Shallow groundwater resources and future climate change impacts: a comparison of the Ovens and Namoi catchments, Eastern Australia

Energy Technology Data Exchange (ETDEWEB)

Smith, T.J., E-mail: tjsmith@skm.com.au [Sinclair Knight Merz, Malvern, Victoria (Australia); Mudd, G.M., E-mail: gavin.mudd@monash.edu [Monash University, Clayton, Victoria (Australia). Dept. of Civil Engineering

2010-07-01

The Murray-Darling Basin (MDB) river system is a critical province and water resource for Eastern Australia. Over the past decade the MDB has been subject to a protracted and severe drought, as well undergoing major institutional, social and economic reforms. A lesser understood area of MDB water resource issues is the status of groundwater, especially with respect to trends in groundwater resources, groundwater-surface water issues and the longer term susceptibility of groundwater to climate variability and climate change. Following the cap on MDB surface water allocations in 1994, a major expansion of groundwater use was observed across many parts of the MDB, which has probably been further exacerbated by the current drought leading to lower groundwater recharge. This paper presents an overview of the current status of Murray-Darling Basin groundwater resource use and management, contrasts two case study sites in the Ovens and Namoi catchments of Victoria and New South Wales respectively, assesses the potential risks that climate variability and climate change present, and finally considers some long term solutions to ensure that the MDB continues on its transition to a more sustainable future.

Current Issues in Maritime Health

DEFF Research Database (Denmark)

Wagtmann, Maria Anne

2008-01-01

 In the early part of 2008, Maria Anne Wagtmann had the opportunity to interview the former president of the International Maritime Health Association, Dr. Tim Carter, in London about a number of current maritime health issues. In this interview, Dr. Tim Carter, who is cur­rently employed...... as the Chief Medical Advisor for the British government's Department for Transport, gives his personal - and thus non-official - opinions on these issues....

Natural radioactivity in groundwater--a review.

Science.gov (United States)

Dinh Chau, Nguyen; Dulinski, Marek; Jodlowski, Pawel; Nowak, Jakub; Rozanski, Kazimierz; Sleziak, Monika; Wachniew, Przemyslaw

2011-12-01

The issue of natural radioactivity in groundwater is reviewed, with emphasis on those radioisotopes which contribute in a significant way to the overall effective dose received by members of the public due to the intake of drinking water originating from groundwater systems. The term 'natural radioactivity' is used in this context to cover all radioactivity present in the environment, including man-made (anthropogenic) radioactivity. Comprehensive discussion of radiological aspects of the presence of natural radionuclides in groundwater, including an overview of current regulations dealing with radioactivity in drinking water, is provided. The presented data indicate that thorough assessments of the committed doses resulting from the presence of natural radioactivity in groundwater are needed, particularly when such water is envisaged for regular intake by infants. They should be based on a precise determination of radioactivity concentration levels of the whole suite of radionuclides, including characterisation of their temporal variability. Equally important is a realistic assessment of water intake values for specific age groups. Only such an evaluation may provide the basis for possible remedial actions.

Key policy choices in groundwater quality management

International Nuclear Information System (INIS)

Batie, S.S.; Diebel, P.L.

1990-01-01

The fundamental policy choice of who has the right to do what to whom is a pivotal issue of governance. Over the last few decades, the answer to that question has become more restrictive to those who own and use natural resources as inputs into production processes. Increasingly, the beneficiaries of new policy initiatives are those who desire higher protection of groundwater quality. With respect to groundwater management, policy design increasingly reflects such diverse interests as agriculturists, industrialists, homeowners, local government officials and state officials. Policy design is becoming complex, in part because of this diversity and in part because scientific uncertainty hampers informed policy design. No umbrella federal legislation exists for managing groundwater resources. EPA's role has been mainly an advisory one on groundwater issues. The difficulties and responsibilities of protecting groundwater thus remain with the states. For the near future, it is the states that will address key policy choices with respect to groundwater quality management issues

Nuclear standards: current issues and future trends

International Nuclear Information System (INIS)

Landis, J.W.

1985-01-01

A summary of the important issues that currently face the nuclear standards field is presented and a discussion of how each of these issues is being resolved is given. The economic benefits that properly developed standards produce are listed

Towards sustainable groundwater use: Setting long-term goals, backcasting, and managing adaptively

Science.gov (United States)

Gleeson, T.; Alley, W.M.; Allen, D.M.; Sophocleous, M.A.; Zhou, Y.; Taniguchi, M.; Vandersteen, J.

2012-01-01

The sustainability of crucial earth resources, such as groundwater, is a critical issue. We consider groundwater sustainability a value-driven process of intra- and intergenerational equity that balances the environment, society, and economy. Synthesizing hydrogeological science and current sustainability concepts, we emphasize three sustainability approaches: setting multigenerational sustainability goals, backcasting, and managing adaptively. As most aquifer problems are long-term problems, we propose that multigenerational goals (50 to 100 years) for water quantity and quality that acknowledge the connections between groundwater, surface water, and ecosystems be set for many aquifers. The goals should be set by a watershed- or aquifer-based community in an inclusive and participatory manner. Policies for shorter time horizons should be developed by backcasting, and measures implemented through adaptive management to achieve the long-term goals. Two case histories illustrate the importance and complexity of a multigenerational perspective and adaptive management. These approaches could transform aquifer depletion and contamination to more sustainable groundwater use, providing groundwater for current and future generations while protecting ecological integrity and resilience. ?? 2011, The Author(s). Ground Water ?? 2011, National Ground Water Association.

Ground-water travel time

International Nuclear Information System (INIS)

Bentley, H.; Grisak, G.

1985-01-01

The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Travel Time Subgroup are presented

Regional ground-water system

International Nuclear Information System (INIS)

Long, J.

1985-01-01

The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Regime Subgroup are presented

Declining groundwater level caused by irrigation to row crops in the Lower Mississippi River Basin, Current Situation and Trends

Science.gov (United States)

Feng, G.; Gao, F.; Ouyang, Y.

2017-12-01

The Mississippi River is North America's largest river and the second largest watershed in the world. It flows over 3,700 km through America's heartland to the Gulf of Mexico. Over 3 million hectares in the Lower Mississippi River Basin represent irrigated cropland and 90 percent of those lands currently rely on the groundwater supply. The primary crops grown in this region are soybean, corn, cotton, and rice. Increased water withdrawals for irrigating those crops and stagnant recharging jeopardize the long-term availability of the aquifer and place irrigation agriculture in the region on an unsustainable path. The objectives of this study were to: 1) analyze the current groundwater level in the Lower Mississippi River Basin based on the water table depth observed by Yazoo Mississippi Delta Joint Water Management District from 2000 and 2016; 2) determine trends of change in groundwater level under conventional and groundwater saving irrigation management practices (ET or soil moisture based full irrigation scheduling using all groundwater or different percentages of ground and surface water). The coupled SWAT and MODFLOW model was applied to investigate the trends. Observed results showed that the groundwater level has declined from 33 to 26 m at an annual decrease rate of 0.4 m in the past 17 years. Simulated results revealed that the groundwater storage was decreased by 26 cm/month due to irrigation in crop season. It is promising that the groundwater storage was increased by 23 cm/month, sometimes even 60 cm/month in crop off-growing season because of recharge from rainfall. Our results suggest that alternative ET or soil moisture based groundwater saving irrigation scheduling with conjunctive use of surface water is a sustainable practice for irrigated agriculture in in the Lower Mississippi River Basin.

Current issues in perturbative QCD

International Nuclear Information System (INIS)

Hinchliffe, I.

1994-12-01

This review talk discusses some issues of active research in perturbative QCD. The following topics are discussed: (1) current value of αs; (2) heavy quark production in hadron collisions; (3) production of Ψ and Υ in p anti p collisions; (4) prompt photon production; (5) small-x and related phenomena; and (6) particle multiplicity in heavy quark jets

Groundwater issues relating to an Alaskan methanol spill

International Nuclear Information System (INIS)

Robertson, S.B.

1992-01-01

This paper reports on a Dec. 1989 methanol spill which resulted from sabotage to three railroad tank cars. Samples taken from nearby drinking-water wells and groundwater-monitoring wells were below the analytical detection limit. Monitoring well data demonstrated that groundwater flow was not toward local residential wells. Dilution by snow and subsequent freezing in the soil limited the downward spread of the methanol, an advantage not found in milder, more temperate conditions. Contaminated material was removed and processed to reclaim the methanol. Volatilization and biodegradation should remove any remaining methanol. Cleanup options were limited by the possible hazardous waste classification of the contaminated soil. The regulatory status of spilled methanol waste should be re-evaluated, especially if use of methanol as a motor fuel increases

Current and future groundwater recharge in West Africa as estimated from a range of coupled climate model outputs

Science.gov (United States)

Verhoef, Anne; Cook, Peter; Black, Emily; Macdonald, David; Sorensen, James

2017-04-01

This research addresses the terrestrial water balance for West Africa. Emphasis is on the prediction of groundwater recharge and how this may change in the future, which has relevance to the management of surface and groundwater resources. The study was conducted as part of the BRAVE research project, "Building understanding of climate variability into planning of groundwater supplies from low storage aquifers in Africa - Second Phase", funded under the NERC/DFID/ESRC Programme, Unlocking the Potential of Groundwater for the Poor (UPGro). We used model output data of water balance components (precipitation, surface and subsurface run-off, evapotranspiration and soil moisture content) from ERA-Interim/ERA-LAND reanalysis, CMIP5, and high resolution model runs with HadGEM3 (UPSCALE; Mizielinski et al., 2014), for current and future time-periods. Water balance components varied widely between the different models; variation was particularly large for sub-surface runoff (defined as drainage from the bottom-most soil layer of each model). In-situ data for groundwater recharge obtained from the peer-reviewed literature were compared with the model outputs. Separate off-line model sensitivity studies with key land surface models were performed to gain understanding of the reasons behind the model differences. These analyses were centered on vegetation, and soil hydraulic parameters. The modelled current and future recharge time series that had the greatest degree of confidence were used to examine the spatiotemporal variability in groundwater storage. Finally, the implications for water supply planning were assessed. Mizielinski, M.S. et al., 2014. High-resolution global climate modelling: the UPSCALE project, a large-simulation campaign. Geoscientific Model Development, 7(4), pp.1629-1640.

Current uses of ground penetrating radar in groundwater-dependent ecosystems research.

Science.gov (United States)

Paz, Catarina; Alcalá, Francisco J; Carvalho, Jorge M; Ribeiro, Luís

2017-10-01

Ground penetrating radar (GPR) is a high-resolution technique widely used in shallow groundwater prospecting. This makes GPR ideal to characterize the hydrogeological functioning of groundwater-dependent ecosystems (GDE). This paper reviews current uses of GPR in GDE research through the construction of a database comprising 91 worldwide GPR case studies selected from the literature and classified according to (1) geological environments favouring GDE; (2) hydrogeological research interests; and (3) field technical and (4) hydrogeological conditions of the survey. The database analysis showed that inland alluvial, colluvial, and glacial formations were the most widely covered geological environments. Water-table depth was the most repeated research interest. By contrast, weathered-marl and crystalline-rock environments as well as the delineation of salinity interfaces in coastal and inland areas were less studied. Despite that shallow groundwater propitiated GDE in almost all the GPR case studies compiled, only one case expressly addressed GDE research. Common ranges of prospecting depth, water-table depth, and volumetric water content deduced by GPR and other techniques were identified. Antenna frequency of 100MHz and the common offset acquisition technique predominated in the database. Most of GPR case studies were in 30-50° N temperate latitudes, mainly in Europe and North America. Eight original radargrams were selected from several GPR profiles performed in 2014 and 2015 to document database classes and identified gaps, as well as to define experimental ranges of operability in GDE environments. The results contribute to the design of proper GPR surveys in GDE research. Copyright © 2017 Elsevier B.V. All rights reserved.

Food supply reliance on groundwater

Science.gov (United States)

Dalin, Carole; Puma, Michael; Wada, Yoshihide; Kastner, Thomas

2016-04-01

Water resources, essential to sustain human life, livelihoods and ecosystems, are under increasing pressure from population growth, socio-economic development and global climate change. As the largest freshwater resource on Earth, groundwater is key for human development and food security. Yet, excessive abstraction of groundwater for irrigation, driven by an increasing demand for food in recent decades, is leading to fast exhaustion of groundwater reserves in major agricultural areas of the world. Some of the highest depletion rates are observed in Pakistan, India, California Central Valley and the North China Plain aquifers. In addition, the growing economy and population of several countries, such as India and China, makes prospects of future available water and food worrisome. In this context, it is becoming particularly challenging to sustainably feed the world population, without exhausting our water resources. Besides, food production and consumption across the globe have become increasingly interconnected, with many areas' agricultural production destined to remote consumers. In this globalisation era, trade is crucial to the world's food system. As a transfer of water-intensive goods, across regions with varying levels of water productivity, food trade can save significant volumes of water resources globally. This situation makes it essential to address the issue of groundwater overuse for global food supply, accounting for international food trade. To do so, we quantify the current, global use of non-renewable groundwater for major crops, accounting for various water productivity and trade flows. This will highlight areas requiring quickest attention, exposing major exporters and importers of non-renewable groundwater, and thus help explore solutions to improve the sustainability of global food supply.

A review of global outlook on fluoride contamination in groundwater with prominence on the Pakistan current situation.

Science.gov (United States)

Rasool, Atta; Farooqi, Abida; Xiao, Tangfu; Ali, Waqar; Noor, Sifat; Abiola, Oyebamiji; Ali, Salar; Nasim, Wajid

2017-12-19

Several million people are exposed to fluoride (F - ) via drinking water in the world. Current review emphasized the elevated level of fluoride concentrations in the groundwater and associated potential health risk globally with a special focus on Pakistan. Millions of people are deeply dependent on groundwater from different countries of the world encompassing with an elevated level of fluoride. The latest estimates suggest that around 200 million people, from among 25 nations the world over, are under the dreadful fate of fluorosis. India and China, the two most populous countries of the world, are the worst affected. In Pakistan, fluoride data of 29 major cities are reviewed and 34% of the cities show fluoride levels with a mean value greater than 1.5 mg/L where Lahore, Quetta and Tehsil Mailsi are having the maximum values of 23.60, 24.48, > 5.5 mg/L, respectively. In recent years, however, other countries have minimized, even eliminated its use due to health issues. High concentration of fluoride for extended time period causes adverse effects of health such as skin lesions, discoloration, cardiovascular disorders, dental fluorosis and crippling skeletal fluorosis. This review deliberates comprehensive strategy of drinking water quality in the global scenario of fluoride contamination, especially in Pakistan with prominence on major pollutants, mitigation technologies, sources of pollution and ensuing health problems. Considering these verities, health authorities urgently need to establish alternative means of water decontamination in order to prevent associated health problems.

Incorporation of GRACE Data into a Bayesian Model for Groundwater Drought Monitoring

Science.gov (United States)

Slinski, K.; Hogue, T. S.; McCray, J. E.; Porter, A.

2015-12-01

Groundwater drought, defined as the sustained occurrence of below average availability of groundwater, is marked by below average water levels in aquifers and reduced flows to groundwater-fed rivers and wetlands. The impact of groundwater drought on ecosystems, agriculture, municipal water supply, and the energy sector is an increasingly important global issue. However, current drought monitors heavily rely on precipitation and vegetative stress indices to characterize the timing, duration, and severity of drought events. The paucity of in situ observations of aquifer levels is a substantial obstacle to the development of systems to monitor groundwater drought in drought-prone areas, particularly in developing countries. Observations from the NASA/German Space Agency's Gravity Recovery and Climate Experiment (GRACE) have been used to estimate changes in groundwater storage over areas with sparse point measurements. This study incorporates GRACE total water storage observations into a Bayesian framework to assess the performance of a probabilistic model for monitoring groundwater drought based on remote sensing data. Overall, it is hoped that these methods will improve global drought preparedness and risk reduction by providing information on groundwater drought necessary to manage its impacts on ecosystems, as well as on the agricultural, municipal, and energy sectors.

Quality of groundwater resources in Afghanistan.

Science.gov (United States)

Hayat, Ehsanullah; Baba, Alper

2017-07-01

Water is the main source of energy production and economy in Afghanistan where agriculture accounts for more than 50% of the country's gross domestic product (GDP). Access to safe drinking water is still a problem in the country, which has caused different health issues and even child mortality especially in rural areas. Groundwater is the main source of drinking water in the country. However, little knowledge is available about the quality of groundwater throughout the entire country, and its quality has not been investigated extensively yet like in other countries in the world. While most people think that consuming groundwater is a reliable and safe source of drinking water for health, the United Nations (UN) agencies report various kinds of waterborne diseases and even child mortalities due to drinking water quality in the country. In this article, significant geogenic and anthropogenic factors that play a vital role in groundwater contamination of the country are identified and explained. Different geogenic contaminations such as arsenic, fluoride, sulfate, and boron occur in several areas of Afghanistan that have a direct effect on human health. The water quality mapping for Afghanistan is completed for half of the country, which shows that groundwater is plagued by high levels of fluoride and arsenic in some areas. The water quality mapping of the other half of the country cannot be completed due to security concerns currently. Also, there are different kinds of waterborne diseases such as diarrhea, cholera, and dysentery that can be seen in different parts of the country because of anthropogenic activities which continuously deteriorate groundwater.

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

Science.gov (United States)

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

2015-10-01

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

Groundwater flow modelling under ice sheet conditions. Scoping calculations

International Nuclear Information System (INIS)

Jaquet, O.; Namar, R.; Jansson, P.

2010-10-01

The potential impact of long-term climate changes has to be evaluated with respect to repository performance and safety. In particular, glacial periods of advancing and retreating ice sheet and prolonged permafrost conditions are likely to occur over the repository site. The growth and decay of ice sheets and the associated distribution of permafrost will affect the groundwater flow field and its composition. As large changes may take place, the understanding of groundwater flow patterns in connection to glaciations is an important issue for the geological disposal at long term. During a glacial period, the performance of the repository could be weakened by some of the following conditions and associated processes: - Maximum pressure at repository depth (canister failure). - Maximum permafrost depth (canister failure, buffer function). - Concentration of groundwater oxygen (canister corrosion). - Groundwater salinity (buffer stability). - Glacially induced earthquakes (canister failure). Therefore, the GAP project aims at understanding key hydrogeological issues as well as answering specific questions: - Regional groundwater flow system under ice sheet conditions. - Flow and infiltration conditions at the ice sheet bed. - Penetration depth of glacial meltwater into the bedrock. - Water chemical composition at repository depth in presence of glacial effects. - Role of the taliks, located in front of the ice sheet, likely to act as potential discharge zones of deep groundwater flow. - Influence of permafrost distribution on the groundwater flow system in relation to build-up and thawing periods. - Consequences of glacially induced earthquakes on the groundwater flow system. Some answers will be provided by the field data and investigations; the integration of the information and the dynamic characterisation of the key processes will be obtained using numerical modelling. Since most of the data are not yet available, some scoping calculations are performed using the

Groundwater flow modelling under ice sheet conditions. Scoping calculations

Energy Technology Data Exchange (ETDEWEB)

Jaquet, O.; Namar, R. (In2Earth Modelling Ltd (Switzerland)); Jansson, P. (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden))

2010-10-15

The potential impact of long-term climate changes has to be evaluated with respect to repository performance and safety. In particular, glacial periods of advancing and retreating ice sheet and prolonged permafrost conditions are likely to occur over the repository site. The growth and decay of ice sheets and the associated distribution of permafrost will affect the groundwater flow field and its composition. As large changes may take place, the understanding of groundwater flow patterns in connection to glaciations is an important issue for the geological disposal at long term. During a glacial period, the performance of the repository could be weakened by some of the following conditions and associated processes: - Maximum pressure at repository depth (canister failure). - Maximum permafrost depth (canister failure, buffer function). - Concentration of groundwater oxygen (canister corrosion). - Groundwater salinity (buffer stability). - Glacially induced earthquakes (canister failure). Therefore, the GAP project aims at understanding key hydrogeological issues as well as answering specific questions: - Regional groundwater flow system under ice sheet conditions. - Flow and infiltration conditions at the ice sheet bed. - Penetration depth of glacial meltwater into the bedrock. - Water chemical composition at repository depth in presence of glacial effects. - Role of the taliks, located in front of the ice sheet, likely to act as potential discharge zones of deep groundwater flow. - Influence of permafrost distribution on the groundwater flow system in relation to build-up and thawing periods. - Consequences of glacially induced earthquakes on the groundwater flow system. Some answers will be provided by the field data and investigations; the integration of the information and the dynamic characterisation of the key processes will be obtained using numerical modelling. Since most of the data are not yet available, some scoping calculations are performed using the

Environmental Sciences Division Groundwater Program Office

International Nuclear Information System (INIS)

1993-01-01

This first edition of the Martin Marietta Energy Systems, Inc., (Energy Systems) Groundwater Program Annual Report summarizes the work carried out by the Energy Systems GWPO for fiscal year (FY) 1993. This introductory section describes the GWPO's staffing, organization, and funding sources. The GWPO is responsible for coordination and oversight for all components of the groundwater program at the three Oak Ridge facilities [ORNL, the Oak Ridge Y-12 Plant, and the Oak Ridge K-25 Site], and the PGDP and PORTS, respectively. Several years ago, Energy systems senior management recognized that the manner in which groundwater activities were conducted at the five facilities could result in unnecessary duplication of effort, inadequate technical input to decisions related to groundwater issues, and could create a perception within the regulatory agencies of a confusing and inconsistent approach to groundwater issues at the different facilities. Extensive interactions among management from Environmental Compliance, Environmental Restoration (ER), Environmental Sciences Division, Environmental Safety and Health, and the five facilities ultimately led to development of a net technical umbrella organization for groundwater. On April 25, 1991, the GWPO was authorized to be set up within ORNL thereby establishing a central coordinating office that would develop a consistent technical and administrative direction for the groundwater programs of all facilities and result in compliance with all relevant U.S. Environmental Protection Agency (EPA) regulations such as RCRA and Comprehensive Environmental Restoration, Compensation and Liability Act (CERCLA) as well as U.S. Department of Energy (DOE) regulations and orders. For example, DOE Order 5400.1, issued on November 9, 1988, called for each DOE facility to develop an environmental monitoring program for all media (e.g., air, surface water, and groundwater)

Sustainable groundwater management in California

Science.gov (United States)

Phillips, Steven P.; Rogers, Laurel Lynn; Faunt, Claudia

2015-12-01

The U.S. Geological Survey (USGS) uses data collection, modeling tools, and scientific analysis to help water managers plan for, and assess, hydrologic issues that can cause “undesirable results” associated with groundwater use. This information helps managers understand trends and investigate and predict effects of different groundwater-management strategies.

Current resistance issues in antimicrobial therapy | Senekal ...

African Journals Online (AJOL)

Continuing Medical Education. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 28, No 2 (2010) >. Log in or Register to get access to full text downloads.

Trends in Current Issues, Y2K-2005

Science.gov (United States)

Maltz, Leslie; DeBlois, Peter B.

2005-01-01

EDUCAUSE inaugurated its annual Current Issues Survey in 2000 by asking the primary representatives, typically CIOs, of its member institutions to identify up to three critical IT issues (five starting in 2004) from among 30 to 40 in response to each of four questions. The survey response rate has typically been 35 to 40 percent, with a…

An early warning system for groundwater pollution based on the assessment of groundwater pollution risks.

Science.gov (United States)

Zhang, Weihong.; Zhao, Yongsheng; Hong, Mei; Guo, Xiaodong

2009-04-01

Groundwater pollution usually is complex and concealed, remediation of which is difficult, high cost, time-consuming, and ineffective. An early warning system for groundwater pollution is needed that detects groundwater quality problems and gets the information necessary to make sound decisions before massive groundwater quality degradation occurs. Groundwater pollution early warning were performed by considering comprehensively the current groundwater quality, groundwater quality varying trend and groundwater pollution risk . The map of the basic quality of the groundwater was obtained by fuzzy comprehensive evaluation or BP neural network evaluation. Based on multi-annual groundwater monitoring datasets, Water quality state in sometime of the future was forecasted using time-sequenced analyzing methods. Water quality varying trend was analyzed by Spearman's rank correlative coefficient.The relative risk map of groundwater pollution was estimated through a procedure that identifies, cell by cell,the values of three factors, that is inherent vulnerability, load risk of pollution source and contamination hazard. DRASTIC method was used to assess inherent vulnerability of aquifer. Load risk of pollution source was analyzed based on the potential of contamination and pollution degree. Assessment index of load risk of pollution source which involves the variety of pollution source, quantity of contaminants, releasing potential of pollutants, and distance were determined. The load risks of all sources considered by GIS overlay technology. Early warning model of groundwater pollution combined with ComGIS technology organically, the regional groundwater pollution early-warning information system was developed, and applied it into Qiqiha'er groundwater early warning. It can be used to evaluate current water quality, to forecast water quality changing trend, and to analyze space-time influencing range of groundwater quality by natural process and human activities. Keywords

Integrated groundwater management: An overview of concepts and challenges

Science.gov (United States)

Jakeman, Anthony J.; Barreteau, Olivier; Hunt, Randall J.; Rinaudo, Jean-Daniel; Ross, Andrew; Jakeman, Anthony J.; Barreteau, Olivier; Hunt, Randall J.; Rinaudo, Jean-Daniel; Ross, Andrew

2016-01-01

Managing water is a grand challenge problem and has become one of humanity’s foremost priorities. Surface water resources are typically societally managed and relatively well understood; groundwater resources, however, are often hidden and more difficult to conceptualize. Replenishment rates of groundwater cannot match past and current rates of depletion in many parts of the world. In addition, declining quality of the remaining groundwater commonly cannot support all agricultural, industrial and urban demands and ecosystem functioning, especially in the developed world. In the developing world, it can fail to even meet essential human needs. The issue is: how do we manage this crucial resource in an acceptable way, one that considers the sustainability of the resource for future generations and the socioeconomic and environmental impacts? In many cases this means restoring aquifers of concern to some sustainable equilibrium over a negotiated period of time, and seeking opportunities for better managing groundwater conjunctively with surface water and other resource uses. However, there are many, often-interrelated, dimensions to managing groundwater effectively. Effective groundwater management is underpinned by sound science (biophysical and social) that actively engages the wider community and relevant stakeholders in the decision making process. Generally, an integrated approach will mean “thinking beyond the aquifer”, a view which considers the wider context of surface water links, catchment management and cross-sectoral issues with economics, energy, climate, agriculture and the environment. The aim of the book is to document for the first time the dimensions and requirements of sound integrated groundwater management (IGM). The primary focus is on groundwater management within its system, but integrates linkages beyond the aquifer. The book provides an encompassing synthesis for researchers, practitioners and water resource managers on the concepts and

Power quality issues current harmonics

CERN Document Server

Mikkili, Suresh

2015-01-01

Power Quality Issues: Current Harmonics provides solutions for the mitigation of power quality problems related to harmonics. Focusing on active power filters (APFs) due to their excellent harmonic and reactive power compensation in two-wire (single phase), three-wire (three-phase without neutral), and four-wire (three-phase with neutral) AC power networks with nonlinear loads, the text:Introduces the APF technology, describing various APF configurations and offering guidelines for the selection of APFs for specific application considerationsCompares shunt active filter (SHAF) control strategi

Current issues in asteroseismology

Energy Technology Data Exchange (ETDEWEB)

Bazot, Michael; Monteiro, Mario J P F G; Straka, Christian W [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

2008-10-15

In this contribution we briefly review some of the current issues and promises for the future by asteroseismology. We are entering a new phase in this field driven by the wealth of data that has been collected and data that will soon be available for asteroseismology across the HR Diagram. Major difficulties in the descriptions of stellar interiors that arose in the second half of the 20th century may now be in part addressed and solved (this is the expectation{exclamation_point}) by asteroseismology with unprecedented precision. In this contribution we list some of the key open questions in stellar physics, the seismic data we expect to collect in the near future, and some techniques that will provide the tools to connect data and models.

Ukraine: Current Issues and U.S. Policy

Science.gov (United States)

2014-09-04

as Putin’s attempt to test how far he can go in destabilizing Ukraine while avoiding the imposition of additional sanctions by the EU and United...cooperative threat reduction and other nonproliferation activities with Russia. Figure 1. Ukraine Ukraine: Current Issues and U.S. Policy

Proceedings of the 2010 PTAC soil and groundwater forum and poster session

International Nuclear Information System (INIS)

2010-01-01

This conference focused on emerging environmental issues and advances in soil and groundwater remediation research. It provided a forum to discuss current research and environmental regulations pertaining to the remediation and reclamation of oil and gas production sites as well as soils along pipeline routes. Methods for accurately identifying the source of hydrocarbon contamination in soils and wetlands were also presented. Recent advances in technological solutions for soil and groundwater remediation were reviewed along with methods for addressing salts, petroleum hydrocarbons, and process chemicals. The conference featured 18 presentations, of which 3 have been catalogued separately for inclusion in this database. refs., tabs., figs.

Sexting: Current Research Gaps and Legislative Issues

OpenAIRE

Ngo, Fawn; Jaishankar, K; Agustina, Jose R.

2017-01-01

'Sexting, the portmanteau of Sex and Texting, has become a hot topic of debate between the legislators, researchers, educators, parents and teens' (Jaishankar, 2009, para 1). In spite of the considerable and growing body of literature on sexting, there are significant gaps in the current research. A review of research to date also reveals a dearth of cross-national and cross-cultural research on the topic of sexting. Notably, legal and ethical issues abound with the current method for punishi...

Current health issues in Korean adolescents

Directory of Open Access Journals (Sweden)

Chang Ho Hong

2011-10-01

Full Text Available During the adolescent period, they experience rapid physical, emotional, cognitive developments while they establish their lifestyle and habitual routines that strongly influence adult health and life. Recent rapid economic growth in Korea, and the earlier onset of physical, sexual, and psychological maturation of adolescents, has resulted in changes in the health status of adolescents from many years ago. Risk-taking behaviors such as drinking alcohol, smoking, and sexual experiences are critical issues that affect the health of, adolescents. Therefore, it is important for pediatricians to note the that risk-taking behaviors of adolescents in Korea that are caused by individual psychosocial factors. This review article illustrates the current health status of Korean adolescents and provides an overview of risktaking behaviors, to inform pediatricians about some of the key issues.

Status report groundwater: the challenge for UMTRA completion

International Nuclear Information System (INIS)

D'Antonio, J.R.

1988-01-01

UMTRA is working aggressively towards meeting the intent of the draft EPA Groundwater Protection Standards. Since September 1987, the major UMTRA thrust has been threefold: (1) perform special studies directed towards design enhancements; (2) provide design enhancements, where possible for projects under construction; and (3) evaluate the remaining sites under design for design enhancements under the proposed standards. At the time, the NRC has taken a very guarded approach towards approving proposed cover systems. UMTRA believes current cell designs will meet proposed standards. UMTRA is working closely with the NRC towards understanding the resolution of issues related to the acceptability of designs to meet the EPA groundwater standards. UMTRA met with NRC the week of October 17, 1988 to discuss results of recent special studies. Recent studies include: field moisture content validations of completed covers, soil/rock covers, rock durability, soil amendments, freeze-thaw, and erosion protection and constructability questions. When completed, UMTRA will issue final special study reports. Two of the above areas, freeze-thaw and rock durability, will be presented in the presentations which follow this one. Another of the special studies addressing design approaches to cell designs is presented in Session V

DOE groundwater protection strategy

International Nuclear Information System (INIS)

Lichtman, S.

1988-01-01

EH is developing a DOE-wide Groundwater Quality Protection Strategy to express DOE's commitment to the protection of groundwater quality at or near its facilities. This strategy responds to a September 1986 recommendation of the General Accounting Office. It builds on EPA's August 1984 Ground-Water Protection Strategy, which establishes a classification system designed to protect groundwater according to its value and vulnerability. The purposes of DOE's strategy are to highlight groundwater protection as part of current DOE programs and future Departmental planning, to guide DOE managers in developing site-specific groundwater protection practices where DOE has discretion, and to guide DOE's approach to negotiations with EPA/states where regulatory processes apply to groundwater protection at Departmental facilities. The strategy calls for the prevention of groundwater contamination and the cleanup of groundwater commensurate with its usefulness. It would require long-term groundwater protection with reliance on physical rather than institutional control methods. The strategy provides guidance on providing long-term protection of groundwater resources; standards for new remedial actions;guidance on establishing points of compliance; requirements for establishing classification review area; and general guidance on obtaining variances, where applicable, from regulatory requirements. It also outlines management tools to implement this strategy

Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health

Science.gov (United States)

Lapworth, D. J.; Nkhuwa, D. C. W.; Okotto-Okotto, J.; Pedley, S.; Stuart, M. E.; Tijani, M. N.; Wright, J.

2017-06-01

Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.

Implementation of the EU-policy framework WFD and GWD in Europe - Activities of CIS Working Group Groundwater

Science.gov (United States)

Grath, Johannes; Ward, Rob; Hall, Anna

2013-04-01

At the European level, the basic elements for groundwater management and protection are laid down in the Water Framework Directive (WFD) (2000/60/EC) and the Groundwater Daughter Directive (2006/118/EC). EU Member States, Norway and the European Commission (EC) have jointly developed a common strategy for supporting the implementation of the WFD. The main aim of this Common Implementation Strategy (CIS) is to ensure the coherent and harmonious implementation of the directives through the clarification of a number of methodological questions enabling a common understanding to be reached on the technical and scientific implications of the WFD (European Communities, 2008). Groundwater specific issues are dealt with in Working Group C Groundwater. Members of the working group are experts nominated by Member states, Norway, Switzerland and Accession Countries (from administrative bodies, research institutes, …) and representatives from relevant stakeholders and NGOs. Working Group C Groundwater has produced numerous guidance documents and technical reports that have been endorsed by EU Water Directors to support and enable Member States to implement the directives. All the documents are published by the EC. Access is available via the following link: http://ec.europa.eu/environment/water/water-framework/groundwater/activities.htm Having addressed implementations issues during the 1st river basin planning cycle, WG C Groundwater is currently focussing on the following issues: groundwater dependent ecosystems, and climate change and groundwater. In the future, the outcome and recommendations of the "Blueprint" - to safeguard Europe's water resources - which was recently published by the EC will be of utmost importance in setting the agenda for the group. Most likely this will include water pricing, water demand management and water abstraction. Complementory to the particular working groups, a Science Policy Interface (SPI) activity has been established. Its purpose is

Groundwater recharge in desert playas: current rates and future effects of climate change

Science.gov (United States)

McKenna, Owen P.; Sala, Osvaldo E.

2018-01-01

Our results from playas, which are topographic low areas situated in closed-catchments in drylands, indicated that projected climate change in Southwestern USA would have a net positive impact over runon and groundwater recharge beneath playas. Expected increased precipitation variability can cause up to a 300% increase in annual groundwater recharge beneath playas. This increase will overshadow the effect of decreased precipitation amount that could cause up to a 50% decrease in recharge beneath playas. These changes could have a significant impact on groundwater and carbon storage. These results are important given that groundwater resources in Southwestern USA continue to decline due to human consumption outpacing natural recharge of aquifers. Here, we report on groundwater recharge rates ranging from less than 1 mm to greater than 25 mm per year beneath desert playas. Playas located in larger and steeper catchments with finer-textured soils had the highest rates of recharge. Vegetation cover had no effect on recharge beneath playas. We modeled catchment runoff generation and found that the amount of runon a playa receives annually strongly correlated to the rate of groundwater recharge beneath that playa. Runon occurred during precipitation events larger than 20 mm and increased linearly with events above that threshold.

Groundwater: A review of the 1989 literature

International Nuclear Information System (INIS)

Miller, C.T.; Mayer, A.S.

1990-01-01

This review was prepared under the auspices of the WPCF Research Committee of the annual Literature Review issue of the Journal; because of logistical reasons it could not be published in June. However, in view of the growing importance of the subject, the review is presented here as a supplement to the June Literature Review issue that has not been through the Journal peer review process. In this review, distinctions are made between single-, two-, and three-phase systems. Single-phase systems refer to groundwater systems subjected to saturated flow conditions, whereas the two- and three-phase systems include groundwater systems subjected to unsaturated flow conditions, or conditions influenced by immiscible organic fluids such as petroleum products. Within the single-, two-, and three-phase system categories, subdivisions are made between physical, chemical, or biological processes such as hydrodynamics, sorption/desorption, chemical reactions, and biodegradation. Specialized areas such as radon and radionuclide transport, facilitated transport, and saline groundwaters also are treated separately. Rounding out this year's review, papers concerning groundwater quality monitoring, remediation, and management are discussed

Internet governance origins, current issues, and future possibilities

CERN Document Server

Balleste, Roy

2015-01-01

Internet Governance: Origins, Current Issues, and Future Possibilities provides an introductory, multidisciplinary account of the forces at work in the evolving concept of internet governance and includes computer history, Internet beginnings, institutions and stakeholders, proposed models of governance, and human rights.

Book Review: Current Issues in International Human Resource Management and Strategy Research

DEFF Research Database (Denmark)

Gretzinger, Susanne

2009-01-01

The article reviews the book "Current Issues in International Human Resource Management and Strategy Research," edited by Marion Festing and Susanne Royer.......The article reviews the book "Current Issues in International Human Resource Management and Strategy Research," edited by Marion Festing and Susanne Royer....

Hydrogeochemical assessment of groundwater in Kashmir Valley ...

Indian Academy of Sciences (India)

Ravi, occupies an oval shaped depression between two major orogenic axis of ..... tion well network that showed water-level increase due to rapid groundwater ... Other issues such as ecological and social issues need to be taken into account ...

Baseline groundwater model update for p-area groundwater operable unit, NBN

Energy Technology Data Exchange (ETDEWEB)

Ross, J. [Savannah River Site (SRS), Aiken, SC (United States); Amidon, M. [Savannah River Site (SRS), Aiken, SC (United States)

2015-09-01

This report documents the development of a numerical groundwater flow and transport model of the hydrogeologic system of the P-Area Reactor Groundwater Operable Unit at the Savannah River Site (SRS) (Figure 1-1). The P-Area model provides a tool to aid in understanding the hydrologic and geochemical processes that control the development and migration of the current tritium, tetrachloroethene (PCE), and trichloroethene (TCE) plumes in this region.

Groundwater flow simulation of the Savannah River Site general separations area

Energy Technology Data Exchange (ETDEWEB)

Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bagwell, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bennett, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-09-07

The most recent groundwater flow model of the General Separations Area, Savannah River Site, is referred to as the “GSA/PORFLOW” model. GSA/PORFLOW was developed in 2004 by porting an existing General Separations Area groundwater flow model from the FACT code to the PORFLOW code. The preceding “GSA/FACT” model was developed in 1997 using characterization and monitoring data through the mid-1990’s. Both models were manually calibrated to field data. Significantly more field data have been acquired since the 1990’s and model calibration using mathematical optimization software has become routine and recommended practice. The current task involved updating the GSA/PORFLOW model using selected field data current through at least 2015, and use of the PEST code to calibrate the model and quantify parameter uncertainty. This new GSA groundwater flow model is named “GSA2016” in reference to the year in which most development occurred. The GSA2016 model update is intended to address issues raised by the DOE Low-Level Waste (LLW) Disposal Facility Federal Review Group (LFRG) in a 2008 review of the E-Area Performance Assessment, and by the Nuclear Regulatory Commission in reviews of tank closure and Saltstone Disposal Facility Performance Assessments.

Why is the Groundwater Level Rising? A Case Study Using HARTT to Simulate Groundwater Level Dynamic.

Science.gov (United States)

Yihdego, Yohannes; Danis, Cara; Paffard, Andrew

2017-12-01

  Groundwater from a shallow unconfined aquifer at a site in coastal New South Wales has been causing recent water logging issues. A trend of rising groundwater level has been anecdotally observed over the last 10 years. It was not clear whether the changes in groundwater levels were solely natural variations within the groundwater system or whether human interference was driving the level up. Time series topographic images revealed significant surrounding land use changes and human modification to the environment of the groundwater catchment. A statistical model utilising HARTT (multiple linear regression hydrograph analysis method) simulated the groundwater level dynamics at five key monitoring locations and successfully showed a trend of rising groundwater level. Utilising hydrogeological input from field investigations, the model successfully simulated the rise in the water table over time to the present day levels, whilst taking into consideration rainfall and land changes. The underlying geological/land conditions were found to be just as significant as the impact of climate variation. The correlation coefficient for the monitoring bores (MB), excluding MB4, show that the groundwater level fluctuation can be explained by the climate variable (rainfall) with the lag time between the atypical rainfall and groundwater level ranging from 4 to 7 months. The low R2 value for MB4 indicates that there are factors missing in the model which are primarily related to human interference. The elevated groundwater levels in the affected area are the result of long term cumulative land use changes, instigated by humans, which have directly resulted in detrimental changes to the groundwater aquifer properties.

Data-driven behavioural characterization of dry-season groundwater ...

Indian Academy of Sciences (India)

This paper looks at the crucial issue of dry-season groundwater-availability in the state of Maharashtra, India. We look at the two key hydro-climatological measurements which are used to implement ground-water policy in the state, viz., water levels in 5000+ observation wells across the state and aggregate rainfall data.

Groundwater: from mystery to management

International Nuclear Information System (INIS)

Narasimhan, T N

2009-01-01

Groundwater has been used for domestic and irrigation needs from time immemorial. Yet its nature and occurrence have always possessed a certain mystery because water below the land surface is invisible and relatively inaccessible. The influence of this mystery lingers in some tenets that govern groundwater law. With the birth of modern geology during the late nineteenth century, groundwater science became recognized in its own right. Over the past two centuries, groundwater has lost its shroud of mystery, and its scientific understanding has gradually grown hand-in-hand with its development for human use. Groundwater is a component of the hydrological cycle, vital for human sustenance. Its annual renewability from precipitation is limited, and its chemical quality is vulnerable to degradation by human action. In many parts of the world, groundwater extraction is known to greatly exceed its renewability. Consequently, its rational management to benefit present and future generations is a matter of deep concern for many nations. Groundwater management is a challenging venture, requiring an integration of scientific knowledge with communal will to adapt to constraints of a finite common resource. As scientists and policy makers grapple with the tasks of groundwater management, it is instructive to reflect on the evolution of groundwater knowledge from its initial phase of demystification at the beginning of the nineteenth century, through successive phases of technological conquest, scientific integration, discovery of unintended consequences and the present recognition of an imperative for judicious management. The following retrospective provides a broad context for unifying the technical contributions that make up this focus issue on groundwater resources, climate and vulnerability.

Summary of current issues regarding space flight habitability.

Science.gov (United States)

Novak, J B

2000-09-01

One of the implicit, yet often under-emphasized qualities of human tended spaceflight is the habitability of the spacecraft and mission. This document summarizes some of the points that characterize the current status of this topic. In addition, the summary concludes with goals for future development for this issue.

Assess arsenic distribution in groundwater applying GIS in capital of Punjab, Pakistan

Science.gov (United States)

Akhtar, M. M.; Zhonghua, T.; Sissou, Z.; Mohamadi, B.

2015-03-01

Arsenic contamination of groundwater resources threatens the health of millions of people worldwide, particularly in the densely populated river deltas of Southeast Asia. Arsenic causes health concerns due to its significant toxicity and worldwide presence in portable water. The major sources of arsenic pollution may be natural process such as dissolution of arsenic containing minerals and anthropogenic activities. Lahore is groundwater dependent city, arsenic contamination is a major issue of portable water and has recently been most environmental health management issue especially in the plain region, where population density is very high. GIS was used in this study for visualizing distribution of arsenic groundwater concentration through geostatistics analysis technique, and exposure risk zones for two years (2010 and 2012). Town's data was compared and concentration variation evaluated. ANOVA test was also applied to compare concentration between cities and years. Arsenic concentrations widely range 7.3-67.8 and 5.2-69.3 μg L-1 in 2010 and 2012, respectively. Over 71% area is represented arsenic concentration range from 20 to 30 μg L-1 in both analyzed years. However, in 2012 arsenic concentration over 40 μg L-1 has covered 7.6% area of Data Gunjbuksh and 8.1% of Ravi Town, while over 90% area of Allama Iqbal, Aziz Bhatti and Samanabad Town contain arsenic concentration between 20-30 μg L-1. ANOVA test depicts concentration probability less than 0.05, while differences were detected among towns. In light of current results, it needs urgent step to ensure groundwater protection and preservation for future.

Current issues and actions

Energy Technology Data Exchange (ETDEWEB)

Black, D.G.

1995-06-01

This section of the 1994 Hanford Site Environmental Report summarizes the progress that has been made toward achieving full regulatory compliance at the Hanford Site. Ongoing compliance self-assessments, implementation of the Tri-Party Agreement, and public meetings continue to identify environmental compliance issues. These issues are discussed openly with the regulatory agencies and with the public to ensure that all environmental compliance issues are addressed.

Current issues and actions

International Nuclear Information System (INIS)

Black, D.G.

1995-01-01

This section of the 1994 Hanford Site Environmental Report summarizes the progress that has been made toward achieving full regulatory compliance at the Hanford Site. Ongoing compliance self-assessments, implementation of the Tri-Party Agreement, and public meetings continue to identify environmental compliance issues. These issues are discussed openly with the regulatory agencies and with the public to ensure that all environmental compliance issues are addressed

Exploring Current Issues through the Hot Topics Poster

Science.gov (United States)

Nisbett, Nancy

2012-01-01

This paper describes a research paper and poster assignment used in an undergraduate leisure and human behavior course. The intent of this learning activity is to increase student knowledge of current issues within the industry as well as to enhance students' professional communication skills. A description of the assignment is shared along with…

Brackish groundwater in the United States

Science.gov (United States)

Stanton, Jennifer S.; Anning, David W.; Brown, Craig J.; Moore, Richard B.; McGuire, Virginia L.; Qi, Sharon L.; Harris, Alta C.; Dennehy, Kevin F.; McMahon, Peter B.; Degnan, James R.; Böhlke, John Karl

2017-04-05

For some parts of the Nation, large-scale development of groundwater has caused decreases in the amount of groundwater that is present in aquifer storage and that discharges to surface-water bodies. Water supply in some areas, particularly in arid and semiarid regions, is not adequate to meet demand, and severe drought is affecting large parts of the United States. Future water demand is projected to heighten the current stress on groundwater resources. This combination of factors has led to concerns about the availability of freshwater to meet domestic, agricultural, industrial, mining, and environmental needs. To ensure the water security of the Nation, currently [2016] untapped water sources may need to be developed.Brackish groundwater is an unconventional water source that may offer a partial solution to current and future water demands. In support of the national census of water resources, the U.S. Geological Survey completed the national brackish groundwater assessment to better understand the occurrence and characteristics of brackish groundwater in the United States as a potential water resource. Analyses completed as part of this assessment relied on previously collected data from multiple sources; no new data were collected. Compiled data included readily available information about groundwater chemistry, horizontal and vertical extents and hydrogeologic characteristics of principal aquifers (regionally extensive aquifers or aquifer systems that have the potential to be used as a source of potable water), and groundwater use. Although these data were obtained from a wide variety of sources, the compiled data are biased toward shallow and fresh groundwater resources; data representing groundwater that is at great depths and is saline were not as readily available.One of the most important contributions of this assessment is the creation of a database containing chemical characteristics and aquifer information for the known areas with brackish groundwater

ERC hazard classification matrices for above ground structures and groundwater and soil remediation activities

International Nuclear Information System (INIS)

Curry, L.R.

1997-01-01

This document provides the status of the preliminary hazard classification (PHC) process for the Environmental Restoration Contractor (ERC) above ground structures and groundwater and soil remediation activities currently underway for planned for fiscal year (FY) 1997. This classification process is based on current US Department of Energy (DOE), Richland Operations Office (RL) guidance for the classification of facilities and activities containing radionuclide and nonradiological hazardous material inventories. The above ground structures presented in the matrices were drawn from the Bechtel Hanford, Inc. (BHI) Decontamination and Decommissioning (D and D) Project Facility List (DOE 1996), which identifies the facilities in the RL-Environmental Restoration baseline contract in 1997. This document contains the following two appendices: (1) Appendix A, which consists of a matrix identifying PHC documents that have been issued for BHI's above ground structures and groundwater and soil remediation activities underway or planned for FY 1997, and (2) Appendix B, which consists of a matrix showing anticipated PHCs for above ground structures, and groundwater and soil remediation activities underway or planned for FY 1997. Appendix B also shows the schedule for finalization of PHCs for above ground structures with an anticipated classification of Nuclear

Current issues in medical education | Al Shehri | West African ...

African Journals Online (AJOL)

West African Journal of Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 22, No 4 (2003) >. Log in or Register to get access to full text downloads.

Groundwater science in water-utility operations: global reflections on current status and future needs

Science.gov (United States)

Foster, Stephen; Sage, Rob

2017-08-01

The relevance of groundwater science to water-utility operations is analysed from a broad international perspective, identifying key concerns and specific opportunities for the future. The strategic importance worldwide of water utilities assuming the role of lead stakeholders for integrated groundwater resource management, recognizing their often considerable technical know-how and highly significant data holdings, is emphasized. Concurrently, the utilities themselves will need an ever-closer appreciation of groundwater-system behaviour if they are to manage efficiently their water-supply and wastewater operations.

Current Issues in LPP Research and Their Impact on Society

Science.gov (United States)

Darquennes, Jeroen

2013-01-01

After a very broad description of what language policy and planning is about this paper presents an overview of some of the current preoccupations of researchers focusing on language policy and planning as one of the blooming fields of applied linguistics. The current issues in language policy and planning research that are dealt with include…

Physics issues of high bootstrap current tokamaks

International Nuclear Information System (INIS)

Ozeki, T.; Azumi, M.; Ishii, Y.

1997-01-01

Physics issues of a tokamak plasma with a hollow current profile produced by a large bootstrap current are discussed based on experiments in JT-60U. An internal transport barrier for both ions and electrons was obtained just inside the radius of zero magnetic shear in JT-60U. Analysis of the toroidal ITG microinstability by toroidal particle simulation shows that weak and negative shear reduces the toroidal coupling and suppresses the ITG mode. A hard beta limit was observed in JT-60U negative shear experiments. Ideal MHD mode analysis shows that the n = 1 pressure-driven kink mode is a plausible candidate. One of the methods to improve the beta limit against the kink mode is to widen the negative shear region, which can induce a broader pressure profile resulting in a higher beta limit. The TAE mode for the hollow current profile is less unstable than that for the monotonic current profile. The reason is that the continuum gaps near the zero shear region are not aligned when the radius of q min is close to the region of high ∇n e . Finally, a method for stable start-up for a plasma with a hollow current profile is describe, and stable sustainment of a steady-state plasma with high bootstrap current is discussed. (Author)

Groundwater resources of the Devils Postpile National Monument—Current conditions and future vulnerabilities

Science.gov (United States)

Evans, William C.; Bergfeld, Deborah

2017-06-15

This study presents an extensive database on groundwater conditions in and around Devils Postpile National Monument. The database contains chemical analyses of springs and the monument water-supply well, including major-ion chemistry, trace element chemistry, and the first information on a list of organic compounds known as emerging contaminants. Diurnal, seasonal, and annual variations in groundwater discharge and chemistry are evaluated from data collected at five main monitoring sites, where streams carry the aggregate flow from entire groups of springs. These springs drain the Mammoth Mountain area and, during the fall months, contribute a significant fraction of the San Joaquin River flow within the monument. The period of this study, from fall 2012 to fall 2015, includes some of the driest years on record, though the seasonal variability observed in 2013 might have been near normal. The spring-fed streams generally flowed at rates well below those observed during a sequence of wet years in the late 1990s. However, persistence of flow and reasonably stable water chemistry through the recent dry years are indicative of a sizeable groundwater system that should provide a reliable resource during similar droughts in the future. Only a few emerging contaminants were detected at trace levels below 1 microgram per liter (μg/L), suggesting that local human visitation is not degrading groundwater quality. No indication of salt from the ski area on the north side of Mammoth Mountain could be found in any of the groundwaters. Chemical data instead show that natural mineral water, such as that discharged from local soda springs, is the main source of anomalous chloride in the monument supply well and in the San Joaquin River. The results of the study are used to develop a set of recommendations for future monitoring to enable detection of deleterious impacts to groundwater quality and quantity

Thermal use of groundwater: International legislation and ecological considerations

Science.gov (United States)

Hähnlein, S.; Griebler, C.; Blum, P.; Bayer, P.

2009-04-01

Groundwater fulfills various functions for nature, animals and humans. Certainly, groundwater has highest relevance as freshwater resource. Another increasingly important issue - especially considering rising oil and gas prices - is the use of aquifers as renewable energy reservoirs. In view of these two somehow conflictive uses it seems important to define legal regulations and management strategies where exploitation and protection of aquifers is balanced. Thermal use of groundwater with e.g. ground source heat pump (GSHP) systems results in temperature anomalies (cold or heat plumes) in the subsurface. The extension of these temperture plumes has to be known in order to interpret their influence on adjacent geothermal installations. Beside this technological constraint, there exists an ecological one: man made thermal anomalies may have undesirable effects on the groundwater ecosystem. To promote geothermal energy as an economically attractive, sustainable and environmentally friendly energy source, such constraints have to be integrated in regulations, planning and maintenance (Hähnlein et al. 2008a,b). The objective of this study is to review the current legal status of the thermal use of groundwater and to present first results how the ecosystem is influenced. • Legal viewpoint: The international legal situation on thermal groundwater use is very heterogeneous. Nationally and internationally there is no consistent legal situation. Minimum distances between GSHP and temperature limits for heating and cooling the groundwater vary strongly. Until now there are no scientifically based thresholds. And it is also legally unexplained which temperature changes are detrimental. This is due to the fact that there are no ecological and economical parameters established for sustainable groundwater use. • Ecological viewpoint: First results show that temperature changes that arise with the thermal use of groundwater can noticeably influence the composition of

Will farmers save water? A theoretical analysis of groundwater conservation policies

Science.gov (United States)

The development of agricultural irrigation systems has generated significant increases in food production and farm income. However, unplanned and unconstrained groundwater use could also cause serious consequences. To extend the economic life of groundwater, water conservation issues have become the...

