a tracer test was performed to investigate groundwater flow velocity and to demonstrate rapid volumetric monitoring of natural attenuation processes. A saline tracer was injected into the confined aquifer, and its motion and evolution were visualised directly in high-resolution tomographic images in near real-time. Breakthrough curves were calculated from independent resistivity measurements, and the estimated seepage velocities from the monitoring images and the breakthrough curves were found to be in good agreement with each other and with estimates based on the piezometric gradient and assumed material parameters.

  15. Superfund Record of Decision (EPA Region 2): NL Industries, Salem County, Pedricktown, NJ. (First remedial action), September 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-27

    The 44-acre NL Industries site is an inactive, secondary lead smelting facility in Pedricktown, Salem County, New Jersey. The site overlies the Cape May aquifer, a potential source of drinking water for local residents. In 1989, EPA began a multi-phased removal action. The Focused Feasibility Study resulted in the issuance of the Early Remedial Action Record of Decision (ROD), designated as Operable Unit (OU2). The nature and extent of remaining contamination on the site and areas adjacent to the site in various environmental media, such as soil, sediment, ground water, surface water, and air, are currently being evaluated and will be addressed as OU1 in a subsequent ROD. The primary contaminants of concern affecting the slag and lead oxide piles, sediment, debris, and standing surface water are metals including arsenic, chromium, and lead. The selected remedial action for the site is included.

  16. Physics of DNAPL Migration and Remediation in the Presence of Heterogeneities; TOPICAL

    International Nuclear Information System (INIS)

    CONRAD, STEPHEN H.; GLASS, ROBERT J.

    1999-01-01

    The goal of our research is to develop a fundamental quantitative understanding of the role of physical heterogeneities on DNAPL migration and remediation in aquifers. Such understanding is critical to cost effectively identify the location of the subsurface zone of contamination and design remediation schemes focused on removing the source of the contamination, the DNAPL itself. To reach this goal, the following objectives for the proposed research are defined: Objective 1: Develop fundamental understanding of the physics of DNAPL migration processes within heterogeneous porous media: (a) Conduct a suite of two-dimensional physical experiments within controlled and systematically varied heterogeneous porous media at scales up to one meter. Vary system parameters to consider a range of capillary and bond numbers within these heterogeneous porous structures. (b) Develop a new DNAPL migration model based on an up-scaling of invasion percolation (UP) to model the migration process. Compare the model predictions to experimental results. Accomplishing objective 1 provides a series of experiments against which we will be able to evaluate the validity of existing multi-phase flow theory as formulated in both percolation codes and in continuum flow codes. These experimental results will also provide new insights into DNAPL migration behavior. Development of the UIP model will provide an exciting alternative to continuum multi-phase flow codes since UIP offers several advantages for modeling DNAPL migration. The UIP model is fast, allowing for: (1) modeling in three dimensions; (2) the incorporation of much more geologic detail; and (3) its use in probabilistic modeling by way of Monte Carlo techniques. Objective 2: Develop fundamental understanding of the physics of DNAPL remediation processes within heterogeneous porous media: Conduct a suite of physical experiments within controlled and systematically varied heterogeneous porous media at scales up to one meter that

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-15

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO{sub 3}{sup −}) loading to surface and groundwater. We investigate variability and sources of NO{sub 3}{sup −} in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO{sub 3}{sup −} stable isotopes (δ{sup 15}N and δ{sup 18}O). These data were augmented by historical data collected from 1937 to 2007. NO{sub 3}{sup −} concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO{sub 3}{sup −} concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO{sub 3}{sup −} concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO{sub 3}{sup −}. These results highlight the vulnerability of karst aquifers to NO{sub 3}{sup −} contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO{sub 3}{sup −} than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO 3 − ) loading to surface and groundwater. We investigate variability and sources of NO 3 − in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO 3 − stable isotopes (δ 15 N and δ 18 O). These data were augmented by historical data collected from 1937 to 2007. NO 3 − concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO 3 − concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO 3 − concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO 3 − . These results highlight the vulnerability of karst aquifers to NO 3 − contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO 3 − than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates that subaqueous nitrification of organic N in the aquifer, as opposed to in soils, might be a

  19. Light Pollution Responses and Remedies

    CERN Document Server

    Mizon, Bob

    2012-01-01

    Light pollution is a major threat to astronomy across the entire developed world. The night sky that most of us can see bears little relationship to the spectacular vistas that our ancestors have gazed at for tens of thousands of years. It is ironic that as our understanding of the universe has improved, our ability to see it has been dramatically reduced by the skyglow of our civilization. In the second edition of Light Pollution - Responses and Remedies, Bob Mizon delves into the history and practice of lighting and how its misue has not only stolen the stars, but blighted our lives and those of our fellow-creatures on this planet. This book suggests how we can win back the night sky and at the same time save energy and money, improve our health, and even lower crime rate! It also includes a list of targets for urban stargazers, and recommendations for ensuring sane lighting worldwide.

  20. Introduction: Mediating and Remediating Death

    DEFF Research Database (Denmark)

    Christensen, Dorthe Refslund; Sandvik, Kjetil

    2014-01-01

    In this second volume we explore how people, groups and institutions deal with death through processes of mediation (the presentation of something through media), remediation (the representation of one medium in another, see below) and mediatization (the process through which core elements...... of a social or cultural activity assume media form, see below). The volume presents a wide variety of ethnographies of death from Norway, Finland, Sweden, the US, Papua New Guinea, Bosnia and Hercegovina, Libya, Tibet, Uganda and Denmark as well as a number of online sites and social media material....... These are analyzed through a vast number of theoretical and analytical perspectives in order to investigate how very diverse practices surrounding death and dying - mourning and commemoration, ritualization, politicization, re-enactment, traditionalization, activism or documentarism: private or public, offline...

  1. Biological Remediation of Petroleum Contaminants

    Science.gov (United States)

    Kuhad, Ramesh Chander; Gupta, Rishi

    Large volumes of hazardous wastes are generated in the form of oily sludges and contaminated soils during crude oil transportation and processing. Although many physical, chemical and biological treatment technologies are available for petroleum contaminants petroleum contaminants in soil, biological methods have been considered the most cost-effective. Practical biological remediation methods typically involve direct use of the microbes naturally occurring in the contaminated environment and/or cultured indigenous or modified microorganisms. Environmental and nutritional factors, including the properties of the soil, the chemical structure of the hydrocarbon(s), oxygen, water, nutrient availability, pH, temperature, and contaminant bioavailability, can significantly affect the rate and the extent of hydrocarbon biodegradation hydrocarbon biodegradation by microorganisms in contaminated soils. This chapter concisely discusses the major aspects of bioremediation of petroleum contaminants.

  2. Deterring and remedying employee theft.

    Science.gov (United States)

    Buzogany, Bill; Mueller, Michael J

    2010-01-01

    Employee theft of patient-related information for personal financial gain is a serious threat to the success and financial viability of many healthcare providers. You can safeguard your financial interest in your patient base by taking three preventative measures designed to dissuade your employees from stealing from you. The first step is the implementation of policies and procedures that inform your employees that patient-related information is a valuable business asset that you vigorously protect from misappropriation. The second step is strictly limiting and monitoring employee access to patient-related information. The third step is educating your employees of the potential legal consequences to them in the event they steal from you and, in the event of theft, pursuing all legal remedies available to you.

  3. Novel sorbents for environmental remediation

    Science.gov (United States)

    Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Werner, David

    2014-05-01

    Nowadays, one of the major environmental problems is the pollution of aquatic systems and soil by persistent pollutants. Persistent pollutants have been found widespread in sediments, surface waters, and drinking water supplies. The removal of pollutants can be accomplished prior to their discharge to receiving bodies or by immobilizing them onto soil. Sorption is the most commonly applied process, and activated carbons have been widely used. Rapid progress in nanotechnology and a new focus on biomass-based instead of non-renewable starting materials have produced a wide range of novel engineered sorbents including biosorbents, biochars, carbon-based nanoparticles, bio-nano hybrid materials, and iron-impregnated activated carbons. Sorbent materials have been used in environmental remediation processes and especially in agricultural soil, sediments and contaminated soil, water treatment, and industrial wastewater treatment. Furthermore, sorbents may enhance the synergistic action of other processes, such as volatilization and biodegradation. Novel sorbents have been employed for the removal or immobilization of persistent pollutants such as and include heavy metals (As, Cr, Cu, Pb, Cd, and Hg), halogenated organic compounds, endocrine disrupting chemicals, metalloids and non-metallic elements, and other organic pollutants. The development and evaluation of novel sorbents requires a multidisciplinary approach encompassing environmental, nanotechnology, physical, analytical, and surface chemistry. The necessary evaluations encompass not only the efficiency of these materials to remove pollutants from surface waters and groundwater, industrial wastewater, polluted soils and sediments, etc., but also the potential side-effects of their environmental applications. The aim of this work is to present the results of the use of biochar and impregnated carbon sorbents for the removal of organic pollutants and metals. Furthermore, the new findings from the forthcoming session

  4. Remedial transactions curtailment via optimization

    Directory of Open Access Journals (Sweden)

    Maksimović Viktor

    2009-01-01

    Full Text Available The new method developed in this paper is aiming at transmission congestion management (CM. The new, Optimal Transactions Management method (OTM, is based on linear programming (LP, DC load flow (DCLF and linear security constraints. The OTM method is embedded in Available Transfer Capabilities (ATCs and Power Transfer Distribution Factors (PTDFs definitions' environment. Well-suited for both preventive and corrective modes of operation, the OTM method aids transmission system operator in running a congested power system network, where congestions are due to transactions. Potential congestion threat is solved by finding the 'culprit' transaction and its optimal reduction. Besides the proposed downsizing of scheduled and/or committed transactions, controls of the OTM method also include redispatching of generation and load levels. The task is to establish a system state without constraint violations. To ensure the feasible network solution, both DC and AC power flows are used. The common 5 nodes/7 lines Ward&Hale sample power system is used to clarify the OTM method. Besides, six other power system networks including the real-life power system network of Serbia, Macedonia and Montenegro (part of the South East Europe - SEE grid are used to test remedial potentials and CPU-time performances of the method. The 24-hour daily demand diagram is used with all test networks to study the effects of transactions as they are being superimposed to the regional grid. The remedial, transactions-curtailing OTM method is found well suited for market-related analyses precluding the hour-ahead, the day-ahead dispatch, as well as the real-time generation dispatch. It could also suit for the novel, Day Ahead Congestion Forecast (DACF procedure used in power markets. .

  5. Flow assurance intervention, hydrates remediation

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Christopher S. [Oceaneering International Inc., Houston, TX (United States)

    2012-07-01

    This paper addresses the issues of removing hydrates in sub sea flow lines and associated equipment with an Remotely Operated Vehicle (ROV) of opportunity and a multi-service-vessel (MSV). The paper is split into three topics: the equipment used with the ROV, assessing the interface points and handling fluids produced from drawing down the pressure. Each section is explained thoroughly and backed up with real world experience. The equipment section details information from actual jobs performed and why the particular components were utilized. The system is generally contained in an ROV mounted skid. Pumps are utilized to draw down the pressure inside the hydrated section of equipment, removing one of the three necessary components for hydrates formation. Once the section is pumped down, several options exist for handling the fluids pumped out of the system: pumping to surface, re-injection into the well, or injection into an operating flow line. This method of hydrates remediation is both economical and timely. Hydrate blockages form in low temperatures and high pressures. Reducing the pressure or increasing the temperature so the conditions lie to the right of the hydrate dissociation curve will slowly decompose the blockage. Depressurization and the use of MEG or methanol will give favorable conditions to remove the hydrate plug. Oceaneering has the capabilities to remove hydrates using the FRS in conjunction with an installation vessel to dispose of the gas and fluid removed from the flow line. Hydrate remediation techniques should be implemented into the initial design to reduce costs later. The cost of stopped production combined with the day rate for equipment needed for hydrate removal outweighs the costs if no technique is utilized. (author)

  6. Innovative vitrification for soil remediation

    International Nuclear Information System (INIS)

    Jetta, N.W.; Patten, J.S.; Hart, J.G.

    1995-01-01

    The objective of this DOE demonstration program is to validate the performance and operation of the Vortec Cyclone Melting System (CMS trademark) for the processing of LLW contaminated soils found at DOE sites. This DOE vitrification demonstration project has successfully progressed through the first two phases. Phase 1 consisted of pilot scale testing with surrogate wastes and the conceptual design of a process plant operating at a generic DOE site. The objective of Phase 2, which is scheduled to be completed the end of FY 95, is to develop a definitive process plant design for the treatment of wastes at a specific DOE facility. During Phase 2, a site specific design was developed for the processing of LLW soils and muds containing TSCA organics and RCRA metal contaminants. Phase 3 will consist of a full scale demonstration at the DOE gaseous diffusion plant located in Paducah, KY. Several DOE sites were evaluated for potential application of the technology. Paducah was selected for the demonstration program because of their urgent waste remediation needs as well as their strong management and cost sharing financial support for the project. During Phase 2, the basic nitrification process design was modified to meet the specific needs of the new waste streams available at Paducah. The system design developed for Paducah has significantly enhanced the processing capabilities of the Vortec vitrification process. The overall system design now includes the capability to shred entire drums and drum packs containing mud, concrete, plastics and PCB's as well as bulk waste materials. This enhanced processing capability will substantially expand the total DOE waste remediation applications of the technology

  7. Aquifer thermal energy storage in Finland

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-01-01

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

  8. Study of Aquifer Thermal Energy Storage

    Science.gov (United States)

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

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

  9. Policy and Strategies for Environmental Remediation

    International Nuclear Information System (INIS)

    2015-01-01

    In the environmental remediation of a given site, concerned and interested parties have diverse and often conflicting interests with regard to remediation goals, the time frames involved, reuse of the site, the efforts necessary and cost allocation. An environmental remediation policy is essential for establishing the core values on which remediation is to be based. It incorporates a set of principles to ensure the safe and efficient management of remediation situations. Policy is mainly established by the national government and may become codified in the national legislative system. An environmental remediation strategy sets out the means for satisfying the principles and requirements of the national policy. It is normally established by the relevant remediation implementer or by the government in the case of legacy sites. Thus, the national policy may be elaborated in several different strategies. To ensure the safe, technically optimal and cost effective management of remediation situations, countries are advised to formulate an appropriate policy and strategies. Situations involving remediation include remediation of legacy sites (sites where past activities were not stringently regulated or adequately supervised), remediation after emergencies (nuclear and radiological) and remediation after planned ongoing operation and decommissioning. The environmental policy involves the principles of justification, optimization of protection, protection of future generations and the environment, efficiency in the use of resources, and transparent interaction with stakeholders. A typical policy will also take into account the national legal framework and institutional structure and applicable international conventions while providing for the allocation of responsibilities and resources, in addition to safety and security objectives and public information and participation in the decision making process. The strategy reflects and elaborates the goals and requirements set

  10. Computer-model analysis of ground-water flow and simulated effects of contaminant remediation at Naval Weapons Industrial Reserve Plant, Dallas, Texas

    Science.gov (United States)

    Barker, Rene A.; Braun, Christopher L.

