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Sample records for adversely impact groundwater

  1. Assessing the spatial variability of constraints on groundwater abstractions due to potential adverse resource impacts on surface water ecosystems - a GIS based approach

    NASA Astrophysics Data System (ADS)

    Watson, K. A.; Mayer, A. S.; Reeves, H. W.

    2010-12-01

    Groundwater contributions to streams, particularly in periods of low flow, can be critical to sustaining aquatic ecosystems. Groundwater abstractions in areas where the groundwater is in hydraulic connection with the surface water can deplete these flows potentially causing adverse resource impacts. In particular, the passage of the Great Lakes—St. Lawrence Basin Water Resources Compact in 2008 has brought increasing awareness to this issue in the Great Lakes Basin. As a requirement of this legislation, each of the Great Lakes States must take steps to limit water withdrawals that may potentially impact water-dependent natural resources. The State of Michigan has developed an automated “Water Withdrawal Assessment Tool” to assist in this process. By using the methodology as developed for the Michigan Water Withdrawal Assessment Tool, this study examines spatial variations in maximum allowable pumping rates under these constraints. The pumping rates are constrained either by the local hydrogeology or concerns related to adverse impacts to the surface water ecosystems. A simple analytical model is used to calculate streamflow depletion as a function of hypothetical groundwater abstraction rates and positions. The inputs to this model are obtained from a GIS database including such spatially relevant information as aquifer characteristics, streamflows, and a stream network. The maximum pumping rates are averaged over the HUC-8 watershed scale. We explore the characteristics that play the largest role in the variability of maximum pumping rates, such as hydrogeologic parameters, stream density, and stream flows. We also discuss limitations of the analytical approach to assessing water availability. Understanding how these restrictions on adverse resource impacts constrain groundwater usage and which hydrogeologic characteristics and spatial variables have the most influence on potential streamflow depletions have important water resources policy and management

  2. Reducing Adverse Impact: One City's Efforts.

    ERIC Educational Resources Information Center

    Prewitt, Jeff

    Following a workshop on "Innovations in Employment Testing that Improve Validity and Reduce Adverse Impact," the City of Louisville (Kentucky) implemented a strategy to develop a comprehensive testing and recruiting program for police recruits. To improve candidate expectations and preparation, the following activities were undertaken: intense…

  3. Adverse weather impacts on arable cropping systems

    NASA Astrophysics Data System (ADS)

    Gobin, Anne

    2016-04-01

    Damages due to extreme or adverse weather strongly depend on crop type, crop stage, soil conditions and management. The impact is largest during the sensitive periods of the farming calendar, and requires a modelling approach to capture the interactions between the crop, its environment and the occurrence of the meteorological event. The hypothesis is that extreme and adverse weather events can be quantified and subsequently incorporated in current crop models. Since crop development is driven by thermal time and photoperiod, a regional crop model was used to examine the likely frequency, magnitude and impacts of frost, drought, heat stress and waterlogging in relation to the cropping season and crop sensitive stages. Risk profiles and associated return levels were obtained by fitting generalized extreme value distributions to block maxima for air humidity, water balance and temperature variables. The risk profiles were subsequently confronted with yields and yield losses for the major arable crops in Belgium, notably winter wheat, winter barley, winter oilseed rape, sugar beet, potato and maize at the field (farm records) to regional scale (statistics). The average daily vapour pressure deficit (VPD) and reference evapotranspiration (ET0) during the growing season is significantly lower (p < 0.001) and has a higher variability before 1988 than after 1988. Distribution patterns of VPD and ET0 have relevant impacts on crop yields. The response to rising temperatures depends on the crop's capability to condition its microenvironment. Crops short of water close their stomata, lose their evaporative cooling potential and ultimately become susceptible to heat stress. Effects of heat stress therefore have to be combined with moisture availability such as the precipitation deficit or the soil water balance. Risks of combined heat and moisture deficit stress appear during the summer. These risks are subsequently related to crop damage. The methodology of defining

  4. Geospatial association between adverse birth outcomes and arsenic in groundwater in New Hampshire, USA

    USGS Publications Warehouse

    Xun Shi,; Ayotte, Joseph; Akikazu Onda,; Stephanie Miller,; Judy Rees,; Diane Gilbert-Diamond,; Onega, Tracy L; Gui, Jiang; Karagas, Margaret R.; Moeschler, John B

    2015-01-01

    >10 µg/L. At the county level for younger mothers, positive r values prevail, but for older mothers, it is a mix. For both birth problems, the several most populous counties—with 60–80% of the state’s population and clustering at the southwest corner of the state—are largely consistent in having a positive r across different smoothing thresholds. We found evident spatial associations between the two adverse human reproductive outcomes and groundwater arsenic in New Hampshire, USA. However, the degree of associations and their sensitivity to different representations of arsenic level are variable. Generally, preterm birth has a stronger spatial association with groundwater arsenic than term LBW, suggesting an inconsistency in the impact of arsenic on the two reproductive outcomes. For both outcomes, younger maternal age has stronger spatial associations with groundwater arsenic.

  5. Geospatial association between adverse birth outcomes and arsenic in groundwater in New Hampshire, USA.

    PubMed

    Shi, Xun; Ayotte, Joseph D; Onda, Akikazu; Miller, Stephanie; Rees, Judy; Gilbert-Diamond, Diane; Onega, Tracy; Gui, Jiang; Karagas, Margaret; Moeschler, John

    2015-04-01

    younger mothers, positive r values prevail, but for older mothers, it is a mix. For both birth problems, the several most populous counties-with 60-80 % of the state's population and clustering at the southwest corner of the state-are largely consistent in having a positive r across different smoothing thresholds. We found evident spatial associations between the two adverse human reproductive outcomes and groundwater arsenic in New Hampshire, USA. However, the degree of associations and their sensitivity to different representations of arsenic level are variable. Generally, preterm birth has a stronger spatial association with groundwater arsenic than term LBW, suggesting an inconsistency in the impact of arsenic on the two reproductive outcomes. For both outcomes, younger maternal age has stronger spatial associations with groundwater arsenic.

  6. Reducing Adverse Impact Via a Measure of Applicant Disadvantagedness.

    ERIC Educational Resources Information Center

    Mann, Walter G.

    Recent attempts to reduce the adverse impact of examinations have focused on alternatives to written tests. The present report, however, demonstrates how the adverse impact of written tests can be reduced by correcting for the degree to which a job applicant had been educationally and/or economically disadvantaged or deprived. A measure of…

  7. Mining's impact on groundwater assessed

    NASA Astrophysics Data System (ADS)

    Detailed studies have indicated that groundwater is contaminated in the immediate vicinity of many mines in the eastern United States. However, no underground mines and very few refuse disposal areas have monitoring systems that can provide adequate warning of impending threats to groundwater quality.This was one of the conclusions of a 3-year study by Geraghty & Miller, Inc., a firm of consulting groundwater geologists and hydrologists based in Syosset, New York. The study focused on mines east of the 100th meridian. These mines will produce an estimated 1.1 billion tons of coal and 200 million tons of waste by 1985.

  8. Groundwater impact assessment report for the 100-D Ponds

    SciTech Connect

    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.

  9. The impact on students of adverse experiences during medical school.

    PubMed

    Wilkinson, Tim J; Gill, Denzil J; Fitzjohn, Julie; Palmer, Claire L; Mulder, Roger T

    2006-03-01

    This study aimed to determine the consequences for, and coping method used by, medical students who experienced adverse experiences during their training. A nationwide questionnaire based census of all current medical students in New Zealand. The response rate was 83% (1384/1660). Two-thirds of students had at least one adverse experience, with humiliation being the most common and having the greatest adverse impact. Unwanted sexual advances, unfair treatment on the basis of gender or race had a lesser impact for most students. Most students took several hours or several days to get over an adverse episode and most commonly they then avoided that person or department. Around one half sought help. Only one-quarter felt it motivated their learning while one-sixth felt it made them consider leaving medical school. The most common perpetrators were senior doctors or nurses. Unwanted sexual advances were most common from other students or from patients. Humiliation is the experience that affected students the most and had a significant adverse effect on learning. There is a disturbing rate of unacceptable practice within medical schools, not all of which is from doctors. PMID:16707293

  10. Potential Impacts of Climate Change on Groundwater in California

    NASA Astrophysics Data System (ADS)

    Miller, N. L.

    2011-12-01

    California's water resources are primarily from snowmelt runoff from the Sierra Nevada and Rocky Mountains. Depending on the year, Sierra Nevada snowmelt provides seventy percent of the water resources needed to sustain urban, agricultural, ecological, and other sector needs. With increasing temperatures due to climate change the Sierra Nevada snowmelt is occurring earlier and with decreasing snow cover area. Such change may mimic drought scenarios and dramatically alter water resource availability and management in California. A fundamental requirement for drought water management is knowledge of the total groundwater resources and the rate in which it is depleted. Application of remote sensed Gravity Recovery and Climate Experiment (GRACE) data represents an important new approach toward quantifying these values. The primary uncertainties are the spatial scale required for an accurate GRACE analysis and an insufficient number and frequency of well observations for ground-truth. In this study, an initial quantification of long-term droughts - an analogue for climate change related snowpack reduction - has been performed to illustrate the potential for subsurface storage to limit the adverse impacts of drought and snowpack reduction on water supply in the California. This includes estimates of the impacts of changes in groundwater levels, surface supply, and crop water demands. Analysis of California Central Valley impacts of sustained droughts are based on a series of specified reductions in net surface flows corresponding to historical 30% (below average), 50% (dry), and 70% (critically dry) effective reduction, for periods ranging from 10 to 60 years, and applied to the California Department of Water Resource's California Central Valley Groundwater-Surface Water Simulation Model. The impacts of the droughts are modeled for four different regions in the Central Valley, including the Sacramento Basin, Eastside, the San Joaquin Basin, and the Tulare Basin. Results

  11. Groundwater Impact Assessment of Tailings Storage Facility, Western Turkey

    NASA Astrophysics Data System (ADS)

    Peksezer-Sayit, A.; Yazicigil, H.

    2015-12-01

    A tailings storage facility (TSF) is a fundamental part of the mining process and should be carefully designed and managed to prevent any adverse environmental effects. TSF is site-specific and its design criteria are determined by regulations. The new mine waste regulation for the deposition of hazardous waste in a tailings storage facility in Turkey enforces, from bottom to top, 0.5 m thick compacted clay layer with K less than or equal to 1X10-9 m/s , 2 mm thick HDPE geomembrane, and a protective natural material or geotextile. Although these criteria seem to be enough to prevent leakage from the base, in practice, manufacturing and application errors may cause leakage and subsequent contamination of groundwater. The purpose of this study is to assess potential impacts of leakage from the base of TSF on groundwater quality both in operational and post-closure period of a mine site in western Turkey. For this purpose, analytical and 2-D and 3-D numerical models are used together. The potential leakage rate of sulphate-bearing solution from the base of TSF is determined from analytical model. 2-D finite element models (SEEP/W and CTRAN/W) are used to simulate unsaturated flow conditions and advective-dispersive contaminant transport below the TSF under steady-state and transient conditions for the operating period. The long-term impacts of leakage from the base of TSF on groundwater resources are evaluated by 3-D numerical groundwater flow (MODFLOW) and contaminant transport models (MT3DMS). The model results suggest that sulphate-bearing solution leaking from the base of TSF can reach water table in about 290 years. Hence, during the operational period (i.e. 21 years), no interaction is expected between the solution and groundwater. Moreover, long-term simulation results show that about 500 years later, the sulphate concentration in groundwater will be below the maximum allowable limits (i.e. 250 mg/L).