Comparison of groundwater residence time using isotope techniques and numerical groundwater flow model in Gneissic Terrain, Korea

International Nuclear Information System (INIS)

Bae, D.S.; Kim, C.S.; Koh, Y.K.; Kim, K.S.; Song, M.Y.

1997-01-01

The prediction of groundwater flow affecting the migration of radionuclides is an important component of the performance assessment of radioactive waste disposal. Groundwater flow in fractured rock mass is controlled by fracture networks, transmissivity and hydraulic gradient. Furthermore the scale-dependent and anisotropic properties of hydraulic parameters are resulted mainly from irregular patterns of fracture system, which are very complex to evaluate properly with the current techniques available. For the purpose of characterizing a groundwater flow in fractured rock mass, the discrete fracture network (DFN) concept is available on the basis of assumptions of groundwater flowing only along fractures and flowpaths in rock mass formed by interconnected fractures. To increase the reliability of assessment in groundwater flow phenomena, numerical groundwater flow model and isotopic techniques were applied. Fracture mapping, borehole acoustic scanning were performed to identify conductive fractures in gneissic terrane. Tracer techniques, using deuterium, oxygen-18 and tritium were applied to evaluate the recharge area and groundwater residence time

Calculation of groundwater travel time

International Nuclear Information System (INIS)

Arnett, R.C.; Sagar, B.; Baca, R.G.

1984-12-01

Pre-waste-emplacement groundwater travel time is one indicator of the isolation capability of the geologic system surrounding a repository. Two distinct modeling approaches exist for prediction of groundwater flow paths and travel times from the repository location to the designated accessible environment boundary. These two approaches are: (1) the deterministic approach which calculates a single value prediction of groundwater travel time based on average values for input parameters and (2) the stochastic approach which yields a distribution of possible groundwater travel times as a function of the nature and magnitude of uncertainties in the model inputs. The purposes of this report are to (1) document the theoretical (i.e., mathematical) basis used to calculate groundwater pathlines and travel times in a basalt system, (2) outline limitations and ranges of applicability of the deterministic modeling approach, and (3) explain the motivation for the use of the stochastic modeling approach currently being used to predict groundwater pathlines and travel times for the Hanford Site. Example calculations of groundwater travel times are presented to highlight and compare the differences between the deterministic and stochastic modeling approaches. 28 refs

Interactions of water quality and integrated groundwater management: Examples from the United States and Europe: Chapter 14

Science.gov (United States)

Warner, Kelly L.; Barataud, Fabienne; Hunt, Randall J.; Benoit, Marc; Anglade, Juliette; Borchardt, Mark A.

2015-01-01

Groundwater is available in many parts of the world, but the quality of the water may limit its use. Contaminants can limit the use of groundwater through concerns associated with human health, aquatic health, economic costs, or even societal perception. Given this broad range of concerns, this chapter focuses on examples of how water quality issues influence integrated groundwater management. One example evaluates the importance of a naturally occurring contaminant Arsenic (As) for drinking water supply, one explores issues resulting from agricultural activities on the land surface and factors that influence related groundwater management, and the last examines unique issues that result from human-introduced viral pathogens for groundwater-derived drinking water vulnerability. The examples underscore how integrated groundwater management lies at the intersections of environmental characterization, engineering constraints, societal needs, and human perception of acceptable water quality. As such, water quality factors can be a key driver for societal decision making.

Transboundary Groundwater Along the Canadian-American Border

Science.gov (United States)

Rivera, A.

2009-05-01

Canada does not have obvious problems as a consequence of the intensive use of surface water or groundwater. Canada mostly struggles to keep the quality of its waters, in the highest standards, and to overcome the knowledge gaps of its groundwater resources. In assessing water resources, it has become obvious that both surface and groundwater resources are equally important. Because of this shift, Canada is interested in transboundary groundwater issues, both between provinces and internationally. There is no competition in Canada for groundwater resources between provinces or internationally. When an aquifer extends beneath the border of two jurisdictions, conflict may arise when one jurisdiction depletes groundwater resources that affect the quantity and quality of water available to the other jurisdiction. The most important cases of transboundary aquifers within Canada are located in the Prairie Provinces, but no competition has been reported. The equitable and "reasonable" use of shared waters is the most essential principle considered when negotiating a groundwater apportionment method. Other factors considered are: the priority use, the sustainable yield of the aquifer, and the joint apportionment of surface water and groundwater Over 20 million Canadians live in watersheds that cross the Canada-US border (over 17 million of them in the Great Lakes-St Lawrence watershed), and are therefore affected by American policies, or else affect American water quality. The International Joint Commission is one well-developed and valuable mechanism for coordinating policies between Canada and the United States. Other mechanisms include provisions under the North American Free Trade Agreement, supported by its environmental commission, which attempt to ensure that the Agreement's policies are consistent with environmental protection and conservation as well as strengthening the development and enforcement of environmental laws and regulations. Policies affecting

Proceedings of the fifth international groundwater conference on the assessment and management of groundwater resources in hard rock systems with special reference to basaltic terrain

International Nuclear Information System (INIS)

Thangarajan, M.; Mayilswami, C.; Kulkarni, P.S.; Singh, V.P.

2012-01-01

Groundwater resources in hard rock regions with limited renewable potential have to be managed judiciously to ensure adequate supplies of dependable quantity and quality. It is a natural resource with economic, strategic and environmental value, which is under stress both due to changing climatic and anthropogenic factors. Therefore the management strategies need to be aimed at sustenance of this limited resource. In India, and also elsewhere in the world major parts of the semi-arid regions are characterized by hard rocks and it is of vital importance to understand the nature of the aquifer systems and its current stress conditions. Though the achievements through scientific development in exploration and exploitation are commendable, it has adversely affected the hard rock aquifer system, both in terms of quantity and quality; which is of major concern today. In order to reverse the situation, better management strategy of groundwater resources needs to be devised for prevention of further degradation of quality and meeting out the future demand of quantity. This necessitates: understanding the flow mechanism, evaluating the potential and evolving optimal utilization schemes, and assessing and monitoring quality in the changing scenario of anthropogenically induced agricultural, urban, industrial and climatic change. The groundwater flow mechanism through fractures in hard rocks is yet to be fully understood in terms of fracture geometry and its relation to groundwater flow. The characterization of flow geometry in basaltic aquifer is yet to be fully explored. Groundwater pollution due to anthropogenic factors is very slow process with long-term impacts on carbon cycle and global climatic change on one hand and quality on the other. It is generally recognized that the prevention of groundwater pollution is cheaper than its remedial measures in the long run. Furthermore, because of the nature of groundwater flow and the complexity and management uncertainty of

Hydrodynamic analysis of the interaction of two operating groundwater sources, case study: Groundwater supply of Bečej

Directory of Open Access Journals (Sweden)

Polomčić Dušan M.

2014-01-01

Full Text Available The existing groundwater source 'Vodokanal' for the public water supply of Bečej city in Serbia tapping groundwater from three water-bearing horizons over 15 wells with summary capacity of 100 l/s. Near the public water source of Bečej exists groundwater source 'Soja Protein' for industry with current capacity of 12 l/s which tapped same horizons. In the coming period is planned to increase summary capacity of this groundwater source up to 57 l/s. Also, the increase of summary city's source capacity is planned for 50 l/s in the next few years. That is means an increase of groundwater abstraction for an additional 84 % from the same water-bearing horizons. Application of hydrodynamic modeling, based on numerical method of finite difference will show the impact of increasing the total capacity of the source 'Soja Protein' on the groundwater level in groundwater source 'Vodokanal' and effects of additional decrease in groundwater levels, in all three water-bearing horizons, on the wells of the 'Vodokanala' groundwater source due to operation of industrial source. It was done 7 variant solutions of the extensions of groundwater sources and are their effects for a period of 10 years with the aim of the sustainable management of groundwater.

Y-12 Groundwater Protection Program Groundwater And Surface Water Sampling And Analysis Plan For Calendar Year 2012

Energy Technology Data Exchange (ETDEWEB)

Elvado Environmental, LLC

2011-09-01

the CY 2012 groundwater and surface water monitoring activities. Section 2 describes the monitoring locations in each regime and the processes used to select the sampling locations. A description of the field measurements and laboratory analytes is provided in Section 3. Sample collection methods and procedures are described in Section 4, and Section 5 lists the documents cited for more detailed operational and technical information. The narrative sections of the report reference several appendices. Figures (maps and diagrams) and tables (excluding a data summary table presented in Section 4) are in Appendix A and Appendix B, respectively. Groundwater Monitoring Schedules (when issued throughout CY 2012) will be inserted in Appendix C, and addenda to this plan (if issued) will be inserted in Appendix D. Laboratory requirements (bottle lists, holding times, etc.) are provided in Appendix E, and an approved Waste Management Plan is provided in Appendix F.

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

International Nuclear Information System (INIS)

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

1997-03-01

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

Identification of groundwater prospective zones by using remote ...

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 114; Issue 5. Identification of groundwater prospective zones by using remote sensing and geoelectrical methods in Jharia and Raniganj coalfields, Dhanbad district, Jharkhand state. Basudeo Rai A Tiwari V S Dubey. Volume 114 Issue 5 October 2005 pp 515-522 ...

Groundwater monitoring program plan and conceptual site model for the Al-Tuwaitha Nuclear Research Center in Iraq.

Energy Technology Data Exchange (ETDEWEB)

Copland, John Robin; Cochran, John Russell

2013-07-01

The Radiation Protection Center of the Iraqi Ministry of Environment is developing a groundwater monitoring program (GMP) for the Al-Tuwaitha Nuclear Research Center located near Baghdad, Iraq. The Al-Tuwaitha Nuclear Research Center was established in about 1960 and is currently being cleaned-up and decommissioned by Iraqs Ministry of Science and Technology. This Groundwater Monitoring Program Plan (GMPP) and Conceptual Site Model (CSM) support the Radiation Protection Center by providing: A CSM describing the hydrogeologic regime and contaminant issues, recommendations for future groundwater characterization activities, and descriptions of the organizational elements of a groundwater monitoring program. The Conceptual Site Model identifies a number of potential sources of groundwater contamination at Al-Tuwaitha. The model also identifies two water-bearing zones (a shallow groundwater zone and a regional aquifer). The depth to the shallow groundwater zone varies from approximately 7 to 10 meters (m) across the facility. The shallow groundwater zone is composed of a layer of silty sand and fine sand that does not extend laterally across the entire facility. An approximately 4-m thick layer of clay underlies the shallow groundwater zone. The depth to the regional aquifer varies from approximately 14 to 17 m across the facility. The regional aquifer is composed of interfingering layers of silty sand, fine-grained sand, and medium-grained sand. Based on the limited analyses described in this report, there is no severe contamination of the groundwater at Al-Tuwaitha with radioactive constituents. However, significant data gaps exist and this plan recommends the installation of additional groundwater monitoring wells and conducting additional types of radiological and chemical analyses.

Groundwater impacts of foreseeable human activities on a HLW repository

International Nuclear Information System (INIS)

Coleman, N.M.

1993-01-01

The Nuclear Regulatory Commission (NRC) staff has begun a program of Systematic Regulatory Analysis (SRA) to help ensure that all important technical issues related to the disposal of civilian, high-level nuclear wastes will be identified prior to the receipt of a license application. Large-scale groundwater withdrawals near a repository could have significant impacts on the groundwater flow system. Future large-scale withdrawals of groundwater could occur to support irrigation to growing population centers, such as Las Vegas. Various scenarios of groundwater withdrawals, along with other scenarios of future human activity, will need to be tested before evaluation of the Yucca Mountain site is complete

Effects of intensive urbanization on the intrusion of shallow groundwater into deep groundwater: Examples from Bangkok and Jakarta

International Nuclear Information System (INIS)

Onodera, Shin-ichi; Saito, Mitsuyo; Sawano, Misa; Hosono, Takahiro; Taniguchi, Makoto; Shimada, Jun; Umezawa, Yu; Lubis, Rachmat Fajar; Buapeng, Somkid; Delinom, Robert

2008-01-01

Asian megacities have severe pollution problems in both coastal and urban areas. In addition, the groundwater potential has decreased and land subsidence has occurred because of intensive groundwater pumping in urban areas. To prevent the adverse effects of urbanization on groundwater quality, it is necessary to confirm the changes in groundwater flow and contaminant transport caused by urbanization. We examined the effects of urbanization on contaminant transport in groundwater. The research areas were located around Bangkok, Thailand, and akarta, Indonesia, cities with populations of approximately 8 and 12 million, respectively. Each metropolitan city is located on a river delta and is adjacent to a bay. We measured the water level and collected water samples at boreholes at multiple depths (100 to 200 m) in 2004 and 2006 in Bangkok and Jakarta, respectively. The current hydraulic potential is below sea level in both cities because of prior excess abstraction of groundwater. As a result, the direction of groundwater flow is now downward in the coastal area. The Cl - concentration and δ 18 O distributions in groundwater suggest that the decline in hydraulic potential has caused the intrusion of seawater and shallow groundwater into deep groundwater. Concentrations of Mn and NO3 - -N in groundwater suggest the intrusion of these contaminants from shallow to deep aquifers with downward groundwater flow and implies an accumulation of contaminants in deep aquifers. Therefore, it is important to recognize the possibility of future contaminant transport with the discharge of deep groundwater into the sea after the recovery of groundwater potential in the coastal areas

In situ bioremediation of Hanford groundwater

International Nuclear Information System (INIS)

Skeen, R.S.; Roberson, K.R.; Workman, D.J.; Petersen, J.N.; Shouche, M.

1992-04-01

Liquid wastes containing radioactive, hazardous, and regulated chemicals have been generated throughout the 40+ years of operations at the US Department of Energy's (DOE) Hanford Site. Some of these wastes were discharged to the soil column and many of the waste components, including nitrate, carbon tetrachloride (CCl 4 ), and several radionuclides, have been detected in the Hanford groundwater. Current DOE policy prohibits the disposal of contaminated liquids directly to the environment, and remediation of existing contaminated groundwaters may be required. In situ bioremediation is one technology currently being developed at Hanford to meet the need for cost effective technologies to clean groundwater contaminated with CCl 4 , nitrate, and other organic and inorganic contaminants. This paper focuses on the latest results of an on going effort to develop effective in situ remediation strategies through the use of predictive simulations

How Sustainable is Groundwater Abstraction? A Global Assessment.

Science.gov (United States)

de Graaf, I.; Van Beek, R.; Gleeson, T. P.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

2017-12-01

Groundwater is the world's largest accessible freshwater resource and is of critical importance for irrigation, and thus for global food security. For regions with high demands, groundwater abstractions often exceed recharge and persistent groundwater depletion occurs. The direct effects of depletion are falling groundwater levels, increased pumping costs, land subsidence, and reduced baseflows to rivers. Water demands are expected to increase further due to growing population, economic development, and climate change, posing the urgent question how sustainable current water abstractions are worldwide and where and when these abstractions approach conceivable economic and environmental limits. In this study we estimated trends over 1960-2100 in groundwater levels, resulting from changes in demand and climate. We explored the limits of groundwater abstraction by predicting where and when groundwater levels drop that deep that groundwater gets unattainable for abstraction (economic limit) or, that groundwater baseflows to rivers drop below environmental requirements (environmental limit). We used a global hydrological model coupled to a groundwater model, meaning lateral groundwater flows, river infiltration and drainage, and infiltration and capillary-rise are simulated dynamically. Historical data and projections are used to prescribe water demands and climate forcing to the model. For the near future we used RCP8.5 and applied globally driest, average, and wettest GCM to test climate sensitivity. Results show that in general environmental limits are reached before economic limits, for example starting as early as the 1970s compared to the 1980s for economic limits in the upper Ganges basin. Economic limits are mostly related to regions with depletion, while environmental limits are reached also in regions were groundwater and surface water withdrawals are significant but depletion is not taking place (yet), for example in Spain and Portugal. In the near future

Global scale groundwater flow model

Science.gov (United States)

Sutanudjaja, Edwin; de Graaf, Inge; van Beek, Ludovicus; Bierkens, Marc

2013-04-01

As the world's largest accessible source of freshwater, groundwater plays vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and supplies water for agricultural and industrial activities. During times of drought, groundwater sustains water flows in streams, rivers, lakes and wetlands, and thus supports ecosystem habitat and biodiversity, while its large natural storage provides a buffer against water shortages. Yet, the current generation of global scale hydrological models does not include a groundwater flow component that is a crucial part of the hydrological cycle and allows the simulation of groundwater head dynamics. In this study we present a steady-state MODFLOW (McDonald and Harbaugh, 1988) groundwater model on the global scale at 5 arc-minutes resolution. Aquifer schematization and properties of this groundwater model were developed from available global lithological model (e.g. Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moorsdorff, in press). We force the groundwtaer model with the output from the large-scale hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the long term net groundwater recharge and average surface water levels derived from routed channel discharge. We validated calculated groundwater heads and depths with available head observations, from different regions, including the North and South America and Western Europe. Our results show that it is feasible to build a relatively simple global scale groundwater model using existing information, and estimate water table depths within acceptable accuracy in many parts of the world.

Prospective of groundwater overexploitation through participatory approaches: Saiss Plain in Morocco

Science.gov (United States)

Ameur, Fatah; Lejars, Caroline; Dionnet, Mathieu; Quarouch, Hassan; Kuper, Marcel

2015-04-01

In the Saiss plain, groundwater overexploitation is often explained by two phenomena. The first one is a natural phenomenon (droughts), which seems therefore uncontrollable; the other one is human as groundwater is largely used by the agricultural sector. The main issue of groundwater governance is to find an acceptable balance in the use of the water resource without compromising the socio-economic development generated by this resource. Our study aims to contribute to understanding the differential contribution of different categories of groundwater users and the socio-economic and agrarian dynamics impacted by the overuse of groundwater. We adopted a participatory approach to explore with the different actors involved in the management and use of groundwater to identify the different viewpoints on the issue of overexploitation and to engage prospective and collective thinking of present situation of groundwater overexploitation. We organized multi-stakeholder workshops and designed a role-playing game to identify and qualify the existing links between the water resource, and the economic and social dynamics in order to better understand the human behavior to economic and environmental crises and the adaptive strategies of farmers confronted with an increasingly scarce groundwater resource. Our results showed considerable differences in the viewpoints of different categories of farmers regarding overexploitation. Agricultural investors who arrived over the past 5 years in the area practicing arboriculture consider themselves modern farmers using precise and water-saving irrigation technologies (drip irrigation, especially) who cannot be blamed for overexploitation of groundwater resources. Lessees practicing horticulture put considerable pressure on water resources, but were not interested in debates on overexploitation and the sustainability of groundwater resources. In fact, they did not turn up for the workshops. Finally, the local small-scale farmers who have

Reforming health care in Canada: current issues

Directory of Open Access Journals (Sweden)

Baris Enis

1998-01-01

Full Text Available This paper examines the current health care reform issues in Canada. The provincial health insurance plans of the 1960s and 1970s had the untoward effects of limiting the federal government's clout for cost control and of promoting a system centered on inpatient and medical care. Recently, several provincial commissions reported that the current governance structures and management processes are outmoded in light of new knowledge, new fiscal realities and the evolution of power among stake-holders. They recommend decentralized governance and restructuring for better management and more citizen participation. Although Canada's health care system remains committed to safeguarding its guiding principles, the balance of power may be shifting from providers to citizens and "technocrats". Also, all provinces are likely to increase their pressure on physicians by means of salary caps, by exploring payment methods such as capitation, limiting access to costly technology, and by demanding practice changes based on evidence of cost-effectiveness.

Dissolved Organic Carbon 14C in Southern Nevada Groundwater and Implications for Groundwater Travel Times

Energy Technology Data Exchange (ETDEWEB)

Hershey, Ronald L. [Nevada University, Reno, NV (United States). Desert Research Institute; Fereday, Wyall [Nevada University, Reno, NV (United States). Desert Research Institute; Thomas, James M [Nevada University, Reno, NV (United States). Desert Research Institute

2016-08-01

Dissolved inorganic carbon (DIC) carbon-14 (¹⁴C) ages must be corrected for complex chemical and physical reactions and processes that change the amount of ¹⁴C in groundwater as it flows from recharge to downgradient areas. Because of these reactions, DIC ¹⁴C can produce unrealistically old ages and long groundwater travel times that may, or may not, agree with travel times estimated by other methods. Dissolved organic carbon (DOC) ¹⁴C ages are often younger than DIC ¹⁴C ages because there are few chemical reactions or physical processes that change the amount of DOC ¹⁴C in groundwater. However, there are several issues that create uncertainty in DOC ¹⁴C groundwater ages including limited knowledge of the initial (A₀) DOC ¹⁴C in groundwater recharge and potential changes in DOC composition as water moves through an aquifer. This study examines these issues by quantifying A₀ DOC ¹⁴C in recharge areas of southern Nevada groundwater flow systems and by evaluating changes in DOC composition as water flows from recharge areas to downgradient areas. The effect of these processes on DOC ¹⁴C groundwater ages is evaluated and DOC and DIC ¹⁴C ages are then compared along several southern Nevada groundwater flow paths. Twenty-seven groundwater samples were collected from springs and wells in southern Nevada in upgradient, midgradient, and downgradient locations. DOC ¹⁴C for upgradient samples ranged from 96 to 120 percent modern carbon (pmc) with an average of 106 pmc, verifying modern DOC ¹⁴C ages in recharge areas, which decreases uncertainty in DOC ¹⁴C A₀ values, groundwater ages, and travel times. The HPLC spectra of groundwater along a flow path in the Spring Mountains show the same general pattern indicating that the DOC compound composition does not change along this flow path

Innovative technologies for groundwater cleanup

International Nuclear Information System (INIS)

Yow, J.L. Jr.

1992-09-01

These notes provide a broad overview of current developments in innovative technologies for groundwater cleanup. In this context, groundwater cleanup technologies include site remediation methods that deal with contaminants in ground water or that may move from the vadose zone into ground water. This discussion attempts to emphasize approaches that may be able to achieve significant improvements in groundwater cleanup cost or effectiveness. However, since data for quantitative performance and cost comparisons of new cleanup methods are scarce, preliminary comparisons must be based on the scientific approach used by each method and on the site-specific technical challenges presented by each groundwater contamination situation. A large number of technical alternatives that are now in research, development, and testing can be categorized by the scientific phenomena that they employ and by the site contamination situations that they treat. After reviewing a representative selection of these technologies, one of the new technologies, the Microbial Filter method, is discussed in more detail to highlight a promising in situ groundwater cleanup technology that is now being readied for field testing

Death Valley regional groundwater flow system, Nevada and California-Hydrogeologic framework and transient groundwater flow model

Science.gov (United States)

Belcher, Wayne R.; Sweetkind, Donald S.

2010-01-01

by acquiring additional data, by reevaluating existing data using current technology and concepts, and by refining earlier interpretations to reflect the current understanding of the regional groundwater flow system. Groundwater flow in the Death Valley region is composed of several interconnected, complex groundwater flow systems. Groundwater flow occurs in three subregions in relatively shallow and localized flow paths that are superimposed on deeper, regional flow paths. Regional groundwater flow is predominantly through a thick Paleozoic carbonate rock sequence affected by complex geologic structures from regional faulting and fracturing that can enhance or impede flow. Spring flow and ET are the dominant natural groundwater discharge processes. Groundwater also is withdrawn for agricultural, commercial, and domestic uses. Groundwater flow in the DVRFS was simulated using MODFLOW-2000, the U.S. Geological Survey 3D finitedifference modular groundwater flow modeling code that incorporates a nonlinear least-squares regression technique to estimate aquifer parameters. The DVRFS model has 16 layers of defined thickness, a finite-difference grid consisting of 194 rows and 160 columns, and uniform cells 1,500 meters (m) on each side. Prepumping conditions (before 1913) were used as the initial conditions for the transient-state calibration. The model uses annual stress periods with discrete recharge and discharge components. Recharge occurs mostly from infiltration of precipitation and runoff on high mountain ranges and from a small amount of underflow from adjacent basins. Discharge occurs primarily through ET and spring discharge (both simulated as drains) and water withdrawal by pumping and, to a lesser amount, by underflow to adjacent basins simulated by constant-head boundaries. All parameter values estimated by the regression are reasonable and within the range of expected values. The simulated hydraulic heads of the final calibrated transient mode

Report on the Current Technical Issues on ASME Nuclear Code and Standard

International Nuclear Information System (INIS)

Koo, Gyeong Hoi; Lee, B. S.; Yoo, S. H.

2008-11-01

This report describes the analysis on the current revision movement related to the mechanical design issues of the U.S ASME nuclear code and standard. ASME nuclear mechanical design in this report is composed of the nuclear material, primary system, secondary system and high temperature reactor. This report includes the countermeasures based on the ASME Code meeting for current issues of each major field. KAMC(ASME Mirror Committee) of this project is willing to reflect a standpoint of the domestic nuclear industry on ASME nuclear mechanical design and play a technical bridge role for the domestic nuclear industry in ASME Codes application

Hanford Site Groundwater Protection Management Program: Revision 1

International Nuclear Information System (INIS)

1993-11-01

Groundwater protection is a national priority that is promulgated in a variety of environmental regulations at local, state, and federal levels. To effectively coordinate and ensure compliance with applicable regulations, the US Department of Energy has issued DOE Order 5400.1 (now under revision) that requires all US Department of Energy facilities to prepare separate groundwater protection program descriptions and plans. This document describes the Groundwater Protection Management Program for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the Groundwater Protection Management Program cover the following general topical areas: (1) documentation of the groundwater regime, (2) design and implementation of a groundwater monitoring program to support resource management and comply with applicable laws and regulations, (3) a management program for groundwater protection and remediation, (4) a summary and identification of areas that may be contaminated with hazardous waste, (5) strategies for controlling these sources, (6) a remedial action program, and (7) decontamination and decommissioning and related remedial action requirements. Many of the above elements are covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing groundwater protection activities. Additionally, it describes how information needs are identified and can be incorporated into existing or proposed new programs. The Groundwater Protection Management Program provides the general scope, philosophy, and strategies for groundwater protection/management at the Hanford Site. Subtier documents provide the detailed plans for implementing groundwater-related activities and programs. Related schedule and budget information are provided in the 5-year plan for environmental restoration and waste management at the Hanford Site

Radiation risk - historical perspective and current issues

Energy Technology Data Exchange (ETDEWEB)

Kellerer, Albrecht M. [Strahlenbiologisches Institut, Ludwig-Maximilians-Universitaet, Munich, Germany and Institute for Radiation Biology, GSF-National Research Center for Environment and Health, Neuherberg (Germany)

2002-09-01

The assessment of radiation risk needs to be seen against the background of a historical development that has reversed the initial belief in a general beneficial effect of radiation to apprehension and fear. Numerical risk estimates are, today, based on large epidemiological studies, and the observations on the A-bomb survivors are outlined as the primary source of information. Since the epidemiological findings are obtained from relatively high radiation exposures, extrapolations are required to the much lower doses that are relevant to radiation protection. The evolution of extrapolation procedures up to current attempts at mechanistic modelling is outlined, and some of the open issues are reviewed. (author)

Radiation risk - historical perspective and current issues

International Nuclear Information System (INIS)

Kellerer, Albrecht M.

2002-01-01

The assessment of radiation risk needs to be seen against the background of a historical development that has reversed the initial belief in a general beneficial effect of radiation to apprehension and fear. Numerical risk estimates are, today, based on large epidemiological studies, and the observations on the A-bomb survivors are outlined as the primary source of information. Since the epidemiological findings are obtained from relatively high radiation exposures, extrapolations are required to the much lower doses that are relevant to radiation protection. The evolution of extrapolation procedures up to current attempts at mechanistic modelling is outlined, and some of the open issues are reviewed. (author)

Effect of Pumping on Groundwater Levels: A Case Study

Science.gov (United States)

Sindhu, G.; Vijayachandran, Lekshmi

2018-06-01

Groundwater is a major source for drinking and domestic purposes. Nowadays, extensive pumping has become a major issue of concern since pumping has led to rapid decline in the groundwater table, thus imposing landward gradient, leading to saline water intrusion especially in coastal areas. Groundwater pumping has seen its utmost effect on coastal aquifer systems, where the sea-ward gradient gets disturbed due to anthropogenic influences. Hence, a groundwater flow modelling of an aquifer system is essential for understanding the various hydro-geologic conditions, which can be used to study the responses of the aquifer system with regard to various pumping scenarios. Besides, a model helps to predict the water levels for the future period with respect to changing environment. In this study, a finite element groundwater flow model of a coastal aquifer system at Aakulam, Trivandrum district is developed, calibrated and simulated using the software Finite Element subsurface Flow system (FEFLOW 6.2).This simulated model is then used to predict the groundwater levels for a future 5 year period during pre monsoon and post monsoon season.

Effect of Pumping on Groundwater Levels: A Case Study

Science.gov (United States)

Sindhu, G.; Vijayachandran, Lekshmi

2018-03-01

Groundwater is a major source for drinking and domestic purposes. Nowadays, extensive pumping has become a major issue of concern since pumping has led to rapid decline in the groundwater table, thus imposing landward gradient, leading to saline water intrusion especially in coastal areas. Groundwater pumping has seen its utmost effect on coastal aquifer systems, where the sea-ward gradient gets disturbed due to anthropogenic influences. Hence, a groundwater flow modelling of an aquifer system is essential for understanding the various hydro-geologic conditions, which can be used to study the responses of the aquifer system with regard to various pumping scenarios. Besides, a model helps to predict the water levels for the future period with respect to changing environment. In this study, a finite element groundwater flow model of a coastal aquifer system at Aakulam, Trivandrum district is developed, calibrated and simulated using the software Finite Element subsurface Flow system (FEFLOW 6.2).This simulated model is then used to predict the groundwater levels for a future 5 year period during pre monsoon and post monsoon season.

Evaluating groundwater flow using passive electrical measurements

Science.gov (United States)

Voytek, E.; Revil, A.; Singha, K.

2016-12-01

Accurate quantification of groundwater flow patterns, both in magnitude and direction, is a necessary component of evaluating any hydrologic system. Groundwater flow patterns are often determined using a dense network of wells or piezometers, which can be limited due to logistical or regulatory constraints. The self-potential (SP) method, a passive geophysical technique that relies on currents generated by water movement through porous materials, is a re-emerging alternative or addition to traditional piezometer networks. Naturally generated currents can be measured as voltage differences at the ground surface using only two electrodes, or a more complex electrode array. While the association between SP measurements and groundwater flow was observed as early as 1890s, the method has seen resurgence in hydrology since the governing equations were refined in the 1980s. The method can be used to analyze hydrologic processes at various temporal and spatial scales. Here we present the results of multiple SP surveys collected a multiple scales (1 to 10s of meters). Here single SP grid surveys are used to evaluate flow patterns through artic hillslopes at a discrete point in time. Additionally, a coupled groundwater and electrical model is used to analyze multiple SP data sets to evaluate seasonal changes in groundwater flow through an alpine meadow.

CALL FOR PAPERS: Special issue on Current Trends in Integrability and Nonlinear Phenomena Special issue on Current Trends in Integrability and Nonlinear Phenomena

Science.gov (United States)

Gómez-Ullate, D.; Lombardo, S.; Mañas, M.; Mazzocco, M.; Nijhoff, F.; Sommacal, M.

2009-12-01

may be found at www.iop.org/Journals/jphysa. Contributions to the special issue should if possible be submitted electronically by web upload at www.iop.org/Journals/jphysa, or by email to jphysa@iop.org, quoting 'JPhysA Special Issue: Current Trends in Integrability and Nonlinear Phenomena' Submissions should ideally be in standard LaTeX form. Please see the website for further information on electronic submissions. Authors unable to submit electronically may send hard-copy contributions to: Publishing Administrators, Journal of Physics A, IOP Publishing, Dirac House, Temple Back, Bristol BS1 6BE, UK. Please quote 'JPhysA Special Issue—Current Trends in Integrability and Nonlinear Phenomena'. All contributions should be accompanied by a read-me file or covering letter giving the postal and e-mail addresses for correspondence. The Publishing Office should be notified of any subsequent change of address. This special issue will be published in the paper and online version of the journal.

Burn site groundwater interim measures work plan.

Energy Technology Data Exchange (ETDEWEB)

Witt, Jonathan L. (North Wind, Inc., Idaho Falls, ID); Hall, Kevin A. (North Wind, Inc., Idaho Falls, ID)

2005-05-01

This Work Plan identifies and outlines interim measures to address nitrate contamination in groundwater at the Burn Site, Sandia National Laboratories/New Mexico. The New Mexico Environment Department has required implementation of interim measures for nitrate-contaminated groundwater at the Burn Site. The purpose of interim measures is to prevent human or environmental exposure to nitrate-contaminated groundwater originating from the Burn Site. This Work Plan details a summary of current information about the Burn Site, interim measures activities for stabilization, and project management responsibilities to accomplish this purpose.

Coalbed methane produced water in China: status and environmental issues.

Science.gov (United States)

Meng, Yanjun; Tang, Dazhen; Xu, Hao; Li, Yong; Gao, Lijun

2014-01-01

As one of the unconventional natural gas family members, coalbed methane (CBM) receives great attention throughout the world. The major associated problem of CBM production is the management of produced water. In the USA, Canada, and Australia, much research has been done on the effects and management of coalbed methane produced water (CMPW). However, in China, the environmental effects of CMPW were overlooked. The quantity and the quality of CMPW both vary enormously between coal basins or stratigraphic units in China. The unit produced water volume of CBM wells in China ranges from 10 to 271,280 L/well/day, and the concentration of total dissolved solids (TDS) ranges from 691 to 93,898 mg/L. Most pH values of CMPW are more than 7.0, showing the alkaline feature, and the Na-HCO3 and Na-HCO3-Cl are typical types of CMPW in China. Treatment and utilization of CMPW in China lag far behind the USA and Australia, and CMPW is mainly managed by surface impoundments and evaporation. Currently, the core environmental issues associated with CMPW in China are that the potential environmental problems of CMPW have not been given enough attention, and relevant regulations as well as environmental impact assessment (EIA) guidelines for CMPW are still lacking. Other potential issues in China includes (1) water quality monitoring issues for CMPW with special components in special areas, (2) groundwater level decline issues associated with the dewatering process, and (3) potential environmental issues of groundwater pollution associated with hydraulic fracturing.

DOE`s approach to groundwater compliance on the UMTRA project

Energy Technology Data Exchange (ETDEWEB)

Metzler, D. [Dept. of Energy, Washington, DC (United States); Gibb, J.P. [Geraghty and Miller, Inc. (United States); Glover, W.A. [Roy F. Weston, Inc. (United States)

1993-03-01

Compliance with the mandate of the Uranium Mill Tailings Radiation Control Act (UMTRCA) at Uranium Mill Tailings Remedial Action (UMTRA) Project sites requires implementation of a groundwater remedial action plan that meets the requirements of Subpart B of the US Environmental Protection Agency`s proposed groundwater protection standards (40 CFR 192). The UMTRA Groundwater Project will ensure that unacceptable current risk or potential risk to the public health, safety and the environment resulting from the groundwater contamination attributable to the UMTRA sites, is mitigated in a timely and cost-efficient manner. For each UMTRA processing site and vicinity property where contamination exists, a groundwater remedial action plan must be developed that identifies hazardous constituents and establishes acceptable concentration limits for the hazardous constituents as either (a) alternate concentration limits (ACL), (b) maximum concentration limits (MCLs), (c) supplemental standards, or (d) background groundwater quality levels. Project optimization is a strategy that will aggressively work within the current regulatory framework using all available options to meet regulatory requirements. This strategy is outlined within.

Evaluating the impact of irrigation on surface water - groundwater interaction and stream temperature in an agricultural watershed.

Science.gov (United States)

Essaid, Hedeff I; Caldwell, Rodney R

2017-12-01

Changes in groundwater discharge to streams caused by irrigation practices can influence stream temperature. Observations along two currently flood-irrigated reaches in the 640-square-kilometer upper Smith River watershed, an important agricultural and recreational fishing area in west-central Montana, showed a downstream temperature decrease resulting from groundwater discharge to the stream. A watershed-scale coupled surface water and groundwater flow model was used to examine changes in streamflow, groundwater discharge to the stream and stream temperature resulting from irrigation practices. The upper Smith River watershed was used to develop the model framework including watershed climate, topography, hydrography, vegetation, soil properties and current irrigation practices. Model results were used to compare watershed streamflow, groundwater recharge, and groundwater discharge to the stream for three scenarios: natural, pre-irrigation conditions (PreIrr); current irrigation practices involving mainly stream diversion for flood and sprinkler irrigation (IrrCurrent); and a hypothetical scenario with only groundwater supplying sprinkler irrigation (IrrGW). Irrigation increased groundwater recharge relative to natural PreIrr conditions because not all applied water was removed by crop evapotranspiration. Groundwater storage and groundwater discharge to the stream increased relative to natural PreIrr conditions when the source of irrigation water was mainly stream diversion as in the IrrCurrent scenario. The hypothetical IrrGW scenario, in which groundwater withdrawals were the sole source of irrigation water, resulted in widespread lowering of the water table and associated decreases in groundwater storage and groundwater discharge to the stream. A mixing analysis using model predicted groundwater discharge along the reaches suggests that stream diversion and flood irrigation, represented in the IrrCurrent scenario, has led to cooling of stream temperatures

Current and future groundwater withdrawals: Effects, management and energy policy options for a semi-arid Indian watershed

Science.gov (United States)

Sishodia, Rajendra P.; Shukla, Sanjay; Graham, Wendy D.; Wani, Suhas P.; Jones, James W.; Heaney, James

2017-12-01

Effects of future expansion/intensification of irrigated agriculture on groundwater and surface water levels and availability in a semi-arid watershed were evaluated using an integrated hydrologic model (MIKE SHE/MIKE 11) in conjunction with biophysical measurements. Improved water use efficiency, water storage, and energy policy options were evaluated for their ability to sustain the future (2035) increased groundwater withdrawals. Three future withdrawal scenarios (low = 20, medium = 30, high = 50 wells/100 km2/year) based on the historical rate of growth of irrigation wells were formulated. While well drying from falling groundwater levels was limited to drought and consecutive below average rainfall years, under the current (2015) withdrawals, significant increases in frequency and duration (17-97 days/year) of well drying along with 13-26% (19-37 mm) reductions in surface flows were predicted under the future withdrawals. Higher (27-108%) energy demands of existing irrigation pumps due to declining groundwater levels and reduced hydroelectric generation due to decreased surface flows would create a vicious water-food-energy nexus in the future. Crop failure, one of the main causes of farmers' emotional distress and death in the region, is predicted to exacerbate under the future withdrawal scenarios. Shift to negative net recharge (-63 mm) and early and prolonged drying of wells under the high scenario will reduce the groundwater availability and negatively affect crop production in more than 60% and 90% of cropped areas in the Rabi (November-February) and summer (March-May) seasons, respectively during a drought year. Individual and combined demand (drip irrigation and reduced farm electricity subsidy) and supply (water storage) management options improved groundwater levels and reduced well drying by 55-97 days/year compared to business-as-usual management under the high scenario. The combined management (50% drip conversion, 50% reduction in subsidy, and

Continuous Groundwater Monitoring Collocated at USGS Streamgages

Science.gov (United States)

Constantz, J. E.; Eddy-Miller, C.; Caldwell, R.; Wheeer, J.; Barlow, J.

2012-12-01

USGS Office of Groundwater funded a 2-year pilot study collocating groundwater wells for monitoring water level and temperature at several existing continuous streamgages in Montana and Wyoming, while U.S. Army Corps of Engineers funded enhancement to streamgages in Mississippi. To increase spatial relevance with in a given watershed, study sites were selected where near-stream groundwater was in connection with an appreciable aquifer, and where logistics and cost of well installations were considered representative. After each well installation and surveying, groundwater level and temperature were easily either radio-transmitted or hardwired to existing data acquisition system located in streamgaging shelter. Since USGS field personnel regularly visit streamgages during routine streamflow measurements and streamgage maintenance, the close proximity of observation wells resulted in minimum extra time to verify electronically transmitted measurements. After field protocol was tuned, stream and nearby groundwater information were concurrently acquired at streamgages and transmitted to satellite from seven pilot-study sites extending over nearly 2,000 miles (3,200 km) of the central US from October 2009 until October 2011, for evaluating the scientific and engineering add-on value of the enhanced streamgage design. Examination of the four-parameter transmission from the seven pilot study groundwater gaging stations reveals an internally consistent, dynamic data suite of continuous groundwater elevation and temperature in tandem with ongoing stream stage and temperature data. Qualitatively, the graphical information provides appreciation of seasonal trends in stream exchanges with shallow groundwater, as well as thermal issues of concern for topics ranging from ice hazards to suitability of fish refusia, while quantitatively this information provides a means for estimating flux exchanges through the streambed via heat-based inverse-type groundwater modeling. In June

Groundwater vulnerability mapping in Guadalajara aquifers system (Western Mexico)

Science.gov (United States)

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

2016-04-01

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

Proven Alternatives for Aboveground Treatment of Arsenic in Groundwater

Science.gov (United States)

This issue paper, developed for EPA's Engineering Forum, identifies and summarizes experiences with proven aboveground treatment alternatives for arsenic in groundwater, and provides information on their relative effectiveness and cost.

Arsenic geochemistry of groundwater in Southeast Asia.

Science.gov (United States)

Kim, Kyoung-Woong; Chanpiwat, Penradee; Hanh, Hoang Thi; Phan, Kongkea; Sthiannopkao, Suthipong

2011-12-01

The occurrence of high concentrations of arsenic in the groundwater of the Southeast Asia region has received much attention in the past decade. This study presents an overview of the arsenic contamination problems in Vietnam, Cambodia, Lao People's Democratic Republic and Thailand. Most groundwater used as a source of drinking water in rural areas has been found to be contaminated with arsenic exceeding the WHO drinking water guideline of 10 μg·L(-1). With the exception of Thailand, groundwater was found to be contaminated with naturally occurring arsenic in the region. Interestingly, high arsenic concentrations (> 10 μg·L(-1)) were generally found in the floodplain areas located along the Mekong River. The source of elevated arsenic concentrations in groundwater is thought to be the release of arsenic from river sediments under highly reducing conditions. In Thailand, arsenic has never been found naturally in groundwater, but originates from tin mining activities. More than 10 million residents in Southeast Asia are estimated to be at risk from consuming arsenic-contaminated groundwater. In Southeast Asia, groundwater has been found to be a significant source of daily inorganic arsenic intake in humans. A positive correlation between groundwater arsenic concentration and arsenic concentration in human hair has been observed in Cambodia and Vietnam. A substantial knowledge gap exists between the epidemiology of arsenicosis and its impact on human health. More collaborative studies particularly on the scope of public health and its epidemiology are needed to conduct to fulfill the knowledge gaps of As as well as to enhance the operational responses to As issue in Southeast Asian countries.

Current Economic Issues in Employee Benefits. Background Paper No. 39.

Science.gov (United States)

Woodbury, Stephen A.

A multitude of public policy issues currently surround the tax treatment of employee benefits, particularly since the tax-favored status of employer contributions to pensions and health insurance has been blamed for a shrinking tax base that has exacerbated the federal budget deficit, an inefficient and bloated health-care sector, overinsurance by…

Groundwater and human development: challenges and opportunities in livelihoods and environment.

Science.gov (United States)

Shah, T

2005-01-01

At less than 1000 km3/year, the world's annual use of groundwater is 1.5% of renewable water resource but contributes a lion's share of water-induced human welfare. Global groundwater use however has increased manifold in the past 50 years; and the human race has never had to manage groundwater use on such a large scale. Sustaining the massive welfare gains groundwater development has created without ruining the resource is a key water challenge facing the world today. In exploring this challenge, we have focused a good deal on conditions of resource occurrence but less so on resource use. I offer a typology of five groundwater demand systems as Groundwater Socio-ecologies (GwSE), each embodying a unique pattern of interactions between socio-economic and ecological variables, and each facing a distinct groundwater governance challenge. During the past century, a growing corpus of experiential knowledge has accumulated in the industrialized world on managing groundwater in various uses and contexts. A daunting global groundwater issue today is to apply this knowledge intelligently to by far the more formidable challenge that has arisen in developing regions of Asia and Africa, where groundwater irrigation has evolved into a colossal anarchy supporting billions of livelihoods but threatening the resource itself.

Characterization of redox conditions in groundwater contaminant plumes

Science.gov (United States)

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

2000-10-01

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

Gravity survey of groundwater characterization at Labuan Basin

Science.gov (United States)

Handayani, L.; Wardhana, D. D.; Hartanto, P.; Delinom, R.; Sudaryanto; Bakti, H.; Lubis, RF

2018-02-01

Labuan groundwater basin currently has an abundance of water. As a deltaic area of Lada Bay, groundwater supply comes from local precipitation and also from recharge region in mountain ranges surrounding. However, Labuan has been experiencing a fast economic development with high population and tourism industry growth. Such progress would lead to the increase of water consumption. A comprehensive groundwater management should be prepared for possible future problems. Therefore, a groundwater investigation is a necessary step towards that purpose. Gravity method was applied to identify the regional condition of the basement. The assessment of deep buried basin and basement relationship using gravity data is a challenge in groundwater investigation, but previous studies had indicated the efficiency of the method to obtain basic information and can be used as a foundation for more advanced studies.

National survey of molecular bacterial diversity of New Zealand groundwater: relationships between biodiversity, groundwater chemistry and aquifer characteristics.

Science.gov (United States)

Sirisena, Kosala A; Daughney, Christopher J; Moreau-Fournier, Magali; Ryan, Ken G; Chambers, Geoffrey K

2013-12-01

Groundwater is a vital component of rural and urban water supplies in New Zealand. Although extensive monitoring of chemical and physical properties is conducted due to the high demand for this valuable resource, current information on its bacterial content is limited. However, bacteria provide an immense contribution to drive the biogeochemical processes in the groundwater ecosystem as in any other ecosystem. Therefore, a proper understanding of bacterial diversity is crucial to assess the effectiveness of groundwater management policies. In this study, we investigated the bacterial community structure in NZ groundwater at a national scale using the terminal restriction fragment length polymorphism (T-RFLP) molecular profiling tool and determined the relationships between bacterial diversity and groundwater chemistry, geological parameters and human impact. Considerable bacterial diversity was present and the community structures were strongly related to groundwater chemistry, and in particular to redox potential and human impact, reflecting their potential influence on determination of bacterial diversity. Further, the mean residence time of groundwater also showed relationships with bacterial community structure. These novel findings pertaining to community composition and its relationships with environmental parameters will provide a strong foundation for qualitative exploration of the bacterial diversity in NZ groundwater in relation to sustainable management of this valuable resource. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Current and Emerging Ethical Issues in Counseling: A Delphi Study of Expert Opinions

Science.gov (United States)

Herlihy, Barbara; Dufrene, Roxane L.

2011-01-01

A Delphi study was conducted to ascertain the opinions of panel experts regarding the most important current and emerging ethical issues facing the counseling profession. Expert opinions on ethical issues in counselor preparation also were sought. Eighteen panelists responded to 3 rounds of data collection interspersed with feedback. Themes that…

Groundwater arsenic contamination throughout China.

Science.gov (United States)

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

2013-08-23

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

Validating a continental-scale groundwater diffuse pollution model using regional datasets.

Science.gov (United States)

Ouedraogo, Issoufou; Defourny, Pierre; Vanclooster, Marnik

2017-12-11

In this study, we assess the validity of an African-scale groundwater pollution model for nitrates. In a previous study, we identified a statistical continental-scale groundwater pollution model for nitrate. The model was identified using a pan-African meta-analysis of available nitrate groundwater pollution studies. The model was implemented in both Random Forest (RF) and multiple regression formats. For both approaches, we collected as predictors a comprehensive GIS database of 13 spatial attributes, related to land use, soil type, hydrogeology, topography, climatology, region typology, nitrogen fertiliser application rate, and population density. In this paper, we validate the continental-scale model of groundwater contamination by using a nitrate measurement dataset from three African countries. We discuss the issue of data availability, and quality and scale issues, as challenges in validation. Notwithstanding that the modelling procedure exhibited very good success using a continental-scale dataset (e.g. R 2  = 0.97 in the RF format using a cross-validation approach), the continental-scale model could not be used without recalibration to predict nitrate pollution at the country scale using regional data. In addition, when recalibrating the model using country-scale datasets, the order of model exploratory factors changes. This suggests that the structure and the parameters of a statistical spatially distributed groundwater degradation model for the African continent are strongly scale dependent.

Groundwater recharge: The intersection between humanity and hydrogeology

Science.gov (United States)

Smerdon, Brian D.; Drewes, Jörg E.

2017-12-01

Groundwater recharge is an essential part of subsurface water circulation and the beginning of groundwater flow systems that can vary in duration from days to millennia. Globally, there is a growing body of evidence suggesting that many of Earth's aquifers contain 'fossil' groundwater that was recharged more than 12,000 years ago (Jasechko et al., 2017), and a very small portion of groundwater that was recharged within the last 50 years (Gleeson et al., 2015). Together, this information demonstrates the irregular distribution of groundwater circulation within the Earth and the wide variability of recharge conditions that replenish aquifer systems (Befus et al., 2017). Knowledge of groundwater recharge rates and distribution are needed for evaluating and regulating the quantity and quality of water resources, understanding consequences of landscapes use, identifying where managed aquifer recharge can augment supply, and predicting how groundwater systems will respond to a changing climate. In-turn, these topics are of central importance for the health of humans and ecosystems, and security of food and energy. Yet, despite the global importance, quantifying groundwater recharge remains challenging as it cannot be measured directly, and there is uncertainty associated with all currently known estimation methods (Scanlon et al., 2002).

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

Science.gov (United States)

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

2016-01-01

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

Feminism and nurse-midwifery. Historical overview and current issues.

Science.gov (United States)

McCool, W F; McCool, S J

1989-01-01

Despite the fact that the profession of nurse-midwifery and feminism are both disciplines concerned with women and issues affecting women's lives, there has been little investigation or acknowledgement of relationships between their two paradigms. The work presented here is an attempt to discover both similarities and differences between nurse-midwifery and feminist thought. Using a historical approach, it is shown that despite the common goal of improving and maintaining women's status in the world, whether in general or more specifically with regard to health, feminist theorists and nurse-midwives, to a large degree, have worked separately from each other, rarely acknowledging in any formal way the importance of the other discipline. Current issues that have an effect on the practice of nurse-midwifery today--lay midwifery, the profession of nursing, and nurse-midwifery research--are presented in relation to contemporary feminist thought.

Groundwater age and chemistry, and future nutrient loads for selected Rotorua Lakes catchments

International Nuclear Information System (INIS)

Morgenstern, U.; Reevers, R.R.; Daugney, C.J.; Cameron, S.; Gordon, D.

2005-01-01

Hydrochemical analysis and age dating of groundwater and groundwater-fed streams were carried out in the Lake Rotorua and Okareka catchments to assess the past and current states, and future trends in groundwater chemistry. The study was undertaken because of declining lake water quality due to observed increases in nutrient loads entering these lakes. THe hydrogeology of the Rotorua Lakes area can be described as a permeable pumiceous surface tephra layer that allows easy penetration of rainwater recharge to deeper rhyolite and ignimbrite aquifers. These aquifers are essentially unconfined and yield high volumes of groundwater that discharges to spring-fed streams or directly to the lake. The hydrochemistry of groundwaters is characterised by much lower concentrations of Ca, Mg and SO 4 and much higher concentrations of PO 4 -P and SiO 2 than other groundwaters in New Zealand. This chemical signature reflects the volcanic origin of the aquifer lithology. Because the aquifers in the Rotorua area have large water storage capacity there is a long residence time for nutrient-laden groundwater. It takes decades for the water after being recharged to reach the spring-fed streams and the lakes. The large groundwater bodies have therefore 'silently' been contaminated over decades, with the old pristine groundwater being progressively replaced by younger nutrient-laden water that will discharge to the spring-fed streams and finally to the lakes. This study involved age dating of springs, wells, and groundwater-fed streams to assess how long it takes for nutrient-enriched groundwater to travel from pastoral land to springs and streams, and to the lakes. Most of the springs and wells in the Lake Rotorua and Okareka catchments contained relatively old groundwaters, with mean residence times between 40 and >170 years (only two wells have younger water of 26 and 31 years mean residence time). This corresponds to young water fractions (water recharged within the last 55 years

Geostatistical analysis of groundwater chemistry in Japan. Evaluation of the base case groundwater data set

Energy Technology Data Exchange (ETDEWEB)

Salter, P.F.; Apted, M.J. [Monitor Scientific LLC, Denver, CO (United States); Sasamoto, Hiroshi; Yui, Mikazu

1999-05-01

The groundwater chemistry is one of important geological environment for performance assessment of high level radioactive disposal system. This report describes the results of geostatistical analysis of groundwater chemistry in Japan. Over 15,000 separate groundwater analyses have been collected of deep Japanese groundwaters for the purpose of evaluating the range of geochemical conditions for geological radioactive waste repositories in Japan. The significance to issues such as radioelement solubility limits, sorption, corrosion of overpack, behavior of compacted clay buffers, and many other factors involved in safety assessment. It is important therefore, that a small, but representative set of groundwater types be identified so that defensible models and data for generic repository performance assessment can be established. Principal component analysis (PCA) is used to categorize representative deep groundwater types from this extensive data set. PCA is a multi-variate statistical analysis technique, similar to factor analysis or eigenvector analysis, designed to provide the best possible resolution of the variability within multi-variate data sets. PCA allows the graphical inspection of the most important similarities (clustering) and differences among samples, based on simultaneous consideration of all variables in the dataset, in a low dimensionality plot. It also allows the analyst to determine the reasons behind any pattern that is observed. In this study, PCA has been aided by hierarchical cluster analysis (HCA), in which statistical indices of similarity among multiple samples are used to distinguish distinct clusters of samples. HCA allows the natural, a priori, grouping of data into clusters showing similar attributes and is graphically represented in a dendrogram Pirouette is the multivariate statistical software package used to conduct the PCA and HCA for the Japanese groundwater dataset. An audit of the initial 15,000 sample dataset on the basis of

Ground-water development and problems in Idaho

Science.gov (United States)

Crosthwaite, E.G.