    2000-01-01

    In June 1993, the Department of the Navy, Southern Division Naval Facilities Engineering Command (SOUTHDIV), began a Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) of the Naval Weapons Industrial Reserve Plant (NWIRP) in north-central Texas. The RFI has found trichloroethene, dichloroethene, vinyl chloride, as well as chromium, lead, and other metallic residuum in the shallow alluvial aquifer underlying NWIRP. These findings and the possibility of on-site or off-site migration of contaminants prompted the need for a ground-water-flow model of the NWIRP area. The resulting U.S. Geological Survey (USGS) model: (1) defines aquifer properties, (2) computes water budgets, (3) delineates major flowpaths, and (4) simulates hydrologic effects of remediation activity. In addition to assisting with particle-tracking analyses, the calibrated model could support solute-transport modeling as well as help evaluate the effects of potential corrective action. The USGS model simulates steadystate and transient conditions of ground-water flow within a single model layer.The alluvial aquifer is within fluvial terrace deposits of Pleistocene age, which unconformably overlie the relatively impermeable Eagle Ford Shale of Late Cretaceous age. Over small distances and short periods, finer grained parts of the aquifer are separated hydraulically; however, most of the aquifer is connected circuitously through randomly distributed coarser grained sediments. The top of the underlying Eagle Ford Shale, a regional confining unit, is assumed to be the effective lower limit of ground-water circulation and chemical contamination.The calibrated steady-state model reproduces long-term average water levels within +5.1 or –3.5 feet of those observed; the standard error of the estimate is 1.07 feet with a mean residual of 0.02 foot. Hydraulic conductivity values range from 0.75 to 7.5 feet per day, and average about 4 feet per day. Specific yield values range from 0

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

    NARCIS (Netherlands)

    Zuurbier, Koen

    2016-01-01

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

  12. Carbon-14 measurements in aquifers with methane

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  13. DOE's Assurance Program for Remedial Action (APRA)

    International Nuclear Information System (INIS)

    Denham, D.H.; Stenner, R.D.; Welty, C.G. Jr.; Needels, T.S.

    1985-01-01

    The US Department of Energy's (DOE) Office of Operational Safety (OOS) is presently developing and implementing the Assurance Program for Remedial Action (APRA) to overview DOE's Remedial Action programs. APRA's objective is to ensure the adequacy of environmental, safety and health (ES and H) protection practices within the four DOE Remedial Action programs: Grand Junction Remedial Action Program (GJRAP), Uranium Mill Tailings Remedial Action Program (UMTRAP), Formerly Utilized Sites Remedial Action Program (FUSRAP), and Surplus Facilities Management Program (SFMP). APRA encompasses all ES and H practices of DOE and its contractors/subcontractors within the four Remedial Action programs. Specific activities of APRA include document reviews, selected site visits, and program office appraisals. Technical support and assistance to OOS is being provided by APRA contractors in the evaluation of radiological standards and criteria, quality assurance measures, radiation measurements, and risk assessment practices. This paper provides an overview of these activities and discusses program to date, including the roles of OOS and the respective contractors. The contractors involved in providing technical support and assistance to OOS are Aerospace Corporation, Oak Ridge Associated Universities, and Pacific Northwest Laboratory

  14. Remedial action of radium contaminated residential properties

    International Nuclear Information System (INIS)

    White, D.; Eng, J.

    1986-01-01

    Since November 1983, the New Jersey Department of Environmental Protection (NJDEP) and the US Environmental Protection Agency (USEPA) have been in the process of identifying properties in Montclair, Glen Ridge and West Orange, New Jersey, which were built over radium contaminated soil landfilled areas. Elevated indoor radon concentrations prompted the Centers for Disease Control (CDC) to issue a health advisory which included permanent remediation of radon progeny levels in excess of 0.02 Working Levels within two years of discovery. In order to expedite remedial action, NJDEP undertook a ten million dollar cleanup program. Remedial Action at the 12 residential properties encountered some unanticipated problems despite the efforts of numerous government agencies and their contractors to characterize the contamination as much as possible prior to remediation. Some of the unanticipated issues include contamination from other radionuclides, underestimation of removal volumes, and controversy over the transportation and disposal of the radium contaminated soil at a commercial facility in Nevada. This paper will review the approach taken by NJDEP to the remedial action for radium contaminated soil, discuss some of the issues encountered during the remedial action, and provide post remedial action data

  15. Proceedings of the remediation technologies symposium 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This conference provided a forum to discuss the remediation of contaminated sites. It was attended by all industry sectors that have an interest in learning about technical issues in environmental remediation research and the latest innovations in soil and groundwater remediation and industrial pollutant treatments. Cost effective in-situ and ex-situ soil reclamation strategies were presented along with groundwater and surface water remediation strategies. The diversified sessions at this conference were entitled: regulatory update; Montreal Centre of Excellence in Brownfields Rehabilitation; soil and groundwater remediation through the Program of Energy Research and Development at Environment Canada; technology from the Netherlands; bioremediation; hydrocarbons; in-situ remediation; phytoremediation; salt management; unique locations; and, miscellaneous issues. Some areas and case studies covered in the presentations included: biological and non-biological treatments; thermal desorption; encapsulation; natural attenuation; multi-phase extraction; electrochemical remediation; and membrane technology. The conference featured 63 presentations, of which 23 have been catalogued separately for inclusion in this database. tabs., figs.

  16. Proceedings of the remediation technologies symposium 2007

    International Nuclear Information System (INIS)

    2007-01-01

    This conference provided a forum to discuss the remediation of contaminated sites. It was attended by all industry sectors that have an interest in learning about technical issues in environmental remediation research and the latest innovations in soil and groundwater remediation and industrial pollutant treatments. Cost effective in-situ and ex-situ soil reclamation strategies were presented along with groundwater and surface water remediation strategies. The diversified sessions at this conference were entitled: regulatory update; Montreal Centre of Excellence in Brownfields Rehabilitation; soil and groundwater remediation through the Program of Energy Research and Development at Environment Canada; technology from the Netherlands; bioremediation; hydrocarbons; in-situ remediation; phytoremediation; salt management; unique locations; and, miscellaneous issues. Some areas and case studies covered in the presentations included: biological and non-biological treatments; thermal desorption; encapsulation; natural attenuation; multi-phase extraction; electrochemical remediation; and membrane technology. The conference featured 63 presentations, of which 23 have been catalogued separately for inclusion in this database. tabs., figs

  17. Risk-based remediation: Approach and application

    International Nuclear Information System (INIS)

    Frishmuth, R.A.; Benson, L.A.

    1995-01-01

    The principle objective of remedial actions is to protect human health and the environment. Risk assessments are the only defensible tools available to demonstrate to the regulatory community and public that this objective can be achieved. Understanding the actual risks posed by site-related contamination is crucial to designing cost-effective remedial strategies. All to often remedial actions are overdesigned, resulting in little to no increase in risk reduction while increasing project cost. Risk-based remedial actions have recently been embraced by federal and state regulators, industry, government, the scientific community, and the public as a mechanism to implement rapid and cost-effective remedial actions. Emphasizing risk reduction, rather than adherence to ambiguous and generic standards, ensures that only remedial actions required to protect human health and the environment at a particular site are implemented. Two sites are presented as case studies on how risk-based approaches are being used to remediate two petroleum hydrocarbon contaminated sites. The sites are located at two US Air Force Bases, Wurtsmith Air Force Base (AFB) in Oscoda, Michigan and Malmstrom AFB in Great Falls, Montana

  18. DOE's Assurance Program for Remedial Action (APRA)

    International Nuclear Information System (INIS)

    Denham, D.H.; Stenner, R.D.; Welty, C.G. Jr.; Needels, T.S.

    1984-10-01

    The US Department of Energy's (DOE) Office of Operational Safety (OOS) is presently developing and implementing the Assurance Program for Remedial Action (APRA) to overview DOE's Remedial Action programs. APRA's objective is to ensure the adequacy of environmental, safety and health (ES and H) protection practices within the four DOE Remedial Action programs: Grand Junction Remedial Action Program (GJRAP), Uranium Mill Tailings Remedial Action Program (UMTRAP), Formerly Utilized Sites Remedial Action Program (FUSRAP), and Surplus Facilities Management Program (SFMP). APRA encompasses all ES and H practices of DOE and its contractors/subcontractors within the four Remedial Action programs. Specific activities of APRA include document reviews, selected site visits, and program office appraisals. Technical support and assistance to OOS is being provided by APRA contractors in the evaluation of radiological standards and criteria, quality assurance measures, radiation measurements, and risk assessment practices. This paper provides an overview of these activities and discusses progress to date, including the roles of OOS and the respective contractors. The contractors involved in providing technical support and assistance to OOS are Aerospace Corporation, Oak Ridge Associated Universities, and Pacific Northwest Laboratory

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

    Science.gov (United States)

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

    1997-01-01

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

  20. Phase 1 remediation of jet fuel contaminated soil and groundwater at JFK International Airport using dual phase extraction and bioventing

    International Nuclear Information System (INIS)

    Roth, R.; Bianco, P. Rizzo, M.

    1995-01-01

    Soil and groundwater contaminated with jet fuel at Terminal One of the JFK International Airport in New York have been remediated using dual phase extraction (DPE) and bioventing. Two areas were remediated using 51 DPE wells and 20 air sparging/air injection wells. The total area remediated by the DPE wells is estimated to be 4.8 acres. Groundwater was extracted to recover nonaqueous phase and aqueous phase jet fuel from the shallow aquifer and treated above ground by the following processes; oil/water separation, iron-oxidation, flocculation, sedimentation, filtration, air stripping and liquid-phase granular activated carbon (LPGAC) adsorption. The extracted vapors were treated by vapor-phase granular activated carbon (VPGAC) adsorption in one area, and catalytic oxidation and VPGAC adsorption in another area. After 6 months of remediation, approximately 5,490 lbs. of volatile organic compounds (VOCs) were removed by soil vapor extraction (SVE), 109,650 lbs. of petroleum hydrocarbons were removed from the extracted groundwater, and 60,550 lbs. of petroleum hydrocarbons were biologically oxidized by subsurface microorganisms. Of these three mechanisms, the rate of petroleum hydrocarbon removal was the highest for biological oxidation in one area and by groundwater extraction in another area

  1. Phytoremediation potential of willow tress for aquifers contaminated with ethanol-blended gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Corseuil, H.X. [Universidade Federal de Santa Catarina, Florianopolis (Brazil). Departamento de Engenharia Sanitaria e Ambiental; Moreno, F.N. [Universidade do Sul de Santa Catarina, Palhoca (Brazil). Centro de Ciencias Agrarias e das Engenharias

    2001-07-01

    Ethanol-blended gasoline has been used in Brazil for 20 years and, probably, is going to be more widely used in North America due to the MtBE environmental effects on groundwater. The potential impacts caused by the presence of ethanol in UST spills are related to the co-solvency effect and the preferential degradation of ethanol over the BTEX compounds. These interactions may increase the length of dissolved hydrocarbon plumes and the costs associated with site remediation. This study investigates the advantages of phytoremediation to overcome the problems associated with the presence of ethanol in groundwater contaminated with gasoline-ethanol mixtures. Experiments were performed under lab conditions with cuttings of Willow tree (Salix babylonica) cultivated hydroponically. Results showed that the cuttings were able to reduce ethanol and benzene concentrations by more than 99% in less than a week. The uptake of both contaminants was confirmed by blank controls and was significantly related to cuttings transpiration capacity. Sorption onto roots biomass also markedly affected the behavior of contaminants in solution. Experiments to evaluate plants' toxicity to ethanol indicated that plants were only affected when aqueous ethanol concentration reached 2000mgl{sup -1}. Results suggest that phytoremediation can be a good complement to intrinsic remediation in shallow aquifer sites contaminated with ethanol-blended gasoline spills. (Author)

  2. Remediation of spatial processing disorder (SPD).

    Science.gov (United States)

    Graydon, Kelley; Van Dun, Bram; Tomlin, Dani; Dowell, Richard; Rance, Gary

    2018-05-01

    To determine the efficacy of deficit-specific remediation for spatial processing disorder, quantify effects of remediation on functional listening, and determine if remediation is maintained. Participants had SPD, diagnosed using the Listening in Spatialised Noise-Sentences test. The LiSN and Learn software was provided as auditory training. Post-training, repeat LiSN-S testing was conducted. Questionnaires pre- and post-training acted as subjective measures of remediation. A late-outcome assessment established long-term effects of remediation. Sixteen children aged between 6;3 [years; months] and 10;0 completed between 20 and 146 training games. Post-training LiSN-S improved in measures containing spatial cues (p ≤ 0.001) by 2.0 SDs (3.6 dB) for DV90, 1.8 SDs for SV90 (3.2 dB), 1.4 SDs for spatial advantage (2.9 dB) and 1.6 SDs for total advantage (3.3 dB). Improvement was also found in the DV0 condition (1.4 dB or 0.5 SDs). Post-training changes were not significant in the talker advantage measure (1.0 dB or 0.4 SDs) or the SV0 condition (0.3 dB or 0.1 SDs). The late-outcome assessment demonstrated improvement was maintained. Subjective improvement post-remediation was observed using the parent questionnaire. Children with SPD had improved ability to utilise spatial cues following deficit-specific remediation, with the parent questionnaire sensitive to remediation. Effects of the remediation also appear to be sustained.

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

    Directory of Open Access Journals (Sweden)

    Sarva Mangala Praveena

    2010-01-01

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

  4. Present status of the Zavratec remediation project

    International Nuclear Information System (INIS)

    Zeleznik, N.; Stepisnik, M.; Mele, I.

    1997-01-01

    In 1992 the responsibility for the remediation of the temporary storage of radioactive waste near Zavratec was assigned to the Agency for Radwaste Management. The project was divided into two phases. First, in a study, different options for remediation were considered. In the second phase, performed in 1996, the measurements, inventorying and repacking of radioactive waste were carried out. Simultaneously with these activities a programme for covering public relations was prepared. One of the results of the public relation campaign is also a 15-minute video film, which was prepared from documentary material recorded during remedial activities, and will be presented here. (author)

  5. Lessons Learned from Environmental Remediation Programmes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-03-15

    Several remediation projects have been developed to date, and experience with these projects has been accumulated. Lessons learned span from non-technical to technical aspects, and need to be shared with those who are beginning or are facing the challenge to implement environmental remediation works. This publication reviews some of these lessons. The key role of policy and strategies at the national level in framing the conditions in which remediation projects are to be developed and decisions made is emphasized. Following policy matters, this publication pays attention to the importance of social aspects and the requirement for fairness in decisions to be made, something that can only be achieved with the involvement of a broad range of interested parties in the decision making process. The publication also reviews the funding of remediation projects, planning, contracting, cost estimates and procurement, and issues related to long term stewardship. Lessons learned regarding technical aspects of remediation projects are reviewed. Techniques such as the application of cover systems and soil remediation (electrokinetics, phytoremediation, soil flushing, and solidification and stabilization techniques) are analysed with respect to performance and cost. After discussing soil remediation, the publication covers issues associated with water treatment, where techniques such as ‘pump and treat’ and the application of permeable barriers are reviewed. Subsequently, there is a section dedicated to reviewing briefly the lessons learned in the remediation of uranium mining and processing sites. Many of these sites throughout the world have become orphaned, and are waiting for remediation. The publication notes that little progress has been made in the management of some of these sites, particularly in the understanding of associated environmental and health risks, and the ability to apply prediction to future environmental and health standards. The publication concludes

  6. Electrochemical remediation of copper contaminated clay soils

    Energy Technology Data Exchange (ETDEWEB)

    Korolev, V.A.; Babakina, O.A.; Mitojan, R.A. [Moscow State Univ. (Russian Federation)

    2001-07-01

    The study objective focused on electrochemical remediation copper polluted soils in the presence of adjuvant substances and conditions that are more effective for the treatment. Some of these substances were studied in different researches. Moreover, authors obtained a result of extraction copper rate higher than 90%. In this connection the following problems were set: - Influence organic and inorganic substances on copper mobility in soil under the DC current. - Moisture effect on copper migration in clay. - Electrochemical remediation soils different mineralogical composition. - A washing conditions contribution to electrochemical remediation of soil from copper. - Accuracy rating experimental dates. (orig.)