  12. Groundwater resources impact assessment for triazine herbicides

    SciTech Connect

    Waldman, E.; Barrett, M.R.; Behl, E.

    1996-10-01

    The Environmental Fate and Ground Water Branch of EPA`s Office of Pesticide Programs (OPP) has conducted a Water Resources Impact Assessment of the potential for triazine herbicides to be transported to ground and surface waters (only ground-water is discussed in this paper). The herbicides discussed in this document include atrazine, cyanazine, simazine, and prometon. Part of OPP`s regulatory mission is to prevent contamination of ground and surface water resources resulting from the normal use of registered pesticides. OPP has recently produced several resource documents to support such activities at the federal, state, and local levels (e.g., the Pesticides and Ground-Water Strategy and the Pesticides in Ground Water Database). This Water Resources Impact Assessment will also be useful in assisting state and regional agencies in customizing risk reduction strategies and to implement proposed pollution prevention measures. Major conclusions include: Atrazine is the most frequently detected pesticide in ground water in virtually the entire Midwestern United States, and especially in Nebraska, Iowa, Illinois, and Indiana. The Pesticides in Ground Water Database 1992 Report indicates that atrazine has been detected in 32 out of the 40 states that have reported monitoring data, and in 1,512 wells (6%) of the wells sampled. Based on EPA`s National Pesticide Survey (NPS), 4.7% of rural domestic drinking water wells in the U.S. (490,000 wells) are estimated to contain atrazine, mostly at concentrations less than 0.12 {mu}g/L (the MCL for atrazine is 3 {mu}g/L). Triazine herbicides other than atrazine (simazine, cyanazine, and prometon) have had much less impact on ground-water quality than atrazine, primarily because they are less intensively used.

  13. Impacts of Groundwater Pumping on Regional and Global Water Resources

    NASA Technical Reports Server (NTRS)

    Wada, Yoshihide

    2016-01-01

    Except frozen water in ice and glaciers (68%), groundwater is the world's largest distributed store of freshwater (30%), and has strategic importance to global food and water security. In this chapter, the most recent advances assessing human impact on regional and global groundwater resources are reviewed. This chapter critically evaluates the recently advanced modeling approaches quantifying the effect of groundwater pumping in regional and global groundwater resources and the evidence of feedback to the Earth system including sea-level rise associated with groundwater use. At last, critical challenges and opportunities are identified in the use of groundwater to adapt to growing food demand and uncertain climate.

  14. Groundwater Impacts of Radioactive Wastes and Associated Environmental Modeling Assessment

    SciTech Connect

    Ma, Rui; Zheng, Chunmiao; Liu, Chongxuan

    2012-11-01

    This article provides a review of the major sources of radioactive wastes and their impacts on groundwater contamination. The review discusses the major biogeochemical processes that control the transport and fate of radionuclide contaminants in groundwater, and describe the evolution of mathematical models designed to simulate and assess the transport and transformation of radionuclides in groundwater.

  15. Do oral health conditions adversely impact young adults?

    PubMed

    Carvalho, Joana C; Mestrinho, Heliana D; Stevens, Sophie; van Wijk, Arjen J

    2015-01-01

    This study assessed the extent to which clinically measured oral health conditions, adjusted for sociodemographic and oral health behavior determinants, impact adversely on the oral health-related quality of life (OHRQoL) in a sample of Belgian young adults. The null hypothesis was that, among young adults, the oral health conditions would have no impact on their quality of life. The participants were 611 new patients aged 16-32 years seeking consultation at the Saint-Luc University Hospital in Brussels in 2010-2011. The patients (56.0% female) were examined for their oral health conditions and answered a validated questionnaire about sociodemographic and oral health behavior determinants in addition to questions about their OHRQoL. The abridged Oral Health Impact Profile-14 was used to assess the OHRQoL. Interexaminer reliability for caries was 0.86 (95% CI 0.84-0.89, nonweighted κ). The outcome was a high score on the OHRQoL (median split). Hierarchical logistic regression analysis showed that young adults with clinical absolute D1MFS scores between 9 and 16 (OR = 2.14, p = 0.031) and between 17 and 24 (OR = 3.10, p = 0.003) were significantly more likely to report a high impact on their quality of life than those with lower scores. Also, periodontal conditions compromised significantly (OR = 1.79, p = 0.011) the quality of life of young adults. In conclusion, this study identified oral health conditions with a significant adverse effect on the OHRQoL of young adults. However, the prevalence of young adults reporting impacts on at least 1 performance affected fairly often or very often was limited to 18.7% of the sample. PMID:25832802

  16. Groundwater

    USGS Publications Warehouse

    Stonestrom, David A.; Wohl, Ellen E.

    2016-01-01

    , including nutrients and dissolved oxygen. Groundwater withdrawals can negatively impact riparian habitats by depriving ecosystems of adequate fresh water and fragmenting communities when streams go dry. Biochemical reactions in shallow groundwater can remove anthropogenically elevated nitrogen compounds and reduce—but only to a point—the greening of waterways and shorelines with periphyton and harmful algal blooms. Groundwater extraction for beneficial use is increasingly limited by water-quality constraints imposed by naturally occurring and introduced substances. Overdrafting can cause land-surface subsidence, damaging buildings and roads and disrupting canals, sewers, and other gravity-flow conveyances. Increases in groundwater levels can cause soil salinization in dry regions and erosive sapping and flooding in wet regions. Coastal saltwater intrusion, groundwater flooding, salinization associated with groundwater-irrigated agriculture, induced seismicity from injected wastes, and the detrimental impacts of groundwater depletion are among the major environmental challenges of our time.

  17. Impacts of urbanization on groundwater quality and recharge in a semi-arid alluvial basin

    NASA Astrophysics Data System (ADS)

    Carlson, Mark A.; Lohse, Kathleen A.; McIntosh, Jennifer C.; McLain, Jean E. T.

    2011-10-01

    SummaryThe management of groundwater resources is paramount in semi-arid regions experiencing urban development. In the southwestern United States, enhancing recharge of urban storm runoff has been identified as a strategy for augmenting groundwater resources. An understanding of how urbanization may impact the timing of groundwater recharge and its quality is a prerequisite for mitigating water scarcity and identifying vulnerability to contamination. We sampled groundwater wells along the Rillito Creek in southern Arizona that had been previously analyzed for tritium in the late 1980s to early 1990s and analyzed samples for tritium ( 3H) and helium-3 ( 3H/ 3He) to evaluate changes in 3H and age date groundwaters. Groundwater samples were also analyzed for chlorofluorocarbons (CFCs) and basic water quality metrics. Substantial changes in 3H values from waters sampled in the early 1990s compared to 2009 were identified after accounting for radioactive decay and indicate areas of rapid recharge. 3H- 3He groundwater ages ranged from 22 years before 2009 to modern recharge. CFC-11, -12 and -113 concentrations were anomalously high across the basin, and non-point source pollution in runoff and/or leaky infrastructure was identified as the most plausible source of this contamination. CFCs were strongly and positively correlated to nitrate ( r2 = 0.77) and a mobile trace metal, nickel ( r2 = 0.71), suggesting that solutes were derived from a similar source. Findings from this study suggest new waters from urban non-point sources are contributing to groundwater recharge and adversely affecting water quality. Reducing delivery of contaminants to areas of focused recharge will be critical to protect future groundwater resources.

  18. Impact of oil on groundwater chemical composition

    NASA Astrophysics Data System (ADS)

    Brakorenko, N. N.

    2015-11-01

    The objective of the paper is to characterize the chemical composition of groundwater samples from the monitoring wells drilled in the petrol station areas within the vicinity of Tomsk. The level of contamination has increased since many macro - and microcomponent concentrations (such as petroleum products, chlorine, sulphates, carbon dioxide and lead, etc.) in groundwater samples of the present study is higher than that in previous period samples.

  19. Impacts of swine manure pits on groundwater quality

    USGS Publications Warehouse

    Krapac, I.G.; Dey, W.S.; Roy, W.R.; Smyth, C.A.; Storment, E.; Sargent, S.L.; Steele, J.D.

    2002-01-01

    Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and ??15N and ??18O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human health. Fecal streptococcus bacteria were detected at least once in groundwater from all monitoring wells at both sites

  20. Impacts of swine manure pits on groundwater quality.

    PubMed

    Krapac, I G; Dey, W S; Roy, W R; Smyth, C A; Storment, E; Sargent, S L; Steele, J D

    2002-01-01

    Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and delta15N and delta15O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human health. Fecal streptococcus bacteria were detected at least once in groundwater from all monitoring wells at both

  1. The impacts of groundwater over-abstraction on the environment

    NASA Astrophysics Data System (ADS)

    Sophocleous, M. A.

    2009-12-01

    Groundwater is a highly vulnerable and important resource for both humans and the environment; therefore, it is essential to understand the environmental implications of groundwater overexploitation. This presentation emphasizes the hydrologic fundamentals for such understanding, which involve groundwater flow system concepts, factors controlling aquifer responses to development, and surface water-groundwater interactions. It also highlights the environmental consequences of groundwater overexploitation throughout the world. Expanding irrigated agriculture and increasing world population are having a pronounced effect on global water resources and the environment. Overexploitation and pollution in many regions of the world are threatening groundwater resources, with serious consequences for human welfare and the environment. Groundwater overexploitation not only results in aquifer depletion and water-quality degradation, but also impacts the ecological integrity of streams and wetlands and results in significant losses of habitat and biodiversity. Thus, it is necessary for societies to recognize that the water resources are finite and vulnerable, and find ways to reconcile the demands of human development with the tolerance of nature. The essential first step for making water use sustainable is awareness and knowledge of human impacts on the environment.