1954-01-01

The development of groundwater for irrigation in Idaho, as most of you know, has proceeded at phenomenal rate since the Second World War. In the period 1907 to 1944 inclusive only about 328 valid permits and licenses to appropriate ground water were issued by the state. thereafter 28 permits became valid in 1945, 83 in 1946, and 121 in 1947. Sine 1947 permits and licenses have been issued at the rate of more than 400 a year.  

The thermal consequences of river-level variations in an urban groundwater body highly affected by groundwater heat pumps.

Science.gov (United States)

García-Gil, Alejandro; Vázquez-Suñe, Enric; Schneider, Eduardo Garrido; Sánchez-Navarro, José Ángel; Mateo-Lázaro, Jesús

2014-07-01

The extensive implementation of ground source heat pumps in urban aquifers is an important issue related to groundwater quality and the future economic feasibility of existent geothermal installations. Although many cities are in the immediate vicinity of large rivers, little is known about the thermal river-groundwater interaction at a kilometric-scale. The aim of this work is to evaluate the thermal impact of river water recharges induced by flood events into an urban alluvial aquifer anthropogenically influenced by geothermal exploitations. The present thermal state of an urban aquifer at a regional scale, including 27 groundwater heat pump installations, has been evaluated. The thermal impacts of these installations in the aquifer together with the thermal impacts from "cold" winter floods have also been spatially and temporally evaluated to ensure better geothermal management of the aquifer. The results showed a variable direct thermal impact from 0 to 6 °C depending on the groundwater-surface water interaction along the river trajectory. The thermal plumes far away from the riverbed also present minor indirect thermal impacts due to hydraulic gradient variations. Copyright © 2014 Elsevier B.V. All rights reserved.

Large-scale groundwater modeling using global datasets: a test case for the Rhine-Meuse basin

Directory of Open Access Journals (Sweden)

E. H. Sutanudjaja

2011-09-01

Full Text Available The current generation of large-scale hydrological models does not include a groundwater flow component. Large-scale groundwater models, involving aquifers and basins of multiple countries, are still rare mainly due to a lack of hydro-geological data which are usually only available in developed countries. In this study, we propose a novel approach to construct large-scale groundwater models by using global datasets that are readily available. As the test-bed, we use the combined Rhine-Meuse basin that contains groundwater head data used to verify the model output. We start by building a distributed land surface model (30 arc-second resolution to estimate groundwater recharge and river discharge. Subsequently, a MODFLOW transient groundwater model is built and forced by the recharge and surface water levels calculated by the land surface model. Results are promising despite the fact that we still use an offline procedure to couple the land surface and MODFLOW groundwater models (i.e. the simulations of both models are separately performed. The simulated river discharges compare well to the observations. Moreover, based on our sensitivity analysis, in which we run several groundwater model scenarios with various hydro-geological parameter settings, we observe that the model can reasonably well reproduce the observed groundwater head time series. However, we note that there are still some limitations in the current approach, specifically because the offline-coupling technique simplifies the dynamic feedbacks between surface water levels and groundwater heads, and between soil moisture states and groundwater heads. Also the current sensitivity analysis ignores the uncertainty of the land surface model output. Despite these limitations, we argue that the results of the current model show a promise for large-scale groundwater modeling practices, including for data-poor environments and at the global scale.

Death Valley regional ground-water flow system, Nevada and California -- hydrogeologic framework and transient ground-water flow model

Science.gov (United States)

Belcher, Wayne R.

2004-01-01

provided by acquiring additional data, by reevaluating existing data using current technology and concepts, and by refining earlier interpretations to reflect the current understanding of the regional ground-water flow system. Ground-water flow in the Death Valley region is composed of several interconnected, complex ground-water flow systems. Ground-water flow occurs in three subregions in relatively shallow and localized flow paths that are superimposed on deeper, regional flow paths. Regional ground-water flow is predominantly through a thick Paleozoic carbonate rock sequence affected by complex geologic structures from regional faulting and fracturing that can enhance or impede flow. Spring flow and evapotranspiration (ET) are the dominant natural ground-water discharge processes. Ground water also is withdrawn for agricultural, commercial, and domestic uses. Ground-water flow in the DVRFS was simulated using MODFLOW-2000, a 3D finite-difference modular ground-water flow modeling code that incorporates a nonlinear least-squares regression technique to estimate aquifer parameters. The DVRFS model has 16 layers of defined thickness, a finite-difference grid consisting of 194 rows and 160 columns, and uniform cells 1,500 m on each side. Prepumping conditions (before 1913) were used as the initial conditions for the transient-state calibration. The model uses annual stress periods with discrete recharge and discharge components. Recharge occurs mostly from infiltration of precipitation and runoff on high mountain ranges and from a small amount of underflow from adjacent basins. Discharge occurs primarily through ET and spring discharge (both simulated as drains) and water withdrawal by pumping and, to a lesser amount, by underflow to adjacent basins, also simulated by drains. All parameter values estimated by the regression are reasonable and within the range of expected values. The simulated hydraulic heads of the final calibrated transient model gener

A Multi-Methodology for improving Adelaide's Groundwater Management

Science.gov (United States)

Batelaan, Okke; Banks, Eddie; Batlle-Aguilar, Jordi; Breciani, Etienne; Cook, Peter; Cranswick, Roger; Smith, Stan; Turnadge, Chris; Partington, Daniel; Post, Vincent; Pool Ramirez, Maria; Werner, Adrian; Xie, Yueqing; Yang, Yuting

2015-04-01

Groundwater is a strategic and vital resource in South Australia playing a crucial role in sustaining a healthy environment, as well as supporting industries and economic development. In the Adelaide metropolitan region ten different aquifer units have been identified, extending to more than 500 m below sea level. Although salinity within most of these aquifers is variable, water suitable for commercial, irrigation and/or potable use is predominantly found in the deeper Tertiary aquifers. Groundwater currently contributes only 9000 ML/yr of Adelaide's total water consumption of 216,000 ML, while in the Northern Adelaide Plains 17000 ML/yr is used. However, major industries, market gardeners, golf courses, and local councils are highly dependent on this resource. Despite recent rapid expansion in managed aquifer recharge, and the potential for increased extraction of groundwater, particularly for the commercial and irrigation supplies, little is known about the sources and ages of Adelaide's groundwater. The aim of this study is therefore to provide a robust conceptualisation of Adelaide's groundwater system. The study focuses on three important knowledge gaps: 1. Does groundwater flow from the Adelaide Hills into the sedimentary aquifers on the plains? 2. What is the potential for encroachment of seawater if groundwater extraction increases? 3. How isolated are the different aquifers, or does water leak from one to the other? A multi-tool approach has been used to improve the conceptual understanding of groundwater flow processes; including the installation of new groundwater monitoring wells from the hills to the coast, an extensive groundwater sampling campaign of new and existing groundwater wells for chemistry and environmental tracers analysis, and development of a regional scale numerical model rigorously tested under different scenario conditions. The model allows quantification of otherwise hardly quantifiable quantities such as flow across fault zones and

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.

Chernobyl, Three Mile Island and beyond: Lessons for Ontario? Current issue paper 117

Energy Technology Data Exchange (ETDEWEB)

Yeager, K L

1991-03-01

This current issue paper reviews major accidents which have occurred at commercial and military nuclear facilities, and provides basic background on nuclear power and reactor design features to assist the novice in understanding the very complex technical issues surrounding these events. Above all, the role of human factors in the prevention of potential accident situations is emphasized. (author).

Chernobyl, Three Mile Island and beyond: Lessons for Ontario? Current issue paper 117

International Nuclear Information System (INIS)

Yeager, K.L.

1991-03-01

This current issue paper reviews major accidents which have occurred at commercial and military nuclear facilities, and provides basic background on nuclear power and reactor design features to assist the novice in understanding the very complex technical issues surrounding these events. Above all, the role of human factors in the prevention of potential accident situations is emphasized. (author)

Building groundwater modeling capacity in Mongolia

Science.gov (United States)

Valder, Joshua F.; Carter, Janet M.; Anderson, Mark T.; Davis, Kyle W.; Haynes, Michelle A.; Dorjsuren Dechinlhundev,

2016-06-16

Ulaanbaatar, the capital city of Mongolia (fig. 1), is dependent on groundwater for its municipal and industrial water supply. The population of Mongolia is about 3 million people, with about one-half the population residing in or near Ulaanbaatar (World Population Review, 2016). Groundwater is drawn from a network of shallow wells in an alluvial aquifer along the Tuul River. Evidence indicates that current water use may not be sustainable from existing water sources, especially when factoring the projected water demand from a rapidly growing urban population (Ministry of Environment and Green Development, 2013). In response, the Government of Mongolia Ministry of Environment, Green Development, and Tourism (MEGDT) and the Freshwater Institute, Mongolia, requested technical assistance on groundwater modeling through the U.S. Army Corps of Engineers (USACE) to the U.S. Geological Survey (USGS). Scientists from the USGS and USACE provided two workshops in 2015 to Mongolian hydrology experts on basic principles of groundwater modeling using the USGS groundwater modeling program MODFLOW-2005 (Harbaugh, 2005). The purpose of the workshops was to bring together representatives from the Government of Mongolia, local universities, technical experts, and other key stakeholders to build in-country capacity in hydrogeology and groundwater modeling.A preliminary steady-state groundwater-flow model was developed as part of the workshops to demonstrate groundwater modeling techniques to simulate groundwater conditions in alluvial deposits along the Tuul River in the vicinity of Ulaanbaatar. ModelMuse (Winston, 2009) was used as the graphical user interface for MODFLOW for training purposes during the workshops. Basic and advanced groundwater modeling concepts included in the workshops were groundwater principles; estimating hydraulic properties; developing model grids, data sets, and MODFLOW input files; and viewing and evaluating MODFLOW output files. A key to success was

Comparative studies of groundwater vulnerability assessment

Science.gov (United States)

Maria, Rizka

2018-02-01

Pollution of groundwater is a primary issue because aquifers are susceptible to contamination from land use and anthropogenic impacts. Groundwater susceptibility is intrinsic and specific. Intrinsic vulnerability refers to an aquifer that is susceptible to pollution and to the geological and hydrogeological features. Vulnerability assessment is an essential step in assessing groundwater contamination. This approach provides a visual analysis for helping planners and decision makers to achieve the sustainable management of water resources. Comparative studies are applying different methodologies to result in the basic evaluation of the groundwater vulnerability. Based on the comparison of methods, there are several advantages and disadvantages. SI can be overlaid on DRASTIC and Pesticide DRASTIC to extract the divergence in sensitivity. DRASTIC identifies low susceptibility and underestimates the pollution risk while Pesticide DRASTIC and SI represents better risk and is recommended for the future. SINTACS method generates very high vulnerability zones with surface waters and aquifer interactions. GOD method could be adequate for vulnerability mapping in karstified carbonate aquifers at small-moderate scales, and EPIK method can be used for large scale. GOD method is suitable for designing large area such as land management while DRASTIC has good accuracy and more real use in geoenvironmental detailed studies.

Advances in understanding river-groundwater interactions

Science.gov (United States)

Brunner, Philip; Therrien, René; Renard, Philippe; Simmons, Craig T.; Franssen, Harrie-Jan Hendricks

2017-09-01

River-groundwater interactions are at the core of a wide range of major contemporary challenges, including the provision of high-quality drinking water in sufficient quantities, the loss of biodiversity in river ecosystems, or the management of environmental flow regimes. This paper reviews state of the art approaches in characterizing and modeling river and groundwater interactions. Our review covers a wide range of approaches, including remote sensing to characterize the streambed, emerging methods to measure exchange fluxes between rivers and groundwater, and developments in several disciplines relevant to the river-groundwater interface. We discuss approaches for automated calibration, and real-time modeling, which improve the simulation and understanding of river-groundwater interactions. Although the integration of these various approaches and disciplines is advancing, major research gaps remain to be filled to allow more complete and quantitative integration across disciplines. New possibilities for generating realistic distributions of streambed properties, in combination with more data and novel data types, have great potential to improve our understanding and predictive capabilities for river-groundwater systems, especially in combination with the integrated simulation of the river and groundwater flow as well as calibration methods. Understanding the implications of different data types and resolution, the development of highly instrumented field sites, ongoing model development, and the ultimate integration of models and data are important future research areas. These developments are required to expand our current understanding to do justice to the complexity of natural systems.

Arsenic Contamination in Groundwater of Bangladesh: Perspectives on Geochemical, Microbial and Anthropogenic Issues

Directory of Open Access Journals (Sweden)

Shafi M. Tareq

2011-11-01

Full Text Available A groundwater, sediment and soil chemistry and mineralogical study has been performed to investigate the sources and mobilization process of Arsenic (As in shallow aquifers of Bangladesh. The groundwater from the shallow aquifers is characterized by high concentrations of Arsenic (47.5–216.8 µg/L, iron (0.85–5.83 mg/L, and phosphate, along with high electrical conductivity (EC. The groundwater has both very low oxidation-reduction potential (Eh and dissolved oxygen (DO values indicating reducing conditions. By contrast, the deep aquifers and surface waters (pond, canal have very low concentrations of Arsenic ( < 6 µg/L, iron (0.12–0.39 mg/L, and phosphate along with a relatively low EC. Furthermore, the values of Eh and DO are high, indicating oxic to suboxic conditions. Arsenic is inversely correlated with Eh values in the upper aquifer, whereas no relationship in the deeper aquifer is observed. These results suggest that As mobilization is clearly linked to the development of reducing conditions. The clayey silt, enriched in Fe, Mn, Al oxides and organic matter, and deposited in the middle unit of shallow aquifers, contains moderately high concentrations of As, whereas the sediments of deep aquifers and silty mud surface soils from paddy fields and ponds contain a low content of As (Daudkandi area. Arsenic is strongly correlated with the concentrations of Fe, Mn and Al oxides in the core samples from the Daudkandi and Marua areas. Arsenic is present in the oxide phase of Fe and Mn, phyllosilicate minerals and in organic matter in sediments. This study suggests that adsorption or precipitation of As-rich Fe oxyhydroxide on the surface or inner sites of biotite might be responsible for As concentrations found in altered biotite minerals by Seddique et al. Microbially or geochemically mediated reductive dissolution of Fe oxyhydroxides is the main mechanism for As release. The reducing conditions are caused by respiratory decomposition of

The transboundary non-renewable Nubian Aquifer System of Chad, Egypt, Libya and Sudan: classical groundwater questions and parsimonious hydrogeologic analysis and modeling

Science.gov (United States)

Voss, Clifford I.; Soliman, Safaa M.

2014-03-01

Parsimonious groundwater modeling provides insight into hydrogeologic functioning of the Nubian Aquifer System (NAS), the world's largest non-renewable groundwater system (belonging to Chad, Egypt, Libya, and Sudan). Classical groundwater-resource issues exist (magnitude and lateral extent of drawdown near pumping centers) with joint international management questions regarding transboundary drawdown. Much of NAS is thick, containing a large volume of high-quality groundwater, but receives insignificant recharge, so water-resource availability is time-limited. Informative aquifer data are lacking regarding large-scale response, providing only local-scale information near pumps. Proxy data provide primary underpinning for understanding regional response: Holocene water-table decline from the previous pluvial period, after thousands of years, results in current oasis/sabkha locations where the water table still intersects the ground. Depletion is found to be controlled by two regional parameters, hydraulic diffusivity and vertical anisotropy of permeability. Secondary data that provide insight are drawdowns near pumps and isotope-groundwater ages (million-year-old groundwaters in Egypt). The resultant strong simply structured three-dimensional model representation captures the essence of NAS regional groundwater-flow behavior. Model forecasts inform resource management that transboundary drawdown will likely be minimal—a nonissue—whereas drawdown within pumping centers may become excessive, requiring alternative extraction schemes; correspondingly, significant water-table drawdown may occur in pumping centers co-located with oases, causing oasis loss and environmental impacts.

Groundwater and Subsidence Modeling Combining Geological and Multi-Satellite SAR Data over the Alto Guadalentín Aquifer (SE Spain

Directory of Open Access Journals (Sweden)

Pablo Ezquerro

2017-01-01

Full Text Available In the current context of climate change, improving groundwater monitoring and management is an important issue for human communities in arid environments. The exploitation of groundwater resources can trigger land subsidence producing damage in urban structures and infrastructures. Alto Guadalentín aquifer system in SE Spain has been exploited since 1960 producing an average piezometric level drop of 150 m. This work presents a groundwater model that reproduces groundwater evolution during 52 years with an average error below 10%. The geometry of the model was improved introducing a layer of less permeable and deformable soft soils derived from InSAR deformation and borehole data. The resulting aquifer system history of the piezometric level has been compared with ENVISAT deformation data to calculate a first-order relationship between groundwater changes, soft soil thickness, and surface deformation. This relationship has been validated with the displacement data from ERS and Cosmo-SkyMed satellites. The resulting regression function is then used as an empirical subsidence model to estimate a first approximation of the deformation of the aquifer system since the beginning of the groundwater extraction, reaching 1 to 5.5 m in 52 years. These rough estimations highlight the limitations of the proposed empirical model, requiring the implementation of a coupled hydrogeomechanical model.

Conception to set up a new groundwater monitoring network in Serbia

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Stevanović Zoran

2015-01-01

Full Text Available The Water Framework Directive of the European Union (WFD adopted in year 2000. outlines number of water policy and management actions, where monitoring is of primary importance. Following WFD principles Serbia adopted new legislation in water sector aiming to conserve or achieve good ecological, chemical and quantitative status of water resources. Serbia, as most of the countries of former Yugoslavia mostly uses groundwater for drinking water supply (over 75%. However, the current situation in monitoring of groundwater quality and quantity is far from satisfactory. Several hundred piezometers for observation of groundwater level under auspices of the Hydrometeorological Service of Serbia are located mostly in alluviums of major rivers, while some 70 piezometers are used by the Serbian Environmental Protection Agency for controlling groundwater quality. Currently only 20% of delineated groundwater bodies are under observation. This paper evaluates current conditions and proposes to expand national monitoring network to cover most of groundwater bodies or their groups, to raise number of observation points to a density of ca. 1 object /200 km2 and to include as much as possible actual waterworks in this network. Priority in selecting sites for new observation piezometers or springs has to be given to groundwater bodies under threats, either to their water reserves or their water chemical quality. For the former, an assessment of available renewable reserves versus exploitation capacity is needed, while to estimate pressures on water quality, the best way is to compare aquifers’ vulnerability against anthropogenic (diffuse and punctual hazards. [Projekat Ministarstva nauke Republike Srbije, br. 176022

RCRA groundwater data analysis protocol for the Hanford Site, Washington

International Nuclear Information System (INIS)

Chou, C.J.; Jackson, R.L.

1992-04-01

The Resource Conservation and Recovery Act of 1976 (RCRA) groundwater monitoring program currently involves site-specific monitoring of 20 facilities on the Hanford Site in southeastern Washington. The RCRA groundwater monitoring program has collected abundant data on groundwater quality. These data are used to assess the impact of a facility on groundwater quality or whether remediation efforts under RCRA corrective action programs are effective. Both evaluations rely on statistical analysis of groundwater monitoring data. The need for information on groundwater quality by regulators and environmental managers makes statistical analysis of monitoring data an important part of RCRA groundwater monitoring programs. The complexity of groundwater monitoring programs and variabilities (spatial, temporal, and analytical) exhibited in groundwater quality variables indicate the need for a data analysis protocol to guide statistical analysis. A data analysis protocol was developed from the perspective of addressing regulatory requirements, data quality, and management information needs. This data analysis protocol contains four elements: data handling methods; graphical evaluation techniques; statistical tests for trend, central tendency, and excursion analysis; and reporting procedures for presenting results to users

Opportunity for peri-urban Perth groundwater trade

Science.gov (United States)

Gao, Lei; Connor, Jeff; Doble, Rebecca; Ali, Riasat; McFarlane, Don

2013-07-01

Groundwater trade is widely advocated for reallocating scarce groundwater resources between competing users, and managing over-allocated and declining aquifers. However, groundwater markets are still in their infancy, and the potential benefits and opportunities need investigation, particularly where there is a need to reduce the extraction from declining aquifers. This article evaluates economic impacts of reducing groundwater extraction for irrigation use in peri-urban Perth, Australia, where irrigation, a lake-based ecosystem, and public water supply are highly dependent on a declining groundwater resource. We present an assessment of market-based water trading approaches to reduce groundwater extraction with an economic model representing diversity in returns to groundwater use across a population of irrigators. The results indicate that potential economic costs of a proportional reduction in available groundwater for irrigation are 18-21% less if groundwater trade is possible. We also evaluate a water buyback from irrigation to provide public water supply as an alternative to new infrastructure. We find that buying back up to around 50% of current irrigation allocations could create new public water supply only at the cost of 0.32-0.39 million per GL, which is less than one fifth of the costs of new desalinisation or recycled water supply options (2-3 million per GL). We conclude that, with rapid development of computer and internet based trading platforms that allows fast, efficient and low cost multiple party trading, it is increasingly feasible to realise the economic potentials of market-based trade approaches for managing overexploited aquifers.

A high resolution (1 km) groundwater model for Indonesia

Science.gov (United States)

Sutanudjaja, Edwin; Verkaik, Jarno; de Graaf, Inge; van Beek, Rens; Erkens, Gilles; Bierkens, Marc

2015-04-01

results. Also we discuss fundamental challenges in high resolution groundwater modeling and address various issues that range from computational challenges - e.g. computational time, memory, and parallelization issues - to lack of sufficient detail/fine information for model validation and parameterization - including atmospheric forcing and emergent scaling problems. References: de Graaf et al., Hydrology & Earth System Sciences (2014), http://dx.doi.org/10.5194/hessd-11-5217-2014 Dürr et al., Global Biogeochemical Cycles (2005), http://dx.doi.org/10.1029/2005GB002515 Gleeson et al., Geophysical Research Letter (2011), http://dx.doi.org/10.1029/2010GL045565 Gleeson et al., Geophysical Research Letter (2014), http://dx.doi.org/10.1002/2014GL059856 Harbaugh et al., MODFLOW-2000 (2000), http://water.usgs.gov/nrp/gwsoftware/modflow2000/ofr00-92.pdf Hartmann & Moosdorf, Geochemistry Geophysics Geosystems (2012), http://dx.doi.org/10.1029/2012GC004370 Sutanudjaja et al., Hydrology & Earth System Sciences (2011), http://dx.doi.org/10.5194/hess-15-2913-2011 Sutanudjaja et al., Water Resources Research (2014a), http://dx.doi.org/10.1002/2013WR013807 Sutanudjaja et al., AGU Fall Meeting (2014b), see: http://globalhydrology.nl/models/pcr-globwb-2-0/ van Beek et al., Water Resources Research (2011), http://dx.doi.org/10.1029/2010WR009791

Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992--1993

International Nuclear Information System (INIS)

Savard, C.S.

1994-01-01

Quantification of the ground-water recharge from streamflow in the Fortymile Wash watershed will contribute to regional ground-water studies. Regional ground-water studies are an important component in the studies evaluating the ground-water flow system as a barrier to the potential migration of radionuclides from the potential underground high-level nuclear waste repository. Knowledge gained in understanding the ground-water recharge mechanisms and pathways in the Pah Canyon area, which is 10 km to the northeast of Yucca Mountain, may transfer to Yucca site specific studies. The current data collection network in Fortymile Canyon does not permit quantification of ground-water recharge, however a qualitative understanding of ground-water recharge was developed from these data

Problems of irrigated agriculture in saline groundwater areas: farmers' perceptions

International Nuclear Information System (INIS)

Ahmad, S.; Yasin, M.; Ahmad, M.M.; Hussain, Z.; Khan, Z.; Akbar, G.

2005-01-01

A research study was conducted using participatory interactive dialogue in the brackish groundwater area of Mona SCARP-II, Bhalwal district Sargodha, Pakistan. The Participatory Rural Appraisal (PRA) was conducted in thirteen villages to identify macro- and micro-level issues related to irrigated agriculture in saline groundwater areas. SCARP tube wells have been abandoned or few have been handed over to farmers' organizations. Groundwater in the Indus basin contributes around 35% to the total water available for agriculture. Water quality of 60% area of the Indus basin is marginal to brackish. Minimum land holding of cultivated land in the elected villages varied from 0.10 to 4 ha. The maximum land holding of cultivated area in selected villages varied for 6 to 50 ha. However, the average size of farm was around 4 ha. The average salt-affected area per household was 17% of the total cultivated area. The salt-affected lands in 8 villages out of 13 were barren, where mainly rice crop is grown during kharif season. About 67% farms had access to conjunctive use of water, as water from both canal and private tube wells is available. In addition, 10% farms were having tube well water only. Therefore, 77% farms are having access to the groundwater. According to the farmers' perceptions, 100% villages have fresh groundwater to a depth of 7.5 m and 62% villages had depth ranging from 15-30 m. Furthermore, in all thirteen selected villages, groundwater quality beyond 30 m depth was brackish. Laboratory analysis confirmed the farmer's perception that groundwater quality is a function of depth. About 92% farmers groups indicated that non-availability and high price of inputs was a major problem. The second major issue was related to the shortage of canal water supplies and 77% villages are facing this problem. Moreover, 31% farmers' groups of selected villages indicated that water logging and salinity are the major concerns affecting agricultural productivity. This figure is

Radioactive content in groundwater in the island of Tenerife (Canary Islands)

International Nuclear Information System (INIS)

Lopez-Perez, M.; Duarte-Rodriguez, X.; Rodriguez-Perestelo, N.; Catalan-Acosta, A.; Fernandez- De Aldecoa, J. C.; Hernandez Armas, J.

2013-01-01

At present the groundwater in Tenerife is still the main resource to meet the demands of all kinds. Currently, due to the salt content, groundwater is treated using reversible electrodialysis desalination systems before drinking it. (Author)

Groundwater flow modeling focused on the Fukushima Daiichi Nuclear Power Plant Site

International Nuclear Information System (INIS)

Saegusa, Hiromitsu; Onoe, Hironori; Kohashi, Akio; Watanabe, Masahisa

2015-01-01

Fukushima Daiichi nuclear power plant of Tokyo Electric Power Company is facing contaminated water issues in the aftermath of the Great East Japan Earthquake on March 11, 2011. The amount of contaminated water is continuously increasing due to groundwater leakage into the underground part of reactor and turbine buildings. Therefore, it is important to understand the groundwater flow conditions at the site and to predict the impact of countermeasures taken for isolating groundwater from the source of the contamination, i.e. the reactor buildings. Installations, such as of land-side and sea-side impermeable walls have been planned as countermeasures. In this study, groundwater flow modeling has been performed to estimate the response of groundwater flow conditions to the countermeasures. From the modeling, groundwater recharge and discharge areas, major groundwater flow direction, inflow rate into underground part of the buildings, and changes in response to implementation of the countermeasures could be reasonably estimated. The results indicate that the countermeasures will decrease the volume of inflow into the underground part of the buildings. This means that the countermeasures will be effective in reducing the discharge volume of contaminated groundwater to ocean. (author)

Institutions in transitioning peri-urban communities: spatial differences in groundwater access

Science.gov (United States)

Gomes, Sharlene L.; Hermans, Leon M.

2016-05-01

Urbanization creates challenges for water management in an evolving socio-economic context. This is particularly relevant in transitioning peri-urban areas like Khulna, Bangladesh where competing demands have put pressure on local groundwater resources. Users are unable to sufficiently meet their needs through existing institutions. These institutions provide the rules for service provision and act as guidelines for actors to resolve their water related issues. However, the evolving peri-urban context can produce fragmented institutional arrangements. For example in Khulna, water supply is based on urban and rural boundaries that has created water access issues for peri-urban communities. This has motivated local actors to manage their groundwater needs in various ways. General institutional theories are well developed in literature, yet little is known about institutions in transitioning peri-urban areas. Institutions that fail to adapt to changing dynamics run the risk of becoming obsolete or counter-productive, hence the need for investigating institutional change mechanisms in this context. This paper examines peri-urban case studies from Khulna using the Institutional Analysis and Development framework to demonstrate how institutions have contributed to spatial differences in groundwater access with local actors investing in formal and informal institutional change as a means of accessing groundwater.

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

Science.gov (United States)

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

2018-02-01

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

Current knowledge on groundwater microbial pathogens and their control

Science.gov (United States)

Macler, Bruce A.; Merkle, Jon C.

Those who drink groundwater that has not been disinfected are at increased risk of infection and disease from pathogenic microorganisms. Recent studies have shown that up to half of all US drinking-water wells tested had evidence of fecal contamination. A significant fraction of all waterborne disease outbreaks is associated with groundwater. An estimated 750,000 to 5.9million illnesses per year result from contaminated groundwaters in the US. Mortality from these illnesses may be 1400-9400 deaths per year. Control of these pathogens starts with source-water protection activities to prevent fecal contamination of aquifers and wells. These include assessment of wellhead vulnerability to fecal contamination and correction of identified deficiencies. Correction may include control of sources or rehabilitation of the well itself. Disinfection can serve as a useful barrier and is recommended as a prudent public-health policy for all groundwater systems. Ceux qui boivent une eau souterraine non désinfectée présentent un risque accru d'infection et de maladie par des germes pathogènes. De récentes études ont montré que près de la moitié de tous les puits américains testés, captés pour l'eau potable, sont soumis à une contamination fécale. Une fraction significative de l'ensemble des premières manifestations de maladies liées à l'eau est associée aux eaux souterraines. On estime qu'entre 750 000 et 5,9millions de personnes sont malades chaque année aux États-Unis à cause d'eaux souterraines polluées. La mortalité parmi ces malades doit ètre de l'ordre de 1400 à 9400 décès par an. La protection contre ces germes pathogènes commence avec des mesures prises au niveau du captage pour empècher la pollution des aquifères et des puits. Celles-ci comprennent une évaluation de la vulnérabilité des tètes de puits à la pollution fécale et une correction des insuffisances mises en évidence. Cette correction peut comprendre une maîtrise des sources

Hyper-Resolution Groundwater Modeling using MODFLOW 6

Science.gov (United States)

Hughes, J. D.; Langevin, C.

2017-12-01

MODFLOW 6 is the latest version of the U.S. Geological Survey's modular hydrologic model. MODFLOW 6 was developed to synthesize many of the recent versions of MODFLOW into a single program, improve the way different process models are coupled, and to provide an object-oriented framework for adding new types of models and packages. The object-oriented framework and underlying numerical solver make it possible to tightly couple any number of hyper-resolution models within coarser regional models. The hyper-resolution models can be used to evaluate local-scale groundwater issues that may be affected by regional-scale forcings. In MODFLOW 6, hyper-resolution meshes can be maintained as separate model datasets, similar to MODFLOW-LGR, which simplifies the development of a coarse regional model with imbedded hyper-resolution models from a coarse regional model. For example, the South Atlantic Coastal Plain regional water availability model was converted from a MODFLOW-2000 model to a MODFLOW 6 model. The horizontal discretization of the original model is approximately 3,218 m x 3,218 m. Hyper-resolution models of the Aiken and Sumter County water budget areas in South Carolina with a horizontal discretization of approximately 322 m x 322 m were developed and were tightly coupled to a modified version of the original coarse regional model that excluded these areas. Hydraulic property and aquifer geometry data from the coarse model were mapped to the hyper-resolution models. The discretization of the hyper-resolution models is fine enough to make detailed analyses of the effect that changes in groundwater withdrawals in the production aquifers have on the water table and surface-water/groundwater interactions. The approach used in this analysis could be applied to other regional water availability models that have been developed by the U.S. Geological Survey to evaluate local scale groundwater issues.

The Role of Transdisciplinary Approach and Community Participation in Village Scale Groundwater Management: Insights from Gujarat and Rajasthan, India

Directory of Open Access Journals (Sweden)

Basant Maheshwari

2014-11-01

Full Text Available Sustainable use of groundwater is becoming critical in India and requires effective participation from local communities along with technical, social, economic, policy and political inputs. Access to groundwater for farming communities is also an emotional and complex issue as their livelihood and survival depends on it. In this article, we report on transdisciplinary approaches to understanding the issues, challenges and options for improving sustainability of groundwater use in States of Gujarat and Rajasthan, India. In this project, called Managed Aquifer Recharge through Village level Intervention (MARVI, the research is focused on developing a suitable participatory approach and methodology with associated tools that will assist in improving supply and demand management of groundwater. The study was conducted in the Meghraj watershed in Aravalli district, Gujarat, and the Dharta watershed in Udaipur district, Rajasthan, India. The study involved the collection of hydrologic, agronomic and socio-economic data and engagement of local village and school communities through their role in groundwater monitoring, field trials, photovoice activities and education campaigns. The study revealed that availability of relevant and reliable data related to the various aspects of groundwater and developing trust and support between local communities, NGOs and government agencies are the key to moving towards a dialogue to decide on what to do to achieve sustainable use of groundwater. The analysis of long-term water table data indicated considerable fluctuation in groundwater levels from year to year or a net lowering of the water table, but the levels tend to recover during wet years. This provides hope that by improving management of recharge structures and groundwater pumping, we can assist in stabilizing the local water table. Our interventions through Bhujal Jankaars (BJs, (a Hindi word meaning “groundwater informed” volunteers, schools

Arsenic Contamination of Groundwater in Nepal—An Overview

Directory of Open Access Journals (Sweden)

Sudhir Kumar Singh

2010-12-01

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

Hydrogeological and geochemical investigations of elevated arsenic (As) abundances in groundwater in Ireland

International Nuclear Information System (INIS)

Gilligan, M.; Feely, M.; Morrison, L.; Henry, T.; Higgins, T.M.; Zhang, C.

2009-01-01

Full text: This study will use hydrogeology, geochemistry and chemical speciation studies to investigate the presence of elevated arsenic (As) abundances in groundwater in Ireland. Comparative studies of groundwater, bedrock and mineral chemistry will be linked to hydrogeology, GIS and statistical studies. This approach will facilitate characterization of the temporal and spatial distribution of As as a function of groundwater and bedrock geology using the pressures, pathways and receptors approach. Arsenic speciation studies will determine As toxicity, bioavailability and potential for migration in this environment thus addressing human health issues. (author)

Groundwater availability of the Central Valley Aquifer, California

Science.gov (United States)

Faunt, Claudia C.

2009-01-01

California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

Factors influencing groundwater quality: towards an integrated management approach.

Science.gov (United States)

De Giglio, O; Quaranta, A; Barbuti, G; Napoli, C; Caggiano, G; Montagna, M T

2015-01-01

The safety of groundwater resources is a serious issue, particularly when these resources are the main source of water for drinking, irrigation and industrial use in coastal areas. In Italy, 85% of the water used by the public is of underground origin. The aim of this report is to analyze the main factors that make groundwater vulnerable. Soil characteristics and filtration capacity can promote or hinder the diffusion of environmental contaminants. Global climate change influences the prevalence and degree of groundwater contamination. Anthropic pressure causes considerable exploitation of water resources, leading to reduced water availability and the progressive deterioration of water quality. Management of water quality will require a multidisciplinary, dynamic and practical approach focused on identifying the measures necessary to reduce contamination and mitigate the risks associated with the use of contaminated water resources.

Groundwater Vulnerability Assessment of the Tarkwa Mining Area ...

African Journals Online (AJOL)

In view of the extensive mining in the Tarkwa area, quality of groundwater has become an important issue. This study estimates aquifer vulnerability by applying the SINTACS model which uses seven environmental parameters to evaluate aquifer vulnerability and geographical information system (GIS) in the Tarkwa mining ...

Food and Health Some Current Issues and Future Trends

OpenAIRE

Gormley, T. R. (Thomas Ronan)

1991-01-01

This paper deals with some of the many current issues and future trends in the area of food, diet and health in Europe. A complete coverage would be impossible in a short article in view of the extent and complexity of the food system and its major interaction with health. It is also important to stress at the outset that food/diet is only one component of health and other factors such as environment, overall lifestyle and genetics also play a major role. The genetic dimension is of particula...

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

Science.gov (United States)

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

CKM Phenomenology and B-mesons physics-present status and current issues

International Nuclear Information System (INIS)

Ali, A.

2004-01-01

We review the status of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and the CP-violating phases in the CKM-unitarity triangle. The emphasis in these lecture notes is on B-meson physics, through we also review the current status and issues in the light quark sector of this matrix. Selected applications of theoretical methods in QCD used in the interpretation of data are given and some of the issues restricting the theoretical precision on the CKM matrix elements discussed. The overall consistency of the CKM theory with the available data in flavour physics is impressive and we quantify this consistency. Current data also show some anomalies which, however, are not yet statistically significant. They are discussed briefly. some benchmark measurements that remain to be done in experiments at the B-factories and hadron colliders are listed. Together with the already achieved results, they will provide unprecedented test of the CKM theory and by the same token may lead to the discovery of new physics. (Author) 284 refs

Knowledge, transparency, and refutability in groundwater models, an example from the Death Valley regional groundwater flow system

Science.gov (United States)

Hill, Mary C.; Faunt, Claudia C.; Belcher, Wayne; Sweetkind, Donald; Tiedeman, Claire; Kavetski, Dmitri

2013-01-01

This work demonstrates how available knowledge can be used to build more transparent and refutable computer models of groundwater systems. The Death Valley regional groundwater flow system, which surrounds a proposed site for a high level nuclear waste repository of the United States of America, and the Nevada National Security Site (NNSS), where nuclear weapons were tested, is used to explore model adequacy, identify parameters important to (and informed by) observations, and identify existing old and potential new observations important to predictions. Model development is pursued using a set of fundamental questions addressed with carefully designed metrics. Critical methods include using a hydrogeologic model, managing model nonlinearity by designing models that are robust while maintaining realism, using error-based weighting to combine disparate types of data, and identifying important and unimportant parameters and observations and optimizing parameter values with computationally frugal schemes. The frugal schemes employed in this study require relatively few (10–1000 s), parallelizable model runs. This is beneficial because models able to approximate the complex site geology defensibly tend to have high computational cost. The issue of model defensibility is particularly important given the contentious political issues involved.

Groundwater availability of the Mississippi embayment

Science.gov (United States)

Clark, Brian R.; Hart, Rheannon M.; Gurdak, Jason J.

2011-01-01

Groundwater is an important resource for agricultural and municipal uses in the Mississippi embayment. Arkansas ranks first in the Nation for rice and third for cotton production, with both crops dependent on groundwater as a major source of irrigation requirements. Multiple municipalities rely on the groundwater resources to provide water for industrial and public use, which includes the city of Memphis, Tennessee. The demand for the groundwater resource has resulted in groundwater availability issues in the Mississippi embayment including: (1) declining groundwater levels of 50 feet or more in the Mississippi River Valley alluvial aquifer in parts of eastern Arkansas from agricultural pumping, (2) declining groundwater levels of over 360 feet over the last 90 years in the confined middle Claiborne aquifer in southern Arkansas and northern Louisiana from municipal pumping, and (3) litigation between the State of Mississippi and a Memphis water utility over water rights in the middle Claiborne aquifer. To provide information to stakeholders addressing the groundwater-availability issues, the U.S. Geological Survey Groundwater Resources Program supported a detailed assessment of groundwater availability through the Mississippi Embayment Regional Aquifer Study (MERAS). This assessment included (1) an evaluation of how these resources have changed over time through the use of groundwater budgets, (2) development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends, and (3) application of statistical tools to evaluate the importance of individual observations within a groundwater-monitoring network. An estimated 12 million acre-feet per year (11 billion gallons per day) of groundwater was pumped in 2005 from aquifers in the Mississippi embayment. Irrigation constitutes the largest groundwater use, accounting for approximately 10 million acre-feet per year (9 billion gallons per day) in 2000 from the Mississippi

Two passive groundwater treatment installations at DOE facilities

International Nuclear Information System (INIS)

Barton, W.D.; Craig, P.M.; Stone, W.C.

1997-01-01

Groundwater is being successfully treated by reactive media at two DOE sites. Passive treatment utilizing containerized treatment media has been installed on a radioactive groundwater seep at Oak Ridge National Lab, Oak Ridge, Tennessee, and on a TCE plume at the Portsmouth Gaseous Diffusion Plant in Piketon, Ohio. In both applications, flow is conducted by gravity through canisters of reactive treatment media. The canister-based treatment installation at ORNL utilizes a natural sodium-chabazite zeolite to remove radiological cations (Sr, Cs) from contaminated groundwater at greater than 99.9% efficiency. Portsmouth is currently conducting tests on three different types of treatment media for reductive dehalogenation of TCE

Current safety issues related to research reactor operation

International Nuclear Information System (INIS)

Alcala-Ruiz, F.

2000-01-01

The Agency has included activities on research reactor safety in its Programme and Budget (P and B) since its inception in 1957. Since then, these activities have traditionally been oriented to fulfil the Agency's functions and obligations. At the end of the decade of the eighties, the Agency's Research Reactor Safety Programme (RRSP) consisted of a limited number of tasks related to the preparation of safety related publications and the conduct of safety missions to research reactor facilities. It was at the beginning of the nineties when the RRSP was upgraded and expanded as a subprogramme of the Agency's P and B. This subprogramme continued including activities related to the above subjects and started addressing an increasing number of issues related to the current situation of research reactors (in operation and shut down) around the world such as reactor ageing, modifications and decommissioning. The present paper discusses some of the above issues as recognised by various external review or advisory groups (e.g., Peer Review Groups under the Agency's Performance Programme Appraisal System (PPAS) or the standing International Nuclear Safety Advisory Group (INSAG)) and the impact of their recommendations on the preparation and implementation of the part of the Agency's P and B relating to the above subject. (author)

Hydrochemistry and Isotope Hydrology for Groundwater Sustainability of the Coastal Multilayered Aquifer System (Zhanjiang, China

Directory of Open Access Journals (Sweden)

Pengpeng Zhou

2017-01-01

Full Text Available Groundwater sustainability has become a critical issue for Zhanjiang (China because of serious groundwater level drawdown induced by overexploitation of its coastal multilayered aquifer system. It is necessary to understand the origins, material sources, hydrochemical processes, and dynamics of the coastal groundwater in Zhanjiang to support its sustainable management. To this end, an integrated analysis of hydrochemical and isotopic data of 95 groundwater samples was conducted. Hydrochemical analysis shows that coastal groundwater is fresh; however, relatively high levels of Cl−, Mg2+, and total dissolved solid (TDS imply slight seawater mixing with coastal unconfined groundwater. Stable isotopes (δ18O and δ2H values reveal the recharge sources of groundwater in the multilayered aquifer system. The unconfined groundwater originates from local modern precipitation; the confined groundwater in mainland originates from modern precipitation in northwestern mountain area, and the confined groundwater in Donghai and Leizhou is sourced from rainfall recharge during an older period with a colder climate. Ionic relations demonstrate that silicate weathering, carbonate dissolutions, and cation exchange are the primary processes controlling the groundwater chemical composition. Declining trends of groundwater level and increasing trends of TDS of the confined groundwater in islands reveal the landward extending tendency of the freshwater-seawater mixing zone.

Groundwater Security in Yemen: Who is Accountable to Whom? - Comment

Directory of Open Access Journals (Sweden)

Frank van Steenbergen, Omar Bamaga and Adel Al-Weshali

2011-09-01

Full Text Available The overuse of groundwater in Yemen is now recognized as a national security issue. Groundwater exploitation has increased rapidly over the last four decades. While this has boosted high value farming and created rural jobs, there are grave concerns whether agriculture is not bound for a potentially destabilizing setback. This paper discusses the emergence of local management rules – by water users themselves - and their interplay with formal state institutions. It argues that the existence of formal institutions - including the National Water Law – was more important than their actual almost non-existent implementation. Groundwater where managed is managed locally in Yemen – but in spite of this autonomy, the presence of the Water Law creates the context in which these otherwise contentious local rules develop. The implication is that further strengthening and promoting local regulation is the best option for groundwater management rather than refining and investing in national regulatory institutions.

Groundwater quota versus tiered groundwater pricing : two cases of groundwater management in north-west China

NARCIS (Netherlands)

Aarnoudse, Eefje; Qu, Wei; Bluemling, B.; Herzfeld, Thomas

2017-01-01

Difficulties in monitoring groundwater extraction cause groundwater regulations to fail worldwide. In two counties in north-west China local water authorities have installed smart card machines to monitor and regulate farmers’ groundwater use. Data from a household survey and in-depth interviews are

Groundwater recharge estimates in the Athabasca and Cold Lake oil sands areas

International Nuclear Information System (INIS)

MacMillan, G.J.; Smith, A.D.

2009-01-01

Groundwater recharge estimates for the Cold Lake and Athabasca oil sands region were presented. New oil sands projects planned for the future will require approximately 150,000 m 3 per day of groundwater. Regulators and public agencies are now investigating the potential impacts of oil sands operations on both shallow groundwater and surface water in the region. Maximum yields from the aquifers are also being estimated. Measurements are currently being taken to determine transmissivity, hydraulic pressure, storage potential and leakage. Numerical models are currently used to determine saturated zone recharge estimates and water table fluctuations. Isotope tracers are also being used to determine where groundwater flow potential is vertical as well as to determine correction factors for hydrogeological and geochemical conditions at each site. Darcy's Law is used to determine heat flow in the groundwater aquifers. To date, the studies have demonstrated that drilling fluids have been recovered at groundwater sites. Wells are often installed near water supply and supply well networks. It was concluded that new water wells will need to be completed at various depths. Data were presented for aquifers and nest wells. refs., tabs., figs

Comparison of a Conceptual Groundwater Model and Physically Based Groundwater Mode

Science.gov (United States)

Yang, J.; Zammit, C.; Griffiths, J.; Moore, C.; Woods, R. A.

2017-12-01

Groundwater is a vital resource for human activities including agricultural practice and urban water demand. Hydrologic modelling is an important way to study groundwater recharge, movement and discharge, and its response to both human activity and climate change. To understand the groundwater hydrologic processes nationally in New Zealand, we have developed a conceptually based groundwater flow model, which is fully integrated into a national surface-water model (TopNet), and able to simulate groundwater recharge, movement, and interaction with surface water. To demonstrate the capability of this groundwater model (TopNet-GW), we applied the model to an irrigated area with water shortage and pollution problems in the upper Ruamahanga catchment in Great Wellington Region, New Zealand, and compared its performance with a physically-based groundwater model (MODFLOW). The comparison includes river flow at flow gauging sites, and interaction between groundwater and river. Results showed that the TopNet-GW produced similar flow and groundwater interaction patterns as the MODFLOW model, but took less computation time. This shows the conceptually-based groundwater model has the potential to simulate national groundwater process, and could be used as a surrogate for the more physically based model.

The groundwater regime of the Harwell region

International Nuclear Information System (INIS)

Alexander, J.

1983-12-01

A regional hydrogeological assessment has been undertaken in the Harwell area utilizing currently available geological information and water level data. Since the dissolution and transport of any disposed waste would be controlled by the rate and direction of groundwater movement through a potential repository, a detailed knowledge of regional and local hydrogeology is essential. This study is based on the tenet that very slow groundwater movement, through a sequence of clay lithologies, is measurable at widely separated points within intervening high permeability systems. The analysis of available data from high permeability units within a regional groundwater flow-system provides a general flow model which takes into account inter-lithology water movement in general and vertical water movement across low permeability formations in particular. Groundwater contour maps have been constructed for the Chalk, Upper Greensand, Corallian and Great Oolite lithologies. These show that in the Cretaceous and Jurassic formations of the Harwell area, groundwater movement is predominantly in the horizontal direction with a smaller proportion of vertical flow taking place between adjacent formations. The potential for vertical movement, both upwards and downwards through intervening low permeability clay lithologies is evident. The results are discussed. (author)

HYDROGEOPHYSICAL EVALUATION OF THE GROUNDWATER ...

African Journals Online (AJOL)

Timothy Ademakinwa

Vertical Electrical Soundings (VES) and hydrogeological data were used to delineate the subsurface sequence and map the aquifer units with a view to evaluating the groundwater prospect of the central part of Ogun State,. Southwestern Nigeria. Thirty Schlumberger VES with maximum current electrode spacing (AB) of ...

An introduction to geographic information systems as applied to a groundwater remediation program

International Nuclear Information System (INIS)

Hammock, J.K.; Lorenz, R.

1989-01-01

While the attention to environmental issues has grown over the past several years, so has the focus on groundwater protection. Addressing the task of groundwater remediation often involves a large-scale program with numerous wells and enormous amounts of data. This data must be manipulated and analyzed in an efficient manner for the remediation program to be truly effective. Geographic Information System's (GIS) have proven to be an extremely effective tool in handling and interpreting this type of groundwater information. The purpose of this paper is to introduce the audience to GIS technology, describe how it is being used at the Savannah River Site (SRS) to handle groundwater data and demonstrate how it may be used in the corporate Westinghouse environment

Simulation of Groundwater Flow, Denpasar-Tabanan Groundwater Basin, Bali Province

Directory of Open Access Journals (Sweden)

Heryadi Tirtomihardjo

2014-06-01

Full Text Available DOI: 10.17014/ijog.v6i3.123Due to the complex structure of the aquifer systems and its hydrogeological units related with the space in which groundwater occurs, groundwater flows were calculated in three-dimensional method (3D Calculation. The geometrical descritization and iteration procedures were based on an integrated finite difference method. In this paper, all figures and graphs represent the results of the calibrated model. Hence, the model results were simulated by using the actual input data which were calibrated during the simulation runs. Groundwater flow simulation of the model area of the Denpasar-Tabanan Groundwater Basin (Denpasar-Tabanan GB comprises steady state run, transient runs using groundwater abstraction in the period of 1989 (Qabs-1989 and period of 2009 (Qabs-2009, and prognosis run as well. Simulation results show, in general, the differences of calculated groundwater heads and observed groundwater heads at steady and transient states (Qabs-1989 and Qabs-2009 are relatively small. So, the groundwater heads situation simulated by the prognosis run (scenario Qabs-2012 are considerably valid and can properly be used for controlling the plan of groundwater utilization in Denpasar-Tabanan GB.

A high resolution global scale groundwater model

Science.gov (United States)

de Graaf, Inge; Sutanudjaja, Edwin; van Beek, Rens; Bierkens, Marc

2014-05-01

As the world's largest accessible source of freshwater, groundwater plays a vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and supplies water for agricultural and industrial activities. During times of drought, groundwater storage provides a large natural buffer against water shortage and sustains flows to rivers and wetlands, supporting ecosystem habitats and biodiversity. Yet, the current generation of global scale hydrological models (GHMs) do not include a groundwater flow component, although it is a crucial part of the hydrological cycle. Thus, a realistic physical representation of the groundwater system that allows for the simulation of groundwater head dynamics and lateral flows is essential for GHMs that increasingly run at finer resolution. In this study we present a global groundwater model with a resolution of 5 arc-minutes (approximately 10 km at the equator) using MODFLOW (McDonald and Harbaugh, 1988). With this global groundwater model we eventually intend to simulate the changes in the groundwater system over time that result from variations in recharge and abstraction. Aquifer schematization and properties of this groundwater model were developed from available global lithological maps and datasets (Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013), combined with our estimate of aquifer thickness for sedimentary basins. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. Based on our sensitivity analysis, in which we run the model with various hydrogeological parameter settings, we observed that most variance in groundwater

Understanding shallow groundwater contamination in Bwaise slum, Kampala, Uganda

Science.gov (United States)

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

2012-04-01

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

Estimating Groundwater Development area in Jianan Plain using Standardized Groundwater Index

Science.gov (United States)

Yu, Chang Hsiang; Haw, Lee Cheng

2017-04-01

Taiwan has been facing severe water crises in recent years owing to the effects of extreme weather conditions. Changes in precipitation patterns have also made the drought phenomenon increasingly prominent, which has indirectly affected groundwater recharge. Hence, in the present study, long-term monitoring data were collected from the study area of the Jianan plain. The standardized groundwater index (SGI) and was then used to analyse the region's drought characteristics. To analyse the groundwater level by using SGI, making SGI180 groundwater level be the medium water crises, and SGI360 groundwater level be the extreme water crises. Through the different water crises signal in SGI180 and SGI360, we divide groundwater in Jianan plain into two sections. Thereby the water crises indicators establishing groundwater level standard line in Jianan Plain, then using the groundwater level standard line to find the study area where could be groundwater development area in Jianan plain. Taking into account relatively more water scarcity in dry season, so the study screen out another emergency backup groundwater development area, but the long-term groundwater development area is still as a priority development area. After finding suitable locations, groundwater modeling systems(GMS) software is used to simulate our sites to evaluate development volume. Finally, the result of study will help the government to grasp the water shortage situation immediately and solve the problem of water resources deployment.