  7. Technologies for remediation of radioactively contaminated sites

    International Nuclear Information System (INIS)

    1999-06-01

    This report presents particulars on environmental restoration technologies (control and treatment) which can be applied to land based, radioactively contaminated sites. The media considered include soils, groundwater, surface water, sediments, air, and terrestrial and aquatic vegetation. The technologies addressed in this report can be categorized as follows: self-attenuation (natural restoration); in-situ treatment; removal of contamination; ex-situ treatment; and transportation and final disposal. The report provides also background information about and a general approach to remediation of radioactively contaminated sites as well as some guidance for the selection of a preferred remediation technology. Examples of remediation experience in Australia and Canada are given it annexes

  8. Technologies to remediate hazardous waste sites

    International Nuclear Information System (INIS)

    Falco, J.W.

    1990-03-01

    Technologies to remediate hazardous wastes must be matched with the properties of the hazardous materials to be treated, the environment in which the wastes are imbedded, and the desired extent of remediation. Many promising technologies are being developed, including biological treatment, immobilization techniques, and in situ methods. Many of these new technologies are being applied to remediate sites. The management and disposal of hazardous wastes is changing because of federal and state legislation as well as public concern. Future waste management systems will emphasize the substitution of alternatives for the use of hazardous materials and process waste recycling. Onsite treatment will also become more frequently adopted. 5 refs., 7 figs

  9. Technologies for remediation of radioactively contaminated sites

    Energy Technology Data Exchange (ETDEWEB)

    1999-06-01

    This report presents particulars on environmental restoration technologies (control and treatment) which can be applied to land based, radioactively contaminated sites. The media considered include soils, groundwater, surface water, sediments, air, and terrestrial and aquatic vegetation. The technologies addressed in this report can be categorized as follows: self-attenuation (natural restoration); in-situ treatment; removal of contamination; ex-situ treatment; and transportation and final disposal. The report provides also background information about and a general approach to remediation of radioactively contaminated sites as well as some guidance for the selection of a preferred remediation technology. Examples of remediation experience in Australia and Canada are given it annexes Refs, figs, tabs

  10. Lessons Learned from Environmental Remediation Programmes

    International Nuclear Information System (INIS)

    2014-01-01

    Several remediation projects have been developed to date, and experience with these projects has been accumulated. Lessons learned span from non-technical to technical aspects, and need to be shared with those who are beginning or are facing the challenge to implement environmental remediation works. This publication reviews some of these lessons. The key role of policy and strategies at the national level in framing the conditions in which remediation projects are to be developed and decisions made is emphasized. Following policy matters, this publication pays attention to the importance of social aspects and the requirement for fairness in decisions to be made, something that can only be achieved with the involvement of a broad range of interested parties in the decision making process. The publication also reviews the funding of remediation projects, planning, contracting, cost estimates and procurement, and issues related to long term stewardship. Lessons learned regarding technical aspects of remediation projects are reviewed. Techniques such as the application of cover systems and soil remediation (electrokinetics, phytoremediation, soil flushing, and solidification and stabilization techniques) are analysed with respect to performance and cost. After discussing soil remediation, the publication covers issues associated with water treatment, where techniques such as ‘pump and treat’ and the application of permeable barriers are reviewed. Subsequently, there is a section dedicated to reviewing briefly the lessons learned in the remediation of uranium mining and processing sites. Many of these sites throughout the world have become orphaned, and are waiting for remediation. The publication notes that little progress has been made in the management of some of these sites, particularly in the understanding of associated environmental and health risks, and the ability to apply prediction to future environmental and health standards. The publication concludes

  11. Drama, dissensus, remediation and a fluttering butterfly

    DEFF Research Database (Denmark)

    Kusk, Hanne

    2017-01-01

    Why is it important to pay attention to democracy and polyphony when working with remediation in a multimodal drama project in introductory schooling? This question is elucidated and investigated in this article on the basis of a drama project case study conducted at Hundborg Friskole. The study...... is analysed on the basis of the concepts of remediation (Bolter and Grusin 1999; Christoffersen 2009), dissensus (Biesta 2013; Rancière 2013), dialogue and polyphony (Dysthe, Bernhardt and Esbjørn 2012). The examples in the investigation show how dialogue, polyphony and dissensus influence the art......-based process of remediation, and how this impacts children’s democratic education....

  12. Economics of biofiltration for remediation projects

    International Nuclear Information System (INIS)

    Yudelson, J.M.; Tinari, P.D.

    1995-01-01

    Biofilters with granular activated carbon (GAC) filter backup units offer substantial savings compared to conventional GAC filters and catalytic/thermal oxidation (Catox) units in controlling emissions of volatile organic compounds (VOCs) from petroleum remediation projects. Provided that the biofilter supplier is willing to satisfy the client's and consultant's risk-management concerns, biofilters offer anew method for reducing the cost of remediation projects, with savings of up to $10,000 (24%) per facility in 24-month projects and up to $16,000 (32%) per facility in 36-month projects for simple gas station remediation projects. Savings will be greater for longer projects and projects with higher average contaminant loadings

  13. Effect of heterogeneity on enhanced reductive dechlorination: Analysis of remediation efficiency and groundwater acidification

    Science.gov (United States)

    Brovelli, A.; Lacroix, E.; Robinson, C. E.; Gerhard, J.; Holliger, C.; Barry, D. A.

    2011-12-01

    Enhanced reductive dehalogenation is an attractive in situ treatment technology for chlorinated contaminants. The process includes two acid-forming microbial reactions: fermentation of an organic substrate resulting in short-chain fatty acids, and dehalogenation resulting in hydrochloric acid. The accumulation of acids and the resulting drop of groundwater pH are controlled by the mass and distribution of chlorinated solvents in the source zone, type of electron donor, alternative terminal electron acceptors available and presence of soil mineral phases able to buffer the pH (such as carbonates). Groundwater acidification may reduce or halt microbial activity, and thus dehalogenation, significantly increasing the time and costs required to remediate the aquifer. In previous work a detailed geochemical and groundwater flow simulator able to model the fermentation-dechlorination reactions and associated pH change was developed. The model accounts for the main processes influencing microbial activity and groundwater pH, including the groundwater composition, the electron donor used and soil mineral phase interactions. In this study, the model was applied to investigate how spatial variability occurring at the field scale affects dechlorination rates, groundwater pH and ultimately the remediation efficiency. Numerical simulations were conducted to examine the influence of heterogeneous hydraulic conductivity on the distribution of the injected, fermentable substrate and on the accumulation/dilution of the acidic products of reductive dehalogenation. The influence of the geometry of the DNAPL source zone was studied, as well as the spatial distribution of soil minerals. The results of this study showed that the heterogeneous distribution of the soil properties have a potentially large effect on the remediation efficiency. For examples, zones of high hydraulic conductivity can prevent the accumulation of acids and alleviate the problem of groundwater acidification. The

  14. Characteristics of Southern California coastal aquifer systems

    Science.gov (United States)

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

    2009-01-01

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

  15. Microbiological risks of recycling urban stormwater via aquifers.

    Science.gov (United States)

    Page, D; Gonzalez, D; Dillon, P

    2012-01-01

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

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

    KAUST Repository

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

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

    Science.gov (United States)

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

    2007-01-01

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

  19. The limited role of aquifer heterogeneity on metal reduction in an Atlantic coastal plain determined by push-pull tests

    International Nuclear Information System (INIS)

    Mailloux, Brian J.; Devlin, Stephanie; Fuller, Mark E.; Onstott, T.C.; De Flaun, Mary F.; Choi, K.-H.; Green-Blum, Maria; Swift, Donald J.P.; McCarthy, John; Dong Hailiang

    2007-01-01

    Sixty push-pull experiments were conducted to determine the factors controlling Fe(III) and Mn(IV) reduction in a well-characterized, shallow, coastal plain aquifer near Oyster, VA, USA. The five multi-level samplers each equipped with 12 ports sampled a heterogeneous portion of the aquifer from 4.4 to 8m-bgs. Each multi-level sampler (MLS) was injected with groundwater that contained NO 3 - and Br - along with: (1) just groundwater (control treatment), (2) humics, (3) lactate (conducted twice) and (4) lactate plus humics. Microbially mediated Fe(III) reduction caused the aqueous Fe Tot concentrations to increase at every depth in the lactate treatment with significant increases within 1 day even while NO 3 - was present. Little change in the Fe Tot concentrations were observed in the control and humics treatment. Humics may have acted as an electron shuttle to increase Fe(III) reduction in the lactate plus humics treatment. The amount of Mn(IV) reduction was significantly lower than that of Fe(III) reduction. Geochemical modeling indicated that gas formation, sorption on reactive surfaces, and mineral precipitation were important processes and that Fe(III) and SO 4 2- reduction were co-occurring. Conditions were favorable for the precipitation of Fe-carbonates, Fe-sulfides and Fe-silicates. In the lactate treatment protist concentrations increased then decreased and planktonic cell concentrations steadily increased, whereas no change was observed in the control treatment. Correlations of Fe(III) reduction with physical and chemical heterogeneity were weak, probably as a result of the abundance of Fe(III) bearing minerals relative to electron donor abundance and that the push-pull test sampled a representative elemental volume that encompassed the microbial diversity within the aquifer. This work indicates that stimulating metal reduction in aquifer systems is a feasible method for remediating heterogeneous subsurface sites contaminated with metals and

  20. Stability of Cr Remediation Products Linked to Duration of Bioremediation.

    Science.gov (United States)

    Miller, L. G.; Bobb, C.; Bennett, S.; Izbicki, J. A.

    2017-12-01

    Groundwater and alluvium beneath Hinkley Valley, Mojave Desert, California contain elevated levels of anthropogenic Cr(VI). In-situ remediation (ISR) using ethanol as an electron donor is employed at the site to reduce soluble, toxic, Cr(VI) to insoluble and non-hazardous Cr(III). We conducted year-long experiments to determine the fate of isotopically-labeled 50Cr tracer within microcosms consisting of sealed batch reactors containing aquifer material and groundwater from within and near the mapped Cr(VI) plume. Ethanol was added periodically to the reactors to drive biologically mediated reduction of Cr(VI). Reduction and sorption of 50Cr tracer on the solid matrix was examined by selective extractions designed to monitor operationally-defined weakly sorbed, specifically sorbed, amorphous, and well-crystalized strong-acid extractable phases. Recovery of the 50Cr tracer by ICP-MS analysis of each extract revealed the degree of mineralization of the added 50Cr. Initially, the tracer was distributed evenly between the aqueous and weakly sorbed phases, with little present in the strongly sorbed, amorphous or crystalline phases. After several months, most 50Cr was incorporated within the amorphous fraction and by one year increasing amounts were associated with the crystalline phase. Artificial substrates also were prepared as experimental controls. Artificial substrates showed similar trends; however less 50Cr was associated with amorphous Fe in acid-washed Ottowa sand coated with 2-line ferrihydrite than in aquifer sediments. Washed sand without ferrihydrite reacted with site water sorbed very little 50Cr, and no 50Cr was found in the amorphous fraction; however some was converted to the crystalline form with time. This suggests that groundwater-borne organisms alone were capable of reducing Cr(VI) to Cr(III) with ethanol in the absence of Fe(II). A planned metagenomics study of materials from these experiments is expected to highlight changes in microbial community

  1. Remedial action and waste disposal project: 100-B/C remedial action readiness evaluation plan

    International Nuclear Information System (INIS)

    April, J.G.; Bryant, D.L.; Cislo, G.B.

    1996-06-01

    The Readiness Evaluation Plan presents the methodology used to assess the readiness of the 100-B/C Remedial Action Project. The 100 Areas Remedial Action Project will remediate the 100 Areas liquid waste site identified in the Interim Action Record of Decision for the 100- BC-1, 100-DR-1, and 100-HR-1 Operable Units. These sites are located in the 100 Area of the Hanford Site in Richland, Washington

  2. Remedial action and waste disposal project -- 300-FF-1 remedial action readiness assessment plan

    International Nuclear Information System (INIS)

    April, J.G.; Carlson, R.A.; Greif, A.A.; Johnson, C.R.; Orewiler, R.I.; Perry, D.M.; Plastino, J.C.; Roeck, F.V.; Tuttle, B.G.

    1997-04-01

    This Readiness Assessment Plan presents the methodology used to assess the readiness of the 300-FF-1 Remedial Action Project. Remediation involves the excavation, treatment if applicable, and final disposal of contaminated soil and debris associated with the waste sites in the 300-FF-1 Operable Unit. The scope of the 300-FF-1 remediation is to excavate, transport, and dispose of contaminated solid from sites identified in the 300-FF-1 Operable Unit

  3. 46 CFR 298.41 - Remedies after default.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Remedies after default. 298.41 Section 298.41 Shipping... Defaults and Remedies, Reporting Requirements, Applicability of Regulations § 298.41 Remedies after default... governing remedies after a default, which relate to our rights and duties, the rights and duties of the...

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

    Science.gov (United States)

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

    1992-01-01

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

  5. School Finance Reform: Acceptable Remedies for Serrano

    Science.gov (United States)

    Guthrie, James W.

    1974-01-01

    Article examined the remedies available to states in the wake of Serrano and its progeny. As well, it analyzed the strengths and weaknesses of "district power equalizing" and "full state assumption" as alternative methods of financing schools. (Editor/RK)

  6. Land Conversion, Social Impacts, and Legal Remedies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Land Conversion, Social Impacts, and Legal Remedies: Understanding the Role of Community Paralegals in Addressing Impacts of Land Use Change in Asia. This project addresses the ... Pays d' institution. United States. Site internet.

  7. ELECTROKINETIC REMEDIATION: BASICS AND TECHNOLOGY STATUS

    Science.gov (United States)

    Electrokinetic remediation, variably named as electrochemical soil processing, electromigration, electrokinetic decontamination or electroreclamation uses electric currents to extract radionuclides, heavy metals, certain organic compounds, or mixed inorganic species and some orga...

  8. 48 CFR 2009.570-10 - Remedies.

    Science.gov (United States)

    2010-10-01

    ... addition to other remedies permitted by law or contract for a breach of the restrictions in this subpart or... to be provided for this section, the NRC may debar the contractor from subsequent NRC contracts. ...