  2. Climate impact on groundwater systems: the past is the key to the future

    NASA Astrophysics Data System (ADS)

    van der Ploeg, Martine; Cendón, Dioni; Haldorsen, Sylvi; Chen, Jinyao; Gurdak, Jason; Tujchneider, Ofelia; Vaikmäe, Rein; Purtschert, Roland; Chkir Ben Jemâa, Najiba

    2013-04-01

    Groundwater is a significant part of the global hydrological cycle and supplies fresh drinking water to almost half of the world's population. While groundwater supplies are buffered against short-term effects of climate variability, they can be impacted over longer time scales through changes in precipitation, ,evaporation, recharge rate, melting of glaciers or permafrost, vegetation, and land-use. Moreover, uncontrolled groundwater extraction has and will lead to irreversible depletion of fresh water resources in many areas. The impact of climate variability and groundwater extraction on the resilience of groundwater systems is still not fully understood (Green et al. 2011). Groundwater stores environmental and climatic information acquired during the recharge process, which integrates different signals, like recharge temperature, origin of precipitation, and dissolved constituents. This information can be used to estimate palaeo recharge temperatures, palaeo atmospheric dynamics and residence time of groundwater within the aquifer (Stute et al. 1995, Clark and Fritz 1997, Collon et al. 2000, Edmunds et al. 2003, Cartwright et al. 2007, Kreuzer et al. 2009, Currell et al. 2010, Raidla et al. 2012, Salem et al. 2012). The climatic signals incorporated by groundwater during recharge have the potential to provide a regionally integrated proxy of climatic variations at the time of recharge. Groundwater palaeoclimate information is affected by diffusion-dispersion processes (Davison and Airey, 1982) and/or water-rock interaction (Clark and Fritz, 1997), making palaeoclimate information deduced from groundwater inherently a low resolution record. While the signal resolution can be limited, recharge follows major climatic events, and more importantly, shows how those aquifers and their associated recharge varies under climatic forcing. While the characterization of groundwater resources, surface-groundwater interactions and their link to the global water cycle are an

  3. Impact of rehabilitation of Assiut barrage, Nile River, on groundwater rise in urban areas

    NASA Astrophysics Data System (ADS)

    Dawoud, Mohamed A.; El Arabi, Nahed E.; Khater, Ahmed R.; van Wonderen, Jan

    2006-08-01

    To make optimum use of the most vital natural resource of Egypt, the River Nile water, a number of regulating structures (in the form of dams and barrages) for control and diversion of the river flow have been constructed in this river since the start of the 20th century. One of these barrages is the Assiut barrage which will require considerable repairs in the near future. The design of the rehabilitation of the barrage includes a headpond with water levels maintained at a level approximately 0.60 m higher than the highest water level in the headpond of the present barrage. This development will cause an increase of the seepage flow from the river towards the adjacent agricultural lands, Assiut Town and villages. The increased head pond level might cause a rise of the groundwater levels and impedance of drainage outflows. The drainage conditions may therefore be adversely affected in the so-called impacted areas which comprise floodplains on both sides of the Nile for about 70 km upstream of the future barrage. A rise in the groundwater table, particularly when high river levels impede drainage, may result in waterlogging and secondary salinization of the soil profile in agricultural areas and increase of groundwater into cellars beneath buildings in the urban areas. In addition, a rise in the groundwater table could have negative impact on existing sanitation facilities, in particular in the areas which are served with septic tanks. The impacts of increasing the headpond level were assessed using a three-dimensional groundwater model. The mechanisms of interactions between the Nile River and the underlying Quaternary aquifer system as they affect the recharge/discharge processes are comprehensively outlined. The model has been calibrated for steady state and transient conditions against historical data from observation wells. The mitigation measures for the groundwater rise in the urban areas have been tested using the calibrated mode.

  4. Ecological impact of groundwater extraction on wetlands (Douro Basin, Spain)

    NASA Astrophysics Data System (ADS)

    Bernadez, F. G.; Rey Benayas, J. M.; Martinez, A.

    1993-01-01

    Declining water table levels in the Douro River basin, Central Spain, are caused by the extraction of groundwater from a relatively homogeneous aquifer, and results in several types of impact on local wetlands which vary according to their characteristics. These wetlands are local, intermediate and regional groundwater discharge sites, seepages from post-Tertiary deposits, and non-linked ponds to groundwater dynamics. The following important factors influence the type of impact: the recharge or discharge nature of the affected sector of landscape; the type of connection with the regional aquifer; flow lengths and residence time of the water; the interaction between the water and the surface material, particularly clay. A wide range of wetland values and functions are affected according to the type of impact. These include productivity, amenity, recreational, scientific, educational and conservation values.

  5. Impact of geochemical stressors on shallow groundwater quality

    USGS Publications Warehouse

    An, Y.-J.; Kampbell, D.H.; Jeong, S.-W.; Jewell, K.P.; Masoner, J.R.

    2005-01-01

    Groundwater monitoring wells (about 70 wells) were extensively installed in 28 sites surrounding Lake Texoma, located on the border of Oklahoma and Texas, to assess the impact of geochemical stressors to shallow groundwater quality. The monitoring wells were classified into three groups (residential area, agricultural area, and oil field area) depending on their land uses. During a 2-year period from 1999 to 2001 the monitoring wells were sampled every 3 months on a seasonal basis. Water quality assay consisted of 25 parameters including field parameters, nutrients, major ions, and trace elements. Occurrence and level of inorganics in groundwater samples were related to the land use and temporal change. Groundwater of the agricultural area showed lower levels of ferrous iron and nitrate than the residential area. The summer season data revealed more distinct differences in inorganic profiles of the two land use groundwater samples. There is a possible trend that nitrate concentrations in groundwater increased as the proportions of cultivated area increased. Water-soluble ferrous iron occurred primarily in water samples with a low dissolved oxygen concentration and/or a negative redox potential. The presence of brine waste in shallow groundwater was detected by chloride and conductivity in oil field area. Dissolved trace metals and volatile organic carbons were not in a form of concentration to be stressors. This study showed that the quality of shallow ground water could be related to regional geochemical stressors surrounding the lake. ?? 2005 Elsevier B.V. All rights reserved.

  6. Assessment of nitrogen ceilings for Dutch agricultural soils to avoid adverse environmental impacts.

    PubMed

    de Vries, W; Kros, H; Oenema, O; Erisman, J W

    2001-11-01

    In the Netherlands, high traffic density and intensive animal husbandry have led to high emissions of reactive nitrogen (N) into the environment. This leads to a series of environmental impacts, including: (1) nitrate (NO3) contamination of drinking water, (2) eutrophication of freshwater lakes, (3) acidification and biodiversity impacts on terrestrial ecosystems, (4) ozone and particle formation affecting human health, and (5) global climate change induced by emissions of N2O. Measures to control reactive N emissions were, up to now, directed towards those different environmental themes. Here we summarize the results of a study to analyse the agricultural N problem in the Netherlands in an integrated way, which means that all relevant aspects are taken into account simultaneously. A simple N balance model was developed, representing all crucial processes in the N chain, to calculate acceptable N inputs to the farm (so-called N ceiling) and to the soil surface (application in the field) by feed concentrates, organic manure, fertiliser, deposition, and N fixation. The N ceilings were calculated on the basis of critical limits for NO 3 concentrations in groundwater, N concentrations in surface water, and ammonia (NH3) emission targets related to the protection of biodiversity of natural areas. Results show that in most parts of the Netherlands, except the western and the northern part, the N ceilings are limited by NH 3 emissions, which are derived from critical N loads for nature areas, rather than limits for both ground- and surface water. On the national scale, the N ceiling ranges between 372 and 858 kton year(-1) depending on the choice of critical limits. The current N import is 848 kton year(-1). A decrease of nearly 60% is needed to reach the ceilings that are necessary to protect the environment against all adverse impacts of N pollution from agriculture.

  7. Assessment of nitrogen ceilings for Dutch agricultural soils to avoid adverse environmental impacts.

    PubMed

    de Vries, W; Kros, H; Oenema, O; Erisman, J W

    2001-11-01

    In the Netherlands, high traffic density and intensive animal husbandry have led to high emissions of reactive nitrogen (N) into the environment. This leads to a series of environmental impacts, including: (1) nitrate (NO3) contamination of drinking water, (2) eutrophication of freshwater lakes, (3) acidification and biodiversity impacts on terrestrial ecosystems, (4) ozone and particle formation affecting human health, and (5) global climate change induced by emissions of N2O. Measures to control reactive N emissions were, up to now, directed towards those different environmental themes. Here we summarize the results of a study to analyse the agricultural N problem in the Netherlands in an integrated way, which means that all relevant aspects are taken into account simultaneously. A simple N balance model was developed, representing all crucial processes in the N chain, to calculate acceptable N inputs to the farm (so-called N ceiling) and to the soil surface (application in the field) by feed concentrates, organic manure, fertiliser, deposition, and N fixation. The N ceilings were calculated on the basis of critical limits for NO 3 concentrations in groundwater, N concentrations in surface water, and ammonia (NH3) emission targets related to the protection of biodiversity of natural areas. Results show that in most parts of the Netherlands, except the western and the northern part, the N ceilings are limited by NH 3 emissions, which are derived from critical N loads for nature areas, rather than limits for both ground- and surface water. On the national scale, the N ceiling ranges between 372 and 858 kton year(-1) depending on the choice of critical limits. The current N import is 848 kton year(-1). A decrease of nearly 60% is needed to reach the ceilings that are necessary to protect the environment against all adverse impacts of N pollution from agriculture. PMID:12805837

  8. Soil amendment with olive mill wastes: impact on groundwater.

    PubMed

    Caputo, Maria Clementina; De Girolamo, Anna Maria; Volpe, Angela

    2013-12-15

    Two sets of soil lysimeters were amended with solid and liquid olive mill wastes and the composition of leachate was analysed. Five treatments were carried out using: olive mill wastewater (OMW) at two different rates (80 and 320 m(3)/ha); OMW pre-treated by catalytical digestion with MnO2; compost obtained by exhausted olive pomace; freshwater as the control. Electric conductivity, pH, potassium, total polyphenols and nitrates were monitored in the leachate as indexes of potential groundwater contamination. The study demonstrated that the impact of all the selected amendments on groundwater was the minimum. OMW was safely applied to soil even at four times the rate allowed by the Italian law, and pre-treatment by catalytical digestion was not necessary to further reduce the impact on groundwater. The application of olive pomace compost was equally safe.

  9. Pre/post-closure assessment of groundwater pharmaceutical fate in a wastewater-facility-impacted stream reach.

    PubMed

    Bradley, Paul M; Barber, Larry B; Clark, Jimmy M; Duris, Joseph W; Foreman, William T; Furlong, Edward T; Givens, Carrie E; Hubbard, Laura E; Hutchinson, Kasey J; Journey, Celeste A; Keefe, Steffanie H; Kolpin, Dana W

    2016-10-15

    Pharmaceutical contamination of contiguous groundwater is a substantial concern in wastewater-impacted streams, due to ubiquity in effluent, high aqueous mobility, designed bioactivity, and to effluent-driven hydraulic gradients. Wastewater treatment facility (WWTF) closures are rare environmental remediation events; offering unique insights into contaminant persistence, long-term wastewater impacts, and ecosystem recovery processes. The USGS conducted a combined pre/post-closure groundwater assessment adjacent to an effluent-impacted reach of Fourmile Creek, Ankeny, Iowa, USA. Higher surface-water concentrations, consistent surface-water to groundwater concentration gradients, and sustained groundwater detections tens of meters from the stream bank demonstrated the importance of WWTF effluent as the source of groundwater pharmaceuticals as well as the persistence of these contaminants under effluent-driven, pre-closure conditions. The number of analytes (110 total) detected in surface water decreased from 69 prior to closure down to 8 in the first post-closure sampling event approximately 30 d later, with a corresponding 2 order of magnitude decrease in the cumulative concentration of detected analytes. Post-closure cumulative concentrations of detected analytes were approximately 5 times higher in proximal groundwater than in surface water. About 40% of the 21 contaminants detected in a downstream groundwater transect immediately before WWTF closure exhibited rapid attenuation with estimated half-lives on the order of a few days; however, a comparable number exhibited no consistent attenuation during the year-long post-closure assessment. The results demonstrate the potential for effluent-impacted shallow groundwater systems to accumulate pharmaceutical contaminants and serve as long-term residual sources, further increasing the risk of adverse ecological effects in groundwater and the near-stream ecosystem.