Leukemia and radium groundwater contamination

International Nuclear Information System (INIS)

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

1986-01-01

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

Transfer of European Approach to Groundwater Monitoring in China

Science.gov (United States)

Zhou, Y.

2007-12-01

in 3 pilot areas have been conducted to build research capacities of the central and provincial groundwater information centers in providing groundwater information services to decision makers and public. Groundwater regime zoning and pollution risk maps were used to lay-out groundwater quantity and quality monitoring networks, respectively. Automatic groundwater recorders were installed in selected observation wells. ArcGIS based regional groundwater information systems were constructed and used to create groundwater regime zoning and pollution risk maps. Steady state groundwater models have been constructed and calibrated. Transient groundwater models are under calibration. Groundwater resources development scenarios were formulated. The model will be used to predict what will be consequences in next 20 years if current situation continues as business as usual. Possibilities of reducing groundwater abstraction and opportunities of artificially enhanced groundwater recharge will be analyzed. Combination of decreasing abstraction and increasing recharge may lead to a sustainable plan of future groundwater resources development.

A Study on the Surface and Subsurface Water Interaction Based on the Groundwater Recession Curve

Science.gov (United States)

Wang, S. T.; Chen, Y. W.; Chang, L. C.; Chiang, C. J.; Wang, Y. S.

2017-12-01

The interaction of surface to subsurface water is an important issue for groundwater resources assessment and management. The influences of surface water to groundwater are mainly through the rainfall recharge, river recharge and discharge and other boundary sources. During a drought period, the interaction of river and groundwater may be one of the main sources of groundwater level recession. Therefore, this study explores the interaction of surface water to groundwater via the groundwater recession. During drought periods, the pumping and river interaction together are the main mechanisms causing the recession of groundwater level. In principle, larger gradient of the recession curve indicates more groundwater discharge and it is an important characteristic of the groundwater system. In this study, to avoid time-consuming manual analysis, the Python programming language is used to develop a statistical analysis model for exploring the groundwater recession information. First, the slopes of the groundwater level hydrograph at every time step were computed for each well. Then, for each well, the represented slope to each groundwater level was defined as the slope with 90% exceedance probability. The relationship between the recession slope and the groundwater level can then be obtained. The developed model is applied to Choushui River Alluvial Fan. In most wells, the results show strong positive correlations between the groundwater levels and the absolute values of the recession slopes.

Aquifers of Arkansas: protection, management, and hydrologic and geochemical characteristics of groundwater resources in Arkansas

Science.gov (United States)

Kresse, Timothy M.; Hays, Phillip D.; Merriman, Katherine R.; Gillip, Jonathan A.; Fugitt, D. Todd; Spellman, Jane L.; Nottmeier, Anna M.; Westerman, Drew A.; Blackstock, Joshua M.; Battreal, James L.

2014-01-01

Sixteen aquifers in Arkansas that currently serve or have served as sources of water supply are described with respect to existing groundwater protection and management programs, geology, hydrologic characteristics, water use, water levels, deductive analysis, projections of hydrologic conditions, and water quality. State and Federal protection and management programs are described according to regulatory oversight, management strategies, and ambient groundwater-monitoring programs that currently (2013) are in place for assessing and protecting groundwater resources throughout the State.

Current ethical and legal issues in health-related direct-to-consumer genetic testing.

Science.gov (United States)

Niemiec, Emilia; Kalokairinou, Louiza; Howard, Heidi Carmen

2017-09-01

A variety of health-related genetic testing is currently advertized directly to consumers. This article provides a timely overview of direct-to-consumer genetic testing (DTC GT) and salient ethical issues, as well as an analysis of the impact of the recently adopted regulation on in vitro diagnostic medical devices on DTC GT. DTC GT companies currently employ new testing approaches, report on a wide spectrum of conditions and target new groups of consumers. Such activities raise ethical issues including the questionable analytic and clinical validity of tests, the adequacy of informed consent, potentially misleading advertizing, testing in children, research uses and commercialization of genomic data. The recently adopted regulation on in vitro diagnostic medical devices may limit the offers of predisposition DTC GT in the EU market.

Ground-Water Protection and Monitoring Program

Energy Technology Data Exchange (ETDEWEB)

Dresel, P.E.

1995-06-01

This section of the 1994 Hanford Site Environmental Report summarizes the ground-water protection and monitoring program strategy for the Hanford Site in 1994. Two of the key elements of this strategy are to (1) protect the unconfined aquifer from further contamination, and (2) conduct a monitoring program to provide early warning when contamination of ground water does occur. The monitoring program at Hanford is designed to document the distribution and movement of existing ground-water contamination and provides a historical baseline for evaluating current and future risk from exposure to the contamination and for deciding on remedial action options.

Ground-Water Protection and Monitoring Program

International Nuclear Information System (INIS)

Dresel, P.E.

1995-01-01

This section of the 1994 Hanford Site Environmental Report summarizes the ground-water protection and monitoring program strategy for the Hanford Site in 1994. Two of the key elements of this strategy are to (1) protect the unconfined aquifer from further contamination, and (2) conduct a monitoring program to provide early warning when contamination of ground water does occur. The monitoring program at Hanford is designed to document the distribution and movement of existing ground-water contamination and provides a historical baseline for evaluating current and future risk from exposure to the contamination and for deciding on remedial action options

Nuclear power systems: Their safety. Current issue review

International Nuclear Information System (INIS)

Myers, L.C.

1994-04-01

Human beings utilize energy in many forms and from a variety of sources. A number of countries have chosen nuclear-electric generation as a component of their energy system. At the end of 1992, there were 419 power reactors operating in 29 countries, accounting for more than 15% of the world's production of electricity. In 1992, 13 countries derived at least 25% of their electricity from nuclear units, with Lithuania leading at just over 78%, followed closely by France at 72%. In the same year, Canada produced about 16% of its electricity from nuclear units. Some 53 power reactors are under construction in 14 countries outside the former USSR. Within the ex-USSR countries, six new reactors are currently under construction. No human endeavour carries the guarantee of perfect safety and the question of whether of not nuclear-electric generation represents an 'acceptable' risk to society has long been vigorously debated. Until the events of late April 1986 in the then Soviet Union, nuclear safety had indeed been an issue for discussion, for some concern, but not for alarm. The accident at the Chernobyl reactor irrevocably changed all that. This disaster brought the matter of nuclear safety into the public mind in a dramatic fashion. Subsequent opening of the ex-Soviet nuclear power program to outside scrutiny has done little to calm people's concerns about the safety of nuclear power in that part of the world. This paper discusses the issue of safety in complex energy systems and provides brief accounts of some of the most serious reactor accidents that have occurred to date, as well as more recent, less dramatic events touching on the safety issue. (author). 7 refs

Stable isotope and groundwater flow dynamics of agricultural irrigation recharge into groundwater resources of the Central Valley, California

International Nuclear Information System (INIS)

Davisson, M.L.; Criss, R.E.

1995-01-01

Intensive agricultural irrigation and overdraft of groundwater in the Central Valley of California profoundly affect the regional quality and availability of shallow groundwater resources. In the natural state, the δ 18 O values of groundwater were relatively homogeneous (mostly -7.0 ± 0.5 per-thousand), reflecting local meteoric recharge that slowly (1-3m/yr) flowed toward the valley axis. Today, on the west side of the valley, the isotope distribution is dominated by high 18 O enclosures formed by recharge of evaporated irrigation waters, while the east side has bands of low 18 O groundwater indicating induced recharge from rivers draining the Sierra Nevada mountains. Changes in δ 18 O values caused by the agricultural recharge strongly correlate with elevated nitrate concentrations (5 to >100 mg/L) that form pervasive, non-point source pollutants. Small, west-side cities dependent solely on groundwater resources have experienced increases of >1.0 mg/L per year of nitrate for 10-30 years. The resultant high nitrates threaten the economical use of the groundwater for domestic purposes, and have forced some well shut-downs. Furthermore, since >80% of modern recharge is now derived from agricultural irrigation, and because modern recharge rates are ∼10 times those of the natural state, agricultural land retirement by urbanization will severely curtail the current safe-yields and promote overdraft pumping. Such overdrafting has occurred in the Sacramento metropolitan area for ∼40 years, creating cones of depression ∼25m deep. Today, groundwater withdrawal in Sacramento is approximately matched by infiltration of low 18 O water (-11.0 per-thousand) away from the Sacramento and American Rivers, which is estimated to occur at 100-300m/year from the sharp 18 O gradients in our groundwater isotope map

Female sex trafficking: conceptual issues, current debates, and future directions.

Science.gov (United States)

Meshkovska, Biljana; Siegel, Melissa; Stutterheim, Sarah E; Bos, Arjan E R

2015-01-01

Female sex trafficking is a pressing concern. In this article, we provide a comprehensive overview of relevant issues regarding the concept of female sex trafficking and research in the field of human trafficking, drawing on a variety of disciplines, including economics, gender and sexuality studies, psychology, sociology, law, and social work. We discuss the debates surrounding the definition of human trafficking, compare and contrast it with human smuggling, and outline connections between female sex trafficking and the issue of sex work and prostitution. We further discuss the history and current estimations of female sex trafficking. We then outline the main actors in female sex trafficking, including trafficked persons, traffickers, clients, and service providers, and we overview the trafficking process from recruitment to identification, recovery, and (re)integration. Finally, we conclude with recommendations for future research that tie together the concepts of vulnerability, exploitation, and long-term recovery and (re)integration.

Groundwater remediation from the past to the future: A bibliometric analysis.

Science.gov (United States)

Zhang, Shu; Mao, Guozhu; Crittenden, John; Liu, Xi; Du, Huibin

2017-08-01

Groundwater is an important component of terrestrial ecosystems and plays a role in geochemical cycling. Groundwater is also used for agricultural irrigation and for the domestic supply of drinking water in most nations. However, groundwater contamination has led to many research efforts on groundwater remediation technologies and strategies. This study evaluated a total of 5486 groundwater remediation-related publications from 1995 to 2015 using bibliometric technology and social network analysis, to provide a quantitative analysis and a global view on the current research trend and future research directions. Our results underline a strong research interest and an urgent need to remediate groundwater pollution due to the increasing number of both groundwater contamination and remediation publications. In the past two decades, the United States (U.S.) published 41.1% of the papers and it was the core country of the international collaboration network, cooperating with the other 19 most productive countries. Besides the active international collaboration, the funding agencies also played positive roles to foster the science and technology publications. With respect to the analysis of the distribution of funding agencies, the National Science Foundation of China sponsored most of the groundwater remediation research. We also identified the most productive journals, Environmental Science and Technology and Journal of Contaminant Hydrology, which published 334 and 259 scientific articles (including research articles and reviews) over the past 20 years, respectively. In addition to journal publications, a patent analysis was performed to show the impact of intellectual property protection on journal publications. Three major remediation technologies, including chemical oxidation, biodegradation and adsorption, have received increasing interest in both journal publication and patent development. Our results provide a valuable reference and global overview to identify

Groundwater recharge in desert playas: current rates and future effects of climate change

Science.gov (United States)

Our results from playas, which are topographic low areas situated in closed-catchments in drylands, indicated that projected climate change in Southwestern USA would have a net positive impact over runon and groundwater recharge beneath playas. Expected increased precipitation variability can cause ...

Prediction of monthly regional groundwater levels through hybrid soft-computing techniques

Science.gov (United States)

Chang, Fi-John; Chang, Li-Chiu; Huang, Chien-Wei; Kao, I.-Feng

2016-10-01

Groundwater systems are intrinsically heterogeneous with dynamic temporal-spatial patterns, which cause great difficulty in quantifying their complex processes, while reliable predictions of regional groundwater levels are commonly needed for managing water resources to ensure proper service of water demands within a region. In this study, we proposed a novel and flexible soft-computing technique that could effectively extract the complex high-dimensional input-output patterns of basin-wide groundwater-aquifer systems in an adaptive manner. The soft-computing models combined the Self Organized Map (SOM) and the Nonlinear Autoregressive with Exogenous Inputs (NARX) network for predicting monthly regional groundwater levels based on hydrologic forcing data. The SOM could effectively classify the temporal-spatial patterns of regional groundwater levels, the NARX could accurately predict the mean of regional groundwater levels for adjusting the selected SOM, the Kriging was used to interpolate the predictions of the adjusted SOM into finer grids of locations, and consequently the prediction of a monthly regional groundwater level map could be obtained. The Zhuoshui River basin in Taiwan was the study case, and its monthly data sets collected from 203 groundwater stations, 32 rainfall stations and 6 flow stations during 2000 and 2013 were used for modelling purpose. The results demonstrated that the hybrid SOM-NARX model could reliably and suitably predict monthly basin-wide groundwater levels with high correlations (R2 > 0.9 in both training and testing cases). The proposed methodology presents a milestone in modelling regional environmental issues and offers an insightful and promising way to predict monthly basin-wide groundwater levels, which is beneficial to authorities for sustainable water resources management.

Pesticides in groundwater: modelling and data analysis of the past, present and future

DEFF Research Database (Denmark)

Binning, Philip John; McKnight, Ursula S.; Malaguerra, Flavio

Pesticides are the most frequently detected groundwater contaminants in Denmark. However, there is still a great deal of debate about the fate of pesticides and their future occurrence in our environment. We do not really understand the link between past usage and current observations, and are no......Pesticides are the most frequently detected groundwater contaminants in Denmark. However, there is still a great deal of debate about the fate of pesticides and their future occurrence in our environment. We do not really understand the link between past usage and current observations...... to jointly manage our groundwater and surface water resources. Here, observed pesticide data is analyzed and combined with models to address these questions and needs. Groundwater and surface water pesticide observations reflect the fact that these two hydrological components have a strong interaction...

The treatment of Parkinson's disease with deep brain stimulation: current issues.

Science.gov (United States)

Moldovan, Alexia-Sabine; Groiss, Stefan Jun; Elben, Saskia; Südmeyer, Martin; Schnitzler, Alfons; Wojtecki, Lars

2015-07-01

Deep brain stimulation has become a well-established symptomatic treatment for Parkinson's disease during the last 25 years. Besides improving motor symptoms and long-term motor complications, positive effects on patients' mobility, activities of daily living, emotional well-being and health-related quality of life have been recognized. Apart from that, numerous clinical trials analyzed effects on non-motor symptoms and side effects of deep brain stimulation. Several technical issues and stimulation paradigms have been and are still being developed to optimize the therapeutic effects, minimize the side effects and facilitate handling. This review summarizes current therapeutic issues, i.e., patient and target selection, surgical procedure and programming paradigms. In addition it focuses on neuropsychological effects and side effects of deep brain stimulation.

Characteristics and factors of groundwater contamination in Asian coastal megacities

Science.gov (United States)

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

2017-12-01

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

Windows of Opportunity for Groundwater Management

Science.gov (United States)

Foster, T.; Brozovic, N.; Butler, A. P.

2015-12-01

To date, there has been little attention focused on how the value and effectiveness of groundwater management is influenced by the timing of regulatory intervention relative to aquifer depletion. To address this question, we develop an integrated framework that couples an agro-economic model of farmers' field-level irrigation decision-making with a model of a groundwater abstraction borehole. Unlike existing models that only consider the impact of aquifer depletion on groundwater extraction costs, our model also captures the dynamic changes in well productivity and how these in turn affect crop yields and farmer incomes. We use our model to analyze how the value of imposing groundwater quotas is affected by the prior level of depletion before regulations are introduced. Our results demonstrate that there is a range of aquifer conditions within which regulating groundwater use will deliver long-term economic benefits for farmers. In this range, restricting abstraction rates slows the rate of change in well yields and, as a result, increases agricultural production over the simulated planning horizon. Contrastingly, when current saturated thickness is outside this range, regulating groundwater use will provide negligible social benefits and will impose large negative impacts on farm-level profits. We suggest that there are 'windows of opportunity' for managing aquifer depletion that are a function of local hydrology as well as economic characteristics. Regulation that is too early will harm the rural economy needlessly, while regulation that is too late will be unable to prevent aquifer exhaustion. The insights from our model can be a valuable tool to help inform policy decisions about when, and at what level, regulations should be implemented in order to maximize the benefits obtained from limited groundwater resources.

Sensitivity of GRACE-derived estimates of groundwater-level changes in southern Ontario, Canada

Science.gov (United States)

Hachborn, Ellen; Berg, Aaron; Levison, Jana; Ambadan, Jaison Thomas

2017-12-01

Amidst changing climates, understanding the world's water resources is of increasing importance. In Ontario, Canada, low water conditions are currently assessed using only precipitation and watershed-based stream gauges by the Conservation Authorities in Ontario and the Ministry of Natural Resources and Forestry. Regional groundwater-storage changes in Ontario are not currently measured using satellite data by research institutes. In this study, contributions from the Gravity Recovery and Climate Experiment (GRACE) data are compared to a hydrogeological database covering southern Ontario from 2003 to 2013, to determine the suitability of GRACE total water storage estimates for monitoring groundwater storage in this location. Terrestrial water storage data from GRACE were used to determine monthly groundwater storage (GWS) anomaly values. GWS values were also determined by multiplying groundwater-level elevations (from the Provincial Groundwater Monitoring Network wells) by specific yield. Comparisons of GRACE-derived GWS to well-based GWS data determined that GRACE is sufficiently sensitive to obtain a meaningful signal in southern Ontario. Results show that GWS values produced by GRACE are useful for identifying regional changes in groundwater storage in areas with limited available hydrogeological characterization data. Results also indicate that GRACE may have an ability to forecast changes in groundwater storage, which will become useful when monitoring climate shifts in the near future.

Halon-1301, a new Groundwater Age Tracer

Science.gov (United States)

Beyer, Monique; van der Raaij, Rob; Morgenstern, Uwe; Jackson, Bethanna

2015-04-01

Groundwater dating is an important tool to assess groundwater resources in regards to direction and time scale of groundwater flow and recharge and to assess contamination risks and manage remediation. To infer groundwater age information, a combination of different environmental tracers, such as tritium and SF6, are commonly used. However ambiguous age interpretations are often faced, due to a limited set of available tracers and limitations of each tracer method when applied alone. There is a need for additional, complementary groundwater age tracers. We recently discovered that Halon-1301, a water soluble and entirely anthropogenic gaseous substance, may be a promising candidate [Beyer et al, 2014]. Halon-1301 can be determined along with SF6, SF5CF3 and CFC-12 in groundwater using a gas chromatography setup with attached electron capture detector developed by Busenberg and Plummer [2008]. Halon-1301 has not been assessed in groundwater. This study assesses the behaviour of Halon-1301 in water and its suitability as a groundwater age tracer. We determined Halon-1301 in 17 groundwater and various modern (river) waters sites located in 3 different groundwater systems in the Wellington Region, New Zealand. These waters have been previously dated with tritium, CFC-12, CFC-11 and SF6 with mean residence times ranging from 0.5 to over 100 years. The waters range from oxic to anoxic and some show evidence of CFC contamination or degradation. This allows us to assess the different properties affecting the suitability of Halon-1301 as groundwater age tracer, such as its conservativeness in water and local contamination potential. The samples are analysed for Halon-1301 and SF6simultaneously, which allows identification of issues commonly faced when using gaseous tracers such as contamination with modern air during sampling. Overall we found in the assessed groundwater samples Halon-1301 is a feasible new groundwater tracer. No sample indicated significantly elevated

A report on isotope hydrology of groundwater in Bangladesh: implications for characterization and mitigation of arsenic in groundwater

Energy Technology Data Exchange (ETDEWEB)

Aggarwal, P K; Froehlich, K [International Atomic Energy Agency, Isotope Hydrology Section, Vienna (Austria); Basu, A R; Poreda, R J [Department of Earth Sciences, University of Rochester Rochester, New York (United States); Kulkarni, K M [Bhabha Atomic Research Centre, Isotope Hydrology Section, Trombay, Mumbai (India); Tarafdar, S A; Ali, Mohamed; Ahmed, Nasir [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh); Hussain, Alamgir; Rahman, Mizanur; Ahmed, Syed Reazuddin [Bangladesh Water Development Board, Dhaka (Bangladesh)

2000-12-01

An investigation of the source and dynamics of groundwater in Bangladesh has been conducted with environmental isotope tracers. The primary objective of this study was to provide a scientific basis for developing mitigation strategies by characterizing the mechanism of arsenic mobilization in groundwater and the present and future status of arsenic contamination in deeper aquifers. About 55 shallow and deep groundwater samples ranging in depth from 10 to 335 m were collected and analyzed for their chemical and isotopic compositions. Distinct patterns of isotope compositions are found in shallow and deep groundwaters. Arsenic contamination is found to be present mostly in shallow groundwater to depths of less than 70 m. Groundwater samples from deep wells containing elevated arsenic concentrations are found to contain water mostly from shallow aquifers and do not indicate arsenic contamination of deeper aquifers. However, depth in itself is not a criterion that can be reliably or easily used to find arsenic-free, safe drinking water. Water with high arsenic concentrations sampled from 'deep' wells may not be representative of deep aquifers, and presently uncontaminated water from somewhat deeper wells ({approx}100 m) may not remain so over a long period of time. Increased exploitation of deep groundwater ({approx}300 m) such as in the Barisal area appears to be possible without fear of arsenic contamination from shallow aquifers. However, the potential for groundwater mining is clearly evident and the sustainability of this resource needs to be evaluated. The exponential increase in groundwater exploitation between 1979 and 1999 does not appear to have affected the overall hydrodynamics of shallow and deep aquifers and, by implication, the arsenic mobilization processes. Currently favored mechanisms of arsenic mobilization are found to be inconsistent with isotope data. The most likely process of arsenic mobilization may involve desorption from the sediments as a

A report on isotope hydrology of groundwater in Bangladesh: implications for characterization and mitigation of arsenic in groundwater

International Nuclear Information System (INIS)

Aggarwal, P.K.; Froehlich, K.; Basu, A.R.; Poreda, R.J.; Kulkarni, K.M.; Tarafdar, S.A.; Mohamed Ali; Nasir Ahmed; Alamgir Hussain; Mizanur Rahman; Syed Reazuddin Ahmed

2000-12-01

An investigation of the source and dynamics of groundwater in Bangladesh has been conducted with environmental isotope tracers. The primary objective of this study was to provide a scientific basis for developing mitigation strategies by characterizing the mechanism of arsenic mobilization in groundwater and the present and future status of arsenic contamination in deeper aquifers. About 55 shallow and deep groundwater samples ranging in depth from 10 to 335 m were collected and analyzed for their chemical and isotopic compositions. Distinct patterns of isotope compositions are found in shallow and deep groundwaters. Arsenic contamination is found to be present mostly in shallow groundwater to depths of less than 70 m. Groundwater samples from deep wells containing elevated arsenic concentrations are found to contain water mostly from shallow aquifers and do not indicate arsenic contamination of deeper aquifers. However, depth in itself is not a criterion that can be reliably or easily used to find arsenic-free, safe drinking water. Water with high arsenic concentrations sampled from 'deep' wells may not be representative of deep aquifers, and presently uncontaminated water from somewhat deeper wells (∼100 m) may not remain so over a long period of time. Increased exploitation of deep groundwater (∼300 m) such as in the Barisal area appears to be possible without fear of arsenic contamination from shallow aquifers. However, the potential for groundwater mining is clearly evident and the sustainability of this resource needs to be evaluated. The exponential increase in groundwater exploitation between 1979 and 1999 does not appear to have affected the overall hydrodynamics of shallow and deep aquifers and, by implication, the arsenic mobilization processes. Currently favored mechanisms of arsenic mobilization are found to be inconsistent with isotope data. The most likely process of arsenic mobilization may involve desorption from the sediments as a result of

Geomorphology and its implication in urban groundwater environment: case study from Mumbai, India

Science.gov (United States)

Rani, V. R.; Pandalai, H. S.; Sajinkumar, K. S.; Pradeepkumar, A. P.

2015-06-01

Landforms of Mumbai Island have been largely modified by the urban sprawl and the demand for groundwater will increase exponentially in the future. Quality and quantity of groundwater occurrence in island are highly influenced by the geomorphic units. As this metropolis receives heavy rainfall, the area rarely faces the issue of water scarcity, nevertheless, quality always remains a question. The landforms of Mumbai Island have been shaped by a combination of fluvial, denudational and marine processes. These landforms are categorized into two broad zones on the basis of its influence in groundwater occurrence. Denudational landforms are categorized as runoff zones whereas the other two are categorized as storage zones. This classification is on the basis of occurrence and storage of groundwater. Mumbai Island is exposed to frequent sea water incursion and groundwater quality has deteriorated. The varied hydrogeological conditions prevalent in this area prevent rapid infiltration. This combined with the overextraction of groundwater resources for agriculture and industry has caused serious concern about the continued availability of potable water. This study aims at validating the geomorphic classification of the landforms with hydrogeochemistry and borehole data and it proved that geomorphology corroborates with groundwater chemistry and subsurface geology.

Assessing groundwater policy with coupled economic-groundwater hydrologic modeling

Science.gov (United States)

Mulligan, Kevin B.; Brown, Casey; Yang, Yi-Chen E.; Ahlfeld, David P.

2014-03-01

This study explores groundwater management policies and the effect of modeling assumptions on the projected performance of those policies. The study compares an optimal economic allocation for groundwater use subject to streamflow constraints, achieved by a central planner with perfect foresight, with a uniform tax on groundwater use and a uniform quota on groundwater use. The policies are compared with two modeling approaches, the Optimal Control Model (OCM) and the Multi-Agent System Simulation (MASS). The economic decision models are coupled with a physically based representation of the aquifer using a calibrated MODFLOW groundwater model. The results indicate that uniformly applied policies perform poorly when simulated with more realistic, heterogeneous, myopic, and self-interested agents. In particular, the effects of the physical heterogeneity of the basin and the agents undercut the perceived benefits of policy instruments assessed with simple, single-cell groundwater modeling. This study demonstrates the results of coupling realistic hydrogeology and human behavior models to assess groundwater management policies. The Republican River Basin, which overlies a portion of the Ogallala aquifer in the High Plains of the United States, is used as a case study for this analysis.

Groundwater Quantity and Quality Issues in a Water-Rich Region: Examples from Wisconsin, USA

Directory of Open Access Journals (Sweden)

John Luczaj

2015-06-01

Full Text Available The State of Wisconsin is located in an unusually water-rich portion of the world in the western part of the Great Lakes region of North America. This article presents an overview of the major groundwater quantity and quality concerns for this region in a geologic context. The water quantity concerns are most prominent in the central sand plain region and portions of a Paleozoic confined sandstone aquifer in eastern Wisconsin. Water quality concerns are more varied, with significant impacts from both naturally occurring inorganic contaminants and anthropogenic sources. Naturally occurring contaminants include radium, arsenic and associated heavy metals, fluoride, strontium, and others. Anthropogenic contaminants include nitrate, bacteria, viruses, as well as endocrine disrupting compounds. Groundwater quality in the region is highly dependent upon local geology and land use, but water bearing geologic units of all ages, Precambrian through Quaternary, are impacted by at least one kind of contaminant.

Monitoring and Assessing Groundwater Impacts on Vegetation Health in Groundwater Dependent Ecosystems

Science.gov (United States)

Rohde, M. M.; Ulrich, C.; Howard, J.; Sweet, S.

2017-12-01

Sustainable groundwater management is important for preserving our economy, society, and environment. Groundwater supports important habitat throughout California, by providing a reliable source of water for these Groundwater Dependent Ecosystems (GDEs). Groundwater is particularly important in California since it supplies an additional source of water during the dry summer months and periods of drought. The drought and unsustainable pumping practices have, in some areas, lowered groundwater levels causing undesirable results to ecosystems. The Sustainable Groundwater Management Act requires local agencies to avoid undesirable results in the future, but the location and vulnerabilities of the ecosystems that depend on groundwater and interconnected surface water is often poorly understood. This presentation will feature results from a research study conducted by The Nature Conservancy and Lawrence Berkeley National Laboratory that investigated how changes in groundwater availability along an interconnected surface water body can impact the overall health of GDEs. This study was conducted in California's Central Valley along the Cosumnes River, and situated at the boundary of a high and a medium groundwater basin: South American Basin (Sacramento Hydrologic Region) and Cosumnes Basin (San Joaquin Hydrologic Region). By employing geophysical methodology (electrical resistivity tomography) in this study, spatial changes in groundwater availability were determined under groundwater-dependent vegetation. Vegetation survey data were also applied to this study to develop ecosystem health indicators for groundwater-dependent vegetation. Health indicators for groundwater-dependent vegetation were found to directly correlate with groundwater availability, such that greater availability to groundwater resulted in healthier vegetation. This study provides a case study example on how to use hydrological and biological data for setting appropriate minimum thresholds and

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

Directory of Open Access Journals (Sweden)

Daniel Emilio Martínez

2010-12-01

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

Risk-based decision analysis for the 200-BP-5 groundwater operable unit. Revision 2

International Nuclear Information System (INIS)

Chiaramonte, G.R.

1996-02-01

This document presents data from a risk analysis that was performed on three groundwater contaminant plumes within the 200-BP-5 Operable Unit. Hypothetical exposure scenarios were assessed based on current and future plume conditions. For current conditions, a hypothetical industrial groundwater scenarios were assumed. The industrial ingestion scenario, which is derived from HSRAM, was not used for drinking water and should not be implied by this risk analysis that the DOE is advocating use of this groundwater for direct human ingestion. Risk was calculated at each monitoring well using the observed radionuclide concentrations in groundwater from that well. The calculated values represent total radiological incremental lifetime cancer risk. Computer models were used to show the analytical flow and transport of contaminants of concern

A review of arsenic and its impacts in groundwater of the Ganges-Brahmaputra-Meghna delta, Bangladesh.

Science.gov (United States)

Edmunds, W M; Ahmed, K M; Whitehead, P G

2015-06-01

Arsenic in drinking water is the single most important environmental issue facing Bangladesh; between 35 and 77 million of its 156 million inhabitants are considered to be at risk from drinking As-contaminated water. This dominates the list of stress factors affecting health, livelihoods and the ecosystem of the delta region. There is a vast literature on the subject so this review provides a filter of the more important information available on the topic. The arsenic problem arises from the move in the 1980s and 1990s by international agencies to construct tube wells as a source of water free of pathogens, groundwater usually considered a safe source. Since arsenic was not measured during routine chemical analysis and also is difficult to measure at low concentrations it was not until the late 1990s that the widespread natural anomaly of high arsenic was discovered and confirmed. The problem was exacerbated by the fact that the medical evidence of arsenicosis only appears slowly. The problem arises in delta regions because of the young age of the sediments deposited by the GBM river system. The sediments contain minerals such as biotite which undergo slow "diagenetic" reactions as the sediments become compacted, and which, under the reducing conditions of the groundwater, release in the form of toxic As(3+). The problem is restricted to sediments of Holocene age and groundwater of a certain depth (mainly 30-150 m), coinciding with the optimum well depth. The problem is most serious in a belt across southern Bangladesh, but within 50 m of the coast the problem is only minor because of use of deep groundwater; salinity in shallow groundwater here is the main issue for drinking water. The Government of Bangladesh adopted a National Arsenic Policy and Mitigation Action Plan in 2004 for providing arsenic safe water to all the exposed population, to provide medical care for those who have visible symptoms of arsenicosis. There is as yet no national monitoring program in

Groundwater management in northern Iraq

Science.gov (United States)

Stevanovic, Zoran; Iurkiewicz, Adrian

2009-03-01

Groundwater is vital and the sole resource in most of the studied region of northern Iraq. It has a significant role in agriculture, water supply and health, and the elimination of poverty in rural areas. Although Iraq is currently dramatically disturbed by complex political and socio-economic problems, in its northern part, i.e. the Kurdish-inhabited region, fast urbanization and economic expansion are visible everywhere. Monitoring and water management schemes are necessary to prevent aquifer over-exploitation in the region. Artificial recharge with temporary runoff water, construction of subsurface dams and several other aquifer management and regulation measures have been designed, and some implemented, in order to improve the water situation. Recommendations, presented to the local professionals and decision-makers in water management, include creation of Water Master Plans and Water User Associations, synchronization of drilling programmes, rehabilitation of the existing well fields, opening of new well fields, and the incorporation of new spring intakes in some areas with large groundwater reserves, as well as construction of numerous small-scale schemes for initial in situ water treatment where saline groundwater is present.

Nuclear power in the OECD countries results and current issues

International Nuclear Information System (INIS)

Jones, C.F.

1989-01-01

The first use of nuclear power for the generation of electricity on a commercial scale occurred in the United Kingdom in 1956. Today, 13 OECD countries have 318 nuclear units in operation and 66 more in construction or on order. This outstanding achievement is the result of the successful organization, start up, and operation of an industry to design, build, equip, fuel, and maintain these facilites. Nuclear power, however, is currently troubled by a number of issues that may impair its ability to reach its full potential. The industry has acknowledged problems that can be and are being managed. But the industry also has a number of political difficulties that could be beyond its ability to resolve with its own resources. These are issues common to the introduction of new technologies into a complex world. Nevertheless, nuclear power continues to be the means by which we can provide the electric power needed to raise the living standard of everyone on the globe

EUGRIS: ''European Substainable Land and Groundwater Management Information System''

Energy Technology Data Exchange (ETDEWEB)

Frauenstein, J. [Federal Environmental Agency (UBA), Berlin (Germany)

2003-07-01

The presentation outlines and Accompanying Measure with the FP 5 to develop an web based EUropean Sustainable Land and GRoundwater Management Information System information system (EUGRIS). The management of contaminated land and groundwater requires an interdisciplinary approach and a considerable amount of supporting technical information and knowledge. EUGRIS will provide a generally available comprehensive and overarching information and innovation resource, to support both research and practical contaminated land and groundwater management. EUGRI is a gateway to provide a 'one stop shop' for information provided by research projects, legislation, standards, best practice and other technical guidance and policy/regulatory publications from the EC, participating Member and Accession States and from various international networks dealing with groundwater and land management issues. Different types of user can access information through different windows according to their needs. EUGRIS will provide its visitors with summary information (digests) and links to sources of more detailed and/or original information in a scaleable holistic and contexturally meaningful way. EUGRIS is being built in three stages: the design of the information system, the development of its software implementation, and the population of the system with information. The presentation is focussed on the concept of the development of the information system with the individual work packages. In the second part of the lecture in particular the work procedures are presented for the content wise replenishment by EUGRIS. The data collation for the proven pilot countries and the production of a European research data base, which opens contents and results of European-wide locked and current projects, form the emphasis thereby. (orig.)

Challenges in groundwater resource management in coastal aquifers of East Africa: Investigations and lessons learnt in the Comoros Islands, Kenya and Tanzania

Directory of Open Access Journals (Sweden)

Jean-Christophe Comte

2016-03-01

Full Text Available Study region: Coastal areas of Kenya (Kilifi County, Tanzania (Kilwa district and Comoros (Ngazidja island, East Africa. Study focus: Research aimed to understand the physical and societal drivers of groundwater accessibility and identify critical aspects of groundwater access and knowledge gaps that require further monitoring and research. Interdisciplinary societal, environmental and hydrogeological investigations were consistently undertaken in the three areas considered as exemplars of the diversity of the coastal fringes of the wider region. This paper focuses on the hydrogeological outcomes of the research, framed within the principal socio-environmental issues identified. New hydrological insights: Results confirm the fundamental importance of coastal groundwater resources for the development of the region and the urgent need to match groundwater development with demographic and economic growth. Hydrogeological knowledge is fragmented, groundwater lacks a long-term monitoring infrastructure and information transfer from stakeholders to users is limited. Current trends in demography, climate, sea-level and land-use are further threatening freshwater availability. Despite possessing high-productivity aquifers, water quality from wells and boreholes is generally impacted by saltwater intrusion. Shallow large-diameter wells, following the traditional model of these areas, consistently prove to be less saline and more durable than deeper small-diameter boreholes. However, promoting the use of large numbers of shallow wells poses a significant challenge for governance, requiring coherent management of the resource at local and national scales and the engagement of local communities. Keywords: Groundwater, Coastal aquifer, Eastern Africa, Environmental change, Governance, Community engagement

Implications of using on-farm flood flow capture to recharge groundwater and mitigate flood risks along the Kings River, CA.

Science.gov (United States)

Bachand, Philip A M; Roy, Sujoy B; Choperena, Joe; Cameron, Don; Horwath, William R

2014-12-02

The agriculturally productive San Joaquin Valley faces two severe hydrologic issues: persistent groundwater overdraft and flooding risks. Capturing flood flows for groundwater recharge could help address both of these issues, yet flood flow frequency, duration, and magnitude vary greatly as upstream reservoir releases are affected by snowpack, precipitation type, reservoir volume, and flood risks. This variability makes dedicated, engineered recharge approaches expensive. Our work evaluates leveraging private farmlands in the Kings River Basin to capture flood flows for direct and in lieu recharge, calculates on-farm infiltration rates, assesses logistics, and considers potential water quality issues. The Natural Resources Conservation Service (NRCS) soil series suggested that a cementing layer would hinder recharge. The standard practice of deep ripping fractured the layer, resulting in infiltration rates averaging 2.5 in d(-1) (6 cm d(-1)) throughout the farm. Based on these rates 10 acres are needed to infiltrate 1 cfs (100 m(3) h(-1)) of flood flows. Our conceptual model predicts that salinity and nitrate pulses flush initially to the groundwater but that groundwater quality improves in the long term due to pristine flood flows low in salts or nitrate. Flood flow capture, when integrated with irrigation, is more cost-effective than groundwater pumping.

The UMTRA PEIS: A strategy for groundwater remediation

International Nuclear Information System (INIS)

Burt, C.; Ulland, L.; Weston, R.F.; Metzler, D.

1993-01-01

A programmatic environmental impact statement (PEIS) was initiated in 1992 for the uranium mill tailings remedial action (UMTRA) program. The PEIS kicked off the groundwater restoration phase of UMTRA, a project involving remediation of 24 sites in ten states and tribal lands contaminated with tailings from uranium mining and milling operations. The U.S. Department of Energy (DOE) agreed, in early 1992, that a PEIS was an appropriate strategy to comply with the National Environmental Policy Act (NEPA) for this second, groundwater phase of the project. This decision recognized that although a parallel effort was being undertaken in preparing a PEIS for DOE's Environmental Restoration/Waste Management (ER/WM) program, characteristics and the maturity of the UMTRA project made it more appropriate to prepare a separate PEIS. The ER/WM PEIS is intended to examine environmental restoration and waste management issues from a very broad perspective. For UMTRA, with surface remediation completed or well under way at 18 of the 24 sites, a more focused programmatic approach for groundwater restoration is more effective than including the UMTRA project within the ER/WM environmental impact statements. A separate document allows a more focused and detailed analysis necessary to efficiently tier site-specific environmental assessments for groundwater restoration at each of the 24 UMTRA former processing sites

Geochemical Investigations of Groundwater Stability

International Nuclear Information System (INIS)

Bath, Adrian

2006-05-01

The report describes geochemical parameters and methods that provide information about the hydrodynamic stability of groundwaters in low permeability fractured rocks that are potential hosts for radioactive waste repositories. Hydrodynamic stability describes the propensity for changes in groundwater flows over long timescales, in terms of flow rates and flow directions. Hydrodynamic changes may also cause changes in water compositions, but the related issue of geochemical stability of a potential repository host rock system is outside the scope of this report. The main approaches to assessing groundwater stability are numerical modelling, measurement and interpretation of geochemical indicators in groundwater compositions, and analyses and interpretations of secondary minerals and fluid inclusions in these minerals. This report covers the latter two topics, with emphasis on geochemical indicators. The extent to which palaeohydrogeology and geochemical stability indicators have been used in past safety cases is reviewed. It has been very variable, both in terms of the scenarios considered, the stability indicators considered and the extent to which the information was explicitly or implicitly used in assessing FEPs and scenarios in the safety cases. Geochemical indicators of hydrodynamic stability provide various categories of information that are of hydrogeological relevance. Information about groundwater mixing, flows and water sources is potentially provided by the total salinity of groundwaters, their contents of specific non-reactive solutes (principally chloride) and possibly of other solutes, the stable isotopic ratio of water, and certain characteristics of secondary minerals and fluid inclusions. Information pertaining directly to groundwater ages and the timing of water and solute movements is provided by isotopic systems including tritium, carbon-14, chlorine-36, stable oxygen and hydrogen isotopes, uranium isotopes and dissolved mobile gases in

Groundwater sustainability strategies

Science.gov (United States)

Gleeson, Tom; VanderSteen, Jonathan; Sophocleous, Marios A.; Taniguchi, Makoto; Alley, William M.; Allen, Diana M.; Zhou, Yangxiao

2010-01-01

Groundwater extraction has facilitated significant social development and economic growth, enhanced food security and alleviated drought in many farming regions. But groundwater development has also depressed water tables, degraded ecosystems and led to the deterioration of groundwater quality, as well as to conflict among water users. The effects are not evenly spread. In some areas of India, for example, groundwater depletion has preferentially affected the poor. Importantly, groundwater in some aquifers is renewed slowly, over decades to millennia, and coupled climate–aquifer models predict that the flux and/or timing of recharge to many aquifers will change under future climate scenarios. Here we argue that communities need to set multigenerational goals if groundwater is to be managed sustainably.

Ecology and living conditions of groundwater fauna

Energy Technology Data Exchange (ETDEWEB)

Thulin, Barbara [Geo Innova AB (Sweden); Hahn, Hans Juergen [Arbeitsgruppe Grundwasseroekologie, Univ. of Koblenz-Landau (Germany)

2008-09-15

This report presents the current state of ecological knowledge and applied research relating to groundwater. A conceptual picture is given of groundwater fauna occurrence in regard to Swedish environmental conditions. Interpretation features for groundwater fauna and applications are outlined. Groundwater is one of the largest and oldest limnic habitats populated by a rich and diverse fauna. Both very old species and species occurring naturally in brackish or salt water can be found in groundwater. Groundwater ecosystems are heterotrophic; the fauna depends on imports from the surface. Most species are meiofauna, 0.3-1 mm. The food chain of groundwater fauna is the same as for relatives in surface water and salt water. Smaller animals graze biofilms and detritus, larger animals act facutatively as predators. A difference is that stygobiotic fauna has become highly adapted to its living space and tolerates very long periods without food. Oxygen is a limiting factor, but groundwater fauna tolerates periods with low oxygen concentrations, even anoxic conditions. For longer periods of time a minimum oxygen requirement of 1 mg/l should be fulfilled. Geographic features such as Quaternary glaciation and very old Pliocene river systems are important for distribution patterns on a large spatial scale, but aquifer characteristics are important on a landscape scale. Area diversity is often comparable to surface water diversity. However, site diversity is low in groundwater. Site specific hydrological exchange on a geological facies level inside the aquifer, e.g. porous, fractured and karstic aquifers as well as the hyporheic zone, controls distribution patterns of groundwater fauna. For a better understanding of controlling factors indicator values are suggested. Different adequate sampling methods are available. They are representative for the aquifer, but a suitable number of monitoring wells is required. The existence of groundwater fauna in Sweden is considered as very

Ecology and living conditions of groundwater fauna

International Nuclear Information System (INIS)

Thulin, Barbara; Hahn, Hans Juergen

2008-09-01

This report presents the current state of ecological knowledge and applied research relating to groundwater. A conceptual picture is given of groundwater fauna occurrence in regard to Swedish environmental conditions. Interpretation features for groundwater fauna and applications are outlined. Groundwater is one of the largest and oldest limnic habitats populated by a rich and diverse fauna. Both very old species and species occurring naturally in brackish or salt water can be found in groundwater. Groundwater ecosystems are heterotrophic; the fauna depends on imports from the surface. Most species are meiofauna, 0.3-1 mm. The food chain of groundwater fauna is the same as for relatives in surface water and salt water. Smaller animals graze biofilms and detritus, larger animals act facutatively as predators. A difference is that stygobiotic fauna has become highly adapted to its living space and tolerates very long periods without food. Oxygen is a limiting factor, but groundwater fauna tolerates periods with low oxygen concentrations, even anoxic conditions. For longer periods of time a minimum oxygen requirement of 1 mg/l should be fulfilled. Geographic features such as Quaternary glaciation and very old Pliocene river systems are important for distribution patterns on a large spatial scale, but aquifer characteristics are important on a landscape scale. Area diversity is often comparable to surface water diversity. However, site diversity is low in groundwater. Site specific hydrological exchange on a geological facies level inside the aquifer, e.g. porous, fractured and karstic aquifers as well as the hyporheic zone, controls distribution patterns of groundwater fauna. For a better understanding of controlling factors indicator values are suggested. Different adequate sampling methods are available. They are representative for the aquifer, but a suitable number of monitoring wells is required. The existence of groundwater fauna in Sweden is considered as very

Groundwater-surface water interaction

International Nuclear Information System (INIS)

White, P.A.; Clausen, B.; Hunt, B.; Cameron, S.; Weir, J.J.

2001-01-01

This chapter discusses natural and modified interactions between groundwater and surface water. Theory on recharge to groundwater from rivers is introduced, and the relative importance of groundwater recharge from rivers is illustrated with an example from the Ngaruroro River, Hawke's Bay. Some of the techniques used to identify and measure recharge to groundwater from gravel-bed rivers will be outlined, with examples from the Ngaruroro River, where the recharge reach is relatively well defined, and from the Rakaia River, where it is poorly defined. Groundwater recharged from rivers can have characteristic chemical and isotopic signatures, as shown by Waimakariri River water in the Christchurch-West Melton groundwater system. The incorporation of groundwater-river interaction in a regional groundwater flow model is outlined for the Waimea Plains, and relationships between river scour and groundwater recharge are examined for the Waimakariri River. Springs are the result of natural discharge from groundwater systems and are important water sources. The interactions between groundwater systems, springs, and river flow for the Avon River in New Zealand will be outlined. The theory of depletion of stream flow by groundwater pumpage will be introduced with a case study from Canterbury, and salt-water intrusion into groundwater systems with examples from Nelson and Christchurch. The theory of artificial recharge to groundwater systems is introduced with a case study from Hawke's Bay. Wetlands are important to flora, and the relationship of the wetland environment to groundwater hydrology will be discussed, with an example from the South Taupo wetland. (author). 56 refs., 25 figs., 3 tabs

Assessment of BSBA Students' Conversancy in Current Business Issues: A Case Study

Science.gov (United States)

Hogan, Eileen A.; Maskulka, Therese A.; Kaminski, Kathleen A.

2014-01-01

In 2008, the faculty of the College of Business at Kutztown University developed a set of five learning goals for its BSBA program. In fall, 2011, the college's Assurance of Learning Committee began to pursue the assessment of the last of these goals: "BSBA graduates will be conversant in current business issues, including ethics, social…

Groundwater availability as constrained by hydrogeology and environmental flows.

Science.gov (United States)

Watson, Katelyn A; Mayer, Alex S; Reeves, Howard W

2014-01-01

Groundwater pumping from aquifers in hydraulic connection with nearby streams has the potential to cause adverse impacts by decreasing flows to levels below those necessary to maintain aquatic ecosystems. The recent passage of the Great Lakes-St. Lawrence River Basin Water Resources Compact has brought attention to this issue in the Great Lakes region. In particular, the legislation requires the Great Lakes states to enact measures for limiting water withdrawals that can cause adverse ecosystem impacts. This study explores how both hydrogeologic and environmental flow limitations may constrain groundwater availability in the Great Lakes Basin. A methodology for calculating maximum allowable pumping rates is presented. Groundwater availability across the basin may be constrained by a combination of hydrogeologic yield and environmental flow limitations varying over both local and regional scales. The results are sensitive to factors such as pumping time, regional and local hydrogeology, streambed conductance, and streamflow depletion limits. Understanding how these restrictions constrain groundwater usage and which hydrogeologic characteristics and spatial variables have the most influence on potential streamflow depletions has important water resources policy and management implications. © 2013, National Ground Water Association.

Simulation of groundwater flow and interaction of groundwater and surface water on the Lac du Flambeau Reservation, Wisconsin

Science.gov (United States)

Juckem, Paul F.; Fienen, Michael N.; Hunt, Randall J.

2014-01-01

The Lac du Flambeau Band of Lake Superior Chippewa and Indian Health Service are interested in improving the understanding of groundwater flow and groundwater/surface-water interaction on the Lac du Flambeau Reservation (Reservation) in southwest Vilas County and southeast Iron County, Wisconsin, with particular interest in an understanding of the potential for contamination of groundwater supply wells and the fate of wastewater that is infiltrated from treatment lagoons on the Reservation. This report describes the construction, calibration, and application of a regional groundwater flow model used to simulate the shallow groundwater flow system of the Reservation and water-quality results for groundwater and surface-water samples collected near a system of waste-water-treatment lagoons. Groundwater flows through a permeable glacial aquifer that ranges in thickness from 60 to more than 200 feet (ft). Seepage and drainage lakes are common in the area and influence groundwater flow patterns on the Reservation. A two-dimensional, steady-state analytic element groundwater flow model was constructed using the program GFLOW. The model was calibrated by matching target water levels and stream base flows through the use of the parameter-estimation program, PEST. Simulated results illustrate that groundwater flow within most of the Reservation is toward the Bear River and the chain of lakes that feed the Bear River. Results of analyses of groundwater and surface-water samples collected downgradient from the wastewater infiltration lagoons show elevated levels of ammonia and dissolved phosphorus. In addition, wastewater indicator chemicals detected in three downgradient wells and a small downgradient stream indicate that infiltrated wastewater is moving southwest of the lagoons toward Moss Lake. Potential effects of extended wet and dry periods (within historical ranges) were evaluated by adjusting precipitation and groundwater recharge in the model and comparing the

Groundwater availability in the Atlantic Coastal Plain of North and South Carolina

Science.gov (United States)

Campbell, Bruce G.; Coes, Alissa L.

2010-01-01

The Atlantic Coastal Plain aquifers and confining units of North and South Carolina are composed of crystalline carbonate rocks, sand, clay, silt, and gravel and contain large volumes of high-quality groundwater. The aquifers have a long history of use dating back to the earliest days of European settlement in the late 1600s. Although extensive areas of some of the aquifers have or currently (2009) are areas of groundwater level declines from large-scale, concentrated pumping centers, large areas of the Atlantic Coastal Plain contain substantial quantities of high-quality groundwater that currently (2009) are unused. Groundwater use from the Atlantic Coastal Plain aquifers in North Carolina and South Carolina has increased during the past 60 years as the population has increased along with demands for municipal, industrial, and agricultural water needs. While North Carolina and South Carolina work to increase development of water supplies in response to the rapid growth in these coastal populations, both States recognize that they are facing a number of unanswered questions regarding availability of groundwater supplies and the best methods to manage these important supplies. An in-depth assessment of groundwater availability of the Atlantic Coastal Plain aquifers of North and South Carolina has been completed by the U.S. Geological Survey Groundwater Resources Program. This assessment includes (1) a determination of the present status of the Atlantic Coastal Plain groundwater resources; (2) an explanation for how these resources have changed over time; and (3) development of tools to assess the system's response to stresses from potential future climate variability. Results from numerous previous investigations of the Atlantic Coastal Plain by Federal and State agencies have been incorporated into this effort. The primary products of this effort are (1) comprehensive hydrologic datasets such as groundwater levels, groundwater use, and aquifer properties; (2) a

Methods for using argon-39 to age-date groundwater using ultra-low-background proportional counting

Energy Technology Data Exchange (ETDEWEB)

Mace, Emily; Aalseth, Craig; Brandenberger, Jill; Day, Anthony; Hoppe, Eric; Humble, Paul; Keillor, Martin; Kulongoski, Justin; Overman, Cory; Panisko, Mark; Seifert, Allen; White, Signe; Wilcox Freeburg, Eric; Williams, Richard

2017-08-01

Argon-39 can be used as a tracer for age-dating glaciers, oceans, and more recently, groundwater. With a half-life of 269 years, 39Ar fills an intermediate age range gap (50-1,000 years) not currently covered by other common groundwater tracers. Therefore, adding this tracer to the data suite for groundwater studies provides an important tool for improving our understanding of groundwater systems. We present the methods employed for arriving at an age-date for a given sample of argon degassed from groundwater.

Solar-based groundwater pumping for irrigation: Sustainability, policies, and limitations

International Nuclear Information System (INIS)

Closas, Alvar; Rap, Edwin

2017-01-01

The increasing demand for solar-powered irrigation systems in agriculture has spurred a race for projects as it potentially offers a cost-effective and sustainable energy solution to off-grid farmers while helping food production and sustaining livelihoods. As a result, countries such as Morocco and Yemen have been promoting this technology for farmers and national plans with variable finance and subsidy schemes like in India have been put forward. By focusing on the application of solar photovoltaic (PV) pumping systems in groundwater-fed agriculture, this paper highlights the need to further study the impacts, opportunities and limitations of this technology within the Water-Energy-Food (WEF) nexus. It shows how most policies and projects promoting solar-based groundwater pumping for irrigation through subsidies and other incentives overlook the real financial and economic costs of this solution as well as the availability of water resources and the potential negative impacts on the environment caused by groundwater over-abstraction. There is a need to monitor groundwater abstraction, targeting subsidies and improving the knowledge and monitoring of resource use. Failing to address these issues could lead to further groundwater depletion, which could threaten the sustainability of this technology and dependent livelihoods in the future. - Highlights: • Solar pumping projects require assessing environmental and financial sustainability. • Subsidies for solar pumping need to be tied to groundwater pumping regulations. • Solar irrigation projects need to consider groundwater availability and depletion. • Data and monitoring are needed to improve water resource impact assessments.