  9. Nanotechnology for Site Remediation: Fact Sheet

    Science.gov (United States)

    This fact sheet presents a snapshot of nanotechnology and its current uses in remediation. It presents information to help site project managers understand the potential applications of this group of technologies at their sites.

  10. Green Remediation Best Management Practices: Mining Sites

    Science.gov (United States)

    This fact sheet describes best management practices (BMPs) that can be used to reduce the environmental footprint of cleanup activities associated with common project components, cleanup phases, and implementation of remediation technologies.

  11. Land Conversion, Social Impacts, and Legal Remedies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Land Conversion, Social Impacts, and Legal Remedies: Understanding the Role of ... There is a recognized need for intermediary institutions, such as media, ... Birth registration is the basis for advancing gender equality and children's rights.

  12. Developing a disposal and remediation plan

    International Nuclear Information System (INIS)

    Messier, T.S.

    1999-01-01

    The environmental release of wastes generated by the upstream oil and gas industry in Alberta can result in polluted soil and groundwater at several facilities across the province. Responsibility for decommissioning upstream oil and gas facilities falls under the jurisdiction of the Alberta Energy and Utilities Board (EUB) and Alberta Environmental Protection (AEP). This paper outlines a protocol that can serve as a framework for the development of a plan to dispose of oilfield waste and to remediate related contaminated soils. The components involved in developing a disposal and remediation plan for oilfield wastes are: (1) identifying the potential source of pollution and oilfield waste generation, (2) characterizing oilfield wastes, (3) determining the nature and extent of soil and groundwater pollution, (4) preparing a remedial action plan, (5) assessing the viability of various remediation options, and (6) preparing health and safety plan. 12 refs., 2 tabs., 2 figs

  13. Civil Remedies Division Administrative Law Judge Decisions

    Data.gov (United States)

    U.S. Department of Health & Human Services — Decisions issued by Administrative Law Judges of the Departmental Appeals Board's Civil Remedies Division concerning fraud and abuse determinations by the Office of...

  14. REAL TIME DATA FOR REMEDIATION ACTIVITIES (11505)

    International Nuclear Information System (INIS)

    Brock, C.T.

    2011-01-01

    Health physicists from the CH2M HILL Plateau Remediation Company collaborated with Berkeley Nucleonics Corporation to modify the SAM 940 isotope identifier instrument to be used for nuclear waste remediation. These modifications coupled with existing capabilities of the SAM 940 have proven to be invaluable during remediation activities, reducing disposal costs by allowing swift remediation of targeted areas that have been identified as having isotopes of concern (IOC), and eliminating multiple visits to sites by declaring an excavation site clear of IOCs before demobilizing from the site. These advantages are enabled by accumulating spectral data for specific isotopes that is nearly 100 percent free of false positives, which are filtered out in 'real time.'

  15. Kerr Hollow Quarry Remediation Project

    International Nuclear Information System (INIS)

    Walker, K.L.

    1993-01-01

    The Kerr Hollow Quarry is a 3-acre flooded limestone quarry located near the Y-12 Facility on the Oak Ridge Reservation. The quarry was used in the 1940s as a source of construction material for the Department of Energy in Oak Ridge, Tennessee. Its use was discontinued in the early 1950s, and it was allowed to flood with water. The quarry presently has a maximum water depth of approximately 55 ft. During the period between the early 1950s until about 1988, the quarry was used for the treatment and disposal of a variety of materials including water-reactive, alkali metals, shock-sensitive chemicals, and compressed gas cylinders. For some of these materials, the treatment consisted of dropping the vessels containing the materials into the quarry from a high bluff located on one side of the quarry. The vessels were then punctured by gun shot, and the materials were allowed to react with the water and sink to the bottom of the quarry. Very few disposal records exist for the period from 1952 to 1962. The records after that time, from 1962 until 1988, indicate some 50 t of hazardous and nonhazardous materials were disposed of in the quarry. This report documents remediation efforts that have taken place at the quarry beginning in September 1990

  16. Compliance monitoring for remediated sites

    International Nuclear Information System (INIS)

    1999-10-01

    Throughout the world, many countries have experienced problems associated with pollution of the environment. Poorly managed practices in nuclear fuel cycle, medicine, industry, weapons production and testing, research and development activities, as well as accidents, and poor disposal practices have produced a large array of radioactively contaminated facilities and sites. Structures, biota, soils, rocks, and both surface and groundwaters have become contaminated with radionuclides and other associated contaminants, a condition that raises serious concern due to potential health effects to the exposed human populations and the environment. In response to the needs of its Member States in dealing with the problems of radioactive contamination in the environment, the IAEA has established an Environmental Restoration Project. The principal aspects of current IAEA efforts in this area include (1) gathering information and data, performing analyses, and publishing technical summaries, and other documents on key technical aspects of environmental restoration; (2) conducting a Co-ordinated Research Project on Environmental Restoration; and (3) providing direct technical assistance to Member States through technical co-operation programmes. The transfer of technologies to Member States in need of applicable methodologies and techniques for the remediation of contaminated sites is a principal objective of this project

  17. Parsley! Mechanism as antiurolithiasis remedy.

    Science.gov (United States)

    Al-Yousofy, Fayed; Gumaih, Hussein; Ibrahim, Hassan; Alasbahy, Afrah

    2017-01-01

    Parsley is a medicinal plant used widely in urolithiasis. The present study aimed to evaluate the antiurolithiatic effect of parsley and its mechanism. 24 rats divided into four groups: group A (negative control), group B (positive control), group C (cystone ® group) and group D (parsley group). Group B were treated with EG and Ammonium chloride (AC). Group C were treated as B plus cystone ® and group D was treated as B plus parsley. The period of experiment was 15 days. Urine samples were analysis on days 0 and 15 days. Kidneys of rats from all groups were removed, and histopathologically examined. The kidnies of parsley treated group appeared mostly to be calculi-free (less CaOx) even better than the cystone treated group. CaOx crystals was significantly lower both in histological sections and in urine samples in parsley treated group. We further investigated the mechanism of parsley by adding another 6 rats. The latter treated by parsley only after adaptation period. We found significant increase in urine volume and pH in parsley treated rats compared to negative control. We concluded that parsley acts as antiurolithiatic drug through decreasing urinary calcium excretion, increasing urinary pH, dieresis, decreasing urinary protein excretion and its nephroprtective activity. We recommended to use it in pharmaceutical forms as it is safe and effective as antiurolithiasis remedy.

  18. Innovative vitrification for soil remediation

    Energy Technology Data Exchange (ETDEWEB)

    Jetta, N.W.; Patten, J.S.; Hnat, J.G. [Vortec Corp., Collegeville, PA (United States)

    1995-10-01

    The objective of this DOE demonstration program is to validate the performance and operation of the Vortec Cyclone Melting System (CMS{trademark}) for the processing of LLW contaminated soils found at DOE sites. This DOE vitrification demonstration project has successfully progressed through the first two phases. Phase I consisted of pilot scale testing with surrogate wastes and the conceptual design of a process plant operating at a generic DOE site. The objective of Phase 2, which is scheduled to be completed the end of FY 95, is to develop a definitive process plant design for the treatment of wastes at a specific DOE facility. During Phase 2, a site specific design was developed for the processing of LLW soils and muds containing TSCA organics and RCRA metal contaminants. Phase 3 will consist of a full scale demonstration at the DOE gaseous diffusion plant located in Paducah, KY. Several DOE sites were evaluated for potential application of the technology. Paducah was selected for the demonstration program because of their urgent waste remediation needs as well as their strong management and cost sharing financial support for the project.

  19. Remediation of asbestos in soil

    International Nuclear Information System (INIS)

    McFarland, Ross; Dangerfield, David

    2012-01-01

    The former Patea Freezing Works in the Tarankai region of New Zealand began as a canning plant and tallow factory in the late 1800s. Freezing technology was introduced in 1904 and was in continuous operation until 1982. Some of the structures were destroyed by fire in 2008, leaving metal, ash and asbestos. Fragments of Asbestos Containing Material (ACM) were blown over the local town and a large area of the site. A remedial strategy was developed by Aecom and they also provided validation services. . The preferred option was to remove the top layer of ACM impacted soil and place it in an engineered containment cell on site. However this process could not be used due to local cultural objections, and the 'dig and dump' option was adopted. The Western Australian Department of Health (DOH) Guidelines, May 2009, were used in collaboration with local district New Zealand Councils. Monitoring wells were installed, however the monitoring program is not yet underway as the revegetation program is not complete.

  20. Remediation of sites with dispersed radioactive contamination

    International Nuclear Information System (INIS)

    2004-01-01

    To respond to the needs of Member States, the IAEA launched an environmental remediation project to deal with the problems of radioactive contamination worldwide. The IAEA environmental remediation project includes an IAEA Coordinated Research Project, as well as the participation of IAEA experts in concrete remediation projects when requested by individual Member States. The IAEA has prepared several documents dedicated to particular technical or conceptual areas, including documents on the characterization of contaminated sites, technical and non-technical factors relevant to the selection of a preferred remediation strategy and technique, overview of applicable techniques for environmental remediation,, options for the cleanup of contaminated groundwater and planning and management issues. In addition, a number of other IAEA publications dealing with related aspects have been compiled under different IAEA projects; these include TECDOCs on the remediation of uranium mill tailings, the decontamination of buildings and roads and the characterization of decommissioned sites. Detailed procedures for the planning and implementation of remedial measures have been developed over the past decade or so. A critical element is the characterization of the contamination and of the various environmental compartments in which it is found, in order to be able to evaluate the applicability of remediation techniques. The chemical or mineralogical form of the contaminant will critically influence the efficiency of the remediation technique chosen. Careful delineation of the contamination will ensure that only those areas or volumes of material that are actually contaminated are treated. This, in turn, reduces the amount of any secondary waste generated. The application of a remediation technique requires holistic studies examining the technical feasibility of the proposed measures, including analyses of their impact. Consequently, input from various scientific and engineering

  1. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study.

    Science.gov (United States)

    Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Liu, Chongxuan; Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu

    2015-09-15

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO4 and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na2HAsO4) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles. Copyright © 2015

  2. Acid groundwater in an anoxic aquifer: Reactive transport modelling of buffering processes

    International Nuclear Information System (INIS)

    Franken, Gudrun; Postma, Dieke; Duijnisveld, Wilhelmus H.M.; Boettcher, Juergen; Molson, John

    2009-01-01

    The acidification of groundwater, due to acid rain, was investigated in a Quaternary sandy aquifer in the Fuhrberger Feld, near Hannover, Germany. The groundwater, recharged through an area covered by a coniferous forest, had a pH in the range 4-5 down to a depth of 5 m. The evolution in groundwater chemistry along the flow path was investigated in a transect of multisamplers. A 2D groundwater flow model was established delineating the groundwater flow field and a groundwater flow velocity of around 80 m/a along the flow path was derived. Speciation calculations showed the groundwater to be close to equilibrium with the mineral jurbanite (AlOHSO 4 ) over the pH range 4.0-6.5. This suggests an accumulation of acid rain derived SO 4 2- in the aquifer sediment during the decades with high atmospheric S deposition. The groundwater has a pH of around 4.5 in the upstream part of the flow path increasing to near 6 further downstream. 1D reactive transport modelling, using PHREEQC, was used to analyze different combinations of buffering processes. The first model contains ion exchange in combination with jurbanite dissolution. At the ion exchange front Al 3+ is adsorbed leading to the dissolution of jurbanite and an increase in pH. Comparison with field data showed that the simulated increases in pH and alkalinity are much lower than observed in the field. The second model includes organic matter degradation. In addition to ion exchange and jurbanite dissolution, the model included the reduction of SO 4 2- and Fe-oxides as well as the precipitation of Fe sulfide. This model matches the field data well and illustrates the importance of redox processes for pH buffering in the Fuhrberg aquifer. The current progress of the acidification front is about 4 m/a. This corresponds to an average value of 150 a of acid input, which covers large historical variations. Remediation is expected to take the same time span because it requires desorption and neutralization of adsorbed Al 3

  3. Stochastic analysis of the efficiency of coupled hydraulic-physical barriers to contain solute plumes in highly heterogeneous aquifers

    Science.gov (United States)

    Pedretti, Daniele; Masetti, Marco; Beretta, Giovanni Pietro

    2017-10-01

    The expected long-term efficiency of vertical cutoff walls coupled to pump-and-treat technologies to contain solute plumes in highly heterogeneous aquifers was analyzed. A well-characterized case study in Italy, with a hydrogeological database of 471 results from hydraulic tests performed on the aquifer and the surrounding 2-km-long cement-bentonite (CB) walls, was used to build a conceptual model and assess a representative remediation site adopting coupled technologies. In the studied area, the aquifer hydraulic conductivity Ka [m/d] is log-normally distributed with mean E (Ya) = 0.32 , variance σYa2 = 6.36 (Ya = lnKa) and spatial correlation well described by an exponential isotropic variogram with integral scale less than 1/12 the domain size. The hardened CB wall's hydraulic conductivity, Kw [m/d], displayed strong scaling effects and a lognormal distribution with mean E (Yw) = - 3.43 and σYw2 = 0.53 (Yw =log10Kw). No spatial correlation of Kw was detected. Using this information, conservative transport was simulated across a CB wall in spatially correlated 1-D random Ya fields within a numerical Monte Carlo framework. Multiple scenarios representing different Kw values were tested. A continuous solute source with known concentration and deterministic drains' discharge rates were assumed. The efficiency of the confining system was measured by the probability of exceedance of concentration over a threshold (C∗) at a control section 10 years after the initial solute release. It was found that the stronger the aquifer heterogeneity, the higher the expected efficiency of the confinement system and the lower the likelihood of aquifer pollution. This behavior can be explained because, for the analyzed aquifer conditions, a lower Ka generates more pronounced drawdown in the water table in the proximity of the drain and consequently a higher advective flux towards the confined area, which counteracts diffusive fluxes across the walls. Thus, a higher σYa2 results

  4. Natural Remediation at Savannah River Site

    International Nuclear Information System (INIS)

    Lewis, C. M.; Van Pelt, R.

    2002-01-01

    Natural remediation is a general term that includes any technology or strategy that takes advantage of natural processes to remediate a contaminated media to a condition that is protective of human health and the environment. Natural remediation techniques are often passive and minimally disruptive to the environment. They are generally implemented in conjunction with traditional remedial solutions for source control (i.e., capping, stabilization, removal, soil vapor extraction, etc.). Natural remediation techniques being employed at Savannah River Site (SRS) include enhanced bio-remediation, monitored natural attenuation, and phytoremediation. Enhanced bio-remediation involves making nutrients available and conditions favorable for microbial growth. With proper precautions and feeding, the naturally existing microbes flourish and consume the contaminants. Case studies of enhanced bio-remediation include surface soils contaminated with PCBs and pesticides, and Volatile Organic Compound (VOC) contamination in both the vadose zone and groundwater. Monitored natural attenuation (MNA) has been selected as the preferred alternative for groundwater clean up at several SRS waste units. Successful implementation of MNA has been based on demonstration that sources have been controlled, groundwater modeling that indicates that plumes will not expand or reach surface water discharge points at levels that exceed regulatory limits, and continued monitoring. Phytoremediation is being successfully utilized at several SRS waste units. Phytoremediation involves using plants and vegetation to uptake, break down, or manage contaminants in groundwater or soils. Case studies at SRS include managing groundwater plumes of tritium and VOCs with pine trees that are native to the area. Significant decreases in tritium discharge to a site stream have been realized in one phytoremediation project. Studies of other vegetation types, methods of application, and other target contaminants are

  5. International experience in tailings pond remediation

    International Nuclear Information System (INIS)

    Robertson, A.MacG.