  10. Pre/post-closure assessment of groundwater pharmaceutical fate in a wastewater-facility-impacted stream reach.

    PubMed

    Bradley, Paul M; Barber, Larry B; Clark, Jimmy M; Duris, Joseph W; Foreman, William T; Furlong, Edward T; Givens, Carrie E; Hubbard, Laura E; Hutchinson, Kasey J; Journey, Celeste A; Keefe, Steffanie H; Kolpin, Dana W

    2016-10-15

    Pharmaceutical contamination of contiguous groundwater is a substantial concern in wastewater-impacted streams, due to ubiquity in effluent, high aqueous mobility, designed bioactivity, and to effluent-driven hydraulic gradients. Wastewater treatment facility (WWTF) closures are rare environmental remediation events; offering unique insights into contaminant persistence, long-term wastewater impacts, and ecosystem recovery processes. The USGS conducted a combined pre/post-closure groundwater assessment adjacent to an effluent-impacted reach of Fourmile Creek, Ankeny, Iowa, USA. Higher surface-water concentrations, consistent surface-water to groundwater concentration gradients, and sustained groundwater detections tens of meters from the stream bank demonstrated the importance of WWTF effluent as the source of groundwater pharmaceuticals as well as the persistence of these contaminants under effluent-driven, pre-closure conditions. The number of analytes (110 total) detected in surface water decreased from 69 prior to closure down to 8 in the first post-closure sampling event approximately 30 d later, with a corresponding 2 order of magnitude decrease in the cumulative concentration of detected analytes. Post-closure cumulative concentrations of detected analytes were approximately 5 times higher in proximal groundwater than in surface water. About 40% of the 21 contaminants detected in a downstream groundwater transect immediately before WWTF closure exhibited rapid attenuation with estimated half-lives on the order of a few days; however, a comparable number exhibited no consistent attenuation during the year-long post-closure assessment. The results demonstrate the potential for effluent-impacted shallow groundwater systems to accumulate pharmaceutical contaminants and serve as long-term residual sources, further increasing the risk of adverse ecological effects in groundwater and the near-stream ecosystem. PMID:27350092

  11. Pre/post-closure assessment of groundwater pharmaceutical fate in a wastewater‑facility-impacted stream reach

    USGS Publications Warehouse

    Bradley, Paul M.; Barber, Larry B.; Clark, Jimmy M.; Duris, Joseph; Foreman, William; Furlong, Edward T.; Givens, Carrie E.; Hubbard, Laura E.; Hutchinson, Kasey J.; Journey, Celeste A.; Keefe, Steffanie H.; Kolpin, Dana W.

    2016-01-01

    Pharmaceutical contamination of contiguous groundwater is a substantial concern in wastewater-impacted streams, due to ubiquity in effluent, high aqueous mobility, designed bioactivity, and to effluent-driven hydraulic gradients. Wastewater treatment facility (WWTF) closures are rare environmental remediation events; offering unique insights into contaminant persistence, long-term wastewater impacts, and ecosystem recovery processes. The USGS conducted a combined pre/post-closure groundwater assessment adjacent to an effluent-impacted reach of Fourmile Creek, Ankeny, Iowa, USA. Higher surface-water concentrations, consistent surface-water to groundwater concentration gradients, and sustained groundwater detections tens of meters from the stream bank demonstrated the importance of WWTF effluent as the source of groundwater pharmaceuticals as well as the persistence of these contaminants under effluent-driven, pre-closure conditions. The number of analytes (110 total) detected in surface water decreased from 69 prior to closure down to 8 in the first post-closure sampling event approximately 30 d later, with a corresponding 2 order of magnitude decrease in the cumulative concentration of detected analytes. Post-closure cumulative concentrations of detected analytes were approximately 5 times higher in proximal groundwater than in surface water. About 40% of the 21 contaminants detected in a downstream groundwater transect immediately before WWTF closure exhibited rapid attenuation with estimated half-lives on the order of a few days; however, a comparable number exhibited no consistent attenuation during the year-long post-closure assessment. The results demonstrate the potential for effluent-impacted shallow groundwater systems to accumulate pharmaceutical contaminants and serve as long-term residual sources, further increasing the risk of adverse ecological effects in groundwater and the near-stream ecosystem.

  12. Groundwater impact assessment report for the 284-WB Powerplant Ponds

    SciTech Connect

    Alexander, D.J.; Johnson, V.G.; Lindsey, K.A.

    1993-09-01

    As required by the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement Milestone M-17-00A), this report assesses the impact of wastewater discharged to the 284-WB Powerplant Ponds on groundwater quality. The assessment reported herein expands upon the initial analysis conducted between 1989 and 1990 for the Liquid Effluent Study Final Project Plan.

  13. Impact of climate change on groundwater resources in Southern Austria

    NASA Astrophysics Data System (ADS)

    Reszler, C.; Harum, T.; Poltnig, W.; Saccon, P.; Reichl, P.; Ruch, C.; Kopeinig, C.; Freundl, G.; Schlamberger, J.; Zessar, H.; Suette, G.

    2012-04-01

    Groundwater is the most important source for drinking water in Austria. In some parts of Southern Austria water resources already are very vulnerable to unfavourable climate conditions. This paper summarizes case studies of estimating the impact of climate change on groundwater recharge and groundwater flow in Southern Austria in the frame of the ETC-Alpine Space project ALP-WATER-SCARCE. In several pilot regions a distributed hydrological model was set up to simulate groundwater recharge and groundwater flow for a period of 10 to 30 years. The pilot sites range from mountainous catchments with steep hillslopes to Alpine valleys and flatlands with pore aquifers. In the model period comprehensive land data and meteorological data were used, and the models were calibrated to available stream gauge data. Additional low flow monitoring in the frame of the project also allowed for a more detailed regional analysis in some catchments. The simulations were firstly used to extend runoff and groundwater recharge depths on an annual basis up to 200 years into the past by regression analysis with long time meteorological parameters (HISTALP). The historical view shows that groundwater flow and recharge in most of the pilot regions decreased since the beginning of the 20th century, which is mainly the effect of climate change. Changes of land use are of minor relevance in most of the regions. Second, by the calibrated model scenarios were simulated to quantify the impact of a possible future change in the climatic conditions on water resources. The scenarios were generated by altering the model input by a "Delta-Change", under consideration of the historical development. These scenarios can be interpreted as "what if"-scenarios to quantify the sensitivity of the hydrological systems on these climatic variables. The results are compared with actual and projected water uses as a basis for regional water resources management.

  14. Assessing the Impact of Topography on Groundwater Salinization Due to Storm Surge Inundation

    NASA Astrophysics Data System (ADS)

    Yu, X.; Yang, J.; Graf, T.; Koneshloo, M.; O'Neal, M. A.; Michael, H. A.

    2015-12-01

    The sea-level rise and increase in the frequency and intensity of coastal storms due to climate change are likely to exacerbate adverse effects of storm surges on low-lying coastal areas. The landward flow of water during storm surges introduces salt to surficial coastal aquifers and threatens groundwater resources. Coastal topography (e.g. ponds, dunes, canals) likely has a strong impact on overwash and salinization processes, but is generally highly simplified in modeling studies. To understand the topographic impacts on groundwater salinization, we modeled overwash and variable-density groundwater flow and salt transport in 3D using the fully coupled surface and subsurface numerical simulator, HydroGeoSphere. The model simulates the coastal aquifer as an integrated system considering processes such as overland flow, coupled surface and subsurface exchange, variably saturated flow, and variable-density flow. To represent various coastal landscape types, we started with realistic coastal topography from Delaware, USA, and then generated synthetic fields with differing shore-perpendicular connectivity and surface depressions. The groundwater salinization analysis suggested that the topographic connectivity promoting overland flow controls the volume of aquifer that is salinized. In contrast, depression storage of surface water mainly controls the time for infiltrated salt to flush from the aquifer. The results indicate that for a range of synthetic conditions, topography increases the flushing time of salt by 20-300% relative to an equivalent "simple slope" in which topographic variation is absent. Our study suggests that topography have a significant impact on overwash salinization, with important implications for land management at local scales and groundwater vulnerability assessment at regional to global scales.

  15. Rural Land Use Impacts on Floodplain Shallow Groundwater Temperature

    NASA Astrophysics Data System (ADS)

    Kellner, R. E.; Hubbart, J. A.

    2014-12-01

    The temperature of shallow groundwater is tightly coupled to aquatic ecosystem health and rates of subsurface geochemical processes. Shallow groundwater temperatures are understood to respond to soil surface temperatures, which in turn depend on climate and land use. To address gaps in knowledge concerning land use impacts on shallow groundwater quality, a bookended floodplain study was implemented in Hinkson Creek Watershed, central Missouri, USA to better understand rural land use impacts on shallow groundwater temperature (SGW). Study sites included a historic agricultural field (Ag) and remnant bottomland hardwood forest (BHF). Each site included nine piezometers equally spaced in an 80 x 80 m grid. Piezometers were equipped with pressure transducers to monitor SGW temperature and water level at 30 minute intervals during the 2011, 2012, and 2013 water years. Average SGW temperature during the three water years was 11.3 °C at both the Ag and BHF sites. However, the temperature range at the Ag site was 63% greater than the BHF. Results indicate a greater responsiveness to seasonal climate fluctuations in the SGW temperature of the Ag site where there was an absence of forest canopy. Average SGW temperatures at the Ag site were 11.8, 11.1, and 10.9 °C, for piezometer rows located 10, 50, and 90 m from the stream, respectively. Average shallow groundwater temperatures at the BHF site were 11.0, 11.8, and 11.2 °C, for piezometers located 10, 50, and 90 m from the stream, respectively. The range of SGW temperatures at the Ag site also decreased with increasing distance from stream, suggesting a distinct stream influence on Ag site SGW temperature. The 63% greater SGW temperature range indicates the Ag site may contribute warmer water to the stream, relative to the BHF. Results hold broad implications for land managers seeking to mitigate the impact of land use on floodplain processes and groundwater quality.

  16. 25 CFR 170.110 - How can State and local governments prevent discrimination or adverse impacts?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Eligibility Consultation, Collaboration, Coordination § 170.110 How can State and local governments prevent discrimination or adverse impacts? (a) Under 23 U.S.C. 134 and 135, and 23 CFR part 450, State and...

  17. Sources of uncertainty in climate change impacts on groundwater recharge

    NASA Astrophysics Data System (ADS)

    Holman, I. P.