Evaluation of contaminated groundwater cleanup objectives

International Nuclear Information System (INIS)

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

1996-01-01

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

Trace elements in groundwater used for water supply in Latvia

Science.gov (United States)

Retike, Inga; Kalvans, Andis; Babre, Alise; Kalvane, Gunta; Popovs, Konrads

2014-05-01

Latvia is rich with groundwater resources of various chemical composition and groundwater is the main drinking source. Groundwater quality can be easily affected by pollution or overexploitation, therefore drinking water quality is an issue of high importance. Here the first attempt is made to evaluate the vast data base of trace element concentrations in groundwater collected by Latvian Environment, Geology and Meteorology Centre. Data sources here range from National monitoring programs to groundwater resources prospecting and research projects. First available historical records are from early 1960, whose quality is impossible to test. More recent systematic research has been focused on the agricultural impact on groundwater quality (Levins and Gosk, 2007). This research was mainly limited to Quaternary aquifer. Monitoring of trace elements arsenic, cadmium and lead was included in National groundwater monitoring program of Latvia in 2008 and 2009, but due to lack of funding the monitoring was suspended until 2013. As a result there are no comprehensive baseline studies regarding the trace elements concentration in groundwater. The aim of this study is to determine natural major and trace element concentration in aquifers mainly used for water supply in Latvia and to compare the results with EU potable water standards. A new overview of artesian groundwater quality will be useful for national and regional planning documents. Initial few characteristic traits of trace element concentration have been identified. For example, elevated fluorine, strontium and lithium content can be mainly associated with gypsum dissolution, but the highest barium concentrations are found in groundwaters with low sulphate content. The groundwater composition data including trace element concentrations originating from heterogeneous sources will be processed and analyzed as a part of a newly developed geologic and hydrogeological data management and modeling system with working name

Information Technology in New Zealand: Review of Emerging Social Trends, Current Issues, and Policies

OpenAIRE

Erturk, Emre; Fail, Derwyn

2015-01-01

This paper discusses the general state of information technology in New Zealand society, current issues, and policies. It is a qualitative study that reviews recent scholarly articles, periodicals, and surveys in order to create an understanding of some of the information technology issues and trends in New Zealand. After reviewing previous research, it assesses the potential existence and nature of a 'digital divide' in New Zealand society whilst also evaluating possible strategic responses ...

Groundwater quality characterization around Jawaharnagar open dumpsite, Telangana State

Science.gov (United States)

Unnisa, Syeda Azeem; Zainab Bi, Shaik

2017-11-01

In the present work groundwater samples were collected from ten different data points in and around Jawaharnagar municipal dumpsite, Telangana State Hyderabad city from May 2015 to May 2016 on monthly basis for groundwater quality characterization. Pearson's correlation coefficient ( r) value was determined using correlation matrix to identify the highly correlated and interrelated water quality standards issued by Bureau of Indian Standard (IS-10500:2012). It is found that most of the groundwater samples are above acceptable limits and are not potable. The chemical analysis results revealed that pH range from 7.2 to 7.8, TA 222 to 427 mg/l, TDS 512 to 854 mg/l, TH 420 to 584 mg/l, Calcium 115 to 140 mg/l, Magnesium 55 to 115 mg/l, Chlorides 202 to 290 mg/l, Sulphates 170 to 250 mg/l, Nitrates 6.5 to 11.3 mg/l, and Fluoride 0.9 to 1.7 mg/l. All samples showed higher range of physicochemical parameters except nitrate content which was lower than permissible limit. Highly positive correlation was observed between pH-TH ( r = 0.5063), TA-Cl- ( r = 0.5896), TDS-SO4 - ( r = 0.5125), Mg2+-NO3 - ( r = 0.5543) and Cl--F- ( r = 0.7786). The groundwater samples in and around Jawaharnagar municipal dumpsite implies that groundwater samples were contaminated by municipal leachate migration from open dumpsite. The results revealed that the systematic calculations of correlation coefficient between water parameters and regression analysis provide qualitative and rapid monitoring of groundwater quality.

Current legal issues of European integration in the area of peaceful uses of nuclear energy

International Nuclear Information System (INIS)

Handrlica, Jakub

2009-01-01

The main issues of current discussions concerning the status of European integration in the area of peaceful uses of nuclear energy are described with focus on the present and future of the EURATOM Treaty. The basic features of the EURATOM Treaty are highlighted and those issues which are currently subject to discussion in foreign literature (e.g. EURATOM's legitimacy, specification of competencies, obsolete provisions, etc.) are pointed out. The major attempts to reform the wording of the EURATOM Treaty and the relevance of the Treaty to its Member States in the future, in relation to the 'Nuclear New Build' in particular, are also described. (orig.)

Groundwater-level trends and implications for sustainable water use in the Kabul Basin, Afghanistan

Science.gov (United States)

Mack, Thomas J.; Chornack, Michael P.; Taher, Mohammad R.

2013-01-01

The Kabul Basin, which includes the city of Kabul, Afghanistan, with a population of approximately 4 million, has several Afghan, United States, and international military installations that depend on groundwater resources for a potable water supply. This study examined groundwater levels in the Kabul Basin from 2004 to 2012. Groundwater levels have increased slightly in rural areas of the Kabul Basin as a result of normal precipitation after the drought of the early 2000s. However, groundwater levels have decreased in the city of Kabul due to increasing water use in an area with limited recharge. The rate of groundwater-level decrease in the city is greater for the 2008–2012 period (1.5 meters per year (m/yr) on average) than for the 2004–2008 period (0–0.7 m/yr on average). The analysis, which is corroborated by groundwater-flow modeling and a non-governmental organization decision-support model, identified groundwater-level decreases and associated implications for groundwater sustainability in the city of Kabul. Military installations in the city of Kabul (the Central Kabul subbasin) are likely to face water management challenges resulting from long-term groundwater sustainability concerns, such as the potential drying of shallow water-supply wells. Installations in the northern part of the Kabul Basin may have fewer issues with long-term water sustainability. Groundwater-level monitoring and groundwater-flow simulation can be valuable tools for assessing groundwater management options to improve the sustainability of water resources in the Kabul Basin.

Groundwater impact assessment report for the 100-D Ponds

International Nuclear Information System (INIS)

Alexander, D.J.

1993-07-01

The 183-D Water Treatment Facility (WTF) discharges effluent to the 120-0-1 Ponds (100-D Ponds) located north of the 100-D Area perimeter fence. This report satisfies one of the requirements of the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-17-00B as agreed by the US Department of Energy, Washington State Department of Ecology, and the US Environmental Protection Agency. Tri-Party Agreement Milestone M-17-00B includes a requirement to assess impacts to groundwater from disposal of the 183-D WTF effluent to the 100-D Ponds. In addition, the 100-D Ponds are a Resource Conservation and Recovery Act of 1976 treatment, storage, and disposal facility covered by the 100-D Ponds Closure Plan (DOE-RL 1993a). There is evidence of groundwater contamination, primarily nitrate, tritium, and chromium, in the unconfined aquifer beneath the 100-D Area and 100 Areas in general. The contaminant plumes are area wide and are a result of past-practice reactor and disposal operations in the 100-D Area currently being investigated as part of the 100-DR-1 and 100-HR-3 Operable Units (DOE-RL 1992b, 1992a). Based on current effluent conditions, continued operation of the 100-D Ponds will not adversely affect the groundwater quality in the 100-D Area. Monitoring wells near the pond have slightly higher alkaline pH values than wells in the rest of the area. Concentrations of known contaminants in these wells are lower than ambient 100-D Area groundwater conditions and exhibit a localized dilution effect associated with discharges to the pond. Hydraulic impact to the local groundwater system from these discharges is minor. The groundwater monitoring well network for the 100-D Ponds is adequate

Current issues in allogeneic islet transplantation.

Science.gov (United States)

Chang, Charles A; Lawrence, Michael C; Naziruddin, Bashoo

2017-10-01

Transplantation of allogenic pancreatic islets is a minimally invasive treatment option to control severe hypoglycemia and dependence on exogenous insulin among type 1 diabetes (T1D) patients. This overview summarizes the current issues and progress in islet transplantation outcomes and research. Several clinical trials from North America and other countries have documented the safety and efficacy of clinical islet transplantation for T1D patients with impaired hypoglycemia awareness. A recently completed phase 3 clinical trial allows centres in the United States to apply for a Food and Drug Administration Biologics License for the procedure. Introduction of anti-inflammatory drugs along with T-cell depleting induction therapy has significantly improved long-term function of transplanted islets. Research into islet biomarkers, immunosuppression, extrahepatic transplant sites and potential alternative beta cell sources is driving further progress. Allogeneic islet transplantation has vastly improved over the past two decades. Success in restoration of glycemic control and hypoglycemic awareness after islet transplantation has been further highlighted by clinical trials. However, lack of effective strategies to maintain long-term islet function and insufficient sources of donor tissue still impose limitations to the widespread use of islet transplantation. In the United States, wide adoption of this technology still awaits regulatory approval and, importantly, a financial mechanism to support the use of this technology.

Groundwater Quality in the Wassa West District of the Western ...

African Journals Online (AJOL)

B. K. Kortatsi

keep increasing annually to the extent that groundwater is becoming the principal and sometimes the only source ..... Thus, the threat to health from methemoglobinemia and nitrosamines is very low. .... Toxicity to the brain and nervous .... Emerging trends in gold processing and some related environmental issues in Ghana.

Introduction to the Issue on Current Trends in Terahertz Photonics and Applications

DEFF Research Database (Denmark)

2013-01-01

Since the last special issue on terahertz science and technology, nearly three years have been passed. During this period, while there have been further developments in terahertz (THz) sources, detectors, materials, and applications, there have been new discoveries. The purpose of this issue of t...... reviews on recent THz research, the contributed papers cover a wide range of the cutting-edge research in the topics described earlier....... of the IEEE Journal of Selected Topics in Quantum Electronics (JSTQE) is to highlight the advances in materials, devices, and applications and new directions in the THz domain within the last three years. Broad technical areas include: 1) materials; 2) matamaterials, plasmonics, and plasmons; 3) techniques...... and effects; 4) generation and power scaling; 5) detectors; 6) devices; 7) applications. These key THz topics are discussed in both invited and contributed papers published in this issue, providing comprehensive overviews of the current status and future directions as well as publishing original results...

Rationales behind irrationality of decision making in groundwater quality management.

Science.gov (United States)

Ronen, Daniel; Sorek, Shaul; Gilron, Jack

2012-01-01

This issue paper presents how certain policies regarding management of groundwater quality lead to unexpected and undesirable results, despite being backed by seemingly reasonable assumptions. This happened in part because the so-called reasonable decisions were not based on an integrative and quantitative methodology. The policies surveyed here are: (1) implementation of a program for aquifer restoration to pristine conditions followed, after failure, by leaving it to natural attenuation; (2) the "Forget About The Aquifer" (FATA) approach, while ignoring possible damage that contaminated groundwater can inflict on the other environmental systems; (3) groundwater recharge in municipal areas while neglecting the presence of contaminants in the unsaturated zone and conditions exerted by upper impervious surfaces; (4) the Soil Aquifer Treatment (SAT) practice considering aquifers to be "filters of infinite capacity"; and (5) focusing on well contamination vs. aquifer contamination to conveniently defer grappling with the problem of the aquifer as a whole. Possible reasons for the failure of these seemingly rational policies are: (1) the characteristic times of processes associated with groundwater that are usually orders of magnitude greater than the residence times of decision makers in their managerial position; (2) proliferation of improperly trained "groundwater experts" or policymakers with sectoral agendas alongside legitimate differences of opinion among groundwater scientists; (3) the neglect of the cyclic nature of natural phenomena; and (4) ignoring future long-term costs because of immediate costs. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

Coupled Hydro-Economic Dynamics of Groundwater Irrigated Agriculture in a Hard Rock Region of India

Science.gov (United States)

Modi, V.; Fishman, R.; Siegfried, T. U.; Raj, P.; Vasquez, V.; Narula, K.; Lall, U.

2009-12-01

We analyze the dynamics of groundwater and irrigated agriculture in a semi-arid, hard rock region of India, which is characterized by low-yield, limited storativity aquifers. Telengana, in western Andhra Pradesh has witnessed a relentless expansion of the total irrigated area. Total crop irrigation water requirements have increased by more than 50 percent over the last 30 years. Nowadays, more than 80 percent of the net irrigated area in the region is irrigated from groundwater. Given limited, period monsoonal recharge to the aquifers, it can be estimated that groundwater irrigation intensity is surpassing sustainable allocation levels by a factor of 3. It is not further surprising that the region is increasingly affected by widespread groundwater depletion, with negative consequences for farmers and the energy sector as well as the natural environment. Using data on water tables, precipitation and agricultural land use, we show how both rainfall and farmers’ choices effect water tables and how these, in turn, re-effect farmers choices and agricultural outcomes in a dynamic relationship that allows us to model the interaction between the natural hydrological and agricultural-social dynamics. We use the model to elucidate and quantify the meaning of groundwater mining in this hard rock environment. In contrast to deep alluvial aquifers, excessive extraction does not lead to sustained long term deepening of the water table, but to increased fluctuations in the supply of groundwater for irrigation and the loss of the buffering capacity. For the farmers, this potentially translates into increasingly perilous agricultural production outcomes during monsoonal failures. Furthermore, the dry season agricultural production that entirely depends on the availability of sufficient amounts of irrigation water is progressively threatened under the current allocation scenario. Alternative management practices to address the aquifer depletion issues are discussed. We show that

The behavior of U- and Th-series nuclides in groundwater

Science.gov (United States)

Porcelli, D.; Swarzenski, P.W.

2003-01-01

Groundwater has long been an active area of research driven by its importance both as a societal resource and as a component in the global hydrological cycle. Key issues in groundwater research include inferring rates of transport of chemical constituents, determining the ages of groundwater, and tracing water masses using chemical fingerprints. While information on the trace elements pertinent to these topics can be obtained from aquifer tests using experimentally introduced tracers, and from laboratory experiments on aquifer materials, these studies are necessarily limited in time and space. Regional studies of aquifers can focus on greater scales and time periods, but must contend with greater complexities and variations. In this regard, the isotopic systematics of the naturally occurring radionuclides in the U- and Th- decay series have been invaluable in investigating aquifer behavior of U, Th, and Ra. These nuclides are present in all groundwaters and are each represented by several isotopes with very different half-lives, so that processes occurring over a range of time-scales can be studied (Table 1⇓). Within the host aquifer minerals, the radionuclides in each decay series are generally expected to be in secular equilibrium and so have equal activities (see Bourdon et al. 2003). In contrast, these nuclides exhibit strong relative fractionations within the surrounding groundwaters that reflect contrasting behavior during release into the water and during interaction with the surrounding host aquifer rocks. Radionuclide data can be used, within the framework of models of the processes involved, to obtain quantitative assessments of radionuclide release from aquifer rocks and groundwater migration rates. The isotopic variations that are generated also have the potential for providing fingerprints for groundwaters from specific aquifer environments, and have even been explored as a means for calculating groundwater ages.

Groundwater monitoring plan: 200 Areas treated effluent disposal facility (Project W-049H)

International Nuclear Information System (INIS)

Barnett, D.B.; Davis, J.D.; Collard, L.B.; Freeman, P.B.; Chou, C.J.

1995-04-01

This groundwater monitoring plan provides information that supports the US Department of Energy's application (DOE-RL 1994) for waste water discharge permit No. WA-ST-4502 from the State of Washington, under the auspices of Washington Administrative Code 173-216. The monitoring plan has two functions: (1) to summarize the results of a 3-yr characterization of the current hydrogeology and groundwater quality of the discharge site and (2) to provide plans for evaluating the effects of the facility's operation on groundwater quality and document compliance with applicable groundwater quality standards. Three wells were drilled to define the stratigraphy, evaluate sediment characteristics, and establish a groundwater monitoring net work for the discharge facility. These wells monitor groundwater quality upgradient and downgradient in the uppermost aquifer. This report proposes plans for continuing the monitoring of groundwater quality and aquifer characteristics after waste water discharges begin

An overview of groundwater chemistry studies in Malaysia.

Science.gov (United States)

Kura, Nura Umar; Ramli, Mohammad Firuz; Sulaiman, Wan Nor Azmin; Ibrahim, Shaharin; Aris, Ahmad Zaharin

2018-03-01

In this paper, numerous studies on groundwater in Malaysia were reviewed with the aim of evaluating past trends and the current status for discerning the sustainability of the water resources in the country. It was found that most of the previous groundwater studies (44 %) focused on the islands and mostly concentrated on qualitative assessment with more emphasis being placed on seawater intrusion studies. This was then followed by inland-based studies, with Selangor state leading the studies which reflected the current water challenges facing the state. From a methodological perspective, geophysics, graphical methods, and statistical analysis are the dominant techniques (38, 25, and 25 %) respectively. The geophysical methods especially the 2D resistivity method cut across many subjects such as seawater intrusion studies, quantitative assessment, and hydraulic parameters estimation. The statistical techniques used include multivariate statistical analysis techniques and ANOVA among others, most of which are quality related studies using major ions, in situ parameters, and heavy metals. Conversely, numerical techniques like MODFLOW were somewhat less admired which is likely due to their complexity in nature and high data demand. This work will facilitate researchers in identifying the specific areas which need improvement and focus, while, at the same time, provide policymakers and managers with an executive summary and knowledge of the current situation in groundwater studies and where more work needs to be done for sustainable development.

High 36Cl/Cl ratios in Chernobyl groundwater

International Nuclear Information System (INIS)

Roux, Céline; Le Gal La Salle, Corinne; Simonucci, Caroline; Van Meir, Nathalie; Fifield, L. Keith; Diez, Olivier; Bassot, Sylvain

2014-01-01

After the explosion of the Chernobyl Nuclear Power Plant in April 1986, contaminated material was buried in shallow trenches within the exclusion zone. A 90 Sr plume was evidenced downgradient of one of these trenches, trench T22. Due to its conservative properties, 36 Cl is investigated here as a potential tracer to determine the maximal extent of the contamination plume from the trench in groundwater. 36 Cl/Cl ratios measured in groundwater, trench soil water and leaf leachates are 1–5 orders of magnitude higher than the theoretical natural 36 Cl/Cl ratio. This contamination occurred after the Chernobyl explosion and currently persists. Trench T22 acts as an obvious modern point source of 36 Cl, however other sources have to be involved to explain such contamination. 36 Cl contamination of groundwater can be explained by dilution of trench soil water by uncontaminated water (rainwater or deep groundwater). With a plume extending further than that of 90 Sr, radionuclide which is impacted by retention and decay processes, 36 Cl can be considered as a suitable tracer of contamination from the trench in groundwater provided that modern release processes of 36 Cl from trench soil are better characterized. - Highlights: • High 36 Cl/Cl ratios measured in the Chernobyl Pilot Site groundwater. • Trench T22 acts as a modern source of groundwater contamination by 36 Cl but other sources are involved. • Contamination results from dilution of a contaminated “T22” soil water with rainwater. • Processes involved in the modern release need to be investigated

Predicting the behavioural impact of transcranial direct current stimulation: issues and limitations

Directory of Open Access Journals (Sweden)

Archy Otto De Berker

2013-10-01

Full Text Available The transcranial application of weak currents to the human brain has enjoyed a decade of success, providing a simple and powerful tool for non-invasively altering human brain function. However, our understanding of current delivery and its impact upon neural circuitry leaves much to be desired. We argue that the credibility of conclusions drawn with tDCS is contingent upon realistic explanations of how tDCS works, and that our present understanding of tDCS limits the technique’s use to localize function in the human brain. We outline two central issues where progress is required: the localization of currents, and predicting their functional consequence. We encourage experimenters to eschew simplistic explanations of mechanisms of transcranial current stimulation. We suggest the use of individualized current modelling, together with computational neurostimulation to inform mechanistic frameworks in which to interpret the physiological impact of tDCS. We hope that through mechanistically richer descriptions of current flow and action, insight into the biological processes by which transcranial currents influence behaviour can be gained, leading to more effective stimulation protocols and empowering conclusions drawn with tDCS.

Preface. Current Issues in Ethics

OpenAIRE

Holy-Luczaj Magdalena

2017-01-01

This interdisciplinary volume consist of papers on various problems in contemporary ethics. It presents the following issues: equalizing the level of positive liberty, the phenomenon of human cooperation, ethical questions related to artificial intelligence, extending ethical obligations toward artifacts, and soteriological threads of alienation criticism of religion.

Medicare Part D-a roundtable discussion of current issues and trends.

Science.gov (United States)

Balfour, Donald C; Evans, Steven; Januska, Jeff; Lee, Helen Y; Lewis, Sonya J; Nolan, Steve R; Noga, Mark; Stemple, Charles; Thapar, Kishan

2009-01-01

Medicare Part D was introduced with a goal of providing access to prescription drug coverage for all Medicare beneficiaries. Regulatory mandates and the changing landscape of health care require continued evaluation of the state of the Part D benefit. To review the current state of plan offerings and highlight key issues regarding the administration of the Part D benefit. The Part D drug benefit continues to evolve. The benefit value appears to be diluted compared to the benefit value of large employer plans. Regulatory restrictions mandated by the Centers for Medicare and Medicaid Services (CMS) are reported to inhibit the ability of plans to create an effective, competitive drug benefit for Medicare beneficiaries. Management in this restrictive environment impedes competitive price negotiations and formulary coverage issues continue to create confusion especially for patients with chronic diseases. The doughnut hole coverage gap represents a significant cost-shifting issue for beneficiaries that may impact medication adherence and persistence. To address these and other challenges, CMS is working to improve the quality of care for Part D beneficiaries by designing and supporting demonstration projects. Although these projects are in different stages, all stakeholders are hopeful that they will lead to the development of best practices by plans to help manage their beneficiaries more efficiently. A significant number of Medicare beneficiaries are currently receiving prescription drug benefits through Part D. The true value of this benefit has been called into question as a result of plan design parameters that lead to cost-shifting, an increasing burden for enrollees. Concerns regarding the ability to provide a competitive plan given the stringent rules and regulations have been voiced by plan administrators. In an effort to drive toward evidence-based solutions, CMS is working to improve the overall quality of care through numerous demonstration projects.

Explanation of significant differences for the TNX groundwater operable unit

International Nuclear Information System (INIS)

Palmer, E.R.

1997-01-01

This Explanation of Significant Differences (ESD) is being issued by the Department of Energy (DOE), the lead agency for the Savannah River Site (SRS), with concurrence by the Environmental Protection Agency-Region IV (EPA) and South Carolina Department of Health and Environmental Control (SCDHEC) to announce changes in the interim remediation strategy selected for the TNX Groundwater Operable Unit. The TNX Area is located adjacent to the Savannah River in the southwestern portion of SRS. The remedy selected in the Interim Record of Decision (IROD) to achieve the interim action goals was the Hybrid Groundwater Corrective Action (HGCA). The HGCA consisted of a recirculation well system and an air stripper with a series of groundwater extraction wells. The original remediation strategy needs to be modified because the recirculation well system was determined to be ineffective in this area due to geological factors and the nature of the contamination

Current Issues in the Diagnosis of Attention Deficit Hyperactivity Disorder, Oppositional Defiant Disorder, and Conduct Disorder

Science.gov (United States)

Frick, Paul J.; Nigg, Joel T.

2015-01-01

This review evaluates the diagnostic criteria for three of the most common disorders for which children and adolescents are referred for mental health treatment: attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD). Although research supports the validity and clinical utility of these disorders, several issues are highlighted that could enhance the current diagnostic criteria. For ADHD, defining the core features of the disorder and its fit with other disorders, enhancing the validity of the criteria through the lifespan, considering alternative ways to form subtypes of the disorder, and modifying the age-of-onset criterion are discussed relative to the current diagnostic criteria. For ODD, eliminating the exclusionary criteria of CD, recognizing important symptom domains within the disorder, and using the cross-situational pervasiveness of the disorder as an index of severity are highlighted as important issues for improving classification. Finally, for CD, enhancing the current subtypes related to age of onset and integrating callous-unemotional traits into the diagnostic criteria are identified as key issues for improving classification. PMID:22035245

Current issues in the diagnosis of attention deficit hyperactivity disorder, oppositional defiant disorder, and conduct disorder.

Science.gov (United States)

Frick, Paul J; Nigg, Joel T

2012-01-01

This review evaluates the diagnostic criteria for three of the most common disorders for which children and adolescents are referred for mental health treatment: attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD). Although research supports the validity and clinical utility of these disorders, several issues are highlighted that could enhance the current diagnostic criteria. For ADHD, defining the core features of the disorder and its fit with other disorders, enhancing the validity of the criteria through the lifespan, considering alternative ways to form subtypes of the disorder, and modifying the age-of-onset criterion are discussed relative to the current diagnostic criteria. For ODD, eliminating the exclusionary criteria of CD, recognizing important symptom domains within the disorder, and using the cross-situational pervasiveness of the disorder as an index of severity are highlighted as important issues for improving classification. Finally, for CD, enhancing the current subtypes related to age of onset and integrating callous-unemotional traits into the diagnostic criteria are identified as key issues for improving classification.

Environmental risk of climate change and groundwater abstraction on stream ecological conditions

DEFF Research Database (Denmark)

Seaby, Lauren Paige; Bøgh, Eva; Jensen, Niels H.

with DAISY, a one dimensional crop model describing soil water dynamics in the root zone, and MIKE SHE, a distributed groundwater-surface water model. The relative and combined impacts on low flows, groundwater levels, and nitrate leaching are quantified and compared to assess the water resource sensitivity...... and risk to stream ecological conditions. We find low flow and annual discharge to be most impacted by scenarios of climate change, with high variation across climate models (+/- 40% change). Doubling of current groundwater abstraction rates reduces annual discharge by approximately 20%, with higher...... flows and groundwater levels are of interest, as they relate to aquatic habitat and nitrate leaching, respectively. This study evaluates the risk to stream ecological conditions for a lowland Danish catchment under multiple scenarios of climate change and groundwater abstraction. Projections of future...

A Study of Current Trends and Issues Related to Technical/Engineering Design Graphics.

Science.gov (United States)

Clark, Aaron C.; Scales Alice

2000-01-01

Presents results from a survey of engineering design graphics educators who responded to questions related to current trends and issues in the profession of graphics education. Concludes that there is a clear trend in institutions towards the teaching of constraint-based modeling and computer-aided manufacturing. (Author/YDS)

Geochemical Investigations of Groundwater Stability

Energy Technology Data Exchange (ETDEWEB)

Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

2006-05-15

The report describes geochemical parameters and methods that provide information about the hydrodynamic stability of groundwaters in low permeability fractured rocks that are potential hosts for radioactive waste repositories. Hydrodynamic stability describes the propensity for changes in groundwater flows over long timescales, in terms of flow rates and flow directions. Hydrodynamic changes may also cause changes in water compositions, but the related issue of geochemical stability of a potential repository host rock system is outside the scope of this report. The main approaches to assessing groundwater stability are numerical modelling, measurement and interpretation of geochemical indicators in groundwater compositions, and analyses and interpretations of secondary minerals and fluid inclusions in these minerals. This report covers the latter two topics, with emphasis on geochemical indicators. The extent to which palaeohydrogeology and geochemical stability indicators have been used in past safety cases is reviewed. It has been very variable, both in terms of the scenarios considered, the stability indicators considered and the extent to which the information was explicitly or implicitly used in assessing FEPs and scenarios in the safety cases. Geochemical indicators of hydrodynamic stability provide various categories of information that are of hydrogeological relevance. Information about groundwater mixing, flows and water sources is potentially provided by the total salinity of groundwaters, their contents of specific non-reactive solutes (principally chloride) and possibly of other solutes, the stable isotopic ratio of water, and certain characteristics of secondary minerals and fluid inclusions. Information pertaining directly to groundwater ages and the timing of water and solute movements is provided by isotopic systems including tritium, carbon-14, chlorine-36, stable oxygen and hydrogen isotopes, uranium isotopes and dissolved mobile gases in

A quantitative assessment of groundwater resources in the Middle East and North Africa region

Science.gov (United States)

Lezzaik, Khalil; Milewski, Adam

2018-02-01

The Middle East and North Africa (MENA) region is the world's most water-stressed region, with its countries constituting 12 of the 15 most water-stressed countries globally. Because of data paucity, comprehensive regional-scale assessments of groundwater resources in the MENA region have been lacking. The presented study addresses this issue by using a distributed ArcGIS model, parametrized with gridded data sets, to estimate groundwater storage reserves in the region based on generated aquifer saturated thickness and effective porosity estimates. Furthermore, monthly gravimetric datasets (GRACE) and land surface parameters (GLDAS) were used to quantify changes in groundwater storage between 2003 and 2014. Total groundwater reserves in the region were estimated at 1.28 × 106 cubic kilometers (km3) with an uncertainty range between 816,000 and 1.93 × 106 km3. Most of the reserves are located within large sedimentary basins in North Africa and the Arabian Peninsula, with Algeria, Libya, Egypt, and Saudi Arabia accounting for approximately 75% of the region's total freshwater reserves. Alternatively, small groundwater reserves were found in fractured Precambrian basement exposures. As for groundwater changes between 2003 and 2014, all MENA countries except for Morocco exhibited declines in groundwater storage. However, given the region's large groundwater reserves, groundwater changes between 2003 and 2014 are minimal and represent no immediate short-term threat to the MENA region, with some exceptions. Notwithstanding this, the study recommends the development of sustainable and efficient groundwater management policies to optimally utilize the region's groundwater resources, especially in the face of climate change, demographic expansion, and socio-economic development.

Spatiotemporal Assessment of Groundwater Resources in the South Platte Basin, Colorado

Science.gov (United States)

Ruybal, C. J.; McCray, J. E.; Hogue, T. S.

2015-12-01

The South Platte Basin is one of the most economically diverse and fastest growing basins in Colorado. Strong competition for water resources in an over-appropriated system brings challenges to meeting future water demands. Balancing the conjunctive use of surface water and groundwater from the South Platte alluvial aquifer and the Denver Basin aquifer system is critical for meeting future demands. Over the past decade, energy development in the basin has added to the competition for water resources, highlighting the need to advance our understanding of the availability and sustainability of groundwater resources. Current work includes evaluating groundwater storage changes and recharge regimes throughout the South Platte Basin under competing uses, e.g. agriculture, oil and gas, urban, recreational, and environmental. The Gravity Recovery and Climate Experiment satellites in conjunction with existing groundwater data is used to evaluate spatiotemporal variability in groundwater storage and identify areas of high water stress. Spatiotemporal data will also be utilized to develop a high resolution groundwater model of the region. Results will ultimately help stakeholders in the South Platte Basin better understand groundwater resource challenges and contribute to Colorado's strategic future water planning.

Characterizing Normal Groundwater Chemistry in Hawaii

Science.gov (United States)

Tachera, D.; Lautze, N. C.; Thomas, D. M.; Whittier, R. B.; Frazer, L. N.

2017-12-01

Hawaii is dependent on groundwater resources, yet how water moves through the subsurface is not well understood in many locations across the state. As marine air moves across the islands water evaporates from the ocean, along with trace amounts of sea-salt ions, and interacts with the anthropogenic and volcanic aerosols (e.g. sulfuric acid, ammonium sulfate, HCl), creating a slightly more acidic rain. When this rain falls, it has a chemical signature distinctive of past processes. As this precipitation infiltrates through soil it may pick up another distinctive chemical signature associated with land use and degree of soil development, and as it flows through the underlying geology, its chemistry is influenced by the host rock. We are currently conducting an investigation of groundwater chemistry in selected aquifer areas of Hawaii, having diverse land use, land cover, and soil development conditions, in an effort to investigate and document what may be considered a "normal" water chemistry for an area. Through this effort, we believe we better assess anomalies due to contamination events, hydrothermal alteration, and other processes; and we can use this information to better understand groundwater flow direction. The project has compiled a large amount of precipitation, soil, and groundwater chemistry data in the three focus areas distributed across in the State of Hawaii. Statistical analyses of these data sets will be performed in an effort to determine what is "normal" and what is anomalous chemistry for a given area. Where possible, results will be used to trace groundwater flow paths. Methods and preliminary results will be presented.

Preface. Current Issues in Ethics

Directory of Open Access Journals (Sweden)

Holy-Luczaj Magdalena

2017-07-01

Full Text Available This interdisciplinary volume consist of papers on various problems in contemporary ethics. It presents the following issues: equalizing the level of positive liberty, the phenomenon of human cooperation, ethical questions related to artificial intelligence, extending ethical obligations toward artifacts, and soteriological threads of alienation criticism of religion.

Groundwater Sustainability through a Novel Dewatering Technology

Science.gov (United States)

Jin, Y.; Holzbecher, E.; Ebneth, S.

2012-12-01

Groundwater plays a key role in the hydrologic cycle and ecosystem balances. Over the past decades, groundwater is intensively extracted in order to keep construction or mining sites dry. For the latter purpose the pumped water is usually discharged into a nearby surface water body or injected into an aquifer distant from the abstraction sites. As a result, aquifers are depleted and the local eco-system is disrupted as a consequence of falling groundwater tables. Given ongoing pressure on aquifer from abstraction sites, it is vital to bring up adequate attention on groundwater conservation. We demonstrate a novel technique, Düsensauginfiltration (DSI, translated as 'nozzel-suction-infiltration'), which avoids water conveyance but still lowers the groundwater table locally. The method combines abstraction of groundwater at the upper part of the aquifer with injection in the same borehole, but at a greater depth. Hence no water is withdrawn from the system. The method is already used practically in Germany, Netherlands, and China, however, it is not yet fully scientifically understood and evaluated. Currently, two tests sites in Germany, for single and multi well respectively, are selected, at which the DSI technology is currently examined. The project is cooperated with a leading dewatering company (Hoelscher Wasserbau GmbH) and funded by Deutsche Bundesstiftung Umwelt (DBU). To provide the basic principle of the method, we present numerical models solving the differential equation, which is derived from Darcy's Law and mass conservation, describing groundwater flow. We set up stationary numerical models in 2D (vertical cross section for single well case) and 3D (multi well case and/or when ambient groundwater flow is considered) using COMSOL Multiphysics. Since our model region only involves the saturated part of the unconfined aquifer, the numerical model solves a free boundary problem using hydraulic pressure as unknown variable. Two physical modes are included

Numerical simulation of groundwater flow in LILW Repository site:I. Groundwater flow modeling

Energy Technology Data Exchange (ETDEWEB)

Park, Koung Woo; Ji, Sung Hoon; Kim, Chun Soo; Kim, Kyoung Su [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Ji Yeon [Korea Hydro and Nuclear Power Co. Ltd., Seoul (Korea, Republic of)

2008-12-15

Based on the site characterization works in a low and intermediate level waste (LILW) repository site, the numerical simulations for groundwater flow were carried out in order to understand the groundwater flow system of repository site. To accomplish the groundwater flow modeling in the repository site, the discrete fracture network (DFN) model was constructed using the characteristics of fracture zones and background fractures. At result, the total 10 different hydraulic conductivity(K) fields were obtained from DFN model stochastically and K distributions of constructed mesh were inputted into the 10 cases of groundwater flow simulations in FEFLOW. From the total 10 numerical simulation results, the simulated groundwater levels were strongly governed by topography and the groundwater fluxes were governed by locally existed high permeable fracture zones in repository depth. Especially, the groundwater table was predicted to have several tens meters below the groundwater table compared with the undisturbed condition around disposal silo after construction of underground facilities. After closure of disposal facilities, the groundwater level would be almost recovered within 1 year and have a tendency to keep a steady state of groundwater level in 2 year.

High (36)Cl/Cl ratios in Chernobyl groundwater.

Science.gov (United States)

Roux, Céline; Le Gal La Salle, Corinne; Simonucci, Caroline; Van Meir, Nathalie; Fifield, L Keith; Diez, Olivier; Bassot, Sylvain; Simler, Roland; Bugai, Dmitri; Kashparov, Valery; Lancelot, Joël

2014-12-01

After the explosion of the Chernobyl Nuclear Power Plant in April 1986, contaminated material was buried in shallow trenches within the exclusion zone. A (90)Sr plume was evidenced downgradient of one of these trenches, trench T22. Due to its conservative properties, (36)Cl is investigated here as a potential tracer to determine the maximal extent of the contamination plume from the trench in groundwater. (36)Cl/Cl ratios measured in groundwater, trench soil water and leaf leachates are 1-5 orders of magnitude higher than the theoretical natural (36)Cl/Cl ratio. This contamination occurred after the Chernobyl explosion and currently persists. Trench T22 acts as an obvious modern point source of (36)Cl, however other sources have to be involved to explain such contamination. (36)Cl contamination of groundwater can be explained by dilution of trench soil water by uncontaminated water (rainwater or deep groundwater). With a plume extending further than that of (90)Sr, radionuclide which is impacted by retention and decay processes, (36)Cl can be considered as a suitable tracer of contamination from the trench in groundwater provided that modern release processes of (36)Cl from trench soil are better characterized. Copyright © 2014 Elsevier Ltd. All rights reserved.

The treatment of Parkinson′s disease with deep brain stimulation: current issues

Directory of Open Access Journals (Sweden)

Alexia-Sabine Moldovan

2015-01-01

Full Text Available Deep brain stimulation has become a well-established symptomatic treatment for Parkinson′s disease during the last 25 years. Besides improving motor symptoms and long-term motor complications, positive effects on patients′ mobility, activities of daily living, emotional well-being and health-related quality of life have been recognized. Apart from that, numerous clinical trials analyzed effects on non-motor symptoms and side effects of deep brain stimulation. Several technical issues and stimulation paradigms have been and are still being developed to optimize the therapeutic effects, minimize the side effects and facilitate handling. This review summarizes current therapeutic issues, i.e., patient and target selection, surgical procedure and programming paradigms. In addition it focuses on neuropsychological effects and side effects of deep brain stimulation.

Analysis of the Current Technical Issues on ASME Code and Standard for Nuclear Mechanical Design(2009)

International Nuclear Information System (INIS)

Koo, Gyeong Hoi; Lee, B. S.; Yoo, S. H.

2009-11-01

This report describes the analysis on the current revision movement related to the mechanical design issues of the U.S ASME nuclear code and standard. ASME nuclear mechanical design in this report is composed of the nuclear material, primary system, secondary system and high temperature reactor. This report includes the countermeasures based on the ASME Code meeting for current issues of each major field. KAMC(ASME Mirror Committee) of this project is willing to reflect a standpoint of the domestic nuclear industry on ASME nuclear mechanical design and play a technical bridge role for the domestic nuclear industry in ASME Codes application

Analysis of the Current Technical Issues on ASME Code and Standard for Nuclear Mechanical Design(2009)

Energy Technology Data Exchange (ETDEWEB)

Koo, Gyeong Hoi; Lee, B. S.; Yoo, S. H.

2009-11-15

This report describes the analysis on the current revision movement related to the mechanical design issues of the U.S ASME nuclear code and standard. ASME nuclear mechanical design in this report is composed of the nuclear material, primary system, secondary system and high temperature reactor. This report includes the countermeasures based on the ASME Code meeting for current issues of each major field. KAMC(ASME Mirror Committee) of this project is willing to reflect a standpoint of the domestic nuclear industry on ASME nuclear mechanical design and play a technical bridge role for the domestic nuclear industry in ASME Codes application

Application of optimization modeling to groundwater remediation at US Department of Energy facilities

International Nuclear Information System (INIS)

Bakr, A.A.; Dal Santo, D.J.; Smalley, R.C.; Phillips, E.C.

1988-01-01

This paper outlines and explores the fundamentals of the current strategies for groundwater hydraulic and quality management modeling and presents a scheme for the application of such strategies to DOE facilities. The discussion focuses on the DOE-Savannah River Operations (DOE-SR) facility. Remediation of contaminated groundwater at active and abandoned waste disposal sites has become a major element of environmental programs. Traditional groundwater remediation programs (e.g., pumping and treatment) may not represent optimal water quality management strategies at sites to be remediated. Complex, interrelated environmental (geologic/geohydrologic), institutional, engineering, and economic conditions at a site may require a more comprehensive management strategy. Groundwater management models based on the principles of operations research have been developed and used to determine optimal management strategies for water resources needs and for hypothetical remediation programs. Strategies for groundwater remediation programs have ranged from the simple removal of groundwater to complex, hydraulic gradient control programs involving groundwater removal, treatment, and recharge

Current Issues and Distributive Justice.

Science.gov (United States)

Rosal, Lorenca Consuelo

1992-01-01

Provides a lesson plan on the issue of distributive justice, or fairness in the ways things are distributed among individuals and groups. Includes a student reading concerning a proposed guaranteed standard of living. Proposes an activity that calls for student discussion of a constitutional amendment that would offer such a guarantee. (SG)

Current Issues with Environmental Barrier Coatings for Ceramics and Ceramic Composites

Science.gov (United States)

Lee, Kang N.

2004-01-01

The environmental barrier coating (EBC) for SiC/SiC ceramic matrix composites and Si3N4 ceramics is an emerging field as the application of silicon-based ceramics in the gas turbine engine hot section is on the horizon, both for aero and industrial gas turbines. EBC is an enabling technology for silicon-based ceramics because these materials without an EBC cannot be used in combustion environments due to rapid surface recession. Significant progress in EBC development has been made during the last decade through various government-sponsored programs. Current EBCs are based on silicon, mullite (3Al2O3-2SiO2) and BSAS (barium strontium aluminum silicate with celsian structure). Volatility of BSAS, BSAS-silica chemical reaction, and low melting point of silicon limit temperature capability of current EBCs to about 1350 C for long-term applications. There is a need for higher temperature EBCs as the temperature capability of silicon-based ceramics continue to increase. Therefore, research is underway to develop EBCs with improved temperature capability compared to current EBCs. The current status and issues with the advanced EBC development efforts will be discussed.

Sampling and Analysis Plan Update for Groundwater Monitoring 1100-EM-1 Operable Unit

International Nuclear Information System (INIS)

DR Newcomer

1999-01-01

This document updates the sampling and analysis plan (Department of Energy/Richland Operations--95-50) to reflect current groundwater monitoring at the 1100-EM-1Operable Unit. Items requiring updating included sampling and analysis protocol, quality assurance and quality control, groundwater level measurement procedure, and data management. The plan covers groundwater monitoring, as specified in the 1993 Record of Decision, during the 5-year review period from 1995 through 1999. Following the 5-year review period, groundwater-monitoring data will be reviewed by Environmental Protection Agency to evaluate the progress of natural attenuation of trichloroethylene. Monitored natural attenuation and institutional controls for groundwater use at the inactive Horn Rapids Landfill was the selected remedy specified in the Record of Decision

Ground-water solute transport modeling using a three-dimensional scaled model

International Nuclear Information System (INIS)

Crider, S.S.

1987-01-01

Scaled models are used extensively in current hydraulic research on sediment transport and solute dispersion in free surface flows (rivers, estuaries), but are neglected in current ground-water model research. Thus, an investigation was conducted to test the efficacy of a three-dimensional scaled model of solute transport in ground water. No previous results from such a model have been reported. Experiments performed on uniform scaled models indicated that some historical problems (e.g., construction and scaling difficulties; disproportionate capillary rise in model) were partly overcome by using simple model materials (sand, cement and water), by restricting model application to selective classes of problems, and by physically controlling the effect of the model capillary zone. Results from these tests were compared with mathematical models. Model scaling laws were derived for ground-water solute transport and used to build a three-dimensional scaled model of a ground-water tritium plume in a prototype aquifer on the Savannah River Plant near Aiken, South Carolina. Model results compared favorably with field data and with a numerical model. Scaled models are recommended as a useful additional tool for prediction of ground-water solute transport

A review of visual MODFLOW applications in groundwater modelling

Science.gov (United States)

Hariharan, V.; Shankar, M. Uma

2017-11-01

Visual MODLOW is a Graphical User Interface for the USGS MODFLOW. It is a commercial software that is popular among the hydrogeologists for its user-friendly features. The software is mainly used for Groundwater flow and contaminant transport models under different conditions. This article is intended to review the versatility of its applications in groundwater modelling for the last 22 years. Agriculture, airfields, constructed wetlands, climate change, drought studies, Environmental Impact Assessment (EIA), landfills, mining operations, river and flood plain monitoring, salt water intrusion, soil profile surveys, watershed analyses, etc., are the areas where the software has been reportedly used till the current date. The review will provide a clarity on the scope of the software in groundwater modelling and research.

Water quality issues and status in Pakistan

International Nuclear Information System (INIS)

Kahlown, M.A.; Tahir, M. A.; Ashraf, M.

2005-01-01

Per capita water availability in Pakistan has dropped drastically during the last fifty years. Recent extended droughts have further aggravated the situation. In order to meet the shortage and crop water requirements, groundwater is being used extensively in the Indus Basin. Groundwater is also the main source of water for drinking and industrial uses. This increased pressure on groundwater has lowered the water table in many cities. It is reported that water table has dropped by more than 3 m in many cities. This excessive use of groundwater has seriously affected the quality of groundwater and has increased the incidences of water-borne diseases many folds. A recent water quality study has shown that out of 560,000 tube wells of Indus Basin, about 70 percent are pumping sodic water. The use of sodic water has in turn affected the soil health and crop yields. This situation is being further aggravated due to changes in climate and rainfall patterns. To monitor changes in surface and groundwater quality and groundwater levels, Pakistan Council of Research in Water Resources has undertaken a countrywide programme of water quality monitoring. This programme covers twenty-one cities from the four provinces, five rivers, 10 storage reservoirs and lakes and two main drains of Pakistan. Under this programme a permanent monitoring network is established from where water samples are collected and analyzed once every year. The collected water samples are analyzed for aesthetic, chemical and bacteriological parameters to determine their suitability for agricultural, domestic and industrial uses. The results of the present study indicate serious contamination in many cities. Excessive levels of arsenic, fluoride and sodium have been detected in many cities. This paper highlights the major water quality issues and briefly presents the preliminary results of the groundwater analysis for major cities of Pakistan. (author)

Features of groundwater pollution and its relation to overexploitation of groundwater in Shijiazhuang city

International Nuclear Information System (INIS)

Guo Yonghai; Wang Zhiming; Liu Shufen; Li Ping

2005-01-01

The groundwater pollution in Shijiazhuang city is characterized by an excess of some components and parameters over permitted values. The main pollutants are originated from the city sewage which is quite typical for groundwater pollution in many cities of China. On the basis of agonizingly features of groundwater pollution, the relationship between the groundwater pollution and the groundwater overexploitation is discussed in this paper, and the mechanism of intensifying the pollution by overexploitation has been revealed. Finally, it is proposed that the overexploitation of groundwater is an important inducing factor leading to the groundwater pollution in cities. (authors)

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

KAUST Repository

Malivaa, Robert G.; Missimer, Thomas M.

2011-01-01

and pretreatment requirements and lesser volumes of concentrate that require disposal. Development of brackish groundwater wellfields include the same hydraulic issues that affect conventional freshwater wellfields. Managing well interference and prevention

Classification of groundwater at the Nevada Test Site

International Nuclear Information System (INIS)

Chapman, J.B.

1994-08-01

Groundwater occurring at the Nevada Test Site (NTS) has been classified according to the ''Guidelines for Ground-Water Classification Under the US Environmental Protection Agency (EPA) Ground-Water Protection Strategy'' (June 1988). All of the groundwater units at the NTS are Class II, groundwater currently (IIA) or potentially (IIB) a source of drinking water. The Classification Review Area (CRA) for the NTS is defined as the standard two-mile distance from the facility boundary recommended by EPA. The possibility of expanding the CRA was evaluated, but the two-mile distance encompasses the area expected to be impacted by contaminant transport during a 10-year period (EPA,s suggested limit), should a release occur. The CRA is very large as a consequence of the large size of the NTS and the decision to classify the entire site, not individual areas of activity. Because most activities are located many miles hydraulically upgradient of the NTS boundary, the CRA generally provides much more than the usual two-mile buffer required by EPA. The CRA is considered sufficiently large to allow confident determination of the use and value of groundwater and identification of potentially affected users. The size and complex hydrogeology of the NTS are inconsistent with the EPA guideline assumption of a high degree of hydrologic interconnection throughout the review area. To more realistically depict the site hydrogeology, the CRA is subdivided into eight groundwater units. Two main aquifer systems are recognized: the lower carbonate aquifer system and the Cenozoic aquifer system (consisting of aquifers in Quaternary valley fill and Tertiary volcanics). These aquifer systems are further divided geographically based on the location of low permeability boundaries

Quantifying Anthropogenic Stress on Groundwater Resources.

Science.gov (United States)

Ashraf, Batool; AghaKouchak, Amir; Alizadeh, Amin; Mousavi Baygi, Mohammad; R Moftakhari, Hamed; Mirchi, Ali; Anjileli, Hassan; Madani, Kaveh

2017-10-10

This study explores a general framework for quantifying anthropogenic influences on groundwater budget based on normalized human outflow (h out ) and inflow (h in ). The framework is useful for sustainability assessment of groundwater systems and allows investigating the effects of different human water abstraction scenarios on the overall aquifer regime (e.g., depleted, natural flow-dominated, and human flow-dominated). We apply this approach to selected regions in the USA, Germany and Iran to evaluate the current aquifer regime. We subsequently present two scenarios of changes in human water withdrawals and return flow to the system (individually and combined). Results show that approximately one-third of the selected aquifers in the USA, and half of the selected aquifers in Iran are dominated by human activities, while the selected aquifers in Germany are natural flow-dominated. The scenario analysis results also show that reduced human withdrawals could help with regime change in some aquifers. For instance, in two of the selected USA aquifers, a decrease in anthropogenic influences by ~20% may change the condition of depleted regime to natural flow-dominated regime. We specifically highlight a trending threat to the sustainability of groundwater in northwest Iran and California, and the need for more careful assessment and monitoring practices as well as strict regulations to mitigate the negative impacts of groundwater overexploitation.

In-situ remediation of brine impacted soils and groundwater using hydraulic fracturing, desalinization and recharge wells

Energy Technology Data Exchange (ETDEWEB)

Robertson, C. [Wiebe Environmental Services Inc., Calgary, AB (Canada); Ratiu, I. [GeoGrid Environmental Inc., Calgary, AB (Canada)

2006-07-01

This conference presentation focused on the in-stu remediation of brine impacted soils and groundwater using hydraulic fracturing, desalinization and recharge wells. A former oil battery was established in the 1940s, decommissioned in the late 1960s with a reclamation certificate issued in 1972. The land owner reported poor vegetative growth in the former battery area. The purpose of the study was to investigate the cause of poor growth and delineate contaminants of concern and to remediate impacted soil and groundwater associated with the former battery site. The investigation involved agrological, geophysical and hydrogeological investigation into the extent of anthropogenic impacts as well as the development of remediation options and plans to deal with issues of concern. The presentation provided the results of the investigation, options identified, and discussed limitation on salt remediation and treatment of saline soils. Other topics included hydraulic fracturing, injection wells that were installed to re-circulate treated groundwater though the salt plume, desalinization processes, and next steps. figs.

Streamflow depletion by wells--Understanding and managing the effects of groundwater pumping on streamflow

Science.gov (United States)

Barlow, Paul M.; Leake, Stanley A.

2012-11-02

Groundwater is an important source of water for many human needs, including public supply, agriculture, and industry. With the development of any natural resource, however, adverse consequences may be associated with its use. One of the primary concerns related to the development of groundwater resources is the effect of groundwater pumping on streamflow. Groundwater and surface-water systems are connected, and groundwater discharge is often a substantial component of the total flow of a stream. Groundwater pumping reduces the amount of groundwater that flows to streams and, in some cases, can draw streamflow into the underlying groundwater system. Streamflow reductions (or depletions) caused by pumping have become an important water-resource management issue because of the negative impacts that reduced flows can have on aquatic ecosystems, the availability of surface water, and the quality and aesthetic value of streams and rivers. Scientific research over the past seven decades has made important contributions to the basic understanding of the processes and factors that affect streamflow depletion by wells. Moreover, advances in methods for simulating groundwater systems with computer models provide powerful tools for estimating the rates, locations, and timing of streamflow depletion in response to groundwater pumping and for evaluating alternative approaches for managing streamflow depletion. The primary objective of this report is to summarize these scientific insights and to describe the various field methods and modeling approaches that can be used to understand and manage streamflow depletion. A secondary objective is to highlight several misconceptions concerning streamflow depletion and to explain why these misconceptions are incorrect.

Evaluation and prediction of groundwater storage changes in Beijing under the impacts of the South to North Water Diversion Project and climate change using ground observations, remote sensing and modeling

Science.gov (United States)

Long, D.; Wada, Y.; Zhao, J.; Hong, Y.; Liu, D.; You, L.