    2001-01-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  6. New technologies in decommissioning and remediation

    International Nuclear Information System (INIS)

    Fournier, Vincent

    2016-01-01

    New and emerging technologies are making decommissioning and remediation more cost effective, faster and safer. From planning to execution and control, the use of new technologies is on the rise. Before starting decommissioning or environmental remediation, experts need to plan each step of the process, and to do that, they first need a clear idea of the characteristics of the structure and the level of radiation that they can expect to encounter

  7. International experience in tailings pond remediation

    Energy Technology Data Exchange (ETDEWEB)

    MacG. Robertson, A. [Robertson GeoConsultants Ltd., Vancouver (Canada)

    2001-07-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  8. Waste minimization applications at a remediation site

    International Nuclear Information System (INIS)

    Allmon, L.A.

    1995-01-01

    The Fernald Environmental Management Project (FEMP) owned by the Department of Energy was used for the processing of uranium. In 1989 Fernald suspended production of uranium metals and was placed on the National Priorities List (NPL). The site's mission has changed from one of production to environmental restoration. Many groups necessary for producing a product were deemed irrelevant for remediation work, including Waste Minimization. Waste Minimization does not readily appear to be applicable to remediation work. Environmental remediation is designed to correct adverse impacts to the environment from past operations and generates significant amounts of waste requiring management. The premise of pollution prevention is to avoid waste generation, thus remediation is in direct conflict with this premise. Although greater amounts of waste will be generated during environmental remediation, treatment capacities are not always available and disposal is becoming more difficult and costly. This creates the need for pollution prevention and waste minimization. Applying waste minimization principles at a remediation site is an enormous challenge. If the remediation site is also radiologically contaminated it is even a bigger challenge. Innovative techniques and ideas must be utilized to achieve reductions in the amount of waste that must be managed or dispositioned. At Fernald the waste minimization paradigm was shifted from focusing efforts on source reduction to focusing efforts on recycle/reuse by inverting the EPA waste management hierarchy. A fundamental difference at remediation sites is that source reduction has limited applicability to legacy wastes but can be applied successfully on secondary waste generation. The bulk of measurable waste reduction will be achieved by the recycle/reuse of primary wastes and by segregation and decontamination of secondary wastestreams. Each effort must be measured in terms of being economically and ecologically beneficial

  9. Passive remediation strategies for petroleum contaminated sites

    International Nuclear Information System (INIS)

    Everett, L.G.; Cullen, S.J.; Eccles, L.A.

    1991-01-01

    The US EPA is becoming increasingly aware of costs and the limited success of existing remediation strategies. Research teams within the US EPA believe that if passive remediation can be successfully demonstrated, it is a candidate for best available technology. Passive remediation, however, must be demonstrated through the use of monitoring techniques, which demonstrate: contaminants are not moving in the dissolved, adsorbed or free product phase; and contamination is biodegrading in-place. This paper presents a concise monitoring and analysis strategy for passive remediation. Specifically, the paper presents the accuracy, precision and operating range of neutron moderation techniques as a low cost, real-time screening tool to measure the migration of the dissolved phase in soil moisture, the stabilized adsorbed phase and free product movement. In addition, the paper identifies the capillary pressure range through which the dissolved phase will move and identifies techniques for satisfying the risk analysis that movement is not taking place. The rationale for passive remediation taking place is confirmed through a discussion of gas ratios associated with bacterial assimilation of hydrocarbons. Gas ratios which are relatively constant above ground are highly inverted in the subsurface at contamination sites. The use of frequent screening of a vertical geologic profile using least cost techniques and the infrequent analysis of soil gas ratios provides the required data upon which the public will accept passive remediation as best available technology at a particular site. The paper points out that neutron moderation is a high candidate vadose zone monitoring device and identifies alternative techniques using resistivity and dielectric constants, which are in the developmental stage. The economic implications for passive remediation are enormous relative to the excavation and remediation strategies which are currently in use

  10. Sealable joint steel sheet piling for groundwater control and remediation: Case histories

    International Nuclear Information System (INIS)

    Smyth, D.; Jowett, R.; Gamble, M.

    1997-01-01

    The Waterloo Barrier trademark steel sheet piling (patents pending) incorporates a cavity at each interlocking joint that is flushed clean and injected with sealant after the piles have been driven into the ground to form a vertical cutoff wall. The installation and sealing procedures allow for a high degree of quality assurance and control. Bulk wall hydraulic conductivities of 10 -8 to 10 -10 cm/sec have been demonstrated at field installations. Recent case histories are presented in which Waterloo Barrier trademark cutoff walls are used to prevent off-site migration of contaminated groundwater or soil gases to adjacent property and waterways. Full enclosures to isolate DNAPL source zones or portions of contaminated aquifers for pilot-scale remediation testing will also be described. Monitoring data will be used to demonstrate the effectiveness of the Waterloo Barrier trademark in these applications

  11. Waste management facility remediation and decommissioning at a national nuclear research site

    International Nuclear Information System (INIS)

    Cameron, D.J.; Dolinar, G.M.; Killey, R.W.D.

    1994-01-01

    Historic waste management practices at eight locations on AECL's Chalk River site have resulted in the formation of contaminated groundwater plumes, some of which have surfaced and contaminated surface materials. A priority setting process has been used to establish a plan of attack that will lead to the eventual decommissioning of these facilities. In general terms, the preferred approach is to install impermeable covers to prevent further leaching of waste sources and to prevent escape of leachate to the biosphere, followed by cleanup of surface contamination and remediation of aquifers. Final disposal of the waste sources would be delayed for perhaps 20 years. Substantial progress has been made in the treatment of contaminated groundwater, with one field installation in place and another under development. This paper describes how the prioritization task was tackled to produce a long term plan of action and describes initial interventions that have been attempted and their results. 4 refs., 3 tabs., 3 figs

  12. Ethanol content in different gasohol blend spills influences the decision-making on remediation technologies.

    Science.gov (United States)

    Vilela Steiner, Leonardo; Toledo Ramos, Débora; Rubini Liedke, Ana Maria; Serbent, Maria Pilar; Corseuil, Henry Xavier

    2018-04-15

    Gasohol blend spills with variable ethanol content exert different electron acceptor demands in groundwater and the distinct dynamics undergone by these blends underscores the need for field-based information to aid decision-making on suitable remediation technologies for each gasohol blend spill. In this study, a comparison of two gasohol releases (E10 (10:90 ethanol and gasoline, v/v) and E25 (25:75 ethanol and gasoline, v/v) under monitored natural attenuation (MNA) and nitrate biostimulation, respectively) was conducted to assess the most effective remediation strategy for each gasohol release. Microbial communities were assessed to support geochemical data as well as to enable the characterization of important population shifts that evolve during biodegradation processes in E25 and E10 field experiments. Results revealed that natural attenuation processes sufficiently supported ethanol and BTEX compounds biodegradation in E10 release, due to the lower biochemical oxygen demand they exert relative to E25 blend. In E25 release, nitrate reduction was largely responsible for BTEX and ethanol biodegradation, as intended. First-order decay constants demonstrated that ethanol degradation rates were similar (p remediation technologies (2.05 ± 0.15 and 2.22 ± 0.23, for E25 and E10, respectively) whilst BTEX compounds exhibited different degradation rates (p > 0.05) that were higher for the experiment under MNA (0.33 ± 0.06 and 0.43 ± 0.03, for E25 and E10, respectively). Therefore, ethanol content in different gasohol blends can influence the decision-making on the most suitable remediation technology, as MNA processes can be applied for the remediation of gasohol blends with lower ethanol content (i.e., 10% v/v), once the aquifer geochemical conditions provide a sufficient electron acceptor pool. To the best of our knowledge, this is the first field study to monitor two long-term gasohol releases over various time scales in order to assess

  13. The remediation of heavy metals contaminated sediment.

    Science.gov (United States)

    Peng, Jian-Feng; Song, Yong-Hui; Yuan, Peng; Cui, Xiao-Yu; Qiu, Guang-Lei

    2009-01-30

    Heavy metal contamination has become a worldwide problem through disturbing the normal functions of rivers and lakes. Sediment, as the largest storage and resources of heavy metal, plays a rather important role in metal transformations. This paper provides a review on the geochemical forms, affecting factors and remediation technologies of heavy metal in sediment. The in situ remediation of sediment aims at increasing the stabilization of some metals such as the mobile and the exchangeable fractions; whereas, the ex situ remediation mainly aims at removing those potentially mobile metals, such as the Mn-oxides and the organic matter (OM) fraction. The pH and OM can directly change metals distribution in sediment; however oxidation-reduction potential (ORP), mainly through changing the pH values, indirectly alters metals distribution. Mainly ascribed to their simple operation mode, low costs and fast remediation effects, in situ remediation technologies, especially being fit for slight pollution sediment, are applied widely. However, for avoiding metal secondary pollution from sediment release, ex situ remediation should be the hot point in future research.

  14. Nuclear facility decommissioning and site remedial actions

    International Nuclear Information System (INIS)

    Owen, P.T.; Knox, N.P.; Ferguson, S.D.; Fielden, J.M.; Schumann, P.L.

    1989-09-01

    The 576 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the tenth in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types--technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions--have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) General Remedial Action Program Studies. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title work, publication description, geographic location, subject category, and keywords

  15. Hazardous waste treatment and environmental remediation research

    International Nuclear Information System (INIS)

    1989-01-01

    Los Alamos National Laboratory (LANL) is currently evaluating hazardous waste treatment and environmental remediation technologies in existence and under development to determine applicability to remediation needs of the DOE facilities under the Albuquerque Operations Office and to determine areas of research need. To assist LANL is this effort, Science Applications International Corporation (SAIC) conducted an assessment of technologies and monitoring methods that have been demonstrated or are under development. The focus of this assessment is to: (1) identify existing technologies for hazardous waste treatment and environmental remediation of old waste sites; (2) identify technologies under development and the status of the technology; (3) assess new technologies that need development to provide adequate hazardous waste treatment and remedial action technologies for DOD and DOE sites; and (4) identify hazardous waste and remediation problems for environmental research and development. There are currently numerous research and development activities underway nationwide relating to environmental contaminants and the remediation of waste sites. To perform this effort, SAIC evaluated current technologies and monitoring methods development programs in EPA, DOD, and DOE, as these are the primary agencies through which developmental methods are being demonstrated. This report presents this evaluation and provides recommendations as to pertinent research needs or activities to address waste site contamination problems. The review and assessment have been conducted at a programmatic level; site-specific and contaminant-specific evaluations are being performed by LANL staff as a separate, related activity

  16. Hanford sitewide grounwater remediation - supporting technical information

    International Nuclear Information System (INIS)

    Chiaramonte, G.R.

    1996-05-01

    The Hanford Sitewide Groundwater Remediation Strategy was issued in 1995 to establish overall goals for groundwater remediation on the Hanford Site. This strategy is being refined to provide more detailed justification for remediation of specific plumes and to provide a decision process for long-range planning of remediation activities. Supporting this work is a comprehensive modeling study to predict movement of the major site plumes over the next 200 years to help plan the remediation efforts. The information resulting from these studies will be documented in a revision to the Strategy and the Hanford Site Groundwater Protection Management Plan. To support the modeling work and other studies being performed to refine the strategy, this supporting technical information report has been produced to compile all of the relevant technical information collected to date on the Hanford Site groundwater contaminant plumes. The primary information in the report relates to conceptualization of the source terms and available history of groundwater transport, and description of the contaminant plumes. The primary information in the report relates to conceptualization of the source terms and available history of groundwater transport, description of the contaminant plumes, rate of movement based on the conceptual model and monitoring data, risk assessment, treatability study information, and current approach for plume remediation

  17. Nuclear facility decommissioning and site remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.T.; Knox, N.P.; Ferguson, S.D.; Fielden, J.M.; Schumann, P.L.

    1989-09-01

    The 576 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the tenth in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types--technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions--have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) General Remedial Action Program Studies. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title work, publication description, geographic location, subject category, and keywords.

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

    Science.gov (United States)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO3−) loading to surface and groundwater. We investigate variability and sources of NO3− in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO3− stable isotopes (δ15N and δ18O). These data were augmented by historical data collected from 1937 to 2007. NO3− concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO3− concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO3− concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO3−. These results highlight the vulnerability of karst aquifers to NO3− contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO3−than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates that subaqueous nitrification of organic N in the aquifer, as opposed to in soils, might be a previously

  20. Temporal and spatial variations in groundwater quality resulting from policy-induced reductions in nitrate leaching to the Rabis Creek aquifer, Denmark

    Science.gov (United States)

    Jessen, Søren; Engesgaard, Peter; Thorling, Lærke; Müller, Sascha; Leskelä, Jari; Postma, Dieke

    2016-04-01

    Twenty-five years of annual groundwater quality monitoring data from the sandy unconfined Rabis Creek aquifer were used to assess the effects of political actions aimed to reduce nitrate leaching to the aquifer. Data were collected from eight multilevel samplers along a ˜3 km transect, which follows the general direction of groundwater flow. Each multilevel sampler comprises 20 screens placed with a 1 m vertical distance from near the water table downwards. The transect covers areas of livestock, plantation & heath, and agriculture. The history of nitrate leaching to the aquifer was assessed using data from screens close to the water table of multilevel samplers placed within agricultural areas. According to these data, nitrate concentrations of infiltrating 'agricultural' water peaked at 2-3 mM (120-180 mg/L) in the year 1989, and then gradually decreased and stabilized at 0.25-1.0 mM (15-60 mg/L) from year 2000. Local farmers declare having used the maximum fertilization rate allowed during the period. The timing of the observed decrease therefore suggests a direct link to the political action plans implemented in the same period. Parallel to the development in nitrate leaching, although with a transport time lag, the average concentration of nitrate in the oxic zone of the aquifer was roughly halved between 2000 and 2013. As a response to political initiatives of the late 1980'ies, part of the area covering the aquifer was changed from agriculture to non-fertilized grass for livestock; the data shows that this effectively remediated the aquifer underneath in less than 20 years, to become nitrate-free and attain background sulfate levels. The oxidized and pyritic reduced zone of the aquifer is separated by a <1 m redoxcline. Denitrification by the pyrite releases sulfate that is retained down-gradient as a tracer for historical nitrate loading to the aquifer. Thus sulfate concentrations currently increase in the multilevel samplers positioned furthest down

  1. Aquifer thermal energy (heat and chill) storage

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A. (ed.)

    1992-11-01

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

  2. The detection of boundaries in leaky aquifers

    International Nuclear Information System (INIS)

    Cook, A.J.