    2007-12-01

    This paper assesses the significance of the many sources of uncertainty in future groundwater recharge estimation, based on lessons learnt from an integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge in East Anglia, UK. Many factors affect simulations of future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment, and changes in cropping, rotations and management practices. Stochastic modelling of potential recharge showed median annual recharge decreasing under a High emissions future from 75 mm (1961-90) to 56 mm in the 2020s and 45 mm in the 2050s. However, the median values for individual simulations ranged from 46-75 mm (2020s) and 30-71 mm (2050s) highlighting a decreasing but uncertain trend. The impacts of (and uncertainty in) the climate scenarios are generally regionally more important than those of the socio-economic scenarios. However, locally, the impacts of the socio-economic scenarios can be significant, especially where there are large increases in urbanization, agricultural land cover, bioenergy production, or agricultural management practices. For example, management of soil conditions can increase potential groundwater recharge by around 5 %, but poor management can further reduce potential recharge by up to 15 %. The paper will demonstrate that to focus on the direct impacts of climate change is to neglect the potentially important role of policy, societal values and economic processes in shaping the landscape above aquifers. If the likely consequences of future changes of groundwater recharge, resulting from both climate and socio-economic change, are to be assessed, hydrogeologists must increasingly work with researchers from other disciplines, such as socio-economists, agricultural modellers and soil scientists

  18. Groundwater age for identification of baseline groundwater quality and impacts of land-use intensification - The National Groundwater Monitoring Programme of New Zealand

    NASA Astrophysics Data System (ADS)

    Morgenstern, Uwe; Daughney, Christopher J.

    2012-08-01

    SummaryWe identified natural baseline groundwater quality and impacts caused by land use intensification by relating groundwater chemistry with water age. Tritium, the most direct tracer for groundwater dating, including the time of water passage through the unsaturated zone, was overwhelmed over the recent decades by contamination from bomb-tritium from nuclear weapons testing in the early 1960s. In the Southern Hemisphere, this situation has changed now with the fading of the bomb-tritium, and tritium has become a tool for accurate groundwater dating. Tritium dating will become efficient also in the Northern Hemisphere over the next decade. Plotting hydrochemistry and field parameters versus groundwater age allowed us to identify those parameters that have increasing concentrations with age and are therefore from geological sources. These indicators for natural groundwater evolution are: Na, HCO3, SiO2, F, PO4, the redox-sensitive elements and compounds Fe, Mn, NH4, CH4, and pH and conductivity. In young groundwater that was recharged after the intensification of agriculture, nitrate, sulphate, CFC-11 and CFC-12, and pesticides are the most representative indicators for the impact of land-use intensification on groundwater quality, with 66% of the sites showing such an impact. Elevated concentrations of nitrate in oxic groundwater allowed us to reconstruct the timing and magnitude of the impact of land-use intensification on groundwater which in New Zealand occurred in two stages. Old pristine groundwater reflects the natural baseline quality. A transition to slightly elevated concentration due to low-intensity land-use was observed in groundwater recharged since around 1880. A sharp increase in nitrate and other agrochemicals due to high-intensity agriculture was observed in groundwater recharged since 1955. The threshold concentrations that distinguish natural baseline quality water from low-intensity land-use water, and low-intensity from high intensity land

  19. Groundwater impact assessment report for the 216-U-14 Ditch

    SciTech Connect

    Singleton, K.M.; Lindsey, K.A.

    1994-01-01

    Groundwater impact assessments are conducted at liquid effluent receiving sites on the Hanford Site to determine hydrologic and contaminant impacts caused by discharging wastewater to the soil column. The assessments conducted are pursuant to the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-17-00A and M-17-00B, as agreed by the US Department of Energy (DOE), Washington State Department of Ecology (Ecology), and the US Environmental Protection Agency (EPA) (Ecology et al. 1992). This report assesses impacts on the groundwater and vadose zone from wastewater discharged to the 216-U-14 Ditch. Contemporary effluent waste streams of interest are 242-S Evaporator Steam Condensate and UO{sub 3}/U Plant wastewater.

  20. Environmental impacts of open loop geothermal system on groundwater

    NASA Astrophysics Data System (ADS)

    Kwon, Koo-Sang; Park, Youngyun; Yun, Sang Woong; Lee, Jin-Yong

    2013-04-01

    Application of renewable energies such as sunlight, wind, rain, tides, waves and geothermal heat has gradually increased to reduce emission of CO2 which is supplied from combustion of fossil fuel. The geothermal energy of various renewable energies has benefit to be used to cooling and heating systems and has good energy efficiency compared with other renewable energies. However, open loop system of geothermal heat pump system has possibility that various environmental problems are induced because the system directly uses groundwater to exchange heat. This study was performed to collect data from many documents such as papers and reports and to summarize environmental impacts for application of open loop system. The environmental impacts are classified into change of hydrogeological factors such as water temperature, redox condition, EC, change of microbial species, well contamination and depletion of groundwater. The change of hydrogeological factors can induce new geological processes such as dissolution and precipitation of some minerals. For examples, increase of water temperature can change pH and Eh. These variations can change saturation index of some minerals. Therefore, dissolution and precipitation of some minerals such as quartz and carbonate species and compounds including Fe and Mn can induce a collapse and a clogging of well. The well contamination and depletion of groundwater can reduce available groundwater resources. These environmental impacts will be different in each region because hydrogeological properties and scale, operation period and kind of the system. Therefore, appropriate responses will be considered for each environmental impact. Also, sufficient study will be conducted to reduce the environmental impacts and to improve geothermal energy efficiency during the period that a open loop system is operated. This work was supported by the Energy Efficiency and Resources of the Korea Institute of Energy Technology Evaluation and Planning

  1. Groundwater.

    ERIC Educational Resources Information Center

    Braids, Olin C.; Gillies, Nola P.

    1978-01-01

    Presents a literature review of groundwater quality covering publications of 1977. This review includes: (1) sources of groundwater contamination; and (2) management of groundwater. A list of 59 references is also presented. (HM)

  2. Molecular Signature of Organic Nitrogen in Septic-Impacted Groundwater

    NASA Astrophysics Data System (ADS)

    Arnold, W. A.; Longnecker, K.; Kroeger, K. D.; Kujawinski, E. B.

    2014-12-01

    Dissolved organic nitrogen (DON) is altered by anthropogenic inputs and land use changes. The impacts of alterations of the DON pool would be more clearly constrained if specific sources were identified and if the molecular-level composition of DON were better understood. The pharmaceutical carbamazepine was used to identify septic-impacted groundwater in a coastal watershed. Using ultrahigh resolution mass spectrometry data, the nitrogen-containing features of the dissolved organic matter in septic-impacted and non-impacted samples were compared. A larger abundance of nitrogen-containing formulas were present in the septic-impacted groundwater sample. Impacted samples have additional DON features in the regions ascribed as 'protein-like' and 'lipid-like' in van Krevelen space and have more intense nitrogen-containing features in a specific region of a carbon versus mass plot. These features are potential indicators of dissolved organic nitrogen arising from septic effluents. Ultrahigh resolution mass spectrometry is a potentially valuable tool to identify and characterize sources of DON.

  3. Molecular signature of organic nitrogen in septic-impacted groundwater

    USGS Publications Warehouse

    Arnold, William A.; Longnecker, Krista; Kroeger, Kevin D.; Kujawinski, Elizabeth B.

    2014-01-01

    Dissolved inorganic and organic nitrogen levels are elevated in aquatic systems due to anthropogenic activities. Dissolved organic nitrogen (DON) arises from various sources, and its impact could be more clearly constrained if specific sources were identified and if the molecular-level composition of DON were better understood. In this work, the pharmaceutical carbamazepine was used to identify septic-impacted groundwater in a coastal watershed. Using ultrahigh resolution mass spectrometry data, the nitrogen-containing features of the dissolved organic matter in septic-impacted and non-impacted samples were compared. The septic-impacted groundwater samples have a larger abundance of nitrogen-containing formulas. Impacted samples have additional DON features in the regions ascribed as ‘protein-like’ and ‘lipid-like’ in van Krevelen space and have more intense nitrogen-containing features in a specific region of a carbon versus mass plot. These features are potential indicators of dissolved organic nitrogen arising from septic effluents, and this work suggests that ultrahigh resolution mass spectrometry is a valuable tool to identify and characterize sources of DON.

  4. Scenarios of bioenergy development impacts on regional groundwater withdrawals

    USGS Publications Warehouse

    Uden, Daniel R.; Allen, Craig R.; Mitchell, Rob B.; Guan, Qingfeng; McCoy, Tim D.

    2013-01-01

    Irrigation increases agricultural productivity, but it also stresses water resources (Huffaker and Hamilton 2007). Drought and the potential for drier conditions resulting from climate change could strain water supplies in landscapes where human populations rely on finite groundwater resources for drinking, agriculture, energy, and industry (IPCC 2007). For instance, in the North American Great Plains, rowcrops are utilized for livestock feed, food, and bioenergy production (Cassman and Liska 2007), and a large portion is irrigated with groundwater from the High Plains aquifer system (McGuire 2011). Under projected future climatic conditions, greater crop water use requirements and diminished groundwater recharge rates could make rowcrop irrigation less feasible in some areas (Rosenberg et al. 1999; Sophocleous 2005). The Rainwater Basin region of south central Nebraska, United States, is an intensively farmed and irrigated Great Plains landscape dominated by corn (Zea mays L.) and soybean (Glycine max L.) production (Bishop and Vrtiska 2008). Ten starch-based ethanol plants currently service the region, producing ethanol from corn grain (figure 1). In this study, we explore the potential of switchgrass (Panicum virgatum L.), a drought-tolerant alternative bioenergy feedstock, to impact regional annual groundwater withdrawals for irrigation under warmer and drier future conditions. Although our research context is specific to the Rainwater Basin and surrounding North American Great Plains, we believe the broader research question is internationally pertinent and hope that this study simulates similar research in other areas.

  5. Groundwater impact on methane emissions from flooded paddy fields

    NASA Astrophysics Data System (ADS)

    Rizzo, A.; Boano, F.; Revelli, R.; Ridolfi, L.

    2015-09-01

    High methane (CH4) fluxes emitted from paddy fields strongly contribute to the accumulation of greenhouse gases into the atmosphere, compromising the eco-compatibility of one of the most important world foods. A strong link exists between infiltration rates of irrigation water and CH4 emissions. Since depth to the groundwater table affects infiltration rates, a relevant groundwater impact is expected on CH4 emissions from paddy fields. In this work, a theoretical approach is adopted to investigate the aquifer effect on CH4 dynamics in paddies. Infiltration rates are strongly affected by the development of different connection states between aquifer and irrigation ponded water. A strong reduction in infiltration rates results from a water table near to the soil surface, when the system is hydraulically connected. When the groundwater level increases, the infiltration rate reduction due to the switch from disconnected to connected state promotes a relevant increase of CH4 emissions. This is due to a strong reduction of dissolved organic carbon (DOC) percolation, which leads to higher DOC availability for microbial CH4 production and, consequently, higher CH4 emissions. Our simulations show that CH4 fluxes can be reduced by up to 24% when groundwater level is decreased and the aquifer is disconnected from ponding water. In paddies with shallow aquifers, lowering the water table with a drainage system could thus represent a promising CH4 mitigation option.