2017-12-01

As China's Capital, Beijing currently has a population of 22 million people with per capital water resources of less than 100 m3, one twentieth of the national average and one eightieth of the global. Groundwater withdrawals (2.3 billion m3/year) account for approximately two thirds of total water use (3.5 billion m3/year) in Beijing, resulting in significant groundwater depletion and associated environmental issues, such as land subsidence. Increases in human and ecological water demand would add further pressure on Beijing's groundwater resources. Unsustainable groundwater use threatens societal and economic development of Beijing and poses a large uncertainty in future water supply. To partly alleviate the water shortage issue in the more arid and industrialized North China, the Chinese government has launched the largest water diversion project in the world, i.e., the South to North Water Diversion Project (SNWD), which is a multi-decadal mega-infrastructure project, with the aim to transfer 44.8 billion m3 of fresh water annually from the Yangtze River in the more humid south through three canal and pipeline systems (east, central, and west routes). Its central route flows from the upper reaches of the Han River, a tributary of the Yangtze River to Beijing, Tianjin and other major cities in Hebei and Henan Provinces. Since Dec 2014 when the water transferred by the central route reached Beijing to Feb 2017, totally 2 billion m3 of water has been transferred. This has profoundly altered the structure of water supply in Beijing. This study quantifies how the SNWD project impacts groundwater storage of Beijing and projects how groundwater storage changes in the future under different climate and policy scenarios.

Determinants of Shallow Groundwater As Variability in Bangladesh

Science.gov (United States)

Radloff, K. A.; Zheng, Y.; Stute, M.; Rahman, M.; Mihajlov, I.; Siu, H.; Huq, M.; Choudhury, I.; Ahmed, K.; van Geen, A.

2010-12-01

where the As content of groundwater is variable is particularly important. The size of the pool of As adsorbed on the sediment also indicates that current attempts to flush Bangladeshi aquifers “clean” through increased pumping will likely be ineffective. 1. BBS/UNICEF. Bangladesh: Multiple Indicator Cluster Survey, 2009. (Dhaka, Bangladesh, 2009).

Work plan for the Oak Ridge National Laboratory groundwater program: Continuous groundwater collection

International Nuclear Information System (INIS)

1995-08-01

The continuous collection of groundwater data is a basic and necessary part of Lockeheed Martin Energy Systems' ORNL Environmental Restoration Area-Wide Groundwater Program. Continuous groundwater data consist primarily of continually recorded groundwater levels, and in some instances, specific conductivity, pH, and/or temperature measurements. These data will be collected throughout the ORNL site. This Work Plan (WP) addresses technical objectives, equipment requirements, procedures, documentation requirements, and technical instructions for the acquisition of the continuous groundwater data. Intent of this WP is to provide an approved document that meets all the necessary requirements while retaining the flexibility necessary to effectively address ORNL's groundwater problems

The International hydrocoin project. Groundwater hydrology modelling strategies for performance assessment of nuclear waste disposal. Summary report

International Nuclear Information System (INIS)

1992-01-01

In 1984 the Swedish Nuclear Power Inspectorate, SKI, initiated the international cooperation project HYDROCOIN for the study of groundwater flow modelling in the context of radioactive waste disposal. The objective of HYDROCOIN was to improve knowledge of the influence of various strategies for groundwater flow modelling for the safety assessment of final repositories for radioactive wastes. The study comprised: the impact on the groundwater flow calculations of different solution algorithms, the capabilities of different models to describe field tests and bench-scale experiments, and the impact on the groundwater flow calculations of incorporating various physical phenomena. The work was conducted at three levels addressing code verification (Level 1), model validation (Level 2), and sensitivity and uncertainty analysis of groundwater flow calculations (Level 3). This report gives an overview and summary of test cases of HYDROCOIN Level 1, the issue of validation groundwater flow models (HYDROCOIN Level 2), the methodologies used in uncertainty and sensitivity analysis (HYDROCOIN Level 3). 108 figs., 24 tabs., 2 appendices

Current issues regarding radiation risk education in Medical Universities of Japan

International Nuclear Information System (INIS)

Tsuzuki, Teruhisa; Hosoi, Yoshio; Matsuda, Naoki; Kanda, Reiko; Hosoya, Noriko; Miyagawa, Kiyoshi; Awai, Kazuo; Kondo, Takashi

2017-01-01

The main purpose of radiation research is to understand the biological effects of radiation exposure to humans, the molecular mechanisms of biological response m organisms, and its sale application for medical and industrial use. In order to know the current state or education on fundamentals of radiology including radiation biology, a nation-wide questionnaire survey had been performed at medical schools and different co-medical courses in Japanese universities, during the period of 2004 and 2005. The survey results showed: (1) Difference in teaching hours for education on radiation between medical schools with and without department or division of radiation biology or radiation-related field. (2) Teaching hours for education on radiation in nursing course were very limited among the co-medical courses. Although, some improvement have been found about the state of education on radiation risk at medical schools, after the disaster of nuclear accident at Fukushima No.1 Nuclear Power Plant of TEPCO in March 2011. However, still much more effort t is needed to improve basic education on radiation. Science Council of Japan issued the recommendation on September 4, 2014 'Making radiation health risk education compulsory in medical education'. The working group for this purpose was set up under the Council of Head of National Medical Schools of Japan, on January 28, 2015. Here, we describe the details and current issues regarding radiation risk education in medical schools of Japan, as well as the efforts required for its betterment. (author)

Interpersonal Relationships, Motivation, Engagement, and Achievement: Yields for Theory, Current Issues, and Educational Practice

Science.gov (United States)

Martin, Andrew J.; Dowson, Martin

2009-01-01

In this review, we scope the role of interpersonal relationships in students' academic motivation, engagement, and achievement. We argue that achievement motivation theory, current issues, and educational practice can be conceptualized in relational terms. Influential theorizing, including attribution theory, expectancy-value theory, goal theory,…

Groundwater sustainability and groundwater/surface-water interaction in arid Dunhuang Basin, northwest China

Science.gov (United States)

Lin, Jingjing; Ma, Rui; Hu, Yalu; Sun, Ziyong; Wang, Yanxin; McCarter, Colin P. R.

2018-03-01

The Dunhuang Basin, a typical inland basin in northwestern China, suffers a net loss of groundwater and the occasional disappearance of the Crescent Lake. Within this region, the groundwater/surface-water interactions are important for the sustainability of the groundwater resources. A three-dimensional transient groundwater flow model was established and calibrated using MODFLOW 2000, which was used to predict changes to these interactions once a water diversion project is completed. The simulated results indicate that introducing water from outside of the basin into the Shule and Danghe rivers could reverse the negative groundwater balance in the Basin. River-water/groundwater interactions control the groundwater hydrology, where river leakage to the groundwater in the Basin will increase from 3,114 × 104 m3/year in 2017 to 11,875 × 104 m3/year in 2021, and to 17,039 × 104 m3/year in 2036. In comparison, groundwater discharge to the rivers will decrease from 3277 × 104 m3/year in 2017 to 1857 × 104 m3/year in 2021, and to 510 × 104 m3/year by 2036; thus, the hydrology will switch from groundwater discharge to groundwater recharge after implementing the water diversion project. The simulation indicates that the increased net river infiltration due to the water diversion project will raise the water table and then effectively increasing the water level of the Crescent Lake, as the lake level is contiguous with the water table. However, the regional phreatic evaporation will be enhanced, which may intensify soil salinization in the Dunhuang Basin. These results can guide the water allocation scheme for the water diversion project to alleviate groundwater depletion and mitigate geo-environmental problem.

Limits to the availability of groundwater in Africa

Science.gov (United States)

Edmunds, W. Mike

2012-06-01

The recent paper on Africa's groundwater by MacDonald et al (2012) has attracted much attention. This is good news, especially since groundwater has been widely ignored, misunderstood or abused, as a fundamental global resource. This important paper goes a long way to raising the profile of groundwater in Africa by providing first-order estimates of the available storage (taking account of saturated aquifer thickness and porosity) as well as mapping expected water yields (aquifer productivity) in that continent. Reliable estimates of groundwater resources can now be set against the far more widely reported surface water availability. The constraints of the methodology used to compile these maps are duly acknowledged, and are well within the hydrogeological state-of-the-art. The paper is backed by carefully reviewed sources of data and a considerable effort has been made to incorporate the extensive grey literature. It is important that this benchmark study is received with the acclaim it deserves. However, the headline—that groundwater storage is some 100 times the annual renewable surface waters—could be misconstrued as implying that groundwater is an abundant new resource, which it is not. Whilst groundwater is key to sustainable development, renewability and accessibility issues need to be addressed. The paper may therefore be seized upon to justify unsustainable groundwater exploitation, or to provide an argument against funding to NGOs and others, for water provision for needy communities. Some constraints that must be taken into account are elaborated here. The conclusions of the paper (MacDonald et al 2012) demonstrate that modest yields of groundwater are quite widely available at accessible depths and sufficient to sustain small communities and their development, but larger yields (>5 l s-1) suitable for urban development or major agricultural schemes are unlikely outside of the sedimentary terrain. The availability and accessibility of groundwater

Groundwater flow and transport modelling during a glaciation period

International Nuclear Information System (INIS)

Jaquet, O.; Siegel, P.

2003-01-01

Subsequent to earlier work, SKB has decided to carry out additional hydrogeological modelling studies related to glaciation effects at Aespoe. In particular, sub glacial groundwater flow and the impact assessment on a repository require further studies. As compared to the previous model, the domain geometry and processes involved remain identical, but this time, numerical calculations are performed with the NAMMU package (version 7.1.1) using a finite element formulation. Modified assumptions corresponding to specific boundary conditions are implemented and additional variations of the base case are simulated. The objectives of the study are based on the technical specifications established by SKB. The main objectives may be summarised as follows: Enhancement of the understanding of sub glacial groundwater flow due to basal ice melting. Evaluation of the impact of sub glacial roundwater flow on a repository with respect to its position to the ice margin of the glacier. Assessment of the feasibility of performing large 3D simulations of density-driven flow induced by variable salinity of the groundwater using the NAMMU package. The report begins with an account of the modelling approach applied. Then, the results of the different cases simulated are described, analysed and interpreted in detail. Finally, conclusions are drawn up together with some recommendations related to potential modelling issues for the future. The objectives proposed for the groundwater flow and transport modelling for period of glaciation have been met: The results have shown the importance of the ice tunnels in governing sub glacial groundwater flow due to basal ice melting. The influence of the ice tunnels on the salinity distribution is significant as is their impact on the flow trajectories and, hence, on the resulting travel times. The results of simulation S0 have revealed that no steady-state flow conditions are reached. Due to the chosen salt boundary conditions, salt will continue to

Assessing regional groundwater stress for nations using multiple data sources with the groundwater footprint

International Nuclear Information System (INIS)

Gleeson, Tom; Wada, Yoshihide

2013-01-01

Groundwater is a critical resource for agricultural production, ecosystems, drinking water and industry, yet groundwater depletion is accelerating, especially in a number of agriculturally important regions. Assessing the stress of groundwater resources is crucial for science-based policy and management, yet water stress assessments have often neglected groundwater and used single data sources, which may underestimate the uncertainty of the assessment. We consistently analyze and interpret groundwater stress across whole nations using multiple data sources for the first time. We focus on two nations with the highest national groundwater abstraction rates in the world, the United States and India, and use the recently developed groundwater footprint and multiple datasets of groundwater recharge and withdrawal derived from hydrologic models and data synthesis. A minority of aquifers, mostly with known groundwater depletion, show groundwater stress regardless of the input dataset. The majority of aquifers are not stressed with any input data while less than a third are stressed for some input data. In both countries groundwater stress affects agriculturally important regions. In the United States, groundwater stress impacts a lower proportion of the national area and population, and is focused in regions with lower population and water well density compared to India. Importantly, the results indicate that the uncertainty is generally greater between datasets than within datasets and that much of the uncertainty is due to recharge estimates. Assessment of groundwater stress consistently across a nation and assessment of uncertainty using multiple datasets are critical for the development of a science-based rationale for policy and management, especially with regard to where and to what extent to focus limited research and management resources. (letter)

Saline groundwater in crystalline bedrock

International Nuclear Information System (INIS)

Lampen, P.

1992-11-01

The State-of-art report describes research made on deep saline groundwaters and brines found in crystalline bedrock, mainly in site studies for nuclear waste disposal. The occurrence, definitions and classifications of saline groundwaters are reviewed with a special emphasis on the different theories concerning the origins of saline groundwaters. Studies of the saline groundwaters in Finland and Sweden have been reviewed more thoroughly. Also the mixing of different bodies of groundwaters, observations of the contact of saline groundwaters and permafrost, and the geochemical modelling of saline groundwaters as well as the future trends of research have been discussed. (orig.)

Seasonal forecasting of groundwater levels in natural aquifers in the United Kingdom

Science.gov (United States)

Mackay, Jonathan; Jackson, Christopher; Pachocka, Magdalena; Brookshaw, Anca; Scaife, Adam

2014-05-01

Groundwater aquifers comprise the world's largest freshwater resource and provide resilience to climate extremes which could become more frequent under future climate changes. Prolonged dry conditions can induce groundwater drought, often characterised by significantly low groundwater levels which may persist for months to years. In contrast, lasting wet conditions can result in anomalously high groundwater levels which result in flooding, potentially at large economic cost. Using computational models to produce groundwater level forecasts allows appropriate management strategies to be considered in advance of extreme events. The majority of groundwater level forecasting studies to date use data-based models, which exploit the long response time of groundwater levels to meteorological drivers and make forecasts based only on the current state of the system. Instead, seasonal meteorological forecasts can be used to drive hydrological models and simulate groundwater levels months into the future. Such approaches have not been used in the past due to a lack of skill in these long-range forecast products. However systems such as the latest version of the Met Office Global Seasonal Forecast System (GloSea5) are now showing increased skill up to a 3-month lead time. We demonstrate the first groundwater level ensemble forecasting system using a multi-member ensemble of hindcasts from GloSea5 between 1996 and 2009 to force 21 simple lumped conceptual groundwater models covering most of the UK's major aquifers. We present the results from this hindcasting study and demonstrate that the system can be used to forecast groundwater levels with some skill up to three months into the future.

Review: Epidemiological evidence of groundwater contribution to global enteric disease, 1948-2015

Science.gov (United States)

Murphy, Heather M.; Prioleau, Morgan D.; Borchardt, Mark A.; Hynds, Paul D.

2017-06-01

Globally, approximately 2.2 billion people rely on groundwater for daily consumption. It is widely accepted that groundwater is more pristine than surface water but while this assumption is frequently the case, groundwater is not ubiquitously free of contaminants; accordingly, this presumption can result in an unfounded and potentially hazardous sense of security among owners, operators and users. The current paper presents a review of published literature providing epidemiological evidence of the contribution of groundwater to global human enteric infection. An emphasis is placed on enteric pathogens transmitted via the faecal-oral route, and specifically those associated with acute gastrointestinal illness (AGI). The review identified 649 published groundwater outbreaks globally between 1948 and 2013 and several epidemiological studies that show there is an increased risk of AGI associated with the consumption of untreated groundwater. The review identified that the following five pathogens were responsible for most outbreaks: norovirus, Campylobacter, Shigella, Hepatitis A and Giardia. Crudely, the authors estimate that between 35.2 and 59.4 million cases of AGI per year globally could be attributable to the consumption of groundwater. Although groundwater is frequently presumed to be a microbiologically safe source of water for consumption, this review demonstrates that consumers served by an untreated groundwater supply remain at risk to enteric disease. The authors conclude that collaboration between microbiologists, hydrogeologists and epidemiologists is needed to better understand pathogen occurrence, persistence, detection and transport in groundwater as well as build stronger epidemiological evidence documenting the true magnitude of disease associated with groundwater globally.

Particle tracking for selected groundwater wells in the lower Yakima River Basin, Washington

Science.gov (United States)

Bachmann, Matthew P.

2015-10-21

The Yakima River Basin in south-central Washington has a long history of irrigated agriculture and a more recent history of large-scale livestock operations, both of which may contribute nutrients to the groundwater system. Nitrate concentrations in water samples from shallow groundwater wells in the lower Yakima River Basin exceeded the U.S. Environmental Protection Agency drinking-water standard, generating concerns that current applications of fertilizer and animal waste may be exceeding the rate at which plants can uptake nutrients, and thus contributing to groundwater contamination.

Insights and participatory actions driven by a socio-hydrogeological approach for groundwater management: the Grombalia Basin case study (Tunisia)

Science.gov (United States)

Tringali, C.; Re, V.; Siciliano, G.; Chkir, N.; Tuci, C.; Zouari, K.

2017-08-01

Sustainable groundwater management strategies in water-scarce countries need to guide future decision-making processes pragmatically, by simultaneously considering local needs, environmental problems and economic development. The socio-hydrogeological approach named `Bir Al-Nas' has been tested in the Grombalia region (Cap Bon Peninsula, Tunisia), to evaluate the effectiveness of complementing hydrogeochemical and hydrogeological investigations with the social dimension of the issue at stake (which, in this case, is the identification of groundwater pollution sources). Within this approach, the social appraisal, performed through social network analysis and public engagement of water end-users, allowed hydrogeologists to get acquainted with the institutional dimension of local groundwater management, identifying issues, potential gaps (such as weak knowledge transfer among concerned stakeholders), and the key actors likely to support the implementation of the new science-based management practices resulting from the ongoing hydrogeological investigation. Results, hence, go beyond the specific relevance for the Grombaila basin, showing the effectiveness of the proposed approach and the importance of including social assessment in any given hydrogeological research aimed at supporting local development through groundwater protection measures.

Groundwater monitoring strategies at the Weldon Spring site, Weldon Spring, Missouri

International Nuclear Information System (INIS)

Meyer, K.A. Jr.

1988-01-01

This paper presents groundwater monitoring strategies at the Weldon Spring Site in east-central Missouri. The Weldon Spring Site is former ordnance works and uranium processing facility. In 1987, elevated levels of inorganic anions and nitroaromatics were detected in groundwater beneath the site. Studies are currently underway to characterize the hydrogeologic regime and to define groundwater contamination. The complex hydrogeology at the Weldon Spring Site requires innovative monitoring strategies. Combinations of fracture and conduit flow exist in the limestone bedrock. Perched zones are also present near surface impoundments. Losing streams and springs surround the site. Confronting this complex combination of hydrogeologic conditions is especially challenging

Current trends in research and clinical issues in the study of personality and its disorders

DEFF Research Database (Denmark)

Simonsen, Erik; Sørensen, Per; Pedersen, Liselotte

2014-01-01

lecture (Simonsen), a young researchers' symposium (Hopwood, Sharp, and Kaess), and special lectures on the Danish philosopher Soeren Kierkegaard and the poet Hans Christian Andersen. In this article we will survey the presentations and highlight the important issues in order to underline the current......The International Society for the Study of Personality Disorders (ISSPD) celebrated its 25th anniversary in September 2013 in Copenhagen and commemorated the First International Congress at the same site. The overall theme of the congress was "Bridging Personality and Psychopathology: The Person...... Behind the Illness." More than 400 abstracts were submitted, and the program included 8 keynote presentations, 18 invited symposia, a debate on current controversial issues in the classification of personality disorders (Fossati, Tyrer, Livesley, and Krueger), an ISSPD award lecture (Silk), a jubilee...

Evaluating the Potential of Groundwater Pollution in Kherran and Zoweircherry Plains through GIS-based DRASTIC Model

Directory of Open Access Journals (Sweden)

Manouchehr Chitsazan

2006-09-01

Full Text Available Zoweircherry and Kherran plains are located in the northeast ofAhwazin Khuzestan province. The water supply of these plains is a crucial issue and the quality of groundwater is also under the threat as a result of an increase in the use of agrochemicals. For this reason, assessing the vulnerability is an important factor in any policy-making decision for these plains. Focusing on this issue, this paper attempts to produce a groundwater vulnerability map for Zoweircherry and Kherran plains. The map is designed to show areas of highest potential for groundwater pollution on the basis of hydro-geological conditions and human impacts. Seven major hydro-geological factors (depth to water table, net recharge, aquifer media, soil media, topography, impact of vadose zone and hydraulic conductivity were incorporated into DRASTIC model and Geographical Information System (GIS was used to create a groundwater vulnerability map by overlaying the available hydro-geological data. The results of model exhibit that the west and southwest of the aquifer are dominated by medium vulnerability while small areas on northwest and east of the study area have no risk of pollution. Other parts of aquifer have low vulnerability. The nitrate analysis of groundwater samples shows that the existing nitrate on the west and southwest parts of aquifer is more than the existing nitrate on its other parts which, therefore, confirms the results of the vulnerability assessment.

Chemical and Isotopic Tracers of Groundwater Sustainability: an Overview of New Science Directions

Science.gov (United States)

Bullen, T.

2002-12-01

Groundwater sustainability is an emerging concept that is rapidly gaining attention from both scientists and water resource managers, particularly with regard to contamination and degradation of water quality in strategic aquifers. The sustainability of a groundwater resource is a complex function of its susceptibility to factors such as intrusion of poor-quality water from diverse sources, lack of sufficient recharge and reorganization of groundwater flowpaths in response to excessive abstraction. In theory the critical limit occurs when degradation becomes irreversible, such that remediative efforts may be fruitless on a reasonable human time scale. Chemical and isotopic tracers are proving to be especially useful tools for assessment of groundwater sustainability issues such as characterization of recharge, identification of potential sources, pathways and impacts of contaminants and prediction of how hydrology will change in response to excessive abstraction. A variety of relatively cost-efficient tracers are now available with which to assess the susceptibility of groundwater reserves to contamination from both natural and anthropogenic sources, and may provide valuable monitoring and regulatory tools for water resource managers. In this overview, the results of several ongoing groundwater studies by the U.S. Geological Survey will be discussed from the perspective of implications for new science directions for groundwater sustainability research that can benefit water policy development. A fundamental concept is that chemical and isotopic tracers used individually often provide ambiguous information, and are most effective when used in a rigorous "multi-tracer" context that considers the complex linkages between the hydrology, geology and biology of groundwater systems.

Hydro-environmental management of groundwater resources: A fuzzy-based multi-objective compromise approach

Science.gov (United States)

Alizadeh, Mohammad Reza; Nikoo, Mohammad Reza; Rakhshandehroo, Gholam Reza

2017-08-01

Sustainable management of water resources necessitates close attention to social, economic and environmental aspects such as water quality and quantity concerns and potential conflicts. This study presents a new fuzzy-based multi-objective compromise methodology to determine the socio-optimal and sustainable policies for hydro-environmental management of groundwater resources, which simultaneously considers the conflicts and negotiation of involved stakeholders, uncertainties in decision makers' preferences, existing uncertainties in the groundwater parameters and groundwater quality and quantity issues. The fuzzy multi-objective simulation-optimization model is developed based on qualitative and quantitative groundwater simulation model (MODFLOW and MT3D), multi-objective optimization model (NSGA-II), Monte Carlo analysis and Fuzzy Transformation Method (FTM). Best compromise solutions (best management policies) on trade-off curves are determined using four different Fuzzy Social Choice (FSC) methods. Finally, a unanimity fallback bargaining method is utilized to suggest the most preferred FSC method. Kavar-Maharloo aquifer system in Fars, Iran, as a typical multi-stakeholder multi-objective real-world problem is considered to verify the proposed methodology. Results showed an effective performance of the framework for determining the most sustainable allocation policy in groundwater resource management.

Simultaneous arsenic and fluoride removal from synthetic and real groundwater by electrocoagulation process: Parametric and cost evaluation.

Science.gov (United States)

Thakur, Lokendra Singh; Mondal, Prasenjit

2017-04-01

Co-existence of arsenic and fluoride in groundwater has raised severe health issues to living being. Thus, the present research has been conducted for simultaneous removal of arsenic and fluoride from synthetic groundwater by using electrocoagulation process with aluminum electrode. Effects of initial pH, current density, run time, inter electrode distance and NaCl concentration over percentage removal of arsenic and fluoride as well as operating cost have been studied. The optimum experimental conditions are found to be initial pH: 7, current density: 10 A/m 2 , run time: 95 min, inter electrode distance: 1 cm, NaCl concentration: 0.71 g/l for removal of 98.51% arsenic (initial concentration: 550 μg/l) and 88.33% fluoride (initial concentration: 12 mg/l). The concentration of arsenic and fluoride in treated water are found to be 8.19 μg/l and 1.4 mg/l, respectively, with an operating cost of 0.357 USD/m 3 treated water. Pseudo first and second order kinetic model of individual and simultaneous arsenic and fluoride removal in electrocoagulation have also been studied. Produced sludge characterization studies also confirm the presence of arsenic in As(III) form, and fluoride in sludge. The present electrocoagulation process is able to reduce the arsenic and fluoride concentration of synthetic as well as real groundwater to below 10 μg/l and 1.5 mg/l, respectively, which are maximum contaminant level of these elements in drinking water according to WHO guidelines. Copyright © 2016 Elsevier Ltd. All rights reserved.

Independent technical evaluation and recommendations for contaminated groundwater at the department of energy office of legacy management Riverton processing site

Energy Technology Data Exchange (ETDEWEB)

Looney, Brain B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Denham, Miles E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Eddy-Dilek, Carol A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-04-01

The U.S. Department of Energy Office of Legacy Management (DOE-LM) manages the legacy contamination at the Riverton, WY, Processing Site – a former uranium milling site that operated from 1958 to 1963. The tailings and associated materials were removed in 1988-1989 and contaminants are currently flushing from the groundwater. DOE-LM commissioned an independent technical team to assess the status of the contaminant flushing, identify any issues or opportunities for DOE-LM, and provide key recommendations. The team applied a range of technical frameworks – spatial, temporal, hydrological and geochemical – in performing the evaluation. In each topic area, an in depth evaluation was performed using DOE-LM site data (e.g., chemical measurements in groundwater, surface water and soil, water levels, and historical records) along with information collected during the December 2013 site visit (e.g., plant type survey, geomorphology, and minerals that were observed, collected and evaluated).

Global simulation of interactions between groundwater and terrestrial ecosystems

Science.gov (United States)

Braakhekke, M. C.; Rebel, K.; Dekker, S. C.; Smith, B.; Van Beek, L. P.; Sutanudjaja, E.; van Kampenhout, L.; Wassen, M. J.

2016-12-01

In many places in the world ecosystems are influenced by the presence of a shallow groundwater table. In these regions upward water flux due to capillary rise increases soil moisture availability in the root zone, which has strong positive effect on evapotranspiration. Additionally it has important consequences for vegetation dynamics and fluxes of carbon and nitrogen. Under water limited conditions shallow groundwater stimulates vegetation productivity, and soil organic matter decomposition while under saturated conditions groundwater may have a negative effect on these processes due to lack of oxygen. Furthermore, since plant species differ with respect to their root distribution, preference for moisture conditions, and resistance to oxygen stress, shallow groundwater also influences vegetation type. Finally, processes such as denitrification and methane production occur under strictly anaerobic conditions and are thus strongly influenced by moisture availability. Most global hydrological models and several land surface models simulate groundwater table dynamics and their effects on land surface processes. However, these models typically have relatively simplistic representation of vegetation and do not consider changes in vegetation type and structure and are therefore less suitable to represent effects of groundwater on biogeochemical fluxes. Dynamic global vegetation models (DGVMs), describe land surface from an ecological perspective, combining detailed description of vegetation dynamics and structure and biogeochemical processes. These models are thus more appropriate to simulate the ecological and biogeochemical effects of groundwater interactions. However, currently virtually all DGVMs ignore these effects, assuming that water tables are too deep to affect soil moisture in the root zone. We have implemented a tight coupling between the dynamic global ecosystem model LPJ-GUESS and the global hydrological model PCR-GLOBWB. Using this coupled model we aim to

Understanding arsenic contamination of groundwater in Bangladesh

International Nuclear Information System (INIS)

Kabir, Babar

2001-01-01

underneath Bangladesh. Logically, arsenic is likely to be present as compounds within sediments comprising the aquifer systems and may be associated with iron oxides, organic matter, sulfides etc. High arsenic contamination of groundwater in Bangladesh is a serious issue requiring appropriate understanding of the phenomenon relating to the occurrence and release of arsenic in groundwater. The water supply challenge is as much one of quantity as of quality. In many regions of the world, it means bringing water closer to the house. Further, if the water supply is of good quality, it improves public health. Three developments of the past decades have spurred new approaches to water supply and public health. First, the capacity to analyze smaller amounts of constituents in water has advanced substantially. Second, the health status and life expectancy have risen substantially across most countries. Finally, health and epidemiological research have advanced as well, and we are now much better informed of longer-term health effects of prolonged ingestion of contaminants. There are, at present, few (if any) low-cost technology and affordable solutions for the treatment of arsenic in non-piped water systems. Proposed interventions in rural areas must include alternative water sources such as rainwater harvesting, more efficient use of non-contaminated wells in the area, treated surface water, selective well drilling to deeper aquifers, and simple arsenic removal techniques as they are found effective. Arsenic contamination apparently can occur in a wide variety of hydrogeological and socioeconomic conditions. Therefore, any mitigation strategy will have to be tailored to suit the local geological, institutional and financial situation. However, the experience with water supply across the world demonstrates that the offered technical options will be sustainable only when the local community, or the customers, are truly committed to it and are willing to contribute financially to (at

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.

Controversies in the Hydrosphere: an iBook exploring current global water issues for middle school classrooms

Science.gov (United States)

Dufoe, A.; Guertin, L. A.

2012-12-01

This project looks to help teachers utilize iPad technology in their classrooms as an instructional tool for Earth system science and connections to the Big Ideas in Earth Science. The project is part of Penn State University's National Science Foundation (NSF) Targeted Math Science Partnership grant, with one goal of the grant to help current middle school teachers across Pennsylvania engage students with significant and complex questions of Earth science. The free Apple software iBooks Author was used to create an electronic book for the iPad, focusing on a variety of controversial issues impacting the hydrosphere. The iBook includes image slideshows, embedded videos, interactive images and quizzes, and critical thinking questions along Bloom's Taxonomic Scale of Learning Objectives. Outlined in the introductory iBook chapters are the Big Ideas of Earth System Science and an overview of Earth's spheres. Since the book targets the hydrosphere, each subsequent chapter focuses on specific water issues, including glacial melts, aquifer depletion, coastal oil pollution, marine debris, and fresh-water chemical contamination. Each chapter is presented in a case study format that highlights the history of the issue, the development and current status of the issue, and some solutions that have been generated. The next section includes critical thinking questions in an open-ended discussion format that focus on the Big Ideas, proposing solutions for rectifying the situation, and/or assignments specifically targeting an idea presented in the case study chapter. Short, comprehensive multiple-choice quizzes are also in each chapter. Throughout the iBook, students are free to watch videos, explore the content and form their own opinions. As a result, this iBook fulfills the grant objective by engaging teachers and students with an innovative technological presentation that incorporates Earth system science with current case studies regarding global water issues.

Technical considerations for the implementation of subsurface microbial barriers for restoration of groundwater at UMTRA sites

Energy Technology Data Exchange (ETDEWEB)

Tucker, M.D.

1996-01-01

The Uranium Mill Tailings Remediation Action (UMTRA) Program is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the United States. The surface remediation phase, which has primarily focused on containment and stabilization of the abandoned uranium mill tailings piles, is nearing completion. Attention has now turned to the groundwater restoration phase. One alternative under consideration for groundwater restoration at UMTRA sites is the use of in-situ permeable reactive subsurface barriers. In this type of a system, contaminated groundwater will be allowed to flow naturally through a barrier filled with material which will remove hazardous constituents from the water by physical, chemical or microbial processes while allowing passage of the pore water. The subject of this report is a reactive barrier which would remove uranium and other contaminants of concern from groundwater by microbial action (i.e., a microbial barrier). The purpose of this report is to assess the current state of this technology and to determine issues that must be addressed in order to use this technology at UMTRA sites. The report focuses on six contaminants of concern at UMTRA sites including uranium, arsenic, selenium, molybdenum, cadmium and chromium. In the first section of this report, the fundamental chemical and biological processes that must occur in a microbial barrier to control the migration of contaminants are described. The second section contains a literature review of research which has been conducted on the use of microorganisms to immobilize heavy metals. The third section addresses areas which need further development before a microbial barrier can be implemented at an UMTRA site.

Technical considerations for the implementation of subsurface microbial barriers for restoration of groundwater at UMTRA sites

International Nuclear Information System (INIS)

Tucker, M.D.

1996-01-01

The Uranium Mill Tailings Remediation Action (UMTRA) Program is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the United States. The surface remediation phase, which has primarily focused on containment and stabilization of the abandoned uranium mill tailings piles, is nearing completion. Attention has now turned to the groundwater restoration phase. One alternative under consideration for groundwater restoration at UMTRA sites is the use of in-situ permeable reactive subsurface barriers. In this type of a system, contaminated groundwater will be allowed to flow naturally through a barrier filled with material which will remove hazardous constituents from the water by physical, chemical or microbial processes while allowing passage of the pore water. The subject of this report is a reactive barrier which would remove uranium and other contaminants of concern from groundwater by microbial action (i.e., a microbial barrier). The purpose of this report is to assess the current state of this technology and to determine issues that must be addressed in order to use this technology at UMTRA sites. The report focuses on six contaminants of concern at UMTRA sites including uranium, arsenic, selenium, molybdenum, cadmium and chromium. In the first section of this report, the fundamental chemical and biological processes that must occur in a microbial barrier to control the migration of contaminants are described. The second section contains a literature review of research which has been conducted on the use of microorganisms to immobilize heavy metals. The third section addresses areas which need further development before a microbial barrier can be implemented at an UMTRA site

Assessment of groundwater recharge potential zone using GIS approach in Purworejo regency, Central Java province, Indonesia

Science.gov (United States)

Aryanto, Daniel Eko; Hardiman, Gagoek

2018-02-01

Floods and droughts in Purworejo regency are an indication of problems in groundwater management. The current development progress has led to land conversion which has an impact on the problem of water infiltration in Purworejo regency. This study aims to determine the distribution of groundwater recharge potential zones by using geographic information system as the basis for ground water management. The groundwater recharge potential zone is obtained by overlaying all the thematic maps that affect the groundwater infiltration. Each thematic map is weighted according to its effect on groundwater infiltration such as land-use - 25%, rainfall - 20%, litology - 20%, soil - 15%, slope - 10%, lineament - 5%, and river density - 5% to find groundwater recharge potential zones. The groundwater recharge potential zones thus obtained were divided into five categories, viz., very high, high, medium, low and very low zones. The results of this study may be useful for better groundwater planning and management.

Characterisation of fracture network and groundwater preferential ...

African Journals Online (AJOL)

2014-03-18

Mar 18, 2014 ... In this study, we use a new method to present fracture networks and analyse the connectivity of the .... bounded aquifers are currently the most common targets for water supply ... a conceptual model that integrates all of the available data ...... Integrated multi-scale characterization of ground-water flow and.

Current issues in onychomycosis.

Science.gov (United States)

Trépanier, E F; Amsden, G W

1998-02-01

To review the epidemiology, mycology, clinical features and diagnosis, current pharmacotherapy, and pharmacoeconomics of onychomycosis. We conducted a MEDLINE search from 1966 to May 1997. References from these articles, manufacturers of the discussed antimycotics, and relevant abstracts from recent dermatology conferences were used to collect pertinent data. Data were obtained from published controlled studies and case reports. In the pharmacotherapy section, the most weight was placed on fully reported, randomized, controlled comparative trials, but abstracts and case series were included when well-controlled studies were unavailable. Onychomycosis is a common nail disorder that has a substantial impact on patients' quality of life. It is most commonly caused by dermatophytes, but yeasts and molds can also be involved. Diagnosis is made through clinical presentation, potassium hydroxide preparations, and culture of tissue/nail samples. Griseofulvin was the drug of choice for many years, but its low cure rates and the development of newer, more effective drugs made it fall out of favor. Current therapeutic alternatives include fluconazole, itraconazole, and terbinafine. Data on the use of fluconazole are limited to case series and reports. Continuous dosing of itraconazole and terbinafine are well-proven therapies. New data are becoming available on the use of pulse itraconazole dosing, which has recently been approved by the Food and Drug Administration for fingernail infections. These drugs are well tolerated, but attention to drug interactions is necessary with the azoles. Currently, continuous terbinafine appears to be the most cost-effective drug for dermatophyte onychomycosis.

Clopidogrel Resistance: Current Issues

Directory of Open Access Journals (Sweden)

NS Neki

2016-05-01

Full Text Available Antiplatelet agents are mainly used in the prevention and management of atherothrombotic complications. Dual antiplatelet therapy, combining aspirin and clopidogrel, is the standard care for patients having acute coronary syndromes or undergoing percutaneous coronary intervention according to the current ACC/AHA and ESC guidelines. But in spite of administration of dual antiplatelet therapy, some patients develop recurrent cardiovascular ischemic events especially stent thrombosis which is a serious clinical problem. Antiplatelet response to clopidogrel varies widely among patients based on ex vivo platelet function measurements. Clopidogrel is an effective inhibitor of platelet activation and aggregation due to its selective and irreversible blockade of the P2Y12 receptor. Patients who display little attenuation of platelet reactivity with clopidogrel therapy are labeled as low or nonresponders or clopidogrel resistant. The mechanism of clopidogrel resistance remains incompletely defined but there are certain clinical, cellular and genetic factors including polymorphisms responsible for therapeutic failure. Currently there is no standardized or widely accepted definition of clopidogrel resistance. The future may soon be realised in the routine measurement of platelet activity in the same way that blood pressure, cholesterol and blood sugar are followed to help guide the therapy, thus improving the care for millions of people. This review focuses on the methods used to identify patients with clopidogrel resistance, the underlying mechanisms, metabolism, clinical significance and current therapeutic strategies to overcome clopidogrel resistance. J Enam Med Col 2016; 6(1: 38-46

Large-scale groundwater modeling using global datasets: a test case for the Rhine-Meuse basin

NARCIS (Netherlands)

Sutanudjaja, E.H.; Beek, L.P.H. van; Jong, S.M. de; Geer, F.C. van; Bierkens, M.F.P.

2011-01-01

The current generation of large-scale hydrological models does not include a groundwater flow component. Large-scale groundwater models, involving aquifers and basins of multiple countries, are still rare mainly due to a lack of hydro-geological data which are usually only available in

Large-scale groundwater modeling using global datasets: A test case for the Rhine-Meuse basin

NARCIS (Netherlands)

Sutanudjaja, E.H.; Beek, L.P.H. van; Jong, S.M. de; Geer, F.C. van; Bierkens, M.F.P.

2011-01-01

The current generation of large-scale hydrological models does not include a groundwater flow component. Large-scale groundwater models, involving aquifers and basins of multiple countries, are still rare mainly due to a lack of hydro-geological data which are usually only available in developed

Results of Tritium Tracking and Groundwater Monitoring at the Hanford Site 200 Area State-Approved Land Disposal Site-FY 1999

International Nuclear Information System (INIS)

Barnett, D.B.

1999-01-01

The Hanford Site 200 Area Effluent Treatment Facility (ETF) processes contaminated liquids derived from Hanford Site facilities. The clean water generated by these processes is occasionally enriched in tritium and is discharged to the 200 Area State Approved Land Disposal Site (SALDS). Groundwater monitoring for tritium and other constituents is required by the state-issued permit at 21 wells surrounding the facility. During FY 1999, average tritium activities in most wells declined from average activities in 1998. The exception was deep well 69948-77C, where tritium results were at an all-time high (77,000 pCi/L) as a result of the delayed penetration of effluent deeper into the aquifer. Of the 12 constituents with permit enforcement limits, which are monitored in SALDS proximal wells, all were within limits during FY 1999. Water level measurements in nearby wells indicate that a small hydraulic mound exists around the SALDS facility as a result of discharges. This feature is directing groundwater flow radially outward a short distance before the regional northeasterly flow predominates. Evaluation of this condition indicates that the network is currently adequate for tracking potential effects of the SALDS on the groundwater. Recommendations include the discontinuation of ammonia, benzene, tetrahydrofuran, and acetone from the regular groundwater constituent list; designating background well 299-W8-1 as a tritium-tracking well only, and the use of quadruplicate averages of field pH, instead of a single laboratory measurement, as a permit compliance parameter

Proven Alternatives for Aboveground Treatment of Arsenic in Groundwater

Science.gov (United States)

2002-10-01

issue paper does not address three technologies that have been used to treat water containing arsenic: • Biological treatment • Phytoremediation ...arsenic in water, and no aboveground treatments of groundwater conducted at full scale were found. Phytoremediation and electrokinetics are not...Roundtable. September 1998. http://www.frtr.gov/costperf.htm. 1.16 U.S. EPA. Office of Research and Development. Arsenic & Mercury - Workshop on Removal

On the origins of hypersaline groundwater in the Nile Delta Aquifer

Science.gov (United States)

van Engelen, Joeri; Oude Essink, Gualbert H. P.; Kooi, Henk; Bierkens, Marc F. P.

2017-04-01

The fresh groundwater resources in the Nile Delta, Egypt, are of eminent socio-economic importance. These resources are under major stress due to population growth, the anticipated sea level rise and increased groundwater extraction rates, making fresh water availability the most challenging issue in this area. Up till now, numerous groundwater studies mainly focused on sea water intrusion on the top 100m of the groundwater system and assumed salinities not exceeding that of Mediterranean sea water, as there was no knowledge on groundwater in the deeper coastal parts of the Quaternary Nile Delta aquifer (that ranges up to 1000m depth). Recently, however, the Egyptian Research Institute for Groundwater (RIGW) collected salinity measurements and found a widespread occurrence of "hypersaline" groundwater: groundwater with salinities largely exceeding that of sea water at 600m depth (Nofal et al., 2015). This hypersaline groundwater greatly influences flow patterns and the fresh water potential of the aquifer. This research focuses on the origins of the hypersaline groundwater and the possible processes causing its transport. We consider all relevant salinization processes in the Nile Delta aquifer, over a time domain of up to 2.5 million years, which is the time span in which the aquifer got deposited. The following hypotheses were investigated with a combination of analytical solutions and numerical modelling: upward salt transport due to a) molecular diffusion, b) thermal buoyancy, c) consolidation-induced advection and dispersion, or downward transport due to d) composition buoyancy (salt inversion). We conclude that hypotheses a) and b) can be rejected, but c) and d) are both possible with the available information. An enhanced chemical analysis is suggested for further research, to determine the origins of this hypersaline water. This information in combination with the conclusions drawn in this research will give more insight in the potential amount of non

Global depletion of groundwater resources

NARCIS (Netherlands)

Wada, Y.; Beek, L.P.H. van; van Kempen, C.M.; Reckman, J.W.T.M.; Vasak, S.; Bierkens, M.F.P.

2010-01-01

In regions with frequent water stress and large aquifer systems groundwater is often used as an additional water source. If groundwater abstraction exceeds the natural groundwater recharge for extensive areas and long times, overexploitation or persistent groundwater depletion occurs. Here we

Chronic groundwater decline: A multi-decadal analysis of groundwater trends under extreme climate cycles

Science.gov (United States)

Le Brocque, Andrew F.; Kath, Jarrod; Reardon-Smith, Kathryn

2018-06-01

Chronic groundwater decline is a concern in many of the world's major agricultural areas. However, a general lack of accurate long-term in situ measurement of groundwater depth and analysis of trends prevents understanding of the dynamics of these systems at landscape scales. This is particularly worrying in the context of future climate uncertainties. This study examines long-term groundwater responses to climate variability in a major agricultural production landscape in southern Queensland, Australia. Based on records for 381 groundwater bores, we used a modified Mann-Kendall non-parametric test and Sen's slope estimator to determine groundwater trends across a 26-year period (1989-2015) and in distinct wet and dry climatic phases. Comparison of trends between climatic phases showed groundwater level recovery during wet phases was insufficient to offset the decline in groundwater level from the previous dry phase. Across the entire 26-year sampling period, groundwater bore levels (all bores) showed an overall significant declining trend (p 0.05). Spatially, both declining and rising bores were highly clustered. We conclude that over 1989-2015 there is a significant net decline in groundwater levels driven by a smaller subset of highly responsive bores in high irrigation areas within the catchment. Despite a number of targeted policy interventions, chronic groundwater decline remains evident in the catchment. We argue that this is likely to continue and to occur more widely under potential climate change and that policy makers, groundwater users and managers need to engage in planning to ensure the sustainability of this vital resource.

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

Science.gov (United States)

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

1987-01-01

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

Genesis of the gossan at the Las Cruces Ore Deposit (SW Spain). Groundwater-Rock Interaction.

Science.gov (United States)

Scheiber, L.; Ayora, C.; Vázquez-Suñé, E.; Soler, A.

2016-12-01

The Las Cruces deposit has sparked an interest in the scientific community due to the exceptional genesis and mineralogical composition. The original gossan formed by goethite and hematite has been replaced by siderite and galena rock. The current gossan composition is as the result of the interaction of groundwater that circulates through the Niebla-Posadas aquifer and a gossan formed by Fe-oxyhydroxides. The groundwater conditions promoted the reductive dissolution of Pb-bearing goethite by the organic matter degradation and the formation of siderite and galena. Hydrochemical and isotopic characteristics of groundwater endorses this hypothesis. Thus, negative Eh values, the existence of H2S and the tendency to light sulfate isotope values show the reducing conditions of groundwater. The key role of the organic matter degradation is marked by the high ammonium, boron and dissolved organic carbon (DOC) concentrations together the light δ13C values, both in groundwater and siderite. The siderite precipitation is confirmed by the high pH values (up to 10), the low amount of Fe (<10ppb) and the thermodynamic calculations. The Fe-oxyhydroxides are a high adsorption capacity which is capable of absorbing metals as arsenic, lead and antimony. The reductive dissolution of these minerals involves the release of these metal to groundwater. Then, the groundwater rich in sulfur and an excess of lead produce the galena precipitation. The likeness between the δ34S values, both the gossan and groundwater, reveals that the sulfur of the galena come from the currently groundwater. A reactive transport model confirm that the present day groundwater flux and composition is able to form the siderite rock in less than 1Ma, with no external supply of reactants. The limiting factor of the process is the Dissolved Organic Carbon (DOC) concentration in groundwater, i.e., higher concentrations would decrease the formation time, whereas the result is not sensitive to flow conditions.

Isotope method for the recognition of groundwater formation in China's preselected high level radioactive waste disposal repository site

International Nuclear Information System (INIS)

Guo Yonghai; Wang Ju; Liu Shufen; Su Rui; Lu Chuanhe

2005-01-01

Yemaquan region in Beishan area. Gansu province, is one of the preselected sites of disposal repository for high level radioactive waste (HLW) in our country. Hydrogeological condition is an important aspect for site evaluation and the groundwater formation is a key factor to reflect the hydrogeological conditions for a certain area. Isotopic method is the one of the important means to determine the groundwater formation. Through the sampling and analysis of shallow groundwater isotopes of Yemaquan region, combined with geological, hydrogeological and hydrogeochemical characteristics, the issue of groundwater formation in the study region was discussed. The main cognition is that the groundwater in the region was formed from the infiltration of modern rainfall and the strong evaporation was happened for the shallow groundwater, which indicates the circulation conditions were relatively good for the shallow groundwater. This cognition provides very important hydrogeological information and basis for the evaluation of Yemaquan preselected site. (authors)

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

Directory of Open Access Journals (Sweden)

Dorota Porowska

2014-10-01

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

Special Issue: Current Trends in Research in Accounting Finance and Management Control

OpenAIRE

Lassala, Carlos; Ripoll Feliu, Vicente

2017-01-01

On January 27, 2016, an agreement was signed with OmniaScience to select articles to be published in the journal Intangible Capital, in a special issue titled "Current Trends in Research in Accounting, Finance and Management Control." The agreement was reached within the framework of three events at the University of Valencia, from June 27 to 30, 2016: XXI Workshop on Accounting and Management Control. “Memorial Raymond Konopka”, X Iberoamerican Congress of Management Accounting, III  Int...

Simulating groundwater-induced sewer flooding

Science.gov (United States)

Mijic, A.; Mansour, M.; Stanic, M.; Jackson, C. R.

2016-12-01

During the last decade, Chalk catchments of southern England experienced severe groundwater flooding. High groundwater levels resulted in the groundwater ingress into the sewer network that led to restricted toilet use and the overflow of diluted, but untreated sewage to road surfaces, rivers and water courses. In response to these events the water and sewerage company Thames Water Utilities Ltd (TWUL) had to allocate significant funds to mitigate the impacts. It was estimated that approximately £19m was spent responding to the extreme wet weather of 2013-14, along with the use of a fleet of over 100 tankers. However, the magnitude of the event was so large that these efforts could not stop the discharge of sewage to the environment. This work presents the analysis of the risk of groundwater-induced sewer flooding within the Chalk catchment of the River Lambourn, Berkshire. A spatially distributed groundwater model was used to assess historic groundwater flood risk and the potential impacts of changes in future climate. We then linked this model to an urban groundwater model to enable us to simulate groundwater-sewer interaction in detail. The modelling setup was used to identify relationships between infiltration into sewers and groundwater levels at specific points on TWUL's sewer network, and to estimate historic and future groundwater flood risk, and how this varies across the catchment. The study showed the significance of understanding the impact of groundwater on the urban water systems, and producing information that can inform a water company's response to groundwater flood risk, their decision making process and their asset management planning. However, the knowledge gained through integrated modelling of groundwater-sewer interactions has highlighted limitations of existing approaches for the simulation of these coupled systems. We conclude this work with number of recommendations about how to improve such hydrological/sewer analysis.

Hanford Site Groundwater Monitoring for Fiscal Year 2000

Energy Technology Data Exchange (ETDEWEB)

Hartman, Mary J.; Morasch, Launa F.; Webber, William D.

2001-03-01

This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 2000 on the U.S. Department of Energy's Hanford Site, Washington. The most extensive contaminant plumes are tritium, iodine-129, and nitrate, which all had multiple sources and are very mobile in groundwater. Carbon tetrachloride and associated organic constituents form a relatively large plume beneath the central part of the Site. Hexavalent chromium is present in smaller plumes beneath the reactor areas along the river and beneath the central part of the site. Strontium-90 exceeds standards beneath each of the reactor areas, and technetium-99 and uranium are present in the 200 Areas. RCRA groundwater monitoring continued during fiscal year 2000. Vadose zone monitoring, characterization, remediation, and several technical demonstrations were conducted in fiscal year 2000. Soil gas monitoring at the 618-11 burial ground provided a preliminary indication of the location of tritium in the vadose zone and in groundwater. Groundwater modeling efforts focused on 1) identifying and characterizing major uncertainties in the current conceptual model and 2) performing a transient inverse calibration of the existing site-wide model. Specific model applications were conducted in support of the Hanford Site carbon tetrachloride Innovative Treatment Remediation Technology; to support the performance assessment of the Immobilized Low-Activity Waste Disposal Facility; and in development of the System Assessment Capability, which is intended to predict cumulative site-wide effects from all significant Hanford Site contaminants.

Quality-assurance plan for groundwater activities, U.S. Geological Survey, Washington Water Science Center

Science.gov (United States)

Kozar, Mark D.; Kahle, Sue C.

2013-01-01

This report documents the standard procedures, policies, and field methods used by the U.S. Geological Survey’s (USGS) Washington Water Science Center staff for activities related to the collection, processing, analysis, storage, and publication of groundwater data. This groundwater quality-assurance plan changes through time to accommodate new methods and requirements developed by the Washington Water Science Center and the USGS Office of Groundwater. The plan is based largely on requirements and guidelines provided by the USGS Office of Groundwater, or the USGS Water Mission Area. Regular updates to this plan represent an integral part of the quality-assurance process. Because numerous policy memoranda have been issued by the Office of Groundwater since the previous groundwater quality assurance plan was written, this report is a substantial revision of the previous report, supplants it, and contains significant additional policies not covered in the previous report. This updated plan includes information related to the organization and responsibilities of USGS Washington Water Science Center staff, training, safety, project proposal development, project review procedures, data collection activities, data processing activities, report review procedures, and archiving of field data and interpretative information pertaining to groundwater flow models, borehole aquifer tests, and aquifer tests. Important updates from the previous groundwater quality assurance plan include: (1) procedures for documenting and archiving of groundwater flow models; (2) revisions to procedures and policies for the creation of sites in the Groundwater Site Inventory database; (3) adoption of new water-level forms to be used within the USGS Washington Water Science Center; (4) procedures for future creation of borehole geophysics, surface geophysics, and aquifer-test archives; and (5) use of the USGS Multi Optional Network Key Entry System software for entry of routine water-level data

Issues in neutral currents

International Nuclear Information System (INIS)

Sehgal, L.M.

1980-01-01

The experimental results on low energy confirming the structure of the effective Lagrangian of the weak neutral current processes as predicted by the Salam-Weinberg model are reviewed. Some possible modifications of the effective Lagrangian and the feasibility of their experimental verification are also considered. (P.L.)

Groundwater remediation of hexavalent chromium along the Columbia River at the Hanford site in Washington state, USA - 59030

International Nuclear Information System (INIS)

Foss, Dyan L.; Charboneau, Briant L.

2012-01-01

The U.S. Department of Energy Hanford Site, formerly used for nuclear weapons production, encompasses 1500 square kilometers in southeast Washington State along the Columbia River. A principle threat to the river are the groundwater plumes of hexavalent chromium (Cr(VI)), which affect approximately 9.8 square kilometers, and 4.1 kilometers of shoreline. Cleanup goals are to stop Cr(VI) from entering the river by the end of 2012 and remediate the groundwater plumes to the drinking water standards by the end of 2020. Five groundwater pump-and-treat systems are currently in operation for the remediation of Cr(VI). Since the 1990's, over 13.6 billion L of groundwater have been treated; over 1, 435 kg of Cr(VI) have been removed. This paper describes the unique aspects of the site, its environmental setting, hydrogeology, groundwater-river interface, riverine hydraulic effects, remediation activities completed to date, a summary of the current and proposed pump-and-treat operations, the in situ redox manipulation barrier, and the effectiveness of passive barriers, resins, and treatability testing results of calcium polysulfide, bio-stimulation, and electrocoagulation, currently under evaluation. (authors)

Study of Security Attributes of Smart Grid Systems- Current Cyber Security Issues

Energy Technology Data Exchange (ETDEWEB)

Wayne F. Boyer; Scott A. McBride

2009-04-01

This document provides information for a report to congress on Smart Grid security as required by Section 1309 of Title XIII of the Energy Independence and Security Act of 2007. The security of any future Smart Grid is dependent on successfully addressing the cyber security issues associated with the nation’s current power grid. Smart Grid will utilize numerous legacy systems and technologies that are currently installed. Therefore, known vulnerabilities in these legacy systems must be remediated and associated risks mitigated in order to increase the security and success of the Smart Grid. The implementation of Smart Grid will include the deployment of many new technologies and multiple communication infrastructures. This report describes the main technologies that support Smart Grid and summarizes the status of implementation into the existing U.S. electrical infrastructure.