    1989-01-01

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

  3. Geopressured-geothermal aquifers. Final contract report

    Energy Technology Data Exchange (ETDEWEB)

    1983-08-01

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

  4. Denitrification in the karstic Floridan Aquifer

    Science.gov (United States)

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

    2010-12-01

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

  5. SRP baseline hydrogeologic investigation: Aquifer characterization

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-03-31

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

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

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

    Science.gov (United States)

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

    1996-08-01

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

  8. Aquifers in coastal reclaimed lands - real world assessments

    Science.gov (United States)

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

    2017-12-01

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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

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

  12. Hydrologic and isotopic study of the Quito aquifer

    International Nuclear Information System (INIS)

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

    2000-10-01

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

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

    Indian Academy of Sciences (India)

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

  14. In-situ treatment of hydrocarbons contamination through enhanced bio-remediation and two phase extraction system

    International Nuclear Information System (INIS)

    Aglietto, I.; Brunero Bronzin, M.

    2005-01-01

    It happens frequently to find industrial site affected by contamination of subsoil and groundwater with consequent presence of free phase product floating on the water table. The remediation technologies in this case shall be properly selected and coordinated in a way that the interactions between each activities will help to decontaminate the site. The case study deals with an industrial site located near Turin, in Italy, of about 50 hectares of extension where has been found an area of about 4000 square meters with contamination of subsoil and groundwater. The compounds with higher concentrations are petroleum hydrocarbons found both in soil and in groundwater. Another big problem is represented by the presence of a layer of free product floating on the water table with a maximum measured thickness of 70 cm; this situation can be considered in fact one of the major difficulty in management of selected remediation technologies because the complete recover of the free phase is a priority for any kind of remediation system to apply subsequently. The present work is based upon the selection and implementation of a multiple treatment for definitive remediation of subsoil and groundwater. Free product recovery has been faced with a two-phase extraction technology, then for the remediation of subsoil we implemented a bio-venting system to improve biodegradation processes and finally for groundwater treatment we apply an enhanced in situ bio-remediation injecting oxygen release compounds directly into the aquifer. To reach these choices we have to pass through a complex activity of investigation of the site made up of more than 40 sampling point, 8 monitoring wells, about 140 analysis on subsoil samples and 10 on groundwater samples and one well used for an aquifer test. The preliminary design of the remediation system was therefore based on an extensive site characterization that included geological and geochemical, microbiological and hydrological data, together with

  15. Magnetic separation for environmental remediation

    International Nuclear Information System (INIS)

    Schake, A.R.; Avens, L.R.; Hill, D.D.; Padilla, D.D.; Prenger, F.C.; Romero, D.A.; Worl, L.A.; Tolt, T.L.

    1994-01-01

    High Gradient Magnetic Separation (HGMS) is a form of magnetic separation used to separate solids from other solids, liquids or gases. HGMS uses large magnetic field gradients to separate ferromagnetic and paramagnetic particles from diamagnetic host materials. The technology relies only on physical properties, and therefore separations can be achieved while producing a minimum of secondary waste. Actinide and fission product wastes within the DOE weapons complex pose challenging problems for environmental remediation. Because the majority of actinide complexes and many fission products are paramagnetic, while most host materials are diamagnetic, HGMS can be used to concentrate the contaminants into a low volume waste stream. The authors are currently developing HGMS for applications to soil decontamination, liquid waste treatment, underground storage tank waste treatment, and actinide chemical processing residue concentration. Application of HGMS usually involves passing a slurry of the contaminated mixture through a magnetized volume. Field gradients are produced in the magnetized volume by a ferromagnetic matrix material, such as steel wool, expanded metal, iron shot, or nickel foam. The matrix fibers become trapping sites for ferromagnetic and paramagnetic particles in the host material. The particles with a positive susceptibility are attracted toward an increasing magnetic field gradient and can be extracted from diamagnetic particles, which react in the opposite direction, moving away from the areas of high field gradients. The extracted paramagnetic contaminants are flushed from the matrix fibers when the magnetic field is reduced to zero or when the matrix canister is removed from the magnetic field. Results are discussed for the removal of uranium trioxide from water, PuO 2 , U, and Pu from various soils (Fernald, Nevada Test Site), and the waste water treatment of Pu and Am isotopes using HGMS

  16. Remediation of lead contaminated soil

    International Nuclear Information System (INIS)

    Urban, W.; Krishnamurthy, S.

    1992-01-01

    Lead contaminated soil in urban area is of major concern because of the potential health risk to children. Many studies have established a direct correlation between lead in soil and elevated blood lead levels in children. In Minneapolis, Minnesota, Mielke et al. (1983) reported that 50% of the Hmong children with lead poisioning were in areas where soil lead levels were between 500 and 1000 micrograms per gram (ug/g), and 40% of the children suffering from lead poisioning lived in areas where soil lead levels exceeded 1000 ug/g. In urban areas, lead pollution in soil has come from many different sources. The sources include lead paint, lead batteries and automobile exhaust. Olson and Skogerbee (1975) found the following lead compounds in soils where the primary source of pollution was from automobiles: lead sulfate, lead oxide, lead dioxide, lead sulfide, and metallic lead. The primary form of lead found was lead sulfate. Lead sulfate, lead tetraoxide, white lead, and other forms of lead have been used in the manufacture of paints for houses. At present, two remediation techniques, solidification and Bureau of Mines fluosilicic acid leaching, are available for lead-contaminated sites. The objective of the present investigation at the Risk Reduction Engineering Laboratory (RREL), Edison, was to try to solubilize the lead species by appropriate reagents and then recover the contaminants by precipitation as lead sulfate, using environmentally acceptable methods. The apparatus used for mixing was a LabMaster mixer, with variable speed and high-shear impeller. Previous work had used nitric acid for dissolving metallic lead. Owing to the environmental concerns, it was decided to use acetic acid in the presence of oxygen. The theoretical justification for this approach is the favorable redox potential for the reaction between metallic lead, acetic acid, and gaseous oxygen

  17. Groundwater remediation project at Stockem railway station following a pollution with MIAK (Methyl Isoamyl Ketone)

    Energy Technology Data Exchange (ETDEWEB)

    Daelemans, A.; Boden, A.; Schuyteneer, L.W. de; Achter, L.H. van [Soil Service of Belgium, Leuven-Heverlee (Belgium)

    2003-07-01

    On the 20{sup th} of January 2000, a derailment accident happened near the railway station of Stockem in the vicinity of the city of Arlon. An estimated 20.000 litres of MIAK (methyl isoamyl ketone or 5-methyl-2-hexanone) was spilled and lost into the soil. Immediately after the accident, the Soil Service of Belgium received a request from the Belgian National Railway Company to establish an emergency plan for the remediation of the spill, including the design and the follow-up of the clean up operations. The calamity happened to the West of the railway station at a height of 360 m above sea level and in the vicinity of the Semois river (200 m to the South). From a geological point of view, the Formation of Florenville is outcropping at the site. This formation is characterized by an alternation of sandy sediments and sandstone layers. Locally the rock layer are porous allowing vertical migration of the water. The formation is an important but vulnerable aquifer. Further to the South, water is extracted from the aquifer in large quantities for both public distribution and bottling purposes. The spilled product, 5-methyl-2-hexanone (MIAK), has a typical fruity odour and its density is slightly lower than water. The product is relative mobile and fairly easy degraded biologically in low concentrations. (orig.)

  18. Aquifer overexploitation: what does it mean?

    Science.gov (United States)

    Custodio, Emilio

    2002-02-01

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

  19. Simple method for quick estimation of aquifer hydrogeological parameters

    Science.gov (United States)

    Ma, C.; Li, Y. Y.

    2017-08-01

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

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

    Science.gov (United States)

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

    2018-03-01

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

  1. Integrated enhanced bioremediation and vacuum extraction for remediation of a hydrocarbon release in response to oscillating hydrologic conditions 'Traverse Co-Bio-Vac'

    International Nuclear Information System (INIS)

    Korreck, W.M.; Armstrong, J.M.; Douglass, R.H.

    1992-01-01

    The use of enhanced in-situ biological treatment and vacuum extraction has been demonstrated to be successful in the remediation of ground water and soil contaminated with hydrocarbons. Seasonal fluctuations in the ground water causes the zone of contamination to be in the either saturated or unsaturated zone of the aquifer. In order to address these conditions, an integrated engineering design approach is being taken for the full scale remediation of an aviation of an aviation gasoline spill at the US Coast Guard Air Station at Traverse City, Township, Michigan. Enhanced aerobic biodegradation will be utilized during the periods of high water table whereby most of the contaminated interval is saturated. Carbon treated water will be utilized from the existing ground water plume. Oxygen will be injected via an oxygen generator to saturate the process stream prior to discharge to the aquifer. During low water table conditions, the same infrastructure will be utilized as a modified vacuum extraction system. The same injection wells used during the high water table would then be used during the low table condition as vapor extraction wells. The vapors will be routed to an above-ground catalytic incinerator for compound destruction. This integrated approach, entitled 'Traverse Co-Bio-Vac,' should reduce the capital costs of installing a full scale remedial system as well allowing the system to operate efficiently depending on water table conditions. The system is expected to be constructed in 1992

  2. The Aftermath of Remedial Math: Investigating the Low Rate of Certificate Completion among Remedial Math Students

    Science.gov (United States)

    Bahr, Peter Riley

    2013-01-01

    Nationally, a majority of community college students require remedial assistance with mathematics, but comparatively few students who begin the remedial math sequence ultimately complete it and achieve college-level math competency. The academic outcomes of students who begin the sequence but do not complete it are disproportionately unfavorable:…

  3. Remedial action and waste disposal project: 100-DR-1 remedial action readiness evaluation plan

    International Nuclear Information System (INIS)

    April, J.G.; Bryant, D.L.; Calverley, C.

    1996-08-01

    This plan presents the method used to assess the readiness of the 100- DR-1 Remedial Action Project. Remediation of the 100-D sites (located on the Hanford Site) involves the excavation (treatment if applicable) and final disposal of contaminated soil and debris associated with the high-priority waste sites in the 100 Areas

  4. 200-UP-1 groundwater remedial design/remedial action work plan. Revision 1

    International Nuclear Information System (INIS)

    1997-07-01

    This 200-UP-1 remedial design report presents the objective and rationale developed for the design and implementation of the selected interim remedial measure for the 200-UP-1 Operable Unit, located in the 200 West Area of the Hanford Site

  5. Provincial labour market study : mould remediation industry

    International Nuclear Information System (INIS)

    2003-06-01

    Indoor exposure to mold can be problematic to human health, and some molds are considered to be toxigenic. The emergent mold remediation industry in Ontario is fragmented, with various different standards, training and certification processes. This report investigated the labour market for mold remediation workers, with particular reference to training needs and priorities. Research was derived from a literature review in order to analyze the economic, legal, technical and social context of the mold remediation industry. Data on the organized work force were obtained from records of the International Union of Painters and Allied Trades, the Labour Force Historical Review 2002, and various publications. Population data from the Ontario government and Statistics Canada were also used. Surveys of workers and employers were conducted with questionnaires. Results of the surveys indicated that mold remediation projects currently constitute a minority share of most companies' business. However, the importance of mold remediation projects is expected to increase, and industry self-regulation is the most likely scenario for the development of standards and related training programs. It was suggested that the creation of an industry body representing key stakeholder constituencies or the legitimization of an existing industry organization will reduce fragmentation and facilitate research, standard setting and certification, as well as improve marketing and education. If the demand for mold remediation services increases as anticipated, the industry will face the challenge of remaining competitive in the province's projected labour market due to shortages in personnel. There was a strong consensus between employers and workers in the mold remediation industry regarding the need for skills upgrading and compulsory certification. It was concluded that leadership is needed in the development and delivery of training programs, standard setting, recruitment and retention and

  6. Technologies for remediating radioactively contaminated land

    International Nuclear Information System (INIS)

    Pearl, M.

    2000-01-01

    This paper gives an overview of technologies that can be used for the remediation of radioactively contaminated ground. There are a wide variety of techniques available -most have established track records for contaminated ground, though in general many are only just being adapted to use for radioactively contaminated ground. 1) Remediation techniques for radioactively contaminated ground involve either removal of the contamination and transfer to a controlled/contained facility such as the national LLW repository at Drigg, or 2) immobilization, solidification and stabilization of the contamination where the physical nature of the soil is changed, or an 'agent' is added to the soil, to reduce the migration of the contaminants, or 3) isolation and containment of the contaminated ground to reduce contaminant migration and control potential detrimental effects to human health. Where contamination has to be removed, ex situ and in situ techniques are available which minimize the waste requiring disposal to an LLW repository. These techniques include: 1) detector-based segregation 2) soil washing by particle separations 3) oil washing with chemical leaching agents 4) electro remediation 5) phyto remediation. Although many technologies are potentially applicable, their application to the remediation of a specific contaminated site is dependent on a number of factors and related to detailed site characterization studies, results from development trials and BPEO (best practicable environmental option) studies. Those factors considered of particular importance are: 1) the clean-up target 2) technical feasibility relative to the particular site, soil and contaminant characteristics, and time frame 3) site infrastructure arrangements and needs, the working life of the site and the duration of institutional care 4) long-term monitoring arrangements for slow remedial techniques or for immobilization and containment techniques 5) validation of the remediation 6) health and

  7. In Situ Remediation Integrated Program: Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed.

  8. In Situ Remediation Integrated Program: Technology summary

    International Nuclear Information System (INIS)

    1994-02-01

    The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed

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

    Science.gov (United States)

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

    1999-01-01

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

  10. Geomorphic Controls on Aquifer Geometry in Northwestern India

    Science.gov (United States)

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

    2014-12-01

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

  11. Modeling of CO2 storage in aquifers

    International Nuclear Information System (INIS)

    Savioli, Gabriela B; Santos, Juan E

    2011-01-01

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

  12. 14C measurements in aquifers with methane

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  13. Superfund Record of Decision (EPA Region 5): Ossineke Groundwater Contamination Site, Alpena County, Ossineke, MI. (First remedial action), June 1991. Final report

    International Nuclear Information System (INIS)

    1991-01-01

    The Ossineke Ground Water Contamination site is an area overlying a contaminated aquifer in Ossineke, Alpena County, Michigan. The site hydrogeology is characterized by an upper aquifer and lower confined aquifer, both of which supply drinking water to local residents. Historically there have been two contaminant source areas of concern within Ossineke. Area 1 is in the center of the Town of Ossineke where two gas stations are located, consisting of underground storage tanks, and a former automobile rustproofing shop. Area 2 is a laundry and dry cleaning facility that has an associated wash water pond containing chlorinated hydrocarbons and VOCs. The State advised all users of the upper aquifer to stop using their wells. In 1982, the State discovered that a snow plow had hit a gasoline pump causing an unknown amount of gasoline to spill and, subsequently, contaminate the basements of several businesses. In 1986, the State replaced residential wells affected by ground water contamination. Because the contaminants of concern have been confirmed to be related to petroleum releases from underground storage tanks, the Superfund program does not have the authority to address cleanup under CERLCLA. The selected remedial action for the site is that no further action

  14. Remedial Action Programs annual meeting: Proceedings

    International Nuclear Information System (INIS)