  6. Impact of Climate Change on Soil and Groundwater Chemistry Subject to Process Waste Land Application

    NASA Astrophysics Data System (ADS)

    McNab, W. W.

    2013-12-01

    Nonhazardous aqueous process waste streams from food and beverage industry operations are often discharged via managed land application in a manner designed to minimize impacts to underlying groundwater. Process waste streams are typically characterized by elevated concentrations of solutes such as ammonium, organic nitrogen, potassium, sodium, and organic acids. Land application involves the mixing of process waste streams with irrigation water which is subsequently applied to crops. The combination of evapotranspiration and crop salt uptake reduces the downward mass fluxes of percolation water and salts. By carefully managing application schedules in the context of annual climatological cycles, growing seasons, and process requirements, potential adverse environmental impacts to groundwater can be mitigated. However, climate change poses challenges to future process waste land application efforts because the key factors that determine loading rates - temperature, evapotranspiration, seasonal changes in the quality and quantity of applied water, and various crop factors - are all likely to deviate from current averages. To assess the potential impact of future climate change on the practice of land application, coupled process modeling entailing transient unsaturated fluid flow, evapotranspiration, crop salt uptake, and multispecies reactive chemical transport was used to predict changes in salt loading if current practices are maintained in a warmer, drier setting. As a first step, a coupled process model (Hydrus-1D, combined with PHREEQC) was calibrated to existing data sets which summarize land application loading rates, soil water chemistry, and crop salt uptake for land disposal of process wastes from a food industry facility in the northern San Joaquin Valley of California. Model results quantify, for example, the impacts of evapotranspiration on both fluid flow and soil water chemistry at shallow depths, with secondary effects including carbonate mineral

  7. Impact of early life adversity on EMG stress reactivity of the trapezius muscle.

    PubMed

    Luijcks, Rosan; Vossen, Catherine J; Roggeveen, Suzanne; van Os, Jim; Hermens, Hermie J; Lousberg, Richel

    2016-09-01

    Human and animal research indicates that exposure to early life adversity increases stress sensitivity later in life. While behavioral markers of adversity-induced stress sensitivity have been suggested, physiological markers remain to be elucidated. It is known that trapezius muscle activity increases during stressful situations. The present study examined to what degree early life adverse events experienced during early childhood (0-11 years) and adolescence (12-17 years) moderate experimentally induced electromyographic (EMG) stress activity of the trapezius muscles, in an experimental setting. In a general population sample (n = 115), an anticipatory stress effect was generated by presenting a single unpredictable and uncontrollable electrical painful stimulus at t = 3 minutes. Subjects were unaware of the precise moment of stimulus delivery and its intensity level. Linear and nonlinear time courses in EMG activity were modeled using multilevel analysis. The study protocol included 2 experimental sessions (t = 0 and t = 6 months) allowing for examination of reliability.Results show that EMG stress reactivity during the stress paradigm was consistently stronger in people with higher levels of early life adverse events; early childhood adversity had a stronger moderating effect than adolescent adversity. The impact of early life adversity on EMG stress reactivity may represent a reliable facet that can be used in both clinical and nonclinical studies. PMID:27684800

  8. Impact of childhood adversities on the short-term course of illness in psychotic spectrum disorders.

    PubMed

    Schalinski, Inga; Fischer, Yolanda; Rockstroh, Brigitte

    2015-08-30

    Accumulating evidence indicates an impact of childhood adversities on the severity and course of mental disorders, whereas this impact on psychotic disorders remains to be specified. Effects of childhood adversities on comorbidity, on symptom severity of the Positive and Negative Syndrome Scale and global functioning across four months (upon admission, 1 and 4 months after initial assessment), as well as the course of illness (measured by the remission rate, number of re-hospitalizations and dropout rate) were evaluated in 62 inpatients with psychotic spectrum disorders. Adverse experiences (of at least 1 type) were reported by 73% of patients. Patients with higher overall level of childhood adversities (n=33) exhibited more co-morbid disorders, especially alcohol/substance abuse and dependency, and higher dropout rates than patients with a lower levels of adverse experiences (n=29), together with higher levels of positive symptoms and symptoms of excitement and disorganization. Emotional and physical neglect were particularly related to symptom severity. Results suggest that psychological stress in childhood affects the symptom severity and, additionally, a more unfavorable course of disorder in patients diagnosed with psychoses. This impact calls for its consideration in diagnostic assessment and psychiatric care.

  9. The Impact of Childhood Sexual Abuse and Other Forms of Childhood Adversity on Adulthood Parenting

    ERIC Educational Resources Information Center

    Barrett, Betty

    2009-01-01

    This study investigated the independent impact of child sexual abuse on five dimensions of adulthood parenting after controlling for other forms of childhood adversity in a predominantly African-American sample of mothers receiving public assistance (N = 483). An analysis of data previously collected as part of the Illinois Families Study Child…

  10. 25 CFR 170.110 - How can State and local governments prevent discrimination or adverse impacts?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and... discrimination or adverse impacts? (a) Under 23 U.S.C. 134 and 135, and 23 CFR part 450, State and local...) Identify potential discrimination; and (2) Recommend corrective actions to avoid disproportionately...

  11. Evaluating the impact of climate change on groundwater resources in a small Mediterranean watershed.

    PubMed

    Ertürk, Ali; Ekdal, Alpaslan; Gürel, Melike; Karakaya, Nusret; Guzel, Cigdem; Gönenç, Ethem

    2014-11-15

    Western Mediterranean Region of Turkey is subject to considerable impacts of climate change that may adversely affect the water resources. Decrease in annual precipitation and winter precipitation as well as increase in temperatures are observed since 1960s. In this study, the impact of climate change on groundwater resources in part of Köyceğiz-Dalyan Watershed was evaluated. Evaluation was done by quantifying the impacts of climate change on the water budget components. Hydrological modeling was conducted with SWAT model which was calibrated and validated successfully. Climate change and land use scenarios were used to calculate the present and future climate change impacts on water budgets. According to the simulation results, almost all water budget components have decreased. SWAT was able to allocate less irrigation water because of the decrease of overall water due to the climate change. This resulted in an increase of water stressed days and temperature stressed days whereas crop yields have decreased according to the simulation results. The results indicated that lack of water is expected to be a problem in the future. In this manner, investigations on switching to more efficient irrigation methods and to crops with less water consumption are recommended as adaptation measures to climate change impacts.

  12. Is Overweight a Risk Factor for Adverse Events during Removal of Impacted Lower Third Molars?

    PubMed Central

    de Carvalho, Ricardo Wathson Feitosa; do Egito Vasconcelos, Belmiro Cavalcanti

    2014-01-01

    Being overweight is recognised as a significant risk factor for several morbidities; however, the experience of the dentistry faculties focusing on this population is still low. The aim of the present study was to determine the occurrence of adverse events during removal of impacted lower third molars in overweight patients. A prospective cohort study was carried out involving overweight patients subjected to surgical removal of impacted lower third molar as part of a line of research on third molar surgery. Predictor variables indicative of the occurrence of adverse events during surgery were classified by their demographic, clinical, radiographic, and surgical aspects. Descriptive and bivariate statistics were computed. In total, 140 patients fulfilled the eligibility criteria, and 280 surgeries were performed. Patients' mean age was 25.1 ± 2.2 years, and the proportion of women to men was 3 : 1. Eight different adverse events during surgery were recorded. These events occurred in approximately 29.3% of cases and were significantly associated with predictor variables (P < 0.05). Excess weight is recognised as a risk factor for the high rate of adverse events in impacted third molar surgery. The study suggests that overweight patients are highly likely to experience morbidities. PMID:25548786

  13. Groundwater impact assessment for the 216-U-17 Crib, 200 West Area

    SciTech Connect

    Reidel, S.P.; Johnson, V.G.; Kline, N.W.

    1993-06-01

    As required by the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement milestone M-17-00A), this report assesses the impact to groundwater from discharge of process condensate to the ground at the 216-U-17 Crib. The assessment considers impacts associated with moisture movement through soil beneath the crib and the potential transport of contaminants to the groundwater.

  14. Modeling the Factors Impacting Pesticide Concentrations in Groundwater Wells.

    PubMed

    Aisopou, Angeliki; Binning, Philip J; Albrechtsen, Hans-Jørgen; Bjerg, Poul L

    2015-01-01

    This study examines the effect of pumping, hydrogeology, and pesticide characteristics on pesticide concentrations in production wells using a reactive transport model in two conceptual hydrogeologic systems; a layered aquifer with and without a stream present. The pumping rate can significantly affect the pesticide breakthrough time and maximum concentration at the well. The effect of the pumping rate on the pesticide concentration depends on the hydrogeology of the aquifer; in a layered aquifer, a high pumping rate resulted in a considerably different breakthrough than a low pumping rate, while in an aquifer with a stream the effect of the pumping rate was insignificant. Pesticide application history and properties have also a great impact on the effect of the pumping rate on the concentration at the well. The findings of the study show that variable pumping rates can generate temporal variability in the concentration at the well, which helps understanding the results of groundwater monitoring programs. The results are used to provide guidance on the design of pumping and regulatory changes for the long-term supply of safe groundwater. The fate of selected pesticides is examined, for example, if the application of bentazone in a region with a layered aquifer stops today, the concentration at the well can continue to increase for 20 years if a low pumping rate is applied. This study concludes that because of the rapid response of the pesticide concentration at the drinking water well due to changes in pumping, wellhead management is important for managing pesticide concentrations.