Groundwater irrigation and its implications for water policy in semiarid countries: the Spanish experience

Science.gov (United States)

Garrido, Alberto; Martínez-Santos, Pedro; Llamas, M. Ramón

2006-03-01

Over the last decades, groundwater irrigation has become commonplace in many arid and semiarid regions worldwide, including Spain. This is largely a consequence of the advances in drilling and pumping technologies, and of the development of Hydrogeology. Compared with traditional surface water irrigation systems, groundwater irrigation offers more reliable supplies, lesser vulnerability to droughts, and ready accessibility for individual users. Economic forces influence the groundwater irrigation sector and its development. In Spain's Mediterranean regions, abstraction costs often amount to a very small fraction of the value of crops. In the inner areas, groundwater irrigation supports a more stable flow of farm income than rainfed agriculture. The social (jobs/m3) and economic (€/m3) value of groundwater irrigation generally exceeds that of surface water irrigation systems. However, poor groundwater management and legal controversies are currently at the base of Spain's social disputes over water. A thorough and transparent assessment of the relative socio-economic value of groundwater in relation to surface water irrigation might contribute to mitigate or avoid potential future conflicts. Enforcement of the European Union's Water Framework Directive may deliver better groundwater governance and a more sustainable use.

Current issues and perspectives in food safety and risk assessment.

Science.gov (United States)

Eisenbrand, G

2015-12-01

In this review, current issues and opportunities in food safety assessment are discussed. Food safety is considered an essential element inherent in global food security. Hazard characterization is pivotal within the continuum of risk assessment, but it may be conceived only within a very limited frame as a true alternative to risk assessment. Elucidation of the mode of action underlying a given hazard is vital to create a plausible basis for human toxicology evaluation. Risk assessment, to convey meaningful risk communication, must be based on appropriate and reliable consideration of both exposure and mode of action. New perspectives, provided by monitoring human exogenous and endogenous exposure biomarkers, are considered of great promise to support classical risk extrapolation from animal toxicology. © The Author(s) 2015.

Corrective measures evaluation report for Tijeras Arroyo groundwater.

Energy Technology Data Exchange (ETDEWEB)

Witt, Johnathan L (North Wind, Inc., Idaho Falls, ID); Orr, Brennon R. (North Wind, Inc., Idaho Falls, ID); Dettmers, Dana L. (North Wind, Inc., Idaho Falls, ID); Hall, Kevin A. (North Wind, Inc., Idaho Falls, ID); Howard, M. Hope (North Wind, Inc., Idaho Falls, ID)

2005-08-01

This Corrective Measures Evaluation report was prepared as directed by a Compliance Order on Consent issued by the New Mexico Environment Department to document the process of selecting the preferred remedial alternative for Tijeras Arroyo Groundwater. Supporting information includes background concerning the site conditions and potential receptors and an overview of work performed during the Corrective Measures Evaluation. The evaluation of remedial alternatives included identifying and describing four remedial alternatives, an overview of the evaluation criteria and approach, comparing remedial alternatives to the criteria, and selecting the preferred remedial alternative. As a result of the Corrective Measures Evaluation, monitored natural attenuation of the contaminants of concern (trichloroethene and nitrate) is the preferred remedial alternative for implementation as the corrective measure for Tijeras Arroyo Groundwater. Design criteria to meet cleanup goals and objectives and the corrective measures implementation schedule for the preferred remedial alternative are also presented.

Hydrological challenges to groundwater trading: Lessons from south-west Western Australia

Science.gov (United States)

Skurray, James H.; Roberts, E. J.; Pannell, David J.

2012-01-01

SummaryPerth, Western Australia (pop. 1.6 m) derives 60% of its public water supply from the Gnangara groundwater system (GGS). Horticulture, domestic self-supply, and municipal parks are other major consumers of GGS groundwater. The system supports important wetlands and groundwater-dependent ecosystems. Underlying approximately 2200 km 2 of the Swan Coastal Plain, the GGS comprises several aquifer levels with partial interconnectivity. Supplies of GGS groundwater are under unprecedented stress, due to reduced recharge and increases in extraction. Stored reserves in the superficial aquifer fell by 700 GL between 1979 and 2008. Over a similar period, annual extraction for public supply increased by more than 350% from the system overall. Some management areas are over-allocated by as much as 69%. One potential policy response is a trading scheme for groundwater use. There has been only limited trading between GGS irrigators. Design and implementation of a robust groundwater trading scheme faces hydrological and/or hydro-economic challenges, among others. Groundwater trading involves transfers of the right to extract water. The resulting potential for spatial (and temporal) redistribution of the impacts of extraction requires management. Impacts at the respective selling and buying locations may differ in scale and nature. Negative externalities from groundwater trading may be uncertain as well as not monetarily compensable. An ideal groundwater trading scheme would ensure that marginal costs from trades do not exceed marginal benefits, incorporating future effects and impacts on third-parties. If this condition could be met, all transactions would result in constant or improved overall welfare. This paper examines issues that could reduce public welfare if groundwater trading is not subject to well-designed governance arrangements that are appropriate to meeting the above condition. It also outlines some opportunities to address key risks within the design of a

Assessing groundwater availability and the response of the groundwater system to intensive exploitation in the North China Plain by analysis of long-term isotopic tracer data

Science.gov (United States)

Su, Chen; Cheng, Zhongshuang; Wei, Wen; Chen, Zongyu

2018-03-01

The use of isotope tracers as a tool for assessing aquifer responses to intensive exploitation is demonstrated and used to attain a better understanding of the sustainability of intensively exploited aquifers in the North China Plain. Eleven well sites were selected that have long-term (years 1985-2014) analysis data of isotopic tracers. The stable isotopes δ18O and δ2H and hydrochemistry were used to understand the hydrodynamic responses of the aquifer system, including unconfined and confined aquifers, to groundwater abstraction. The time series data of 14C activity were also used to assess groundwater age, thereby contributing to an understanding of groundwater sustainability and aquifer depletion. Enrichment of the heavy oxygen isotope (18O) and elevated concentrations of chloride, sulfate, and nitrate were found in groundwater abstracted from the unconfined aquifer, which suggests that intensive exploitation might induce the potential for aquifer contamination. The time series data of 14C activity showed an increase of groundwater age with exploitation of the confined parts of the aquifer system, which indicates that a larger fraction of old water has been exploited over time, and that the groundwater from the deep aquifer has been mined. The current water demand exceeds the sustainable production capabilities of the aquifer system in the North China Plain. Some measures must be taken to ensure major cuts in groundwater withdrawals from the aquifers after a long period of depletion.

Impacts of vegetation change on groundwater recharge

Science.gov (United States)

Bond, W. J.; Verburg, K.; Smith, C. J.

2003-12-01

Vegetation change is the accepted cause of increasing river salt concentrations and the salinisation of millions of hectares of farm land in Australia. Replacement of perennial native vegetation by annual crops and pastures following European settlement has altered the water balance causing increased groundwater recharge and mobilising the naturally saline groundwater. The Redesigning Agriculture for Australian Landscapes Program, of which the work described here is a part, was established to develop agricultural practices that are more attuned to the delicate water balance described above. Results of field measurements will be presented that contrast the water balance characteristics of native vegetation with those of conventional agricultural plants, and indicate the functional characteristics required of new agricultural practices to reduce recharge. New agricultural practices may comprise different management of current crops and pastures, or may involve introducing totally new species. In either case, long-term testing is required to examine their impact on recharge over a long enough climate record to encompass the natural variability of rainfall that is characteristic of most Australian farming regions. Field experimentation therefore needs to be complemented and extended by computer simulation. This requires a modelling approach that is more robust than conventional crop modelling because (a) it needs to be sensitive enough to predict small changes in the residual recharge term, (b) it needs to be able to simulate a variety of vegetation in different sequences, (c) it needs to be able to simulate continuously for several decades of input data, and (d) it therefore needs to be able to simulate the period between crops, which often has a critical impact on recharge. The APSIM simulation framework will be used to illustrate these issues and to explore the effect of different vegetation combinations on recharge.

Implementation issues on the design of current loops based on resonant regulators for isolated microgrids

DEFF Research Database (Denmark)

Federico, de Bosio; Pastorelli, Michele; Antonio DeSouza Ribeiro, Luiz

2016-01-01

This paper analyzes the influence of state feedback coupling between the capacitor voltage and inductor current in voltage source inverters (VSI) operating in stand-alone microgrids. A decoupling technique is proposed as an effective measure to enhance the dynamics. Further implementation issues ...

Groundwater Managment Districts

Data.gov (United States)

Kansas Data Access and Support Center — This dataset outlines the location of the five Groundwater Management Districts in Kansas. GMDs are locally formed and elected boards for regional groundwater...

Modeling the impact of the nitrate contamination on groundwater at the groundwater body scale : The Geer basin case study (Invited)

Science.gov (United States)

Brouyere, S.; Orban, P.; Hérivaux, C.

2009-12-01

�� where current polluting pressures remain the same and (ii) two contrasted scenarios that simulate the implementation of programs of measures aiming at reaching good chemical status. The results of the hydrogeological model under the “business as usual scenario” have been used to assess the cost for the society of the continuous degradation of the groundwater quality. The results of the hydrogeological model under the two contrasted scenarios have been used to assess the economical benefit as avoided damage resulting from the decrease in the nitrate load. A cost-benefit analysis has been thus performed to assess the programme of mitigation measures which provides the largest benefits at the lowest cost.

Conceptual understanding and groundwater quality of selected basin-fill aquifers in the Southwestern United States

Science.gov (United States)

Thiros, Susan A.; Bexfield, Laura M.; Anning, David W.; Huntington, Jena M.

2010-01-01

The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey has been conducting a regional analysis of water quality in the principal aquifer systems in the southwestern United States (hereinafter, “Southwest”) since 2005. Part of the NAWQA Program, the objective of the Southwest Principal Aquifers (SWPA) study is to develop a better understanding of water quality in basin-fill aquifers in the region by synthesizing information from case studies of 15 basins into a common set of important natural and human-related factors found to affect groundwater quality.The synthesis consists of three major components:1. Summary of current knowledge about the groundwater systems, and the status of, changes in, and influential factors affecting quality of groundwater in basin-fill aquifers in 15 basins previously studied by NAWQA (this report).2. Development of a conceptual model of the primary natural and human-related factors commonly affecting groundwater quality, thereby building a regional understanding of the susceptibility and vulnerability of basin-fill aquifers to contaminants.3. Development of statistical models that relate the concentration or occurrence of specific chemical constituents in groundwater to natural and human-related factors linked to the susceptibility and vulnerability of basin-fill aquifers to contamination.Basin-fill aquifers occur in about 200,000 mi2 of the 410,000 mi2 SWPA study area and are the primary source of groundwater supply for cities and agricultural communities. Four of the principal aquifers or aquifer systems of the United States are included in the basin-fill aquifers of the study area: (1) the Basin and Range basin-fill aquifers in California, Nevada, Utah, and Arizona; (2) the Rio Grande aquifer system in New Mexico and Colorado; (3) the California Coastal Basin aquifers; and (4) the Central Valley aquifer system in California. Because of the generally limited availability of surface-water supplies in

Critical issues in water and wastewater treatment. Proceedings of the 1994 national conference on environmental engineering

International Nuclear Information System (INIS)

Ryan, J.N.; Edwards, M.

1994-01-01

This proceedings, Critical Issues in Water and Wastewater, contains short versions of most of the 114 papers presented at the 1994 Specialty Conference on Environmental Engineering held in Boulder, Colorado on July 11 to 13, 1994. These papers are organized into 23 distinct sessions that focus primarily on water treatment, water distribution, and wastewater treatment. Some of the topics discussed concern microbes in drinking water, contaminated groundwater remediation, and the effects of floods on hazardous waste sites. To summarize, this proceedings provides a practical and timely reference for engineers interested in the current state of water and wastewater concerns

Groundwater Monitoring Plan for the Solid Waste Landfill

International Nuclear Information System (INIS)

Lindberg, J.W.; Chou, C.J.

2000-01-01

The Solid Waste Landfill (SWL) is regulated by the Washington State Department of Ecology under WAC 173-304. Between 1973 and 1976, the landfill received primarily paper waste and construction debris, but it also received asbestos, sewage, and catch tank liquid waste. Groundwater monitoring results indicate the SWL has contaminated groundwater with volatile organic compounds and possibly metals at levels that exceed regulatory limits. DynCorp, Tri-Cities, Inc. operates the facility under an interim closure plan (final closure plan will be released shortly). Pacific Northwest National Laboratory (PNNL) monitors groundwater at the site. This monitoring plan includes well and constituent lists, and summarizes sampling, analytical, and quality control requirements. Changes from the previous monitoring plan include elimination of two radionuclides from the analyte list and some minor changes in the statistical analysis. Existing wells in the current monitoring network only monitor the uppermost portion of the upper-most aquifer. Therefore, two new downgradient wells and one existing upgradient well are proposed to determine whether groundwater waste constituents have reached the lower portion of the uppermost aquifer. The proposed well network includes three upgradient wells and ten downgradient wells. The wells will be sampled quarterly for 14 analytes required by WAC 173-304-490 plus volatile organic compounds and filtered arsenic as site-specific analytes

Groundwater Monitoring Plan for the Solid Waste Landfill

Energy Technology Data Exchange (ETDEWEB)

JW Lindberg; CJ Chou

2000-12-14

The Solid Waste Landfill (SWL) is regulated by the Washington State Department of Ecology under WAC 173-304. Between 1973 and 1976, the landfill received primarily paper waste and construction debris, but it also received asbestos, sewage, and catch tank liquid waste. Groundwater monitoring results indicate the SWL has contaminated groundwater with volatile organic compounds and possibly metals at levels that exceed regulatory limits. DynCorp, Tri-Cities, Inc. operates the facility under an interim closure plan (final closure plan will be released shortly). Pacific Northwest National Laboratory (PNNL) monitors groundwater at the site. This monitoring plan includes well and constituent lists, and summarizes sampling, analytical, and quality control requirements. Changes from the previous monitoring plan include elimination of two radionuclides from the analyte list and some minor changes in the statistical analysis. Existing wells in the current monitoring network only monitor the uppermost portion of the upper-most aquifer. Therefore, two new downgradient wells and one existing upgradient well are proposed to determine whether groundwater waste constituents have reached the lower portion of the uppermost aquifer. The proposed well network includes three upgradient wells and ten downgradient wells. The wells will be sampled quarterly for 14 analytes required by WAC 173-304-490 plus volatile organic compounds and filtered arsenic as site-specific analytes.

Investigation of groundwater-streamflow interactions in the Bega alluvial aquifer using tritium and stable isotope ratios

International Nuclear Information System (INIS)

Stone, D.J.M.; Thomas, M.; Russell, G.

2001-01-01

An isotope hydrology study of the Bega Valley groundwater system has been made. The investigation which focussed on environmental tritium and stable isotope ratios confirms that that the groundwater in the alluvial aquifer of the Bega Valley is sustainable at the current usage rate

Mycoplasma genitalium infections: current treatment options and resistance issues

Directory of Open Access Journals (Sweden)

Sethi S

2017-09-01

Full Text Available Sunil Sethi, Kamran Zaman, Neha Jain Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India Abstract: Mycoplasma genitalium is one of the important causes of non-gonococcal urethritis. Rising incidence and emerging antimicrobial resistance are a major concern these days. The poor clinical outcomes with doxycycline therapy led to the use of azithromycin as the primary drug of choice. Single-dose azithromycin regimen over a period of time was changed to extended regimen following studies showing better clinical cures and less risk of resistance development. However, emerging macrolide resistance, either due to transmission of resistance or drug pressure has further worsened the management of this infection. The issues of drug resistance and treatment failures also exist in cases of M. genitalium infection. At present, the emergence of multidrug-resistant (MDR M. genitalium strains is an alarming sign for its treatment and the associated public health impact due to its complications. However, newer drugs like pristinamycin, solithromycin, sitafloxacin, and others have shown a hope for the clinical cure, but need further clinical trials to optimize the therapeutic dosing schedules and formulate appropriate treatment regimens. Rampant and inappropriate use of these newer drugs will further sabotage future attempts to manage MDR strains. There is currently a need to formulate diagnostic algorithms and etiology-based treatment regimens rather than the syndromic approach, preferably using combination therapy instead of a monotherapy. Awareness about the current guidelines and recommended treatment regimens among clinicians and local practitioners is of utmost importance. Antimicrobial resistance testing and global surveillance are required to assess the efficacy of current treatment regimens and for guiding future research for the early detection and management of MDR M. genitalium infections

A Comparison of Seasonal Patterns Observed in ERS 1 / 2 Differential InSAR, Groundwater Level Data, and Groundwater Production Data in Reno, Nevada, USA.

Science.gov (United States)

Oppliger, G. L.; Goudy, C.; Widmer, M.

2005-12-01

spatial and temporal aliasing issues associated with estimating seasonal GWL dynamics from incomplete coverages were overcome by merging several years of seasonal groundwater level change data into a surface representing average seasonal GWL change. This average change surface proved significantly more robust than any of the individual GWL time differences, and showed the maximum zone of seasonal GWL change was offset 1 km and 2 km, from the groundwater production centroid and the maximum D-InSAR surface change, respectively. Although the spatial relations between these features are not one-to-one, the consistency of the results suggest that it may be possible to map D-InSAR observations to approximate changes in groundwater levels in the Reno study area.

A GIS-Enabled, Michigan-Specific, Hierarchical Groundwater Modeling and Visualization System

Science.gov (United States)

Liu, Q.; Li, S.; Mandle, R.; Simard, A.; Fisher, B.; Brown, E.; Ross, S.

2005-12-01

, automatically extract data and attributes, and simulate unsteady groundwater flow and contaminant transport in response to water and land management decisions; * Visualize and map model simulations and predictions with data from the statewide groundwater database in a seamless interactive environment. IGW-M has the potential to significantly improve the productivity of Michigan groundwater management investigations. It changes the role of engineers and scientists in modeling and analyzing the statewide groundwater database from heavily physical to cognitive problem-solving and decision-making tasks. The seamless real-time integration, real-time visual interaction, and real-time processing capability allows a user to focus on critical management issues, conflicts, and constraints, to quickly and iteratively examine conceptual approximations, management and planning scenarios, and site characterization assumptions, to identify dominant processes, to evaluate data worth and sensitivity, and to guide further data-collection activities. We illustrate the power and effectiveness of the M-IGW modeling and visualization system with a real case study and a real-time, live demonstration.

Hydrogeochemistry and Stable Isotope Studies of Groundwater in the Ga West Municipal Area, Ghana

International Nuclear Information System (INIS)

Saka, David

2011-07-01

This study assesses groundwater in the Ga West Municipal Area of Ghana using hydrogeochemistry and stable isotope approaches. High salinity groundwaters are obtained in the municipality which poses problems for current and future domestic water supply exploitation. The increase in salinity is related to the dissolution of minerals in the host rocks and the evaporative concentration of solutes. The dominant groundwater composition in both shallow and deep wells sampled is Na-Cl, with concentration increasing substantially with well depths. The mixing process between freshwater and saline water was observed in the shift from CaHCO3 facies to Ca-Cl facies. Schoeller diagrams showed that groundwater movement in the study area is mostly vertical, moving from the shallow groundwaters towards the deep groundwaters. There were however few exceptions where no relationship was established between the shallow and the deep groundwaters. The oxygen and hydrogen isotope compositions in the groundwater samples suggest that groundwater recharge is of meteoric origin, with few samples showing evidence of evaporation. An average deuterium excess of rainfall of 14.2‰ was observed, which indicates the significance of kinetic evaporation due to low humidity conditions prevalent in the study area. The d-excess also indicates modern recharge along the Akwapim-Togo Ranges. Groundwater analysis for trace metals indicates that 93% of the groundwaters have Iron concentration above recommended limits. However, Cu, Zn, Pb, Cd and Cr have values within the acceptable limits. Generally, about 40% of the groundwaters sampled are not suitable for drinking and domestic purposes based on comparison with international standards for drinking water. (au)

Groundwater quality in the Owens Valley, California

Science.gov (United States)

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

The 19th KAIF/KNS annual conference growth of nuclear industry and its current issues

International Nuclear Information System (INIS)

Juhn, Poong Eil

2004-01-01

After the president Eisenhower's 'Atoms for Peace' speech at the UN general Conference in December 1953, nuclear industry for peaceful uses of nuclear energy has been developed steadily worldwide through international co-operation and collaboration during last half a century. However, from late 1980s, in particular, after Chernobyl nuclear accident in 1986 and growing public opposition on nuclear waste management and disposal, the growth of nuclear power plants worldwide, except some Asian countries, has been slowed down. Nuclear power currently supplies about 16 % of the world's electricity. In the next 50 years, it is expected that the world energy demand will increase about two times comparing current level while electricity demand will be tripled. Therefore, the nuclear industry should be expanded significantly in the next 50 years to meet the role for 'Prosperity beyond Peace'. The main issues for nuclear industry to take this important role are to increase in economics of nuclear power, and to resolve nuclear waste management and disposal. Some of these issues have been resolved mainly through international co-operation. For example, there are significant efforts to improve economics of nuclear power. This paper reviews worldwide efforts to resolve these issues and mentions what are the remaining ones

Study on the Variation of Groundwater Level under Time-varying Recharge

Science.gov (United States)

Wu, Ming-Chang; Hsieh, Ping-Cheng

2017-04-01

The slopes of the suburbs come to important areas by focusing on the work of soil and water conservation in recent years. The water table inside the aquifer is affected by rainfall, geology and topography, which will result in the change of groundwater discharge and water level. Currently, the way to obtain water table information is to set up the observation wells; however, owing to that the cost of equipment and the wells excavated is too expensive, we develop a mathematical model instead, which might help us to simulate the groundwater level variation. In this study, we will discuss the groundwater level change in a sloping unconfined aquifer with impermeable bottom under time-varying rainfall events. Referring to Child (1971), we employ the Boussinesq equation as the governing equation, and apply the General Integral Transforms Method (GITM) to analyzing the groundwater level after linearizing the Boussinesq equation. After comparing the solution with Verhoest & Troch (2000) and Bansal & Das (2010), we get satisfactory results. To sum up, we have presented an alternative approach to solve the linearized Boussinesq equation for the response of groundwater level in a sloping unconfined aquifer. The present analytical results combine the effect of bottom slope and the time-varying recharge pattern on the water table fluctuations. Owing to the limitation and difficulty of measuring the groundwater level directly, we develop such a mathematical model that we can predict or simulate the variation of groundwater level affected by any rainfall events in advance.

Current Issues of Antipyretic Therapy in Children with Acute Respiratory Infections

Directory of Open Access Journals (Sweden)

E. I. Novikova

2013-01-01

Full Text Available This article discusses the current issues in the pediatric practice of seasonal incidence of children with acute respiratory infections. The basic etiological aspects of this pathology, specific clinical symptoms typical for different pathogens, causes of bursts of disease in certain periods are described. Special attention is paid to the tactics of antipyretic therapy in different groups of children with fever and acute respiratory diseases, understand the typical errors in its appointment. The author discusses the domestic and foreign results of using ibuprofen to relieve fever in children with this pathology, comparative efficacy and safety data of ibuprofen with other analgesics-antipyretics.

Considering groundwater use to improve the assessment of groundwater pumping for irrigation in North Africa

Science.gov (United States)

Massuel, Sylvain; Amichi, Farida; Ameur, Fatah; Calvez, Roger; Jenhaoui, Zakia; Bouarfa, Sami; Kuper, Marcel; Habaieb, Hamadi; Hartani, Tarik; Hammani, Ali

2017-09-01

Groundwater resources in semi-arid areas and especially in the Mediterranean face a growing demand for irrigated agriculture and, to a lesser extent, for domestic uses. Consequently, groundwater reserves are affected and water-table drops are widely observed. This leads to strong constraints on groundwater access for farmers, while managers worry about the future evolution of the water resources. A common problem for building proper groundwater management plans is the difficulty in assessing individual groundwater withdrawals at regional scale. Predicting future trends of these groundwater withdrawals is even more challenging. The basic question is how to assess the water budget variables and their evolution when they are deeply linked to human activities, themselves driven by countless factors (access to natural resources, public policies, market, etc.). This study provides some possible answers by focusing on the assessment of groundwater withdrawals for irrigated agriculture at three sites in North Africa (Morocco, Tunisia and Algeria). Efforts were made to understand the different features that influence irrigation practices, and an adaptive user-oriented methodology was used to monitor groundwater withdrawals. For each site, different key factors affecting the regional groundwater abstraction and its past evolution were identified by involving farmers' knowledge. Factors such as farmer access to land and groundwater or development of public infrastructures (electrical distribution network) are crucial to decode the results of well inventories and assess the regional groundwater abstraction and its future trend. This leads one to look with caution at the number of wells cited in the literature, which could be oversimplified.

Novel patch modelling method for efficient simulation and prediction uncertainty analysis of multi-scale groundwater flow and transport processes

Science.gov (United States)

Sreekanth, J.; Moore, Catherine

2018-04-01

The application of global sensitivity and uncertainty analysis techniques to groundwater models of deep sedimentary basins are typically challenged by large computational burdens combined with associated numerical stability issues. The highly parameterized approaches required for exploring the predictive uncertainty associated with the heterogeneous hydraulic characteristics of multiple aquifers and aquitards in these sedimentary basins exacerbate these issues. A novel Patch Modelling Methodology is proposed for improving the computational feasibility of stochastic modelling analysis of large-scale and complex groundwater models. The method incorporates a nested groundwater modelling framework that enables efficient simulation of groundwater flow and transport across multiple spatial and temporal scales. The method also allows different processes to be simulated within different model scales. Existing nested model methodologies are extended by employing 'joining predictions' for extrapolating prediction-salient information from one model scale to the next. This establishes a feedback mechanism supporting the transfer of information from child models to parent models as well as parent models to child models in a computationally efficient manner. This feedback mechanism is simple and flexible and ensures that while the salient small scale features influencing larger scale prediction are transferred back to the larger scale, this does not require the live coupling of models. This method allows the modelling of multiple groundwater flow and transport processes using separate groundwater models that are built for the appropriate spatial and temporal scales, within a stochastic framework, while also removing the computational burden associated with live model coupling. The utility of the method is demonstrated by application to an actual large scale aquifer injection scheme in Australia.

Groundwater management based on monitoring of land subsidence and groundwater levels in the Kanto Groundwater Basin, Central Japan

Science.gov (United States)

Furuno, K.; Kagawa, A.; Kazaoka, O.; Kusuda, T.; Nirei, H.

2015-11-01

Over 40 million people live on and exploit the groundwater resources of the Kanto Plain. The Plain encompasses metropolitan Tokyo and much of Chiba Prefecture. Useable groundwater extends to the base of the Kanto Plain, some 2500 to 3000 m below sea level. Much of the Kanto Plain surface is at sea level. By the early 1970s, with increasing urbanization and industrial expansion, local overdraft of groundwater resources caused major ground subsidence and damage to commercial and residential structures as well as to local and regional infrastructure. Parts of the lowlands around Tokyo subsided to 4.0 m below sea level; particularly affected were the suburbs of Funabashi and Gyotoku in western Chiba. In the southern Kanto Plain, regulations, mainly by local government and later by regional agencies, led to installation of about 500 monitoring wells and almost 5000 bench marks by the 1990's. Many of them are still working with new monitoring system. Long-term monitoring is important. The monitoring systems are costly, but the resulting data provide continuous measurement of the "health" of the Kanto Groundwater Basin, and thus permit sustainable use of the groundwater resource.

ECO Update / Groundwater Foum Issue Paper: Evaluating Ground-Water/Surface-Water Transition Zones in Ecological Risk Assessments

Science.gov (United States)

This ECO Update builds on the standard approach to ERA (U.S. EPA 1997), by providing a framework for incorporating groundwater/surface-water (GW/SW) interactions into existing ERAs (see U.S. EPA 1997 and 2001a for an introduction to ecological risk....

Hydraulic performance of permeable barriers for in situ treatment of contaminated groundwater

International Nuclear Information System (INIS)

Smyth, D.J.A.; Shikaze, S.G.; Cherry, J.A.

1997-01-01

The passive interception and in situ treatment of dissolved contaminants in groundwater by permeable reactive barriers has recently gained favor at an increasing number of sites as an alternative to conventional approaches to groundwater remediation such as the pump-and-treat method. Permeable reactive barriers have two essential functions. The first is that the barriers must be installed in a position such that all of the plume passes through the reactive system. The second function is to achieve acceptable treatment of the contamination by physical, chemical or biological means within or downgradient of the barrier. In this paper, issues associated with the hydraulic performance of permeable reaction barriers are evaluated using a three-dimensional groundwater flow model. The efficiency of plume capture by permeable wall and funnel-and-gate systems is examined for some generic and for site-specific hydrogeologic systems. The results have important implications to decisions pertaining to the selection, design and installation of permeable reactive barrier systems

Geochemical investigation of groundwater in the Tono area, Japan. Chemical characteristics and groundwater evolution

International Nuclear Information System (INIS)

Iwatsuki, Teruki; Hama, Katsuhiro; Yoshida, Hidekazu

1997-01-01

Geochemical investigations form an important part of the R and D program at the Tono study site, central Japan. Detailed geological structure and groundwater chemistry have been studied to understand the geochemical environment in the sedimentary and crystalline rocks distributed in this area. The chemical evolution of the groundwater in the sedimentary rocks is characterized with the variation in Na + , Ca 2+ and HCO 3 - concentrations, and ion exchange and dissolution of calcite are dominant reactions in the evolution of groundwater. Geological investigation shows that a fracture system of crystalline rock can be classified into:intact zone, moderately fractured zone and intensely fractured zone, according to the frequency and the width of fractures and fractured zones. The groundwater in the intact and fractured zones of crystalline rock are characterized by Na + -Ca 2+ -HCO 3 - or Na + -HCO 3 - dominated water, and Na + -Ca 2+ -Fe 2+ -HCO 3 - dominated water. The chemical evolution of groundwater is, generally, controlled by water-rock interaction between plagioclase, iron minerals and groundwater. The groundwater at depth of G.L.-186m in the crystalline rock at the Tono area is characterized by the mixture between the oxidized surface water and the reduced groundwater. The investigation based on correlation between geological structures and groundwater chemistry can be applied to understand the geochemical environment in deep crystalline rock, and will support the development of a realistic hydrogeochemical model. (author)

Potential groundwater contribution to Amazon evapotranspiration

Science.gov (United States)

Fan, Y.; Miguez-Macho, G.

2010-07-01

Climate and land ecosystem models simulate a dry-season vegetation stress in the Amazon forest, but observations show enhanced growth in response to higher radiation under less cloudy skies, indicating an adequate water supply. Proposed mechanisms include larger soil water store and deeper roots in nature and the ability of roots to move water up and down (hydraulic redistribution). Here we assess the importance of the upward soil water flux from the groundwater driven by capillarity. We present a map of water table depth from observations and groundwater modeling, and a map of potential capillary flux these water table depths can sustain. The maps show that the water table beneath the Amazon can be quite shallow in lowlands and river valleys (2.1 mm day-1 to the land surface averaged over Amazonia, but varies from 0.6 to 3.7 mm day-1 across nine study sites. Current models simulate a large-scale reduction in dry-season photosynthesis under today's climate and a possible dieback under projected future climate with a longer dry season, converting the Amazon from a net carbon sink to a source and accelerating warming. The inclusion of groundwater and capillary flux may modify the model results.

A groundwater mass flux model for screening the groundwater-to-indoor-air exposure pathway

Energy Technology Data Exchange (ETDEWEB)

McHugh, T.; Blanc, P.C. de; Connor, J. [Groundwater Services Inc, Houston, TX (United States)

2003-07-01

The potential for human exposure via volatilisation of groundwater contaminants into indoor air has been a focus of increasing concern in recent years. At a small number of sites, elevated indoor vapour concentrations have been measured within buildings overlying shallow groundwater contaminated with chlorinated solvents, causing public concern over the potential for similar problems at other corrective action sites. In addition, use of the screening-levelmodel developed by Johnson and Ettinger (1991) for the groundwater-to-indoor-air exposure pathway has suggested that low microgram per litre (ug/L)-range concentrations of either chlorinated or non-chlorinated volatile organic compounds dissolved in groundwater could result in indoor vapour concentrations in excess of applicable risk-based exposure limits. As an alternative screening tool, this paper presents a groundwater mass flux model for evaluation of transport to indoor air. The mass flux model is intended to serve as a highly conservative screening tool that over-predicts groundwater-to-indoor-air mass flux, yet still provides sufficient sensitivity to identify sites for which the groundwater-to-indoor air exposure pathway is not a concern. (orig.)

Elucidating hydraulic fracturing impacts on groundwater quality using a regional geospatial statistical modeling approach

Energy Technology Data Exchange (ETDEWEB)

Burton, Taylour G., E-mail: tgburton@uh.edu [Civil and Environmental Engineering, University of Houston, W455 Engineering Bldg. 2, Houston, TX 77204-4003 (United States); Rifai, Hanadi S., E-mail: rifai@uh.edu [Civil and Environmental Engineering, University of Houston, N138 Engineering Bldg. 1, Houston, TX 77204-4003 (United States); Hildenbrand, Zacariah L., E-mail: zac@informenv.com [Inform Environmental, LLC, Dallas, TX 75206 (United States); Collaborative Laboratories for Environmental Analysis and Remediation, University of Texas at Arlington, Arlington, TX 76019 (United States); Carlton, Doug D., E-mail: doug.carlton@mavs.uta.edu [Collaborative Laboratories for Environmental Analysis and Remediation, University of Texas at Arlington, Arlington, TX 76019 (United States); Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX (United States); Fontenot, Brian E., E-mail: brian.fonteno@mavs.uta.edu [Collaborative Laboratories for Environmental Analysis and Remediation, University of Texas at Arlington, Arlington, TX 76019 (United States); Schug, Kevin A., E-mail: kschug@uta.edu [Collaborative Laboratories for Environmental Analysis and Remediation, University of Texas at Arlington, Arlington, TX 76019 (United States); Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX (United States)

2016-03-01

Hydraulic fracturing operations have been viewed as the cause of certain environmental issues including groundwater contamination. The potential for hydraulic fracturing to induce contaminant pathways in groundwater is not well understood since gas wells are completed while isolating the water table and the gas-bearing reservoirs lay thousands of feet below the water table. Recent studies have attributed ground water contamination to poor well construction and leaks in the wellbore annulus due to ruptured wellbore casings. In this paper, a geospatial model of the Barnett Shale region was created using ArcGIS. The model was used for spatial analysis of groundwater quality data in order to determine if regional variations in groundwater quality, as indicated by various groundwater constituent concentrations, may be associated with the presence of hydraulically fractured gas wells in the region. The Barnett Shale reservoir pressure, completions data, and fracture treatment data were evaluated as predictors of groundwater quality change. Results indicated that elevated concentrations of certain groundwater constituents are likely related to natural gas production in the study area and that beryllium, in this formation, could be used as an indicator variable for evaluating fracturing impacts on regional groundwater quality. Results also indicated that gas well density and formation pressures correlate to change in regional water quality whereas proximity to gas wells, by itself, does not. The results also provided indirect evidence supporting the possibility that micro annular fissures serve as a pathway transporting fluids and chemicals from the fractured wellbore to the overlying groundwater aquifers. - Graphical abstract: A relative increase in beryllium concentrations in groundwater for the Barnett Shale region from 2001 to 2011 was visually correlated with the locations of gas wells in the region that have been hydraulically fractured over the same time period

Elucidating hydraulic fracturing impacts on groundwater quality using a regional geospatial statistical modeling approach

International Nuclear Information System (INIS)

Burton, Taylour G.; Rifai, Hanadi S.; Hildenbrand, Zacariah L.; Carlton, Doug D.; Fontenot, Brian E.; Schug, Kevin A.

2016-01-01

Hydraulic fracturing operations have been viewed as the cause of certain environmental issues including groundwater contamination. The potential for hydraulic fracturing to induce contaminant pathways in groundwater is not well understood since gas wells are completed while isolating the water table and the gas-bearing reservoirs lay thousands of feet below the water table. Recent studies have attributed ground water contamination to poor well construction and leaks in the wellbore annulus due to ruptured wellbore casings. In this paper, a geospatial model of the Barnett Shale region was created using ArcGIS. The model was used for spatial analysis of groundwater quality data in order to determine if regional variations in groundwater quality, as indicated by various groundwater constituent concentrations, may be associated with the presence of hydraulically fractured gas wells in the region. The Barnett Shale reservoir pressure, completions data, and fracture treatment data were evaluated as predictors of groundwater quality change. Results indicated that elevated concentrations of certain groundwater constituents are likely related to natural gas production in the study area and that beryllium, in this formation, could be used as an indicator variable for evaluating fracturing impacts on regional groundwater quality. Results also indicated that gas well density and formation pressures correlate to change in regional water quality whereas proximity to gas wells, by itself, does not. The results also provided indirect evidence supporting the possibility that micro annular fissures serve as a pathway transporting fluids and chemicals from the fractured wellbore to the overlying groundwater aquifers. - Graphical abstract: A relative increase in beryllium concentrations in groundwater for the Barnett Shale region from 2001 to 2011 was visually correlated with the locations of gas wells in the region that have been hydraulically fractured over the same time period

Simulation and assessment of groundwater flow and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2003 through 2013: Chapter B of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

Science.gov (United States)

Jones, Perry M.; Roth, Jason L.; Trost, Jared J.; Christenson, Catherine A.; Diekoff, Aliesha L.; Erickson, Melinda L.

2017-09-05

, and White Bear Lake. Simulated lake-water levels and budgets for Snail Lake and White Bear Lake were affected by 30-percent changes in groundwater withdrawals and 5-percent changes in precipitation in the area, whereas the water level in Big Marine Lake was mainly affected by 5-percent precipitation changes. The effects of groundwater withdrawals on the lake-water levels depend on the number of wells and amount of withdrawals from wells near the lakes. Although lake-water levels are sensitive to precipitation changes, increases in groundwater withdrawals during dry periods exacerbate lake-water level declines. The calibrated, groundwater-flow model is a tool that water-resources managers can use to address future water management issues in the northeast Twin Cities Metropolitan Area.

Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

Science.gov (United States)

Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

2016-09-01

Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

Advanced oxidation for groundwater remediation and for soil decontamination

International Nuclear Information System (INIS)

Gehringer, P.; Eschweiler, H.

2001-01-01

The advanced oxidation process (AOP) used in this paper is based on EB irradiation of water in the presence and absence of ozone. The paper describes two distinct sets of experiments, one dealing with groundwater contaminated with perchloroethylene (PCE) and some genotoxic compounds, and the other dealing with soil contaminated with polycyclic aromatic hydrocarbons (PAHs). The combination of ozone and EB irradiation has shown to be able to mineralize trace amounts of PCE contained in groundwater in a single stage process without formation of any by-product to be disposed of. Moreover, experiments performed with real groundwater have demonstrated that the combined ozone/EB irradiation process is also apt for total removal of some genotoxic compounds detected in groundwater contaminated with PCE. The design of an ozone/EB irradiation plant for treating 108 m 3 /h is presented. The issue concerning both the occurrences of genotoxic compounds in oxygen containing groundwater and possible processes for their removal is discussed. In the second part soil contaminated with PAHs has been treated in aqueous suspension using ozone and EB irradiation, respectively. Experiments were performed with low contaminated soil (total PAHs about 332 mg/kg soil). With an ozone consumption of 10 g C) 3 /kg soil a total PAH decomposition of about 21% was recorded. EB irradiation with a reasonable radiation dose of 100 kGy results in about 7% total PAH decomposition at room temperature and about 16%, respectively at 55-60 deg. C. It was recorded that almost no transfer of the PAH takes place from the soil into the water when soil is merely suspended in water. Ozone mainly attacked the high molecular fraction (i.e. consisting of 5 or 6 aromatic rings) of the PAHs investigated while EB irradiation of the aqueous soil suspension mostly decomposed the lower fraction (i.e. consisting up to 4 aromatic rings). (author)

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

Technical approach to groundwater restoration

International Nuclear Information System (INIS)

1993-01-01

The Technical Approach to Groundwater Restoration (TAGR) provides general technical guidance to implement the groundwater restoration phase of the Uranium Mill Tailings Remedial Action (UMTRA) Project. The TAGR includes a brief overview of the surface remediation and groundwater restoration phases of the UMTRA Project and describes the regulatory requirements, the National Environmental Policy Act (NEPA) process, and regulatory compliance. A section on program strategy discusses program optimization, the role of risk assessment, the observational approach, strategies for meeting groundwater cleanup standards, and remedial action decision-making. A section on data requirements for groundwater restoration evaluates the data quality objectives (DQO) and minimum data required to implement the options and comply with the standards. A section on sits implementation explores the development of a conceptual site model, approaches to site characterization, development of remedial action alternatives, selection of the groundwater restoration method, and remedial design and implementation in the context of site-specific documentation in the site observational work plan (SOWP) and the remedial action plan (RAP). Finally, the TAGR elaborates on groundwater monitoring necessary to evaluate compliance with the groundwater cleanup standards and protection of human health and the environment, and outlines licensing procedures

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Groundwater intensive use and mining in south-eastern peninsular Spain: Hydrogeological, economic and social aspects.

Science.gov (United States)

Custodio, Emilio; Andreu-Rodes, José Miguel; Aragón, Ramón; Estrela, Teodoro; Ferrer, Javier; García-Aróstegui, José Luis; Manzano, Marisol; Rodríguez-Hernández, Luis; Sahuquillo, Andrés; Del Villar, Alberto

2016-07-15

Intensive groundwater development is a common circumstance in semiarid and arid areas. Often abstraction exceeds recharge, thus continuously depleting reserves. There is groundwater mining when the recovery of aquifer reserves needs more than 50years. The MASE project has been carried out to compile what is known about Spain and specifically about the south-eastern Iberian Peninsula and the Canary Islands. The objective was the synthetic analysis of available data on the hydrological, economic, managerial, social, and ethical aspects of groundwater mining. Since the mid-20th century, intensive use of groundwater in south-eastern Spain allowed extending and securing the areas with traditional surface water irrigation of cash crops and their extension to former dry lands, taking advantage of good soils and climate. This fostered a huge economic and social development. Intensive agriculture is a main activity, although tourism plays currently an increasing economic role in the coasts. Many aquifers are relatively high yielding small carbonate units where the total groundwater level drawdown may currently exceed 300m. Groundwater storage depletion is estimated about 15km(3). This volume is close to the total contribution of the Tagus-Segura water transfer, but without large investments paid for with public funds. Seawater desalination complements urban supply and part of cash crop cultivation. Reclaimed urban waste water is used for irrigation. Groundwater mining produces benefits but associated to sometimes serious economic, administrative, legal and environmental problems. The use of an exhaustible vital resource raises ethical concerns. It cannot continue under the current legal conditions. A progressive change of water use paradigm is the way out, but this is not in the mind of most water managers and politicians. The positive and negative results observed in south-eastern Spain may help to analyse other areas under similar hydrogeological conditions in a less

Development of a regional groundwater flow model for the area of the Idaho National Engineering Laboratory, Eastern Snake River Plain Aquifer

International Nuclear Information System (INIS)

McCarthy, J.M.; Arnett, R.C.; Neupauer, R.M.

1995-03-01

This report documents a study conducted to develop a regional groundwater flow model for the Eastern Snake River Plain Aquifer in the area of the Idaho National Engineering Laboratory. The model was developed to support Waste Area Group 10, Operable Unit 10-04 groundwater flow and transport studies. The products of this study are this report and a set of computational tools designed to numerically model the regional groundwater flow in the Eastern Snake River Plain aquifer. The objective of developing the current model was to create a tool for defining the regional groundwater flow at the INEL. The model was developed to (a) support future transport modeling for WAG 10-04 by providing the regional groundwater flow information needed for the WAG 10-04 risk assessment, (b) define the regional groundwater flow setting for modeling groundwater contaminant transport at the scale of the individual WAGs, (c) provide a tool for improving the understanding of the groundwater flow system below the INEL, and (d) consolidate the existing regional groundwater modeling information into one usable model. The current model is appropriate for defining the regional flow setting for flow submodels as well as hypothesis testing to better understand the regional groundwater flow in the area of the INEL. The scale of the submodels must be chosen based on accuracy required for the study

Ground Water in the Anchorage Area, Alaska--Meeting the Challenges of Ground-Water Sustainability

Science.gov (United States)

Moran, Edward H.; Galloway, Devin L.

2006-01-01

Ground water is an important component of Anchorage's water supply. During the 1970s and early 80s when ground water extracted from aquifers near Ship Creek was the principal source of supply, area-wide declines in ground-water levels resulted in near record low streamflows in Ship Creek. Since the importation of Eklutna Lake water in the late 1980s, ground-water use has been reduced and ground water has contributed 14-30 percent of the annual supply. As Anchorage grows, given the current constraints on the Eklutna Lake water availability, the increasing demand for water could place an increasing reliance on local ground-water resources. The sustainability of Anchorage's ground-water resources challenges stakeholders to develop a comprehensive water-resources management strategy.

The Heterogeneous Impacts of Groundwater Management Policies in the Republican River Basin of Colorado

Science.gov (United States)

Hrozencik, R. A.; Manning, D. T.; Suter, J. F.; Goemans, C.; Bailey, R. T.

2017-12-01

Groundwater is a critical input to agricultural production across the globe. Current groundwater pumping rates frequently exceed recharge, often by a substantial amount, leading to groundwater depletion and potential declines in agricultural profits over time. As a result, many regions reliant on irrigated agriculture have proposed policies to manage groundwater use. Even when gains from aquifer management exist, there is little information about how policies affect individual producers sharing the resource. In this paper, we investigate the variability of groundwater management policy impacts across heterogeneous agricultural producers. To measure these impacts, we develop a hydroeconomic model that captures the important role of well capacity, productivity of water, and weather uncertainty. We use the model to simulate the impacts of groundwater management policies on producers in the High Plains aquifer of eastern Colorado and compare outcomes to a no-policy baseline. The management policies considered include a pumping fee, a quantity restriction, and an irrigated acreage fee. We find that well capacity and soil type affect policy impacts but in ways that can qualitatively differ across policy type. Model results have important implications for the distributional impacts and political acceptability of groundwater management policies.

1999 Annual Mixed Waste Management Facility Groundwater Correction - Action Report (Volumes I, II, and III)

International Nuclear Information System (INIS)

Chase, J.

2000-01-01

This Corrective Action Report (CAR) for the Mixed Waste Management Facility (MWMF) is being prepared to comply with the Resource Conservation and Recovery Act (RCRA) Permit Number SC1 890 008 989, dated October 31, 1999. This CAR compiles and presents all groundwater sampling and monitoring activities that are conducted at the MWMF. As set forth in previous agreements with South Carolina Department of Health and Environmental Control (SCDHEC), all groundwater associated with the Burial Ground Complex (BGC) (comprised of the MWMF, Low-Level Radioactive Waste Disposal Facility, and Old Radioactive Waste Burial Ground) will be addressed under this RCRA Permit. This CAR is the first to be written for the MWMF and presents monitoring activities and results as an outcome of Interim Status and limited Permitted Status activities. All 1999 groundwater monitoring activities were conducted while the MWMF was operated during Interim Status. Changes to the groundwater monitoring program were made upon receipt of the RCRA Permit, where feasible. During 1999, 152 single-screened and six multi-screened groundwater monitoring wells at the BGC monitored groundwater quality in the uppermost aquifer as required by the South Carolina Hazardous Waste Management Regulations (SCHWMR), settlement agreements 87-52-SW and 91-51-SW, and RCRA Permit SC1 890 008 989. However, overall compliance with the recently issued RCRA Permit could not be implemented until the year 2000 due to the effective date of the RCRA Permit and scheduling of groundwater monitoring activities. Changes have been made to the groundwater monitoring network to meet Permit requirements for all 2000 sampling events

Tracing freshwater nitrate sources in pre-alpine groundwater catchments using environmental tracers

Science.gov (United States)

Stoewer, M. M.; Knöller, K.; Stumpp, C.

2015-05-01

Groundwater is one of the main resources for drinking water. Its quality is still threatened by the widespread contaminant nitrate (NO3-). In order to manage groundwater resources in a sustainable manner, we need to find options of lowering nitrate input. Particularly, a comprehensive knowledge of nitrate sources is required in areas which are important current and future drinking water reservoirs such as pre-alpine aquifers covered with permanent grassland. The objective of the present study was to identify major sources of nitrate in groundwater with low mean nitrate concentrations (8 ± 2 mg/L). To achieve the objective, we used environmental tracer approaches in four pre-alpine groundwater catchments. The stable isotope composition and tritium content of water were used to study the hydrogeology and transit times. Furthermore, nitrate stable isotope methods were applied to trace nitrogen from its sources to groundwater. The results of the nitrate isotope analysis showed that groundwater nitrate was derived from nitrification of a variety of ammonium sources such as atmospheric deposition, mineral and organic fertilizers and soil organic matter. A direct influence of mineral fertilizer, atmospheric deposition and sewage was excluded. Since temporal variation in stable isotopes of nitrate were detected only in surface water and locally at one groundwater monitoring well, aquifers appeared to be well mixed and influenced by a continuous nitrate input mainly from soil derived nitrogen. Hydrogeological analysis supported that the investigated aquifers were less vulnerable to rapid impacts due to long average transit times, ranging from 5 to 21 years. Our study revealed the importance of combining environmental tracer approaches and a comprehensive sampling campaign (local sources of nitrate, soil water, river water, and groundwater) to identify the nitrate sources in groundwater and its vulnerability. In future, the achieved results will help develop targeted

Groundwater nitrate concentration evolution under climate change and agricultural adaptation scenarios: Prince Edward Island, Canada

Science.gov (United States)

Paradis, Daniel; Vigneault, Harold; Lefebvre, René; Savard, Martine M.; Ballard, Jean-Marc; Qian, Budong

2016-03-01

Nitrate (N-NO3) concentration in groundwater, the sole source of potable water in Prince Edward Island (PEI, Canada), currently exceeds the 10 mg L-1 (N-NO3) health threshold for drinking water in 6 % of domestic wells. Increasing climatic and socio-economic pressures on PEI agriculture may further deteriorate groundwater quality. This study assesses how groundwater nitrate concentration could evolve due to the forecasted climate change and its related potential changes in agricultural practices. For this purpose, a tridimensional numerical groundwater flow and mass transport model was developed for the aquifer system of the entire Island (5660 km2). A number of different groundwater flow and mass transport simulations were made to evaluate the potential impact of the projected climate change and agricultural adaptation. According to the simulations for year 2050, N-NO3 concentration would increase due to two main causes: (1) the progressive attainment of steady-state conditions related to present-day nitrogen loadings, and (2) the increase in nitrogen loadings due to changes in agricultural practices provoked by future climatic conditions. The combined effects of equilibration with loadings, climate and agricultural adaptation would lead to a 25 to 32 % increase in N-NO3 concentration over the Island aquifer system. The change in groundwater recharge regime induced by climate change (with current agricultural practices) would only contribute 0 to 6 % of that increase for the various climate scenarios. Moreover, simulated trends in groundwater N-NO3 concentration suggest that an increased number of domestic wells (more than doubling) would exceed the nitrate drinking water criteria. This study underlines the need to develop and apply better agricultural management practices to ensure sustainability of long-term groundwater resources. The simulations also show that observable benefits from positive changes in agricultural practices would be delayed in time due to

Approaches to groundwater travel time

International Nuclear Information System (INIS)

Kaplan, P.; Klavetter, E.; Peters, R.

1989-01-01

One of the objectives of performance assessment for the Yucca Mountain Project is to estimate the groundwater travel time at Yucca Mountain, Nevada, to determine whether the site complies with the criteria specified in the Code of Federal Regulations, Title 10 CFR 60.113 (a). The numerical standard for performance in these criteria is based on the groundwater travel time along the fastest path of likely radionuclide transport from the disturbed zone to the accessible environment. The concept of groundwater travel time as proposed in the regulations, does not have a unique mathematical statement. The purpose of this paper is to discuss the ambiguities associated with the regulatory specification of groundwater travel time, two different interpretations of groundwater travel time, and the effect of the two interpretations on estimates of the groundwater travel time

Academic plastic surgery: a study of current issues and future challenges.