    1988-01-01

    Within the DOE's Office of Nuclear Energy, the Office of Remedial Action and Waste Technology manages a number of programs whose purposes are to complete remedial actions at DOE facilities and sites located throughout the United States. These programs include the Surplus Facilities Management Program, the Formerly Utilized Sites Remedial Action Program, the Uranium Mill Tailings remedial Action Program and the West Valley Demonstration Project. The programs involve the decontamination and decommissioning of radioactively-contaminated structures and equipment, the disposal of uranium mill tailings, and the cleanup or restoration of soils and ground water that have been contaminated with radioactive hazardous substances. Each year the DOE and DOE-contractor staff who conduct these programs meet to exchange information and experience in common technical areas. This year's meeting was hosted by the Surplus Facilities Management Program and was held near DOE Headquarters, in Gaithersburg, Maryland. This volume of proceedings provides the record for the meeting. The proceedings consist of abstracts for each presentation made at the meeting, and the visual aids (if any) used by the speakers. The material is organized in the following pages according to the five different sessions at the meeting: Session 1: Environmental Compliance--Policy; Session 2: Environmental Compliance--Practice; Session 3: Reports from working groups; Session 4: DandD Technology; and Session 5: Remedial Action Technology. The agenda for the meeting and the list of meeting registrants are provided in Appendix A and B, respectively. Individual papers are processed separately for the data base

  15. ICDF Complex Remedial Action Work Plan

    Energy Technology Data Exchange (ETDEWEB)

    W. M. Heileson

    2006-12-01

    This Remedial Action Work Plan provides the framework for operation of the Idaho Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Disposal Facility Complex (ICDF). This facility includes (a) an engineered landfill that meets the substantial requirements of DOE Order 435.1, Resource Conservation and Recovery Act Subtitle C, Idaho Hazardous Waste Management Act, and Toxic Substances Control Act polychlorinated biphenyl landfill requirements; (b) centralized receiving, inspections, administration, storage/staging, and treatment facilities necessary for CERCLA investigation-derived, remedial, and removal waste at the Idaho National Laboratory (INL) prior to final disposition in the disposal facility or shipment off-Site; and (c) an evaporation pond that has been designated as a corrective action management unit. The ICDF Complex, including a buffer zone, will cover approximately 40 acres, with a landfill disposal capacity of approximately 510,000 yd3. The ICDF Complex is designed and authorized to accept INL CERCLA-generated wastes, and includes the necessary subsystems and support facilities to provide a complete waste management system. This Remedial Action Work Plan presents the operational approach and requirements for the various components that are part of the ICDF Complex. Summaries of the remedial action work elements are presented herein, with supporting information and documents provided as appendixes to this work plan that contain specific detail about the operation of the ICDF Complex. This document presents the planned operational process based upon an evaluation of the remedial action requirements set forth in the Operable Unit 3-13 Final Record of Decision.

  16. Lead contamination of paint remediation workers' vehicles.

    Science.gov (United States)

    Boraiko, Carol; Wright, Eva M; Ralston, Faye

    2013-03-01

    Exposure to lead has been shown to be harmful to adults; it is a teratogen, it can damage the peripheral nervous system, and it adversely affects the reproductive system. Professional lead-based paint remediation workers are at risk of exposure to lead dust. The authors' study was conducted to determine if these remediation workers transfer lead from their work site to their vehicles and then potentially expose their families. It was hypothesized that remediation workers transported the lead from the remediation work site to the floorboards of their vehicles due to not following required protective equipment use. The laboratory's level of quantitation for lead on the wipe samples, 10 microg/ft2, was used to indicate lead contamination. This level was exceeded in 50% of the floorboards sampled. These results confirm that many vehicle floorboards used by remediation workers are contaminated with lead dust, potentially resulting in transfer of lead dust. The ultimate detrimental outcome could be the transfer of lead particles to other family members, causing the poisoning of a child or other at-risk person.

  17. Thermal remediation alters soil properties - a review.

    Science.gov (United States)

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Khan, Eakalak; Wick, Abbey F

    2018-01-15

    Contaminated soils pose a risk to human and ecological health, and thermal remediation is an efficient and reliable way to reduce soil contaminant concentration in a range of situations. A primary benefit of thermal treatment is the speed at which remediation can occur, allowing the return of treated soils to a desired land use as quickly as possible. However, this treatment also alters many soil properties that affect the capacity of the soil to function. While extensive research addresses contaminant reduction, the range and magnitude of effects to soil properties have not been explored. Understanding the effects of thermal remediation on soil properties is vital to successful reclamation, as drastic effects may preclude certain post-treatment land uses. This review highlights thermal remediation studies that have quantified alterations to soil properties, and it supplements that information with laboratory heating studies to further elucidate the effects of thermal treatment of soil. Notably, both heating temperature and heating time affect i) soil organic matter; ii) soil texture and mineralogy; iii) soil pH; iv) plant available nutrients and heavy metals; v) soil biological communities; and iv) the ability of the soil to sustain vegetation. Broadly, increasing either temperature or time results in greater contaminant reduction efficiency, but it also causes more severe impacts to soil characteristics. Thus, project managers must balance the need for contaminant reduction with the deterioration of soil function for each specific remediation project. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Position paper on the applicability of supplemental standards to the uppermost aquifer at the Uranium Mill Tailings Vitro Processing Site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1996-03-01

    This report documents the results of the evaluation of the potential applicability of supplemental standards to the uppermost aquifer underlying the Uranium Mill Tailings Remedial Action (UMTRA) Project, Vitro Processing Site, Salt Lake City, Utah. There are two goals for this evaluation: provide the landowner with information to make an early qualitative decision on the possible use of the Vitro property, and evaluate the proposed application of supplemental standards as the ground water compliance strategy at the site. Justification of supplemental standards is based on the contention that the uppermost aquifer is of limited use due to wide-spread ambient contamination not related to the previous site processing activities. In support of the above, this report discusses the site conceptual model for the uppermost aquifer and related hydrogeological systems and establishes regional and local background water quality. This information is used to determine the extent of site-related and ambient contamination. A risk-based evaluation of the contaminants' effects on current and projected land uses is also provided. Reports of regional and local studies and U.S. Department of Energy (DOE) site investigations provided the basis for the conceptual model and established background ground water quality. In addition, a limited field effort (4 through 28 March 1996) was conducted to supplement existing data, particularly addressing the extent of contamination in the northwestern portion of the Vitro site and site background ground water quality. Results of the field investigation were particularly useful in refining the conceptual site model. This was important in light of the varied ground water quality within the uppermost aquifer. Finally, this report provides a critical evaluation, along with the related uncertainties, of the applicability of supplemental standards to the uppermost aquifer at the Salt Lake City Vitro processing site

  19. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Attachment 4, Water resources protection strategy

    International Nuclear Information System (INIS)

    1991-12-01

    To achieve compliance with the proposed US Environmental Protection Agency (EPA) groundwater protection standards (Subpart A of 40 CFR 192), the US Department of Energy (DOE) proposes to meet background concentrations or the EPA maximum concentration limits (MCLS) for hazardous constituents in groundwater in the uppermost aquifer (Cliff House/Menefee aquifer) at the point of compliance (POC) at the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site in Bodo Canyon near Durango, Colorado (DOE, 1989). Details of hydrologic site characterization at the disposal site are provided in Attachment 3, Groundwater Hydrology Report. The principal features of the water resources protection strategy for the Bodo Canyon disposal site are presented in this document

  20. Setting a benchmark in remediation

    International Nuclear Information System (INIS)

    Ong, Jacqueline

    2014-01-01

    Full text: Thiess Services has achieved a first in the treatment of contaminated soil, in the process assisting Orica in successfully removing a toxic legacy. In 1980, when Orica Australia's predecessor ICI Australia constructed its car park waste encapsulation (CPWE) to seal off contaminated soil at Botany Industrial Park, 12km south of the Sydney CBD, treatment methods were not available. Fast-forward more than 30 years and Thiess Services has successfully undertaken treatment of the soil, earning it the 2013 CARE award. The contaminated soil contained hexachlorobutadiene (HCBD), low levels of hexachlorobenzene and hexachloroethane, all by-products of historical manufacturing of chlorinated solvents, including dry cleaning fluid, in the 1960s and 1970s. ICI Australia decided initially to store the contaminated material in drums and place it on a bed of boiler ash. However, drum corrosion led to contamination of the ash bed and underlying soil, so the company decided to encapsulate the material within a synthetic Hypalon liner, covering it with clean soil and capping it with bitumen in a 45,000 cubic metre cell. In 2005, Orica commissioned Thiess to assess a range of remediation methods and technologies to treat the material. Three options were recommended — directly heated thermal desorption, in situ thermal desorption and indirectly heated thermal desorption. “Together with Orica, we decided that directly heated thermal desorption was the appropriate technology to use,” Thiess project manager Joshua Van Der Heiden said. “Essentially, the soil is introduced into a rotary kiln and a flame directly heats up the soil above the contaminants' boiling point (up to a maximum of 450C) so that the contaminants are volatilised and the soil comes out clean. The gas separated from the soil is then heated to around 1000C in a thermal oxidiser, converting it into carbon dioxide and water. To prevent contaminants from reforming, the gas stream is rapidly cooled by a

  1. Pumping Test Determination of Unsaturated Aquifer Properties

    Science.gov (United States)

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

    2008-12-01

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

  2. Conduit enlargement in an eogenetic karst aquifer

    Science.gov (United States)

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

    2010-11-01

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

  3. Technology development activities supporting tank waste remediation

    International Nuclear Information System (INIS)

    Bonner, W.F.; Beeman, G.H.

    1994-06-01

    This document summarizes work being conducted under the U.S. Department of Energy's Office of Technology Development (EM-50) in support of the Tank Waste Remediation System (TWRS) Program. The specific work activities are organized by the following categories: safety, characterization, retrieval, barriers, pretreatment, low-level waste, and high-level waste. In most cases, the activities presented here were identified as supporting tank remediation by EM-50 integrated program or integrated demonstration lead staff and the selections were further refined by contractor staff. Data sheets were prepared from DOE-HQ guidance to the field issued in September 1993. Activities were included if a significant portion of the work described provides technology potentially needed by TWRS; consequently, not all parts of each description necessarily support tank remediation

  4. Remediation of Soil at Nuclear Sites

    International Nuclear Information System (INIS)

    Holmes, R.; Boardman, C.; Robbins, R; Fox, Robert Vincent; Mincher, Bruce Jay

    2000-01-01

    As the major nuclear waste and decontamination and decommissioning projects progress, one of the remaining problems that faces the nuclear industry is that of site remediation. The range of contamination levels and contaminants is wide and varied and there is likely to be a significant volume of soil contaminated with transuranics and hazardous organic materials that could qualify as mixed TRU waste. There are many technologies that offer the potential for remediating this waste but few that tackle all or most of the contaminants and even fewer that have been deployed with confidence. This paper outlines the progress made in proving the ability of Supercritical Fluid Extraction as a method of remediating soil, classified as mixed (TRU) transuranic waste

  5. Uranium mill tailings remedial action technology

    International Nuclear Information System (INIS)

    Hartley, J.N.; Gee, G.W.

    1984-01-01

    The uranium milling process involves the hydrometallurgical extraction of uranium from ores and the resultant generation of large quantities of waste referred to as tailings. Uranium mill tailings have been identified as requiring remediation because they contain residual radioactive material that is not removed in the milling process. Potential radiation exposure can result from direct contact with the tailings, from radon gas emitted by the tailings, and from radioactive contamination of groundwater. As a result, the technology developed under the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) and the US Nuclear Regulatory Commission (NRC) Uranium Recovery Program have focused on radon control, groundwater contamination and the long-term protection of the containment system. This paper briefly summarizes the UMTRAP and NRC remedial action technology development. 33 references, 9 figures, 5 tables

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

    Science.gov (United States)

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

    2013-01-02

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

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

    Science.gov (United States)

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

    2017-09-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

    Osman, Yassin Z.; Bruen, Michael P.

    2002-07-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

  11. Remedial action planning for Trench 1

    International Nuclear Information System (INIS)

    Primrose, A.; Sproles, W.; Burmeister, M.; Wagner, R.; Law, J.; Greengard, T.; Castaneda, N.

    1998-01-01

    The accelerated action to remove the depleted uranium chips and associated soils and wastes from Trench 1 at the Rocky Flats Environmental Technology Site (RFETS) will begin in June 1998. To ensure that the remedial action is conducted safely, a rigorous and disciplined planning process was followed that incorporates the principles of Integrated Safety Management and Enhanced Work Planning. Critical to the success of the planning was early involvement of project staff (salaried and hourly) and associated technical support groups and disciplines. Feedback was and will continue to be solicited, and lessons learned incorporated to ensure the safe remediation of this site

  12. Pulse current enhanced electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian R.; Ottosen, Lisbeth M.; Jensen, Pernille E.

    2012-01-01

    Energy consumption is an important factor influencing the cost of electrodialytic soil remediation (EDR). It has been indicated that the pulse current (in low frequency range) could decrease the energy consumption during EDR. This work is focused on the comparison of energy saving effect at diffe......Energy consumption is an important factor influencing the cost of electrodialytic soil remediation (EDR). It has been indicated that the pulse current (in low frequency range) could decrease the energy consumption during EDR. This work is focused on the comparison of energy saving effect...

  13. A stratigraphic model to support remediation of groundwater contamination in the southern San Francisco Bay area

    International Nuclear Information System (INIS)

    Steinpress, M.G.

    1993-01-01

    Some early regional studies in the southern San Francisco Bay Area applied the term 'older bay mud' to Wisconsin and older deposits thought to be estuarine in origin. This outdated interpretation has apparently contributed to an expectation of laterally-continuous aquifers and aquitards. In fact, heterogeneous alluvial deposits often create complex hydrogeologic settings that defy simple remedial approaches. A more useful stratigraphic model provides a foundation for conducting site investigations and assessing the feasibility of remediation. A synthesis of recent regional studies and drilling results at one site on the southwest margin of the Bay indicate that the upper quaternary stratigraphy consists of four primary units in the upper 200 feet of sediments (oldest to youngest): (1) Illinoian glacial-age alluvium (an important groundwater source); (2) Sangamon interglacial-age deposits, which include fine-grained alluvial deposits and estuarine deposits equivalent to the Yerba Buena Mud (a regional confining layer); (3) Wisconsin glacial-age alluvial fan and floodplain deposits; and (4) Holocene interglacial-age sediments, which include fine-grained alluvial and estuarine deposits equivalent to the 'younger bay mud'. Remedial investigations generally focus on groundwater contamination in the Wisconsin and Holocene alluvial deposits. Detailed drilling results indicate that narrow sand and gravel channels occur in anastomosing patterns within a Wisconsin to Holocene floodplain sequence dominated by interchannel silts and clays. The identification of these small-scale high-permeability conduits is critical to understanding and predicting contaminant transport on a local scale. Discontinuous site-specific aquitards do not provide competent separation where stacked channels occur and the correlation of aquitards over even small distance is often tenuous at best

  14. The use of in-situ dual vacuum extraction for remediation of soil and groundwater

    International Nuclear Information System (INIS)

    Trowbridge, B.E.; Ott, D.E.