  15. Impacts of afforestation on groundwater resources and quality

    NASA Astrophysics Data System (ADS)

    Allen, Alistair; Chapman, Deborah

    2001-07-01

    Plans to double the proportion of land under forest cover in Ireland by the year 2035 have been initiated. The plan, primarily financially driven, ignores potential environmental impacts of forestry, particularly impacts on groundwater resources and quality. Since groundwater supplies almost 25% of Ireland's total potable water, these impacts are important. Field investigations indicate that afforestation leads to a reduction in runoff by as much as 20%, mainly due to interception of rainfall by forest canopies. Clearfelling has the opposite impact. Implications are that uncoordinated forestry practices can potentially exacerbate flooding. Groundwater recharge is affected by forestry, largely due to greater uptake of soil water by trees and to increased water-holding capacity of forest soils, arising from higher organic contents. Recharge rates under forests can be reduced to one tenth that under grass or heathland. Groundwater quality may be affected by enhanced acidification and nitrification under forests, due partly to scavenging of atmospheric pollutants by forest canopies, and partly to greater deposition of highly acid leaf litter. The slower recharge rates of groundwater under forests lead to significant delays in manifestation of deterioration in groundwater quality. Résumé. Des plans sont à l'étude pour doubler la proportion du couvert forestier en Irlande d'ici à 2035. Le plan, primitivement déterminé sur une base financière, ignore les impacts environnementaux potentiels de la foresterie, et particulièrement les impacts sur les ressources en eau souterraine et leur qualité. Du fait que les eaux souterraines satisfont presque 25% du total de l'eau potable de l'Irlande, ces impacts sont importants. Les études de terrain montrent que le reboisement conduit à une réduction du ruissellement d'au moins 20%, principalement à cause d'une interception de la pluie par le couvert forestier. Les coupes ont un impact contraire. Les implications sont

  16. Short and long-term impacts of different groundwater regimes on water balance components of shallow groundwater sites

    NASA Astrophysics Data System (ADS)

    Dietrich, Ottfried; Fahle, Marcus; Kaiser, Thomas

    2016-04-01

    Water management of shallow groundwater table sites is often the subject of discussions between different interest groups. In many cases these sites have a protection status but at the same time they are important for agricultural land use. The most controversial subject is the manipulation of the water tables which is done by a complex system of streams, ditches and weirs. The target water levels that the interest groups aim for differ in height and in time. The groups present different arguments to justify their targets. However, knowledge about the effects of the different water levels on the water budget components is still limited but it is of great importance to find compromises in water resources management that are satisfying for the different groups involved. We used groundwater lysimeters to investigate the impact of different water level regimes on the water balance. The lysimeters are installed directly within a typical shallow water table site. In contrast to common groundwater lysimeters they can use the inflow and outflow to the lysimeter to control the lower boundary condition. Compared to standard groundwater lysimeters, this enables the simulation of additional groundwater management options and results in a more natural behavior of the groundwater level and the water balance components in the lysimeter. Our results show that the groundwater regimes have different effects on the water balance components, both in the short-term and the long-term. Evapotranspiration (ET) increases with higher water levels but only if the vegetation is adapted to these conditions. The abrupt increase of the groundwater level resulted in lower ET values in the first year. After the transition of the vegetation to more wetland typical species in the following years the variants with the highest water levels had always the highest ET. It is a typical long-term effect of the groundwater regime. In the short-term the meteorological conditions have the largest impact on

  17. Recruitment efforts to reduce adverse impact: targeted recruiting for personality, cognitive ability, and diversity.

    PubMed

    Newman, Daniel A; Lyon, Julie S

    2009-03-01

    Noting the presumed tradeoff between diversity and performance goals in contemporary selection practice, the authors elaborate on recruiting-based methods for avoiding adverse impact while maintaining aggregate individual productivity. To extend earlier work on the primacy of applicant pool characteristics for resolving adverse impact, they illustrate the advantages of simultaneous cognitive ability- and personality-based recruiting. Results of an algebraic recruiting model support general recruiting for cognitive ability, combined with recruiting for conscientiousness within the underrepresented group. For realistic recruiting effect sizes, this type of recruiting strategy greatly increases average performance of hires and percentage of hires from the underrepresented group. Further results from a policy-capturing study provide initial guidance on how features of organizational image can attract applicants with particular job-related personalities and abilities, in addition to attracting applicants on the basis of demographic background.

  18. Recruitment efforts to reduce adverse impact: targeted recruiting for personality, cognitive ability, and diversity.

    PubMed

    Newman, Daniel A; Lyon, Julie S

    2009-03-01

    Noting the presumed tradeoff between diversity and performance goals in contemporary selection practice, the authors elaborate on recruiting-based methods for avoiding adverse impact while maintaining aggregate individual productivity. To extend earlier work on the primacy of applicant pool characteristics for resolving adverse impact, they illustrate the advantages of simultaneous cognitive ability- and personality-based recruiting. Results of an algebraic recruiting model support general recruiting for cognitive ability, combined with recruiting for conscientiousness within the underrepresented group. For realistic recruiting effect sizes, this type of recruiting strategy greatly increases average performance of hires and percentage of hires from the underrepresented group. Further results from a policy-capturing study provide initial guidance on how features of organizational image can attract applicants with particular job-related personalities and abilities, in addition to attracting applicants on the basis of demographic background. PMID:19271792

  19. Impact Of Groundwater Discharge On Contaminant Behavior In Sediments

    EPA Science Inventory

    The discharge of groundwater into surface water may influence the concentrations and availability of contaminants in sediments. There are three predominant pathways by which groundwater may affect the characteristics of contaminated sediments: 1) direct contribution of contamin...

  20. Impacts from surface mining on ground-water system: A twenty-year record

    SciTech Connect

    Promma, K.; Mathewson, C.C.

    1998-12-31

    Groundwater impacts from a surface lignite mine in east-central Texas have been predicted and monitored since 1974. Minimal impacts on groundwater quantity and quality were predicted. Because aquifers in the mine area have very low permeabilities, volumes of groundwater to dewatering pits and reclaimed spoils were expected to be small. Potential groundwater contamination was predicted to be insignificant because of the geology of the area. Seeping to and dewatering from the mine pits were predicted to prevent any potential contamination because the flow would be toward the mine pits. The predictions made are proved correct. Groundwater depletion and recovery have been observed in six mine blocks. Compaction of the spoil is heterogeneous. The bottom of the spoil deposit has higher porosity and permeability causing rapid resaturation and preferential flow. Groundwater recovery rate is predictable, reaching a steady-state condition within 7 to 8 years after reclamation begins. Examination of the geochemical evolution of groundwater in spoil aquifers reveals many trends. Most ion concentrations exhibit an increasing trend until groundwater recovery is complete. After that the ion concentrations decline as groundwater is flushed and reacting minerals precipitate. The groundwater quality monitored is not abnormally higher than state groundwater standards.

  1. Urban groundwater age modeling under unconfined condition - Impact of underground structures on groundwater age: Evidence of a piston effect

    NASA Astrophysics Data System (ADS)

    Attard, Guillaume; Rossier, Yvan; Eisenlohr, Laurent

    2016-04-01

    In this paper, underground structures are shown to have a major influence on the groundwater mean age distribution described as a dispersive piston effect. Urban underground development does not occur without impacts on subsoil resources. In particular, groundwater resources can be vulnerable and generate disturbances when this space is exploited. Groundwater age spatial distribution data are fundamental for resource management as it can provide operational sustainability indicators. However, the application of groundwater age modeling is neglected regarding the potential effect of underground structures in urban areas. A three dimensional modeling approach was conducted to quantify the impact of two underground structures: (1) an impervious structure and (2) a draining structure. Both structures are shown to cause significant mixing processes occurring between shallow and deeper aquifers. The design technique used for draining structures is shown to have the greatest impact, generating a decrease in mean age of more than 80% under the structure. Groundwater age modeling is shown to be relevant for highlighting the role played by underground structures in advective-dispersive flows in urban areas.

  2. Shattering world assumptions: A prospective view of the impact of adverse events on world assumptions.

    PubMed

    Schuler, Eric R; Boals, Adriel

    2016-05-01

    Shattered Assumptions theory (Janoff-Bulman, 1992) posits that experiencing a traumatic event has the potential to diminish the degree of optimism in the assumptions of the world (assumptive world), which could lead to the development of posttraumatic stress disorder. Prior research assessed the assumptive world with a measure that was recently reported to have poor psychometric properties (Kaler et al., 2008). The current study had 3 aims: (a) to assess the psychometric properties of a recently developed measure of the assumptive world, (b) to retrospectively examine how prior adverse events affected the optimism of the assumptive world, and (c) to measure the impact of an intervening adverse event. An 8-week prospective design with a college sample (N = 882 at Time 1 and N = 511 at Time 2) was used to assess the study objectives. We split adverse events into those that were objectively or subjectively traumatic in nature. The new measure exhibited adequate psychometric properties. The report of a prior objective or subjective trauma at Time 1 was related to a less optimistic assumptive world. Furthermore, participants who experienced an intervening objectively traumatic event evidenced a decrease in optimistic views of the world compared with those who did not experience an intervening adverse event. We found support for Shattered Assumptions theory retrospectively and prospectively using a reliable measure of the assumptive world. We discuss future assessments of the measure of the assumptive world and clinical implications to help rebuild the assumptive world with current therapies. (PsycINFO Database Record

  3. Assessment of groundwater input and water quality changes impacting natural vegetation in the Loxahatchee River and floodplain ecosystem, Florida

    USGS Publications Warehouse

    Orem, William H.; Swarzenski, Peter W.; McPherson, Benjamin F.; Hedgepath, Marion; Lerch, Harry E.; Reich, Christopher; Torres, Arturo E.; Corum, Margo D.; Roberts, Richard E.

    2007-01-01

    The Loxahatchee River and Estuary are small, shallow, water bodies located in southeastern Florida. Historically, the Northwest Branch (Fork) of the Loxahatchee River was primarily a freshwater system. In 1947, the river inlet at Jupiter was dredged for navigation and has remained permanently open since that time. Drainage patterns within the basin have also been altered significantly due to land development, road construction (e.g., Florida Turnpike), and construction of the C-18 and other canals. These anthropogenic activities along with sea level rise have resulted in significant adverse impacts on the ecosystem over the last several decades, including increased saltwater encroachment and undesired vegetation changes in the floodplain. The problem of saltwater intrusion and vegetation degradation in the Loxahatchee River may be partly induced by diminished freshwater input, from both surface water and ground water into the River system. The overall objective of this project was to assess the seasonal surface water and groundwater interaction and the influence of the biogeochemical characteristics of shallow groundwater and porewater on vegetation health in the Loxahatchee floodplain. The hypothesis tested are: (1) groundwater influx constitutes a significant component of the overall flow of water into the Loxahatchee River; (2) salinity and other chemical constituents in shallow groundwater and porewater of the river floodplain may affect the distribution and health of the floodplain vegetation.

  4. Assessing the impact of chlorinated-solvent sites on metropolitan groundwater resources.

    PubMed

    Brusseau, Mark L; Narter, Matthew

    2013-01-01

    Chlorinated-solvent compounds are among the most common groundwater contaminants in the United States. A majority of the many sites contaminated by chlorinated-solvent compounds are located in metropolitan areas, and most such areas have one or more chlorinated-solvent contaminated sites. Thus, contamination of groundwater by chlorinated-solvent compounds may pose a potential risk to the sustainability of potable water supplies for many metropolitan areas. The impact of chlorinated-solvent sites on metropolitan water resources was assessed for Tucson, Arizona, by comparing the aggregate volume of extracted groundwater for all pump-and-treat systems associated with contaminated sites in the region to the total regional groundwater withdrawal. The analysis revealed that the aggregate volume of groundwater withdrawn for the pump-and-treat systems operating in Tucson, all of which are located at chlorinated-solvent contaminated sites, was 20% of the total groundwater withdrawal in the city for the study period. The treated groundwater was used primarily for direct delivery to local water supply systems or for reinjection as part of the pump-and-treat system. The volume of the treated groundwater used for potable water represented approximately 13% of the total potable water supply sourced from groundwater, and approximately 6% of the total potable water supply. This case study illustrates the significant impact chlorinated-solvent contaminated sites can have on groundwater resources and regional potable water supplies.

  5. The impact of groundwater depletions on groundwater surface water interactions and streamflow across the contiguous US

    NASA Astrophysics Data System (ADS)

    Condon, L. E.; Maxwell, R. M.