Science.gov (United States)

Zetrenne, Eleonore; Kosins, Aaron M; Wirth, Garrett A; Bui, Albert; Evans, Gregory R D; Wells, James H

2008-06-01

The objectives of this study were (1) to evaluate the role of a full-time academic plastic surgeon, (2) to define the indicators predictive of a successful career in academic plastic surgery, and (3) to understand the current issues that will affect future trends in the practice of academic plastic surgery. A questionnaire was developed to evaluate the role of current full-time academic plastic surgeons and to understand the current issues and future challenges facing academic plastic surgery. Each plastic surgery program director in the United States was sent the survey for distribution among all full-time academic plastic surgeons. Over a 6-week period, responses from 143 full-time academic plastic surgeons (approximately 31%) were returned. Fifty-three percent of respondents had been academic plastic surgeons for longer than 10 years. Seventy-three percent of respondents defined academic plastic surgeons as clinicians who are teachers and researchers. However, 53% of respondents believed that academic plastic surgeons were not required to teach or practice within university hospitals/academic centers. The 3 factors reported most frequently as indicative of a successful career in academic plastic surgery were peer recognition, personal satisfaction, and program reputation. Dedication and motivation were the personal characteristics rated most likely to contribute to academic success. Forty-four percent of respondents were unable to identify future academic plastic surgeons from plastic surgery residency applicants, and 27% were not sure. Most (93%) of the respondents believed that academic surgery as practiced today will change. The overall job description of a full-time academic plastic surgeon remains unchanged (teacher and researcher). Whereas peer recognition, personal satisfaction, and program reputation were most frequently cited as indicative of a successful plastic surgery career, financial success was rated the least indicative. Similarly, whereas the

Protecting groundwater resources at biosolids recycling sites.

Science.gov (United States)

McFarland, Michael J; Kumarasamy, Karthik; Brobst, Robert B; Hais, Alan; Schmitz, Mark D

2013-01-01

In developing the national biosolids recycling rule (Title 40 of the Code of Federal Regulation Part 503 or Part 503), the USEPA conducted deterministic risk assessments whose results indicated that the probability of groundwater impairment associated with biosolids recycling was insignificant. Unfortunately, the computational capabilities available for performing risk assessments of pollutant fate and transport at that time were limited. Using recent advances in USEPA risk assessment methodology, the present study evaluates whether the current national biosolids pollutant limits remain protective of groundwater quality. To take advantage of new risk assessment approaches, a computer-based groundwater risk characterization screening tool (RCST) was developed using USEPA's Multimedia, Multi-pathway, Multi-receptor Exposure and Risk Assessment program. The RCST, which generates a noncarcinogenic human health risk estimate (i.e., hazard quotient [HQ] value), has the ability to conduct screening-level risk characterizations. The regulated heavy metals modeled in this study were As, Cd, Ni, Se, and Zn. Results from RCST application to biosolids recycling sites located in Yakima County, Washington, indicated that biosolids could be recycled at rates as high as 90 Mg ha, with no negative human health effects associated with groundwater consumption. Only under unrealistically high biosolids land application rates were public health risks characterized as significant (HQ ≥ 1.0). For example, by increasing the biosolids application rate and pollutant concentrations to 900 Mg ha and 10 times the regulatory limit, respectively, the HQ values varied from 1.4 (Zn) to 324.0 (Se). Since promulgation of Part 503, no verifiable cases of groundwater contamination by regulated biosolids pollutants have been reported. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Groundwater Discharge of Legacy Nitrogen to River Networks: Linking Regional Groundwater Models to Streambed Groundwater-Surface Water Exchange and Nitrogen Processing

Science.gov (United States)

Barclay, J. R.; Helton, A. M.; Briggs, M. A.; Starn, J. J.; Hunt, A.

2017-12-01

Despite years of management, excess nitrogen (N) is a pervasive problem in many aquatic ecosystems. More than half of surface water in the United States is derived from groundwater, and widespread N contamination in aquifers from decades of watershed N inputs suggest legacy N discharging from groundwater may contribute to contemporary N pollution problems in surface waters. Legacy N loads to streams and rivers are controlled by both regional scale flow paths and fine-scale processes that drive N transformations, such as groundwater-surface water exchange across steep redox gradients that occur at stream bed interfaces. Adequately incorporating these disparate scales is a challenge, but it is essential to understanding legacy N transport and making informed management decisions. We developed a regional groundwater flow model for the Farmington River, a HUC-8 basin that drains to the Long Island Sound, a coastal estuary that suffers from elevated N loads despite decades of management, to understand broad patterns of regional transport. To evaluate and refine the regional model, we used thermal infrared imagery paired with vertical temperature profiling to estimate groundwater discharge at the streambed interface. We also analyzed discharging groundwater for multiple N species to quantify fine scale patterns of N loading and transformation via denitrification at the streambed interface. Integrating regional and local estimates of groundwater discharge of legacy N to river networks should improve our ability to predict spatiotemporal patterns of legacy N loading to and transformation within surface waters.

Technical framework for groundwater restoration

International Nuclear Information System (INIS)

1991-04-01

This document provides the technical framework for groundwater restoration under Phase II of the Uranium Mill Tailings Remedial Action (UMTRA) Project. A preliminary management plan for Phase II has been set forth in a companion document titled ''Preplanning Guidance Document for Groundwater Restoration''. General principles of site characterization for groundwater restoration, restoration methods, and treatment are discussed in this document to provide an overview of standard technical approaches to groundwater restoration

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

Science.gov (United States)

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

2016-12-01

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

Dynamics of Agricultural Groundwater Extraction

NARCIS (Netherlands)

Hellegers, P.J.G.J.; Zilberman, D.; Ierland, van E.C.

2001-01-01

Agricultural shallow groundwater extraction can result in desiccation of neighbouring nature reserves and degradation of groundwater quality in the Netherlands, whereas both externalities are often not considered when agricultural groundwater extraction patterns are being determined. A model is

Groundwater protection management program plan

International Nuclear Information System (INIS)

1992-06-01

US Department of Energy (DOE) Order 5400.1 requires the establishment of a groundwater protection management program to ensure compliance with DOE requirements and applicable Federal, state, and local laws and regulations. The Uranium Mill Tailings Remedial Action (UMTRA) Project Office has prepared a ''Groundwater Protection Management Program Plan'' (groundwater protection plan) of sufficient scope and detail to reflect the program's significance and address the seven activities required in DOE Order 5400.1, Chapter 3, for special program planning. The groundwater protection plan highlights the methods designed to preserve, protect, and monitor groundwater resources at UMTRA Project processing and disposal sites. The plan includes an overview of the remedial action status at the 24 designated processing sites and identifies project technical guidance documents and site-specific documents for the UMTRA groundwater protection management program. In addition, the groundwater protection plan addresses the general information required to develop a water resources protection strategy at the permanent disposal sites. Finally, the plan describes ongoing activities that are in various stages of development at UMTRA sites (long-term care at disposal sites and groundwater restoration at processing sites). This plan will be reviewed annually and updated every 3 years in accordance with DOE Order 5400.1

Groundwater monitoring of an open-pit limestone quarry: groundwater characteristics, evolution and their connections to rock slopes.

Science.gov (United States)

Eang, Khy Eam; Igarashi, Toshifumi; Fujinaga, Ryota; Kondo, Megumi; Tabelin, Carlito Baltazar

2018-03-06

Groundwater flow and its geochemical evolution in mines are important not only in the study of contaminant migration but also in the effective planning of excavation. The effects of groundwater on the stability of rock slopes and other mine constructions especially in limestone quarries are crucial because calcite, the major mineral component of limestone, is moderately soluble in water. In this study, evolution of groundwater in a limestone quarry located in Chichibu city was monitored to understand the geochemical processes occurring within the rock strata of the quarry and changes in the chemistry of groundwater, which suggests zones of deformations that may affect the stability of rock slopes. There are three distinct geological formations in the quarry: limestone layer, interbedded layer of limestone and slaty greenstone, and slaty greenstone layer as basement rock. Although the hydrochemical facies of all groundwater samples were Ca-HCO 3 type water, changes in the geochemical properties of groundwater from the three geological formations were observed. In particular, significant changes in the chemical properties of several groundwater samples along the interbedded layer were observed, which could be attributed to the mixing of groundwater from the limestone and slaty greenstone layers. On the rainy day, the concentrations of Ca 2+ and HCO 3 - in the groundwater fluctuated notably, and the groundwater flowing along the interbedded layer was dominated by groundwater from the limestone layer. These suggest that groundwater along the interbedded layer may affect the stability of rock slopes.

Approaches to groundwater travel time

International Nuclear Information System (INIS)

Kaplan, P.; Klavetter, E.; Peters, R.

1989-01-01

One of the objectives of performance assessment for the Yucca Mountain Project is to estimate the groundwater travel time at Yucca Mountain, Nevada, to determine whether the site complies with the criteria specified in the Code of Federal Regulations. The numerical standard for performance in these criteria is based on the groundwater travel time along the fastest path of likely radionuclide transport from the disturbed zone to the accessible environment. The concept of groundwater travel time, as proposed in the regulations, does not have a unique mathematical statement. The purpose of this paper is to discuss (1) the ambiguities associated with the regulatory specification of groundwater travel time, (2) two different interpretations of groundwater travel time, and (3) the effect of the two interpretations on estimates of the groundwater travel time. 3 refs., 2 figs., 2 tabs

Water and rock geochemistry, geologic cross sections, geochemical modeling, and groundwater flow modeling for identifying the source of groundwater to Montezuma Well, a natural spring in central Arizona

Science.gov (United States)

Johnson, Raymond H.; DeWitt, Ed; Wirt, Laurie; Arnold, L. Rick; Horton, John D.

2011-01-01

The National Park Service (NPS) seeks additional information to better understand the source(s) of groundwater and associated groundwater flow paths to Montezuma Well in Montezuma Castle National Monument, central Arizona. The source of water to Montezuma Well, a flowing sinkhole in a desert setting, is poorly understood. Water emerges from the middle limestone facies of the lacustrine Verde Formation, but the precise origin of the water and its travel path are largely unknown. Some have proposed artesian flow to Montezuma Well through the Supai Formation, which is exposed along the eastern margin of the Verde Valley and underlies the Verde Formation. The groundwater recharge zone likely lies above the floor of the Verde Valley somewhere to the north or east of Montezuma Well, where precipitation is more abundant. Additional data from groundwater, surface water, and bedrock geology are required for Montezuma Well and the surrounding region to test the current conceptual ideas, to provide new details on the groundwater flow in the area, and to assist in future management decisions. The results of this research will provide information for long-term water resource management and the protection of water rights.

Assessment of the Groundwater Protection Program Y-12 National Security Complex, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

2005-01-01

The following report contains an assessment of the Y-12 Groundwater Protection Program (GWPP) for the Y-12 National Security Complex at the Oak Ridge Reservation, Tennessee. The GWPP is administered by BWXT Y-12, L.L.C. for the purpose of groundwater surveillance monitoring. After over 20 years of extensive site characterization and delineation efforts, groundwater in the three hydrogeologic areas that comprise the Y-12 Complex requires a long-term monitoring network strategy that will efficiently satisfy surveillance monitoring objectives set forth in DOE Order 450.1. The GWPP assessment consisted of two phases, a qualitative review of the program and a quantitative evaluation of the groundwater monitoring network using the Monitoring and Remediation Optimization System (MAROS) software methodology. The specific objective of the qualitative section of the review of the GWPP was to evaluate the methods of data collection, management, and reporting and the function of the monitoring network for the Y-12 facility using guidance from regulatory and academic sources. The results of the qualitative review are used to suggest modifications to the overall program that would be consistent with achieving objectives for long-term groundwater monitoring. While cost minimization is a consideration in the development of the monitoring program, the primary goal is to provide a comprehensive strategy to provide quality data to support site decision making during facility operations, long-term resource restoration, and property redevelopment. The MAROS software is designed to recommend an improved groundwater monitoring network by applying statistical techniques to existing historic and current site analytical data. The MAROS methodology also considers hydrogeologic factors, regulatory framework, and the location of potential receptors. The software identifies trends and suggests components for an improved monitoring plan by analyzing individual monitoring wells in the current

Potential contribution of groundwater to dry-season ET in the Amazon

Science.gov (United States)

Miguez-Macho, Gonzalo; Fan, Ying

2010-05-01

Climate and land ecosystem models simulate vegetation stress in the Amazon forest in the dry season, but observations show enhanced growth in response to higher radiation under less cloudy skies indicating an adequate water supply. The question is: how does the vegetation obtain sufficient water, and what is missing in the models? Shallow model soil and rooting depth is a factor; the ability of roots to move water up and down (hydraulic redistribution) may be another, but another cause may lie in the buffering effect of the groundwater found in nature but absent in models. We present observational and modeling evidence that the vast groundwater store, consequence of high annual rainfall combined with poor drainage in the Amazon, may provide a stable source for dry-season photosynthesis. The water table beneath the Amazon is sufficiently shallow (38% area 2mm/day to dry-season evapotranspiration, a non-negligible portion of tower-observed flux of 3-4mm/day, the latter including canopy-interception loss and open-water evaporation. This may have important implications to our understanding of Amazonia ecosystem response and feedback to climate change. Current models, lacking groundwater, predict a significant reduction in dry-season photosynthesis under current climate and large-scale dieback under projected future climate converting the Amazon from a net carbon sink to a net source and accelerating warming. If groundwater is considered in the models, the magnitude of the responses and feedbacks may be reduced.

Model Refinement and Simulation of Groundwater Flow in Clinton, Eaton, and Ingham Counties, Michigan

Science.gov (United States)

Luukkonen, Carol L.

2010-01-01

A groundwater-flow model that was constructed in 1996 of the Saginaw aquifer was refined to better represent the regional hydrologic system in the Tri-County region, which consists of Clinton, Eaton, and Ingham Counties, Michigan. With increasing demand for groundwater, the need to manage withdrawals from the Saginaw aquifer has become more important, and the 1996 model could not adequately address issues of water quality and quantity. An updated model was needed to better address potential effects of drought, locally high water demands, reduction of recharge by impervious surfaces, and issues affecting water quality, such as contaminant sources, on water resources and the selection of pumping rates and locations. The refinement of the groundwater-flow model allows simulations to address these issues of water quantity and quality and provides communities with a tool that will enable them to better plan for expansion and protection of their groundwater-supply systems. Model refinement included representation of the system under steady-state and transient conditions, adjustments to the estimated regional groundwater-recharge rates to account for both temporal and spatial differences, adjustments to the representation and hydraulic characteristics of the glacial deposits and Saginaw Formation, and updates to groundwater-withdrawal rates to reflect changes from the early 1900s to 2005. Simulations included steady-state conditions (in which stresses remained constant and changes in storage were not included) and transient conditions (in which stresses changed in annual and monthly time scales and changes in storage within the system were included). These simulations included investigation of the potential effects of reduced recharge due to impervious areas or to low-rainfall/drought conditions, delineation of contributing areas with recent pumping rates, and optimization of pumping subject to various quantity and quality constraints. Simulation results indicate

Coordination of groundwater activities in the 100 N Area

International Nuclear Information System (INIS)

Hartman, M.J.

1995-09-01

The initiation of the N Springs Expedited Response Action (ERA) in the 100 N Area will affect the groundwater monitoring networks of two Resource Conservation and Recovery Act of 1976 (RCRA) units. The 1301-N and 325-N facilities are treatment, storage, or disposal (TSD) units that have been monitored under RCRA since 1987. In September 1994, the Washington State Department of Ecology issued an action memorandum, instructing the US Department of Energy (DOE) to take the action. The planned pump-and-treat system will preclude meeting the specific objectives of interim-status RCRA groundwater monitoring representative samples and detect adverse impacts of the TSD units on. However, under RCRA final-status requirements, which will be implemented in 1999, corrective action for groundwater contamination will probably be required. The US Environmental Protection Agency (EPA) has declared parity between RCRA corrective action and Comprehensive Environmental Response, Compensation, and Liability Act of 1980 remedial action decisions. The 1301-N and 1325-N facilities are still in interim-status and therefore are not in the category of ''RCRA corrective action.'' However, DOE's position is that parity exists between RCRA and the ERA because RCRA corrective action will almost certainly be required in the future

Effect of irrigation return flow on groundwater recharge in an overexploited aquifer in Bangladesh

Science.gov (United States)

Touhidul Mustafa, Syed Md.; Shamsudduha, Mohammad; Huysmans, Marijke

2016-04-01

Irrigated agriculture has an important role in the food production to ensure food security of Bangladesh that is home to over 150 million people. However, overexploitation of groundwater for irrigation, particularly during the dry season, causes groundwater-level decline in areas where abstraction is high and surface geology inhibits direct recharge to underlying shallow aquifer. This is causing a number of potential adverse socio-economic, hydrogeological, and environmental problems in Bangladesh. Alluvial aquifers are primarily recharged during monsoon season from rainfall and surface sources. However, return flow from groundwater-fed irrigation can recharge during the dry months. Quantification of the effect of return flow from irrigation in the groundwater system is currently unclear but thought to be important to ensure sustainable management of the overexploited aquifer. The objective of the study is to investigate the effect of irrigation return flow on groundwater recharge in the north-western part of Bangladesh, also known as Barind Tract. A semi-physically based distributed water balance model (WetSpass-M) is used to simulate spatially distributed monthly groundwater recharge. Results show that, groundwater abstraction for irrigation in the study area has increased steadily over the last 29 years. During the monsoon season, local precipitation is the controlling factor of groundwater recharge; however, there is no trend in groundwater recharge during that period. During the dry season, however, irrigation return-flow plays a major role in recharging the aquifer in the irrigated area compared to local precipitation. Therefore, during the dry season, mean seasonal groundwater recharge has increased and almost doubled over the last 29 years as a result of increased abstraction for irrigation. The increase in groundwater recharge during dry season has however no significant effect in the improvement of groundwater levels. The relation between groundwater

The assessment of groundwater geochemistry of some wells in Rafsanjan plain, Iran

Directory of Open Access Journals (Sweden)

Milad Mirzaei Aminiyan

2016-07-01

Full Text Available Water quality is the critical factor that influence on human health and quantity and quality of grain production in semi-humid and semi-arid area. Groundwater and irrigation water quality play important roles in main production this crop. For this purpose, 94 well water samples were taken from 25 wells and samples analyzed. The results showed that four main types of water were found: Na-Cl, K-Cl, Na-SO4, and K-SO4. It seems that most wells in terms of water quality (salinity and alkalinity and based on Wilcox diagram have critical status. The analysis suggested that more than 87% of the well water samples have high values of EC that these values are higher than into critical limit EC value for irrigation water, which may be due to the sandy soils in this area. Most groundwater were relatively unsuitable for irrigation but it could be used by application of correct management such as removing and reducing the ion concentrations of Cl‾, SO42‾, Na+ and total hardness in groundwater and also the concentrated deep groundwater was required treatment to reduce the salinity and sodium hazard. Given that irrigation water quality in this area was relatively unsuitable for most agriculture production but pistachio tree was adapted to this area conditions. The integrated management of groundwater for irrigation is the way to solve water quality issues not only in Rafsanjan area, but also in other arid and semi-arid areas.

Coastal Zone Hazards Related to Groundwater-Surface Water Interactions and Groundwater Flooding

Science.gov (United States)

Kontar, Y. A.; Ozorovich, Y. R.; Salokhiddinov, A. T.

2009-12-01

Worldwide, as many as half a million people have died in natural and man-made disasters since the turn of the 21st century (Wirtz, 2008). Further, natural and man-made hazards can lead to extreme financial losses (Elsner et al, 2009). Hazards, hydrological and geophysical risk analysis related to groundwater-surface water interactions and groundwater flooding have been to a large extent under-emphasized for coastal zone applications either due to economical limitations or underestimation of its significance. This is particularly true for tsunamis creating salt water intrusion to coastal aquifers, even though most tsunami hazard assessments have in the past relied on scenario or deterministic type models (Geist and Parsons, 2006), and to increasing mineralization of potable water because of intensive water diversions and also the abundance of highly toxic pollutants (mainly pesticides) in water, air and food, which contribute to the deterioration of the coastal population's health (Glantz, 2007). In the wake of pressing environmental and economic issues, it is of prime importance for the scientific community to shed light onto the great efforts by hydrologists and geophysicists to quantify conceptual uncertainties and to provide quality assurances of potential coastal zone hazard evaluation and prediction. This paper proposes consideration of two case studies which are important and significant for future development and essential for feasibility studies of hazards in the coastal zone. The territory of the Aral Sea Region in Central Asia is known as an ecological disaster coastal zone (Zavialov, 2005). It is now obvious that, in order to provide reasonable living conditions to the coastal zone population, it is first of all necessary to drastically improve the quality of the water dedicated to human needs. Due to their intensive pollution by industrial wastes and by drainage waters from irrigated fields, the Syr Darya and Amu Darya rivers can no longer be considered

Field primatology of today: current ethical issues.

Science.gov (United States)

MacKinnon, K C; Riley, E P

2010-09-01

As members of professional organizations such as American Society of Primatologists (ASP) and the International Primatological Society (IPS), primatologists must adhere to a set of nonhuman primate-focused principles outlined in resolutions and policy statements on, for example, the ethical treatment of nonhuman primates. Those of us that work in the field must also address issues such as the protection of primate health in the wild and the conservation of wild primate populations. Moreover, we increasingly find ourselves in complex situations where we must balance human and nonhuman primate needs and interests. The selection of commentary pieces in this edition of the American Journal of Primatology originated from presentations given in the symposium, Field Primatology of Today: Navigating the Ethical Landscape, held at the 32nd Annual Meeting of the American Society of Primatologists (ASP) in September 2009. The goals of that symposium and these resulting commentary pieces are threefold: (1) to revive a discussion of key contemporary ethical issues faced by field primatologists, (2) to highlight the need for centrally placed ethical considerations in various facets of our professional lives, particularly research and teaching, and (3) to consider what a comprehensive ethical code that addresses all of these issues might look like. (c) 2010 Wiley-Liss, Inc.

Application of isotopes to the assessment of pollutant behaviour in the unsaturated zone for groundwater protection. Final report of a coordinated research project 2004-2005

International Nuclear Information System (INIS)

2009-05-01

A coordinated research project (CRP) was conducted by the IAEA with the purpose of studying what isotopic and other ancillary data are required to help understand migration of potential contaminants through the unsaturated zone (UZ) into the underlying groundwater. To this end, research projects were conducted in ten countries to study recharge and infiltration processes, as well as contaminant migration in a wide variety of UZ environments. This publication contains the reports of these ten projects and a summary of the accomplishments of the individual projects. The IAEA-TECDOC reviews the usefulness and current status of application of the combined use of isotope and other hydrogeochemical tools for the assessment of flow and transport processes in the UZ. A number of isotope and hydrochemical tools have been used to simultaneously study groundwater recharge and transport of pollutants in the UZ. This information is relevant for assessing the vulnerability of groundwater to contamination. The ten projects covered climates ranging from humid to arid, and water table depths from the near surface to over 600 m. The studies included measuring movement of water, solutes, and gases through the UZ using an assortment of isotope and geochemical tracers and approaches. Contaminant issues have been studied at most of the ten sites and the UZ was found to be very effective in protecting groundwater from most heavy metal contaminants. The publication is expected to be of interest to hydrologists, hydrogeologists and soil scientists dealing with pollution aspects and protection of groundwater resources, as well as counterparts of TC projects in Member States

Study on protection and reclamation for the groundwater resources in Busan area

Energy Technology Data Exchange (ETDEWEB)

Sung, Ig-Hwan; Cho, Byong-Wook; Lee, Byung-Dae [Korea Institute of Geology Mining and Materials, Taejon (KR)

1999-12-01

This research was carried out to investigate the protection of contaminated groundwater and reclamation in the Pusan area. Groundwater Busan city is highly subjected to groundwater contamination due to its unfavorable geographical features; it is located in the estuaries of the Nakdong river, most of the urban area are composed of highlands, and the large population resides in the downhill. Heavy pumping and deterioration of groundwater are currently found to be significant compared to other major cities, resulting in shortage of water resources and contamination of groundwater. The first step of the research aims at investigating hydrogeological features which includes analysis of climate and hydrologic data, investigation of geology and structural pattern, acquisition of hydrological data, inspection of wells, measurement of groundwater level, analysis of water samples, investigation of groundwater contamination, isotope analysis, and monitoring water level by automated data logger to identify seawater intrusion. The second step is to simulate the two-dimensional flow model after construction of the database. Aside from this, abandoned wells were transformed into observation wells. An effort for remedy of contaminated groundwater was made and the water quality was constantly monitored to improve the deteriorated water to the drinking water. Kriging analysis and geostatistical analysis were carried out in order to verify the effect of seawater intrusion, showing that there is no clear evidence of seawater intrusion. Instead, it is clear that groundwater in the inland district was preferentially contaminated by pollutants originated from human activities. Based on the two-dimensional flow model, only 0.021 m{sup 3} may be allocated to each person a day from public wells for emergency. In order to ensure that protection and remediation of groundwater of the Busan area are able to accomplish, well-controlled management of aquifer systems needs to be maintained and

Representation of an open repository in groundwater flow models

International Nuclear Information System (INIS)

Painter, Scott; Sun, Alexander

2005-08-01

The effect of repository tunnels on groundwater flow has been identified as a potential issue for the nuclear waste repository being considered by SKB for a fractured granite formation in Sweden. In particular, the following pre-closure and post-closure processes have been identified as being important: inflows into open tunnels as functions of estimated grouting efficiencies, drawdown of the water table in the vicinity of the repository, upcoming of saline water, 'turnover' of surface water in the upper bedrock, and resaturation of backfilled tunnels following repository closure. The representation of repository tunnels within groundwater models is addressed in this report. The primary focus is on far-field flow that is modeled with a continuum porous medium approximation. Of particular interest are the consequences of the tunnel representation on the transient response of the groundwater system to repository operations and repository closure, as well as modeling issues such as how the water-table free surface and the coupling to near-surface hydrogeology should be handled. The overall objectives are to understand the consequences of current representations and to identify appropriate approximations for representing open tunnels in future groundwater modeling studies. The following conclusions can be drawn from the results of the simulations: 1. Two-phase flow may be induced in the vicinity of repository tunnels during repository pre-closure operations, but the formation of a two-phase flow region will not significantly affect far-field flow or inflows into tunnels. 2. The water table will be drawn down to the repository horizon and tunnel inflows will reach a steady-state value within about 5 years. 3. Steady-state inflows at the repository edge are estimated to be about 250 m 3 /year per meter of tunnel. Inflows will be greater during the transient de-watering period and less for tunnel locations closer to the repository center. 4. Significant amounts of water

Representation of an open repository in groundwater flow models

Energy Technology Data Exchange (ETDEWEB)

Painter, Scott; Sun, Alexander [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

2005-08-01

The effect of repository tunnels on groundwater flow has been identified as a potential issue for the nuclear waste repository being considered by SKB for a fractured granite formation in Sweden. In particular, the following pre-closure and post-closure processes have been identified as being important: inflows into open tunnels as functions of estimated grouting efficiencies, drawdown of the water table in the vicinity of the repository, upcoming of saline water, 'turnover' of surface water in the upper bedrock, and resaturation of backfilled tunnels following repository closure. The representation of repository tunnels within groundwater models is addressed in this report. The primary focus is on far-field flow that is modeled with a continuum porous medium approximation. Of particular interest are the consequences of the tunnel representation on the transient response of the groundwater system to repository operations and repository closure, as well as modeling issues such as how the water-table free surface and the coupling to near-surface hydrogeology should be handled. The overall objectives are to understand the consequences of current representations and to identify appropriate approximations for representing open tunnels in future groundwater modeling studies. The following conclusions can be drawn from the results of the simulations: 1. Two-phase flow may be induced in the vicinity of repository tunnels during repository pre-closure operations, but the formation of a two-phase flow region will not significantly affect far-field flow or inflows into tunnels. 2. The water table will be drawn down to the repository horizon and tunnel inflows will reach a steady-state value within about 5 years. 3. Steady-state inflows at the repository edge are estimated to be about 250 m{sup 3}/year per meter of tunnel. Inflows will be greater during the transient de-watering period and less for tunnel locations closer to the repository center. 4. Significant

Arsenic Removal from Natural Groundwater by Electrocoagulation Using Response Surface Methodology

Directory of Open Access Journals (Sweden)

A. M. García-Lara

2014-01-01

Full Text Available Contamination of natural groundwater by arsenic (As is a serious problem that appears in some areas of Northern Central Mexico (NCM. In this research, As was removed from NCM wells groundwater by the electrocoagulation (EC technique. Laboratory-scale arsenic electroremoval experiments were carried out at continuous flow rates between 0.25 and 1.00 L min−1 using current densities of 5, 10, and 20 A m−2. Experiments were performed under galvanostatic conditions during 5 min, at constant temperature and pH. The response surface methodology (RSM was used for the optimization of the processing variables (flow rate and current density, response modeling, and predictions. The highest arsenic removal efficiency from underground water (99% was achieved at low flow rates (0.25 L min−1 and high current densities (20 A m−2. The response models developed explained 93.7% variability for As removal efficiency.

Groundwater Availability Within the Salton Sea Basin Final Report

Energy Technology Data Exchange (ETDEWEB)

Tompson, A; Demir, Z; Moran, J; Mason, D; Wagoner, J; Kollet, S; Mansoor, K; McKereghan, P

2008-01-11

in the Salton Sea Basin is the subject of the project described in this report. Much of the project work was done in cooperation with the US Bureau of Reclamation, Lower Colorado Region Office ('Reclamation'), which manages the Salton Sea Restoration project for the US Department of the Interior, and complements other recent assessment efforts (e.g., Imperial County, 1995). In this context, the notion of groundwater availability is defined by four separate, but interrelated concepts or components: (1) Volume and Capacity--This refers to the volume of groundwater available in storage in (or the related storage capacity of) the sediments and geologic media that comprise a groundwater basin. The volume of groundwater in a basin will vary in time as a function of recharge, well production, and land subsidence. (2) Producibility--This refers to the ease or difficulty of extracting groundwater in a basin from wells. Groundwater producibility will be affected by well depth and the formation permeability surrounding the open intervals in wells. (3) Quality--This refers to the extent that water produced from wells is potable or otherwise suitable for domestic or other uses. It may also refer to the chemical compositions of groundwater that are unrelated to potability or suitability issues. Groundwater quality will be affected by its residence time and flow pathway in the formation and will also be influenced by the quality of its original source before entering the groundwater regime. (4) Renewability and Recharge--This refers to the extent that groundwater is recharged to the basin as part of the natural hydrologic cycle or other artificial means. Groundwater renewability is normally a function of recharge derived from precipitation (and thus a function of regional climate), but may also be affected in local areas by irrigation, leaking canals, aquifer storage and recovery operations, and so forth. Along with the other factors, renewability will strongly affect how

Hanford groundwater scenario studies

International Nuclear Information System (INIS)

Arnett, R.C.; Gephart, R.E.; Deju, R.A.; Cole, C.R.; Ahlstrom, S.W.

1977-05-01

This report documents the results of two Hanford groundwater scenario studies. The first study examines the hydrologic impact of increased groundwater recharge resulting from agricultural development in the Cold Creek Valley located west of the Hanford Reservation. The second study involves recovering liquid radioactive waste which has leaked into the groundwater flow system from a hypothetical buried tank containing high-level radioactive waste. The predictive and control capacity of the onsite Hanford modeling technology is used to evaluate both scenarios. The results of the first study indicate that Cold Creek Valley irrigationis unlikely to cause significant changes in the water table underlying the high-level waste areas or in the movement of radionuclides already in the groundwater. The hypothetical tank leak study showed that an active response (in this case waste recovery) can be modeled and is a possible alternative to passive monitoring of radionuclide movement in the unlikely event that high-level waste is introduced into the groundwater

A Practical, Robust Methodology for Acquiring New Observation Data Using Computationally Expensive Groundwater Models

Science.gov (United States)

Siade, Adam J.; Hall, Joel; Karelse, Robert N.

2017-11-01

Regional groundwater flow models play an important role in decision making regarding water resources; however, the uncertainty embedded in model parameters and model assumptions can significantly hinder the reliability of model predictions. One way to reduce this uncertainty is to collect new observation data from the field. However, determining where and when to obtain such data is not straightforward. There exist a number of data-worth and experimental design strategies developed for this purpose. However, these studies often ignore issues related to real-world groundwater models such as computational expense, existing observation data, high-parameter dimension, etc. In this study, we propose a methodology, based on existing methods and software, to efficiently conduct such analyses for large-scale, complex regional groundwater flow systems for which there is a wealth of available observation data. The method utilizes the well-established d-optimality criterion, and the minimax criterion for robust sampling strategies. The so-called Null-Space Monte Carlo method is used to reduce the computational burden associated with uncertainty quantification. And, a heuristic methodology, based on the concept of the greedy algorithm, is proposed for developing robust designs with subsets of the posterior parameter samples. The proposed methodology is tested on a synthetic regional groundwater model, and subsequently applied to an existing, complex, regional groundwater system in the Perth region of Western Australia. The results indicate that robust designs can be obtained efficiently, within reasonable computational resources, for making regional decisions regarding groundwater level sampling.

Preliminary Results from Powell Research Group on Integrating GRACE Satellite and Ground-based Estimates of Groundwater Storage Changes

Science.gov (United States)

Scanlon, B. R.; Zhang, Z.; Reitz, M.; Rodell, M.; Sanford, W. E.; Save, H.; Wiese, D. N.; Croteau, M. J.; McGuire, V. L.; Pool, D. R.; Faunt, C. C.; Zell, W.

2017-12-01

Groundwater storage depletion is a critical issue for many of the major aquifers in the U.S., particularly during intense droughts. GRACE (Gravity Recovery and Climate Experiment) satellite-based estimates of groundwater storage changes have attracted considerable media attention in the U.S. and globally and interest in GRACE products continues to increase. For this reason, a Powell Research Group was formed to: (1) Assess variations in groundwater storage using a variety of GRACE products and other storage components (snow, surface water, and soil moisture) for major aquifers in the U.S., (2) Quantify long-term trends in groundwater storage from ground-based monitoring and regional and national modeling, and (3) Use ground-based monitoring and modeling to interpret GRACE water storage changes within the context of extreme droughts and over-exploitation of groundwater. The group now has preliminary estimates from long-term trends and seasonal fluctuations in water storage using different GRACE solutions, including CSR, JPL and GSFC. Approaches to quantifying uncertainties in GRACE data are included. This work also shows how GRACE sees groundwater depletion in unconfined versus confined aquifers, and plans for future work will link GRACE data to regional groundwater models. The wealth of ground-based observations for the U.S. provides a unique opportunity to assess the reliability of GRACE-based estimates of groundwater storage changes.

Groundwater Assessment Platform

OpenAIRE

Podgorski, Joel; Berg, Michael

2018-01-01

The Groundwater Assessment Platform is a free, interactive online GIS platform for the mapping, sharing and statistical modeling of groundwater quality data. The modeling allows users to take advantage of publicly available global datasets of various environmental parameters to produce prediction maps of their contaminant of interest.

Groundwater Protection Program Management Plan for the U.S. Department of Energy Y-12 National Security Complex, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

None

2001-06-01

This document presents the Groundwater Protection Program (GWPP) management plan for the U.S. Department of Energy (DOE) Y-12 National Security Complex (hereafter referenced as Y-12). The Y-12 GWPP functions as the primary point-of-contact for groundwater-related issues at Y-12, provides stewardship of the extensive network of groundwater monitoring wells at Y-12, and serves as a resource for technical expertise, support, and historical data for groundwater-related activities at Y-12. These organizational functions each serve the primary programmatic purpose of the GWPP, which is to ensure that groundwater monitoring activities within areas under Y-12 administrative control provide representative data in compliance with the multiple purposes of applicable state and federal regulations, DOE orders, and the corporate policies of BWXT Y-12, L.L.C. (hereafter referenced as BWXT Y-12), the Y-12 management and operations (M and O) subcontractor for DOE.

Automated Groundwater Screening

International Nuclear Information System (INIS)

Taylor, Glenn A.; Collard, Leonard B.

2005-01-01

The Automated Intruder Analysis has been extended to include an Automated Ground Water Screening option. This option screens 825 radionuclides while rigorously applying the National Council on Radiation Protection (NCRP) methodology. An extension to that methodology is presented to give a more realistic screening factor for those radionuclides which have significant daughters. The extension has the promise of reducing the number of radionuclides which must be tracked by the customer. By combining the Automated Intruder Analysis with the Automated Groundwater Screening a consistent set of assumptions and databases is used. A method is proposed to eliminate trigger values by performing rigorous calculation of the screening factor thereby reducing the number of radionuclides sent to further analysis. Using the same problem definitions as in previous groundwater screenings, the automated groundwater screening found one additional nuclide, Ge-68, which failed the screening. It also found that 18 of the 57 radionuclides contained in NCRP Table 3.1 failed the screening. This report describes the automated groundwater screening computer application

Current safety issues of CANDU licensing

International Nuclear Information System (INIS)

Lee, Y.; Natalizio, A.

1994-01-01

As requested by Korea Institute of Nuclear Safety(KINS), the status of five generic licensing issues has been examined and their potential impact on a new plant that would be constructed in Canada has been evaluated. The results and conclusions of this evaluation are summarized as follows: steam explosion in calandria, hydrogen explosion in containment, use of PSA in reactor licensing, human factors, safety critical software

Groundwater biofilm dynamics grown in situ along a nutrient gradient.

Science.gov (United States)

Williamson, Wendy M; Close, Murray E; Leonard, Margaret M; Webber, Judith B; Lin, Susan

2012-01-01

This paper describes the in situ response of groundwater biofilms in an alluvial gravel aquifer system on the Canterbury Plains, New Zealand. Biofilms were developed on aquifer gravel, encased in fine mesh bags and suspended in protective columns in monitoring wells for at least 20 weeks. Four sites were selected in the same groundwater system where previous analyses indicated a gradient of increasing nitrate down the hydraulic gradient from Sites 1 to 4. Measurements during the current study classified the groundwater as oligotrophic. Biofilm responses to the nutrient gradients were assessed using bioassays, with biomass determined using protein and cellular and nucleic acid staining and biofilm activity using enzyme assays for lipid, carbohydrate, phosphate metabolism, and cell viability. In general, biofilm activity decreased as nitrate levels increased from Sites 1 to 4, with the opposite relationship for carbon and phosphorus concentrations. These results showed that the groundwater system supported biofilm growth and that the upper catchment supported efficient and productive biofilms (high ratio of activity per unit biomass). © 2012, Institute of Environmental Science & Research Ltd (ESR). Ground Water © 2012, National Ground Water Association.

Isotope hydrology: Investigating groundwater contamination

International Nuclear Information System (INIS)

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

1989-01-01

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

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

Science.gov (United States)

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

2017-12-01

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

Conjunctive use of groundwater and surface water for irrigated agriculture: Risk aversion

Science.gov (United States)

Bredehoeft, John D.; Young, Richard A.

1983-01-01

In examining the South Platte system in Colorado where surface water and groundwater are used conjunctively for irrigation, we find the actual installed well capacity is approximately sufficient to irrigate the entire area. This would appear to be an overinvestment in well capacity. In this paper we examine to what extent groundwater is being developed as insurance against periods of low streamflow. Using a simulation model which couples the hydrology of a conjunctive stream aquifer system to a behavioral-economic model which incorporates farmer behavior in such a system, we have investigated the economics of an area patterned after a reach of the South Platte Valley in Colorado. The results suggest that under current economic conditions the most reasonable groundwater pumping capacity is a total capacity capable of irrigating the available acreage with groundwater. Installing sufficient well capacity to irrigate all available acreage has two benefits: (1) this capacity maximizes the expected net benefits and (2) this capacity also minimizes the variation in annual income: it reduces the variance to essentially zero. As pumping capacity is installed in a conjunctive use system, the value of flow forecasts is diminished. Poor forecasts are compensated for by pumping groundwater.

The assessment of processes controlling the spatial distribution of hydrogeochemical groundwater types in Mali using multivariate statistics

Science.gov (United States)

Keita, Souleymane; Zhonghua, Tang

2017-10-01

Sustainable management of groundwater resources is a major issue for developing countries, especially in Mali. The multiple uses of groundwater led countries to promote sound management policies for sustainable use of the groundwater resources. For this reason, each country needs data enabling it to monitor and predict the changes of the resources. Also given the importance of groundwater quality changes often marked by the recurrence of droughts; the potential impacts of regional and geological setting of groundwater resources requires careful study. Unfortunately, recent decades have seen a considerable reduction of national capacities to ensure the hydrogeological monitoring and production of qualit data for decision making. The purpose of this work is to use the groundwater data and translate into useful information that can improve water resources management capacity in Mali. In this paper, we used groundwater analytical data from accredited, laboratories in Mali to carry out a national scale assessment of the groundwater types and their distribution. We, adapted multivariate statistical methods to classify 2035 groundwater samples into seven main groundwater types and built a national scale map from the results. We used a two-level K-mean clustering technique to examine the hydro-geochemical records as percentages of the total concentrations of major ions, namely sodium (Na), magnesium (Mg), calcium (Ca), chloride (Cl), bicarbonate (HCO3), and sulphate (SO4). The first step of clustering formed 20 groups, and these groups were then re-clustered to produce the final seven groundwater types. The results were verified and confirmed using Principal Component Analysis (PCA) and RockWare (Aq.QA) software. We found that HCO3 was the most dominant anion throughout the country and that Cl and SO4 were only important in some local zones. The dominant cations were Na and Mg. Also, major ion ratios changed with geographical location and geological, and climatic

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

Energy Technology Data Exchange (ETDEWEB)

1993-12-01

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

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

International Nuclear Information System (INIS)

1993-12-01

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

Analysis of groundwater criteria and recent restoration attempts after in situ uranium leaching. Open file report

International Nuclear Information System (INIS)

Buma, G.; Johnson, P.H.; Bienek, G.K.; Watson, C.G.; Noyes, H.J.

1981-10-01

Groundwater restoration is an important aspect of in situ uranium leaching. Information on the effectiveness of the current technology, costs, and the current State and Federal Government permitting regulations is of vital importance to in situ leach operators and firms considering in situ leaching. This study describes (1) all recent restoration attempts at commercial in situ leaching operations, (2) restoration costs reported by the industry, (3) empirical equations that predict the amount of groundwater flushing required to meet the current restoration criteria, and (4) in situ uranium permit requirements for the States of Texas, Wyoming, New Mexico, Utah, Montana, Colorado, and South Dakota, and Federal requirements

Sustainable solar energy capability studies by using S2H model in treating groundwater supply

Science.gov (United States)

Musa, S.; Anuar, M. F.; Shahabuddin, M. M.; Ridzuan, M. B.; Radin Mohamed, R. M. S.; Madun, M. A.

2018-04-01

Groundwater extracted in Research Centre for Soft Soil Malaysia (RECESS) contains a number of pollutants that exceed the safe level for consumption. A Solar-Hydro (S2H) model which is a practical prototype has been introduced to treat the groundwater sustainably by solar energy process (evaporation method). Selected parameters was tested which are sulphate, nitrate, chloride, fluoride, pH and dissolved oxygen. The water quality result shows that all parameters have achieved 100% of the drinking water quality standard issued by the Ministry of Health Malaysia. Evaporation method was proven that this solar energy can be applied in sustainably treating groundwater quality with up to 90% effectiveness. On the other hand, the quantitative analysis has shown that the production of clean water is below than 2% according to time constraints and design factors. Thus, this study can be generate clean and fresh water from groundwater by using a simplified model and it has huge potential to be implemented by the local communities with a larger scale and affordable design.

Investigating groundwater salinity in the Machile-Zambezi Basin (Zambia) with hydrogeophysical methods

DEFF Research Database (Denmark)

Chongo, Mkhuzo; A. Nyambe, Imasiku; Larsen, Flemming

resources worldwide. This thesis presents the application of geo-electrical and electromagnetic methods for the investigation of groundwater salinity in the Machile-Zambezi Basin in south western Zambia, southern central Africa. Aerial and ground based transient electromagnetic measurenments were used...... use of direct current and transient electromagnetic data in one optimization. The result from the regional mapping with transient electromagnetic measurenments showed a spatial distribution of electrical resistivity that indicated block faulting in the Machile-Zambezi Basin. Saline groundwater...... parameters. This was for a coupled flow and solute transport model setup for the Kasaya transect under the forcing of evapotranspiration. Performance of the coupled hydrogeophysical inversion was better with the inclusion of direct current data in comparison to the use of transient electromagnetic data alone...

Groundwater monitoring plan for the Hanford Site 200 Area Treated Effluent Disposal Facility

International Nuclear Information System (INIS)

DB Barnett

2000-01-01

Seven years of groundwater monitoring at the 200 Area Treated Effluent Disposal Facility (TEDF) have shown that the uppermost aquifer beneath the facility is unaffected by TEDF effluent. Effluent discharges have been well below permitted and expected volumes. Groundwater mounding from TEDF operations predicted by various models has not been observed, and waterlevels in TEDF wells have continued declining with the dissipation of the nearby B Pond System groundwater mound. Analytical results for constituents with enforcement limits indicate that concentrations of all these are below Practical Quantitation Limits, and some have produced no detections. Likewise, other constituents on the permit-required list have produced results that are mostly below sitewide background. Comprehensive geochemical analyses of groundwater from TEDF wells has shown that most constituents are below background levels as calculated by two Hanford Site-wide studies. Additionally, major ion proportions and anomalously low tritium activities suggest that groundwater in the aquifer beneath the TEDF has been sequestered from influences of adjoining portions of the aquifer and any discharge activities. This inference is supported by recent hydrogeologic investigations which indicate an extremely slow rate of groundwater movement beneath the TEDF. Detailed evaluation of TEDF-area hydrogeology and groundwater geochemistry indicate that additional points of compliance for groundwater monitoring would be ineffective for this facility, and would produce ambiguous results. Therefore, the current groundwater monitoring well network is retained for continued monitoring. A quarterly frequency of sampling and analysis is continued for all three TEDF wells. The constituents list is refined to include only those parameters key to discerning subtle changes in groundwater chemistry, those useful in detecting general groundwater quality changes from upgradient sources, or those retained for comparison with end

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

International Nuclear Information System (INIS)

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

1992-01-01

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

Scoping assessment of groundwater doses to biota at the Sellafield site, UK

International Nuclear Information System (INIS)

McDonald, P.; Gleizon, P.; Coleman, I.A.; Watts, S.J.; Batlle, L.V.; Smith, A.D.

2008-01-01

In the current climate of investigating the impact of discharges from the nuclear industry on non-human biota, much attention has been given to biota in marine and terrestrial environments in receipt of authorised discharges of liquid and gaseous effluent. Relatively little attention to date has been given to the exposure of biota to groundwater containing man-made radio-nuclides. This area of interest is growing especially in the field of nuclear waste repositories. A scoping assessment has been performed here to determine the impacts due to radiological contamination on organisms living within or coming into contact with groundwater at the Sellafield site, UK. The following potential exposure routes to biota were identified: 1) Organisms living within groundwater; 2) Groundwater discharges to the surface at beach springs (i.e. emerging above the low water line; 3) Groundwater discharges to nearby surface water bodies (e.g. rivers); 4) Groundwater discharges directly to the Irish Sea.. In order to evaluate impacts on organisms living within, contacting or ingesting groundwater, it was necessary to determine the activity concentration of radio-nuclides in the groundwater. For time periods up to 2120, modeling of contaminant release from in-ground inventories and transport in groundwater was carried out for this scoping study using a relatively simple assessment methodology with the MONDRIAN modeling suite. Screening assessments of radiological impacts upon wildlife have been performed for liquid discharges to groundwater from the Sellafield Ltd reprocessing plant at Sellafield, Cumbria. Impacts have been considered for biota at sites within reach of the groundwater flow network. Most calculated total weighted absorbed doses appear to be of no radiological significance whatsoever in relation to the new Environment Agency freshwater ecosystem trigger level (40 microGy h -1 ), thereby obviating the need to conduct further investigations. The one exception to this is

Arsenic species and chemistry in groundwater of southeast Michigan

International Nuclear Information System (INIS)

Kim, M.-J.; Nriagu, Jerome; Haack, Sheridan

2002-01-01

Most of the arsenic detected was arsenite [As(III)]. - Groundwater samples, taken from 73 wells in 10 counties of southeast Michigan in 1997 had arsenic concentrations in the range of 0.5 to 278 μg/l, the average being 29 μg/l. About 12% of these wells had arsenic concentrations that exceeded the current USEPA's maximum contaminant level of 50 μg/l. Most (53-98%) of the arsenic detected was arsenite [As(III)] and other observations supported the arsenic species distribution (low redox potential and DO). In shallow groundwater ( 15 m), the concentration of arsenic is possibly controlled by reductive dissolution of arsenic-rich iron hydroxide/oxyhydroxide and dissolution of arsenic sulfide minerals

Current Therapeutic Cannabis Controversies and Clinical Trial Design Issues

Science.gov (United States)

Russo, Ethan B.

2016-01-01

This overview covers a wide range of cannabis topics, initially examining issues in dispensaries and self-administration, plus regulatory requirements for production of cannabis-based medicines, particularly the Food and Drug Administration “Botanical Guidance.” The remainder pertains to various cannabis controversies that certainly require closer examination if the scientific, consumer, and governmental stakeholders are ever to reach consensus on safety issues, specifically: whether botanical cannabis displays herbal synergy of its components, pharmacokinetics of cannabis and dose titration, whether cannabis medicines produce cyclo-oxygenase inhibition, cannabis-drug interactions, and cytochrome P450 issues, whether cannabis randomized clinical trials are properly blinded, combatting the placebo effect in those trials via new approaches, the drug abuse liability (DAL) of cannabis-based medicines and their regulatory scheduling, their effects on cognitive function and psychiatric sequelae, immunological effects, cannabis and driving safety, youth usage, issues related to cannabis smoking and vaporization, cannabis concentrates and vape-pens, and laboratory analysis for contamination with bacteria and heavy metals. Finally, the issue of pesticide usage on cannabis crops is addressed. New and disturbing data on pesticide residues in legal cannabis products in Washington State are presented with the observation of an 84.6% contamination rate including potentially neurotoxic and carcinogenic agents. With ongoing developments in legalization of cannabis in medical and recreational settings, numerous scientific, safety, and public health issues remain. PMID:27683558

Current Therapeutic Cannabis Controversies and Clinical Trial Design Issues.

Directory of Open Access Journals (Sweden)

Ethan Budd Russo

2016-09-01

Full Text Available This overview covers a wide range of cannabis topics, initially examining issue in dispensaries and self-administration, plus regulatory requirement for production of cannabis-based medicines, particularly the Food and Drug Administration Botanical Guidance. The remainder pertains to various cannabis controversies that certainly require closer examination if the scientific, consumer and governmental stakeholders are ever to reach consensus on safety issues, specifically: whether botanical cannabis displays herbal synergy of its components, pharmacokinetics of cannabis and dose titration, whether cannabis medicines produce cyclo-oxygenase inhibition, cannabis-drug interactions and cytochrome P450 issues, whether cannabis randomized clinical trials are properly blinded, combatting the placebo effect in those trials via new approaches, the drug abuse liability of cannabis-based medicines and their regulatory scheduling, their effects on cognitive function and psychiatric sequelae, immunological effects, cannabis and driving safety, youth usage, issues related to cannabis smoking and vaporization, cannabis concentrates and vape-pens, and laboratory analysis for contamination with bacteria and heavy metals. Finally, the issue of pesticide usage on cannabis crops is addressed. New and disturbing data on pesticide residues in legal cannabis products in Washington State are presented with the observation of an 84.6% contamination rate including potentially neurotoxic and carcinogenic agents. With ongoing developments in legalization of cannabis in medical and recreational settings, numerous scientific, safety and public health issues remain.

Risk assessment of exposure to volatile organic compounds in groundwater in Taiwan

Energy Technology Data Exchange (ETDEWEB)

Fan Chihhao [Department of Safety, Health, and Environmental Engineering, Mingchi University of Technology, Taipei County, Taiwan (China); Wang, G.-S. [Department of Public Health, National Taiwan University, Taipei, Taiwan (China); Chen, Y.-C. [Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu County, Taiwan (China); Ko, C.-H. [School of Forest and Resources Conservation, National Taiwan University, Taipei, Taiwan (China)], E-mail: chunhank@ntu.edu.tw

2009-03-15

The purpose of this study is to assess the risks from exposure to 14 volatile organic compounds (VOCs) in selected groundwater sites in Taiwan. The study employs the multimedia environment pollutant assessment system (MEPAS) model to calculate the specific non-cancer and cancer risks at an exposure level of 1 {mu}g/L of each VOC for a variety of exposure pathways. The results show that the highest specific non-cancer risk is associated with water ingestion of vinyl chloride (VC) and that the highest specific cancer risk is associated with indoor breathing of VC. The three most important exposure pathways for risk assessment for both non-cancer and cancer risks are identified as water ingestion, dermal absorption when showering, and indoor breathing. Excess tetrachloroethylene (PCE), trichloroethylene (TCE), dichloroethylene (DCE), and VC are detected in the groundwater aquifers of one dump site and one factory. However, the study suggests that the pollutants in the contaminated groundwater aquifers do not travel extensively with groundwater flow and that the resulting VOC concentrations are below detectable levels for most of the sampled drinking-water treatment plants. Nevertheless, the non-cancer and cancer risks resulting from use of the contaminated groundwater are found to be hundred times higher than the general risk guidance values. To ensure safe groundwater utilisation, remediation initiatives for soil and groundwater are required. Finally, the study suggests that the current criteria for VOCs in drinking water might not be capable of ensuring public safety when groundwater is used as the primary water supply; more stringent quality criteria for drinking water are proposed for selected VOCs.

Variable infiltration and river flooding resulting in changing groundwater quality - A case study from Central Europe