    1992-01-01

    Dual Extraction provides a rapid and cost-effective method of remediating soil and groundwater impacted by volatile organic compounds (VOC's). Dual Extraction is the removal of both water and vapors through the same borehole using entrainment. This technology provides for the remediation of the vadose zone, capillary fringe, smear zone, and existing water table. The effectiveness of this technology is shown in a case study. A release from an Underground Storage Tank (UST) was responsible for a hydrocarbon plume spreading over approximately 50,000 square feet. The release produced vadose zone contamination in the silty and sandy clays from 10 - 30 feet below ground surface with TPH concentrations up to 1,400 mg/kg. A layer of free floating liquid hydrocarbon was present on a shallow aquifer located at 30 feet bgs in thicknesses ranging from 0.5 feet to 3.0 feet. An in-situ dual-extraction system was installed to remediate the soils and groundwater to levels as required by the Los Angeles Regional Water Quality Control Board (RWQCB). The system operated 24 hours/day for 196 days with an operating efficiency of over 99%. After 196 days, over 17,000 pounds of hydrocarbons had been extracted from the soils. Seven confirmatory soil borings were advanced in the area of highest initial hydrocarbon concentrations and indicated that TPH and BTEX concentrations had decreased over 99% from initial soil concentrations. Three confirmatory groundwater samples were obtained from monitoring wells initially exhibiting up to 3 feet of floating product. Confirmatory samples exhibited non-detectable (ND) concentrations of TPH and BTEX. Based upon the positive confirmatory results, site closure was obtained from the RWQCB in May of 1991. In only 28 weeks of operation, the groundwater contamination was reduced from free floating product to non-detectable concentrations of TPH using Dual Vacuum Extraction

  15. Characterization of deep aquifer dynamics using principal component analysis of sequential multilevel data

    Directory of Open Access Journals (Sweden)

    D. Kurtzman

    2012-03-01

    Full Text Available Two sequential multilevel profiles were obtained in an observation well opened to a 130-m thick, unconfined, contaminated aquifer in Tel Aviv, Israel. While the general profile characteristics of major ions, trace elements, and volatile organic compounds were maintained in the two sampling campaigns conducted 295 days apart, the vertical locations of high concentration gradients were shifted between the two profiles. Principal component analysis (PCA of the chemical variables resulted in a first principal component which was responsible for ∼60% of the variability, and was highly correlated with depth. PCA revealed three distinct depth-dependent water bodies in both multilevel profiles, which were found to have shifted vertically between the sampling events. This shift cut across a clayey bed which separated the top and intermediate water bodies in the first profile, and was located entirely within the intermediate water body in the second profile. Continuous electrical conductivity monitoring in a packed-off section of the observation well revealed an event in which a distinct water body flowed through the monitored section (v ∼ 150 m yr−1. It was concluded that the observed changes in the profiles result from dominantly lateral flow of water bodies in the aquifer rather than vertical flow. The significance of this study is twofold: (a it demonstrates the utility of sequential multilevel observations from deep wells and the efficacy of PCA for evaluating the data; (b the fact that distinct water bodies of 10 to 100 m vertical and horizontal dimensions flow under contaminated sites, which has implications for monitoring and remediation.

  16. Hydrologic time and sustainability of shallow aquifers

    Science.gov (United States)

    Back, William; ,

    1994-01-01

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

  17. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

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

    1991-01-01

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

  18. Optimal Aquifer Pumping Policy to Reduce Contaminant Concentration

    Directory of Open Access Journals (Sweden)

    Ali Abaei

    2012-01-01

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

  19. Contaminant transport in the Snake River Plain Aquifer: Phase 1, Part 1: Simple analytical model of individual plumes

    International Nuclear Information System (INIS)

    Rood, A.S.; Arnett, R.C.; Barraclough, J.T.

    1989-05-01

    A preliminary, semi-quantitative assessment of the migration of INEL effluents in the Snake River Plain Aquifer (SRPA) was performed. This study focused on past tritium, 129 I, and 90 Sr effluents from the Idaho Chemical Processing Plant (ICPP) and Test Reactor Area (TRA) and carbon tetrachloride from the Radioactive Waste Management Complex (RWMC). The disposal ponds at TRA and the ICPP injection well were the primary means of liquid radioactive waste discharge from the ICPP and TRA. Drums containing solidified chlorinated solvents disposed of at the RWMC were the primary source of carbon tetrachloride. Water samples taken from wells located in the SRPA show detectable quantities of the four contaminants. The predicted radionuclide concentrations exceed drinking water limits in limited areas within the INEL boundaries. Without planned remedial action, carbon tetrachloride is predicted to exceed drinking water limits beyond the site boundaries near the middle of the next century. 16 refs., 23 figs., 3 tabs

  20. Strategy paper. Remedial design/remedial action 100 Area. Revision 2

    International Nuclear Information System (INIS)

    Donahoe, R.L.

    1995-10-01

    This strategy paper identifies and defines the approach for remedial design and remedial action (RD/RA) for source waste sites in the 100 Area of the Hanford Site, located in southeastern Washington State. This paper provides the basis for the US Department of Energy (DOE) to assess and approve the Environmental Restoration Contractor's (ERC) approach to RD/RA. Additionally, DOE is requesting review/agreement from the US Environmental Protection Agency (EPA) and Washington State Department of Ecology (Ecology) on the strategy presented in this document in order to expedite remedial activities

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

    Directory of Open Access Journals (Sweden)

    Yong Li

    2016-10-01

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

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

    International Nuclear Information System (INIS)

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

    1974-01-01

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

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

    Science.gov (United States)

    Gonthier, Gerard; Clarke, John S.

    2016-06-02

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

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

    OpenAIRE

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

    2014-01-01

    Karst aquifers occur in a range of climatic and geologic settings. Nonetheless, they are commonly characterized by their vulnerability to water-quality impairment. Two karst aquifers, the Edwards aquifer in south-central Texas and the Upper Floridan aquifer in western Florida, were investigated to assess factors that control the movement of contaminants to public-supply wells (PSWs). The geochemistry of samples from a selected PSW or wellfield in each aquifer was compared with that from nearb...

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

    Science.gov (United States)

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

    2017-12-01

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

  6. Remediation Using Plants and Plant Enzymes: A Progress Report

    National Research Council Canada - National Science Library

    1995-01-01

    .... In every case, the sources are plants growing near the sediment. The use of plants for remediation of hazardous materials such as TNT or other munitions like RDX and HMX has led to a new approach to remediation-- phytoremediation...

  7. Enhanced remediation of an oily sludge with saline water ...

    African Journals Online (AJOL)

    Enhanced remediation of an oily sludge with saline water. ... the remediation of an oily sludge, which was part of the waste stream from the improvement ... m3 of fresh water respectively while 'treatment' reactors C and D received ...

  8. SADA: Ecological Risk Based Decision Support System for Selective Remediation

    Science.gov (United States)

    Spatial Analysis and Decision Assistance (SADA) is freeware that implements terrestrial ecological risk assessment and yields a selective remediation design using its integral geographical information system, based on ecological and risk assessment inputs. Selective remediation ...

  9. Remediation General Permit (RGP) for Massachusetts & New Hampshire

    Science.gov (United States)

    Documents, links & contacts for the Notice of Availability of the National Pollutant Discharge Elimination System (NPDES) General Permit for Remediation Activity Discharges – the Remediation General Permit in MA (MAG910000) and NH (NHG910000).

  10. Electrochemical Remediation of Dredged Material for Beneficial Use

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Gardner, Kevin H.

    2003-01-01

    Two different methods, electrodialytic and electroosmotic remediation, were used to demonstrate the potential of electrochemical methods for remediation of contaminated harbor sediments. In two three-week-long laboratory experiments using electrodialysis and electroosmosis, respectively...

  11. The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-compound DNAPLs with surfactant solutions: Phase 1 -- Laboratory and pilot field-scale testing and Phase 2 -- Solubilization test and partitioning and interwell tracer tests. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-24

    Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). The field test was conducted in the alluvial aquifer which is located 20 to 30 meters beneath a vapor degreasing operation at Paducah Gaseous Diffusion Plant. This aquifer has become contaminated with TCE due to leakage of perhaps 40,000 liters of TCE, which has generated a plume of dissolved TCE extending throughout an area of approximately 3 km{sup 2} in the aquifer. Most of the TCE is believed to be present in the overlying lacustrine deposits and in the aquifer itself as a dense, non-aqueous phase liquid, or DNAPL. The objective of the field test was to assess the efficacy of the surfactant for in situ TCE solubilization. Although the test demonstrated that sorbitan monooleate was unsuitable as a solubilizer in this aquifer, the single-well test was demonstrated to be a viable method for the in situ testing of surfactants or cosolvents prior to proceeding to full-scale remediation.

  12. The in-situ decontamination of sand and gravel aquifers by chemically enhanced solubilization of multiple-compound DNAPLs with surfactant solutions. Phase 1: Laboratory and pilot field-scale testing. Phase 2: Solubilization test and partitioning interwell tracer tests. Final report

    International Nuclear Information System (INIS)

    1997-01-01

    Laboratory, numerical simulation, and field studies have been conducted to assess the potential use of micellar-surfactant solutions to solubilize chlorinated solvents contaminating sand and gravel aquifers. Ninety-nine surfactants were screened for their ability to solubilize trichloroethene (TCE), perchloroethylene (PCE), and carbon tetrachloride (CTET). The field test was conducted in the alluvial aquifer which is located 20 to 30 meters beneath a vapor degreasing operation at Paducah Gaseous Diffusion Plant. This aquifer has become contaminated with TCE due to leakage of perhaps 40,000 liters of TCE, which has generated a plume of dissolved TCE extending throughout an area of approximately 3 km 2 in the aquifer. Most of the TCE is believed to be present in the overlying lacustrine deposits and in the aquifer itself as a dense, non-aqueous phase liquid, or DNAPL. The objective of the field test was to assess the efficacy of the surfactant for in situ TCE solubilization. Although the test demonstrated that sorbitan monooleate was unsuitable as a solubilizer in this aquifer, the single-well test was demonstrated to be a viable method for the in situ testing of surfactants or cosolvents prior to proceeding to full-scale remediation

  13. Functional remediation components: A conceptual method of evaluating the effects of remediation on risks to ecological receptors.

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Bunn, Amoret; Downs, Janelle; Jeitner, Christian; Pittfield, Taryn; Salisbury, Jennifer

    2016-01-01

    Governmental agencies, regulators, health professionals, tribal leaders, and the public are faced with understanding and evaluating the effects of cleanup activities on species, populations, and ecosystems. While engineers and managers understand the processes involved in different remediation types such as capping, pump and treat, and natural attenuation, there is often a disconnect between (1) how ecologists view the influence of different types of remediation, (2) how the public perceives them, and (3) how engineers understand them. The overall goal of the present investigation was to define the components of remediation types (= functional remediation). Objectives were to (1) define and describe functional components of remediation, regardless of the remediation type, (2) provide examples of each functional remediation component, and (3) explore potential effects of functional remediation components in the post-cleanup phase that may involve continued monitoring and assessment. Functional remediation components include types, numbers, and intensity of people, trucks, heavy equipment, pipes, and drill holes, among others. Several components may be involved in each remediation type, and each results in ecological effects, ranging from trampling of plants, to spreading invasive species, to disturbing rare species, and to creating fragmented habitats. In some cases remediation may exert a greater effect on ecological receptors than leaving the limited contamination in place. A goal of this conceptualization is to break down functional components of remediation such that managers, regulators, and the public might assess the effects of timing, extent, and duration of different remediation options on ecological systems.

  14. Petroleum hydrocarbon contaminated sites: a review of investigation and remediation regulations and processes

    Energy Technology Data Exchange (ETDEWEB)

    Epelbaum, Michel; Claudio, Jair R. [Bureau Veritas do Brasil Sociedade Classificadora e Certificadora Ltda., Sao Paulo, SP (Brazil)

    1993-12-31

    This paper discusses alternatives on remediation of petroleum hydrocarbon contaminated sites which include groundwater remediation techniques and soil remediation techniques. Finally, the work points out some trends of sites remediation in Brazil and abroad. 6 refs., 1 fig., 7 tabs.

  15. Petroleum hydrocarbon contaminated sites: a review of investigation and remediation regulations and processes

    Energy Technology Data Exchange (ETDEWEB)

    Epelbaum, Michel; Claudio, Jair R [Bureau Veritas do Brasil Sociedade Classificadora e Certificadora Ltda., Sao Paulo, SP (Brazil)

    1994-12-31

    This paper discusses alternatives on remediation of petroleum hydrocarbon contaminated sites which include groundwater remediation techniques and soil remediation techniques. Finally, the work points out some trends of sites remediation in Brazil and abroad. 6 refs., 1 fig., 7 tabs.

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

    Data.gov (United States)

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

  17. Electrodialytic Remediation of Different Cu-Polluted Soils

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Hansen, Henrik K.; Hansen, Lene

    1999-01-01

    Based on characterization of a polluted soil a proper desorbing agent to be added to the soil before the remediation can be found. The desorbing agent can improve the remediation according to both energy consumption and duration of the action......Based on characterization of a polluted soil a proper desorbing agent to be added to the soil before the remediation can be found. The desorbing agent can improve the remediation according to both energy consumption and duration of the action...

  18. Bioventing feasibility test to aid remediation strategy

    CSIR Research Space (South Africa)

    Pearce, K

    1998-01-01

    Full Text Available A case study is presented where the feasibility of bioventing was assessed for the remediation of a petroleum-contaminated site. This was achieved through the determination of the radius of influence of a single vent well, the soil gas permeability...

  19. Adaptive remediation using portable treatment units

    International Nuclear Information System (INIS)

    Bahowick, S.; Folsom, E.; Pico, T.

    1996-01-01

    Lawrence Livermore National Laboratory (LLNL) is using adaptive remediation to optimize their environmental restoration strategy. Adaptive remediation uses hydrostratigraphic analysis to gain a better understanding of the subsurface characteristics, hydraulic tests to optimize contaminant transport models, and Portable Treatment Units (PTUs) as an alternative to fixed facilities. Hydrostratigraphic analysis is an optimization tool that improves the ability to identify and target contaminant migration pathways, identify the relationship between plumes and source areas, and better define hydraulic capture areas. Hydraulic tests, performed with PTUs, provide valuable data about subsurface characteristics. As clean up progresses, PTUs can be moved to the appropriate extraction wells to optimize contaminant mass removal. PTUs can also be placed to support innovative treatment technologies such as steam injection and microbial filters. Construction of PTUs will reduce by one-half the capital costs of building the rest of the fixed treatment system planned in the Record of Decision. Regulatory agencies are receptive to the use of the PTUs because the same treatment technology is being used and the PTUs will be able to clean up the plume cheaper and faster. Using adaptive remediation, LLNL is more effectively implementing remediation plans, improving cleanup time, and reducing project costs

  20. Electrokinetic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrián; Ottosen, Lisbeth M.

    2007-01-01

    in sulphuric acidified tailings) without bipolar electrodes to 42% when bipolar electrodes were implemented. Furthermore, the results showed that in this system sulphuric acid addition prior to remediation was better than citric acid addition. In addition, applying a too strong electric field (even...