    2015-12-01

    Over the past 50 years, connections between climate change and streamflow trends have been observed in many regions of the Western US. However, much of the work to detect climate change signals in historical hydrologic records has focused on surface water changes in relatively undeveloped basins. While this is necessary to isolate any climate change signal from uncertain water management operations, it also excludes interactions with the concurrent human development that has occurred over the last 100 years. In highly utilized groundwater systems, such as the High Plains Aquifer, groundwater mining has already been linked to streamflow depletions at local to regional scales; but no prior studies have evaluated the role of groundwater declines in historical changes of groundwater surface water interactions at the continental scale. Here we isolate the influence of groundwater depletions from water management operations (e.g. irrigation and surface water diversions) to systematically evaluate how subsurface storage losses alter large-scale hydrologic interactions. Using a fully integrated groundwater surface water model of the contiguous US we simulate dynamic equilibrium conditions of a predevelopment system and a system with groundwater depletions equivalent to all of the groundwater development of the 20th century. Results illustrate the effect of persistent drawdown on streamflows, recharge and groundwater surface water exchanges across many spatial scales. In addition, we run transient simulations to evaluate the effect of these shifts on seasonal surface water variability. Simulations demonstrate the widespread trends in groundwater surface water interactions that have already resulted from ubiquitous groundwater mining in the United States and the potential for such changes to influence future response to climate variability.

  6. Isotope hydrology of deep groundwater in Syria: renewable and non-renewable groundwater and paleoclimate impact

    NASA Astrophysics Data System (ADS)

    Al-Charideh, A.; Kattaa, B.

    2016-02-01

    The Regional Deep Cretaceous Aquifer (RDCA) is the principal groundwater resource in Syria. Isotope and hydrochemical data have been used to evaluate the geographic zones in terms of renewable and non-renewable groundwater and the inter-relation between current and past recharge. The chemical and isotopic character of groundwater together with radiometric 14C data reflect the existence of three different groundwater groups: (1) renewable groundwater, in RDCA outcropping areas, in western Syria along the Coastal and Anti-Lebanon mountains. The mean δ18O value (-7.2 ‰) is similar to modern precipitation with higher 14C values (up to 60-80 pmc), implying younger groundwater (recent recharge); (2) semi-renewable groundwater, which is located in the unconfined section of the RDCA and parallel to the first zone. The mean δ18O value (-7.0 ‰) is also similar to modern precipitation with a 14C range of 15-45 pmc; (3) non-renewable groundwater found in most of the Syrian interior, where the RDCA becomes confined. A considerable depletion in δ18O (-8.0 ‰) relative to the modern rainfall and low values of 14C (<15 pmc) suggest that the large masses of deep groundwater are non-renewable and related to an older recharge period. The wide scatter of all data points around the two meteoric lines in the δ18O-δ2H diagram indicates considerable variation in recharge conditions. There is limited renewable groundwater in the mountain area, and most of the stored deep groundwater in the RDCA is non-renewable, with corrected 14C ages varying between 10 and 35 Kyr BP.

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

    NASA Astrophysics Data System (ADS)

    Brouyere, S.; Orban, P.; Hérivaux, C.

    2009-12-01

    In the next decades, groundwater managers will have to face regional degradation of the quantity and quality of groundwater under pressure of land-use and socio-economic changes. In this context, the objectives of the European Water Framework Directive require that groundwater be managed at the scale of the groundwater body, taking into account not only all components of the water cycle but also the socio-economic impact of these changes. One of the main challenges remains to develop robust and efficient numerical modeling applications at such a scale and to couple them with economic models, as a support for decision support in groundwater management. An integrated approach between hydrogeologists and economists has been developed by coupling the hydrogeological model SUFT3D and a cost-benefit economic analysis to study the impact of agricultural practices on groundwater quality and to design cost-effective mitigation measures to decrease nitrate pressure on groundwater so as to ensure the highest benefit to the society. A new modeling technique, the ‘Hybrid Finite Element Mixing Cell’ approach has been developed for large scale modeling purposes. The principle of this method is to fully couple different mathematical and numerical approaches to solve groundwater flow and solute transport problems. The mathematical and numerical approaches proposed allows an adaptation to the level of local hydrogeological knowledge and the amount of available data. In combination with long time series of nitrate concentrations and tritium data, the regional scale modelling approach has been used to develop a 3D spatially distributed groundwater flow and solute transport model for the Geer basin (Belgium) of about 480 km2. The model is able to reproduce the spatial patterns of nitrate concentrations together nitrate trends with time. The model has then been used to predict the future evolution of nitrate trends for two types of scenarios: (i) a “business as usual scenario

  8. Impact of Adverse Events Following Immunization in Viet Nam in 2013 on chronic hepatitis B infection.

    PubMed

    Li, Xi; Wiesen, Eric; Diorditsa, Sergey; Toda, Kohei; Duong, Thi Hong; Nguyen, Lien Huong; Nguyen, Van Cuong; Nguyen, Tran Hien

    2016-02-01

    Adverse Events Following Immunization in Viet Nam in 2013 led to substantial reductions in hepatitis B vaccination coverage (both the birth dose and the three-dose series). In order to estimate the impact of the reduction in vaccination coverage on hepatitis B transmission and future mortality, a widely-used mathematical model was applied to the data from Viet Nam. Using the model, we estimated the number of chronic infections and deaths that are expected to occur in the birth cohort in 2013 and the number of excessive infections and deaths attributable to the drop in immunization coverage in 2013. An excess of 90,137 chronic infections and 17,456 future deaths were estimated to occur in the 2013 birth cohort due to the drop in vaccination coverage. This analysis highlights the importance of maintaining high vaccination coverage and swiftly responding to reported Adverse Events Following Immunization in order to regain consumer confidence in the hepatitis B vaccine.

  9. Interaction between groundwater and trees in an arid site: Potential impacts of climate variation and groundwater abstraction on trees

    NASA Astrophysics Data System (ADS)

    Yin, Lihe; Zhou, Yangxiao; Huang, Jinting; Wenninger, Jochen; Zhang, Eryong; Hou, Guangcai; Dong, Jiaqiu

    2015-09-01

    The understanding of the interaction between groundwater and trees is vital for sustainable groundwater use and maintenance of a healthy ecosystem in arid regions. The short- and long-term groundwater contribution to tree water use was investigated using the HYDRUS-1D model and stable isotopes. For the short-term simulation, the ratio between the actual transpiration (Ta) and potential transpiration (Tp) approached almost ∼1.0 due to the constant groundwater uptake. The results from the short-term simulation indicated that the groundwater contribution to tree water use ranged between 53% and 56% in the dry season (May-June) and 16-19% in the wet period (August-September). Isotopic analysis indicated that groundwater contributed to 45% of plant water use in the dry season, decreasing to 4-12% during the wet period. Because of canopy interception and transpiration, groundwater recharge only occurred after heavy rainfall and accounted for 3-8% of the total heavy rainfall. For the long-term simulation, Ta/Tp ranged between 0.91 and 1.00 except in 2007 (0.78), when the water table declined because of groundwater abstraction. In the scenario simulation for deep water table conditions caused by anthropogenic activities, Ta/Tp ranged between 0.09 and 0.40 (mean = 0.22) that is significantly lower than the values in the natural conditions. In conclusion, vegetation restoration in arid zones should be cautious as over-planting of trees will decrease the groundwater recharge and potentially cause a rapid drop in water table levels, which in turn may result in the death of planted trees. Trees adapt to arid regions by adopting root patterns that allow soil water uptake by shallow roots and groundwater use by deep roots, thus climatic variation itself may not bring severe negative impact on trees. However, anthropogenic activities, such as groundwater abstraction, will result in significant water table decline that will reduce actual transpiration of trees significantly

  10. Emergency use of groundwater as a backup supply: Quantifying hydraulic impacts and economic benefits

    USGS Publications Warehouse

    Reichard, Eric G.; Li, Zhen; Hermans, Caroline

    2010-01-01

    Groundwater can play an important role in water-supply emergency planning. A framework is presented for assessing the hydraulic impacts and associated costs of using groundwater as a backup supply when imported-water deliveries are disrupted, and for quantifying the emergency benefits of groundwater management strategies that enable better response to such disruptions. Response functions are derived, which relate additional groundwater pumpage during water-supply emergencies to impacts such as increased pumping costs, subsidence, and seawater intrusion. Monte Carlo analysis is employed to estimate the incremental costs of using groundwater as a backup supply. The emergency benefits of alternative groundwater management strategies are computed for different expected durations of imported water disruption, percentages of imported water replaced by groundwater, and threshold drawdowns for subsidence impacts. The methodology is applied to the coastal Los Angeles Basin. For this case study, emergency benefits of artificial recharge strategies are dominated by reduction of potential subsidence costs. The variance of the results also is primarily due to subsidence effects. Incorporation of probability distributions reflecting a larger expected use of groundwater during the imported-water disruption results in higher estimated emergency benefits of artificial recharge strategies. The framework presented for quantifying incremental costs and economic benefits of using groundwater as a backup supply could be applied to a broad range of water emergency planning decisions.

  11. Doctors' experiences of adverse events in secondary care: the professional and personal impact.

    PubMed

    Harrison, Reema; Lawton, Rebecca; Stewart, Kevin

    2014-12-01

    We carried out a cross-sectional online survey of fellows and members of the Royal College of Physicians to establish physicians' experiences of adverse patient safety events and near misses, and the professional and personal impact of these. 1,755 physicians answered at least one question; 1,334 answered every relevant question. Of 1,463 doctors whose patients had an adverse event or near miss, 1,119 (76%) believed this had affected them personally or professionally. 1,077 (74%) reported stress, 995 (68%) anxiety, 840 (60%) sleep disturbance and 886 (63%) lower professional confidence. 1,192 (81%) became anxious about the potential for future errors. Of 1,141 who had used NHS incident reporting systems, only 315 (28%) were satisfied with this process. 201 (14%) received useful feedback, 201 (19%) saw local improvements and 277 (19%) saw system changes. 364 (25%) did not report an incident that they should have. Adverse safety events affect physicians, but few formal sources of support are available. Most doctors use incident-reporting systems, but many describe a lack of useful feedback, systems change or local improvement.

  12. Assessing planetary and regional nitrogen boundaries related to food security and adverse environmental impacts

    NASA Astrophysics Data System (ADS)

    de Vries, Wim; Kros, Hans; Kroeze, Carolien; Seitzinger, Sybil

    2014-05-01

    In this presentation, we first discuss the concept of -, governance interest in- and criticism on planetary boundaries, specifically with respect to the nitrogen (N) cycle. We then systematically evaluate the criticism and argue that planetary N boundaries need to include both the benefits and adverse impacts of reactive N (Nr) and the spatial variability of Nr impacts, in terms of shortage and surplus, being main arguments for not deriving such boundaries. Next, we present an holistic approach for an updated planetary N boundary by considering the need to: (i) avoid adverse impacts of elevated Nr emissions to water, air and soils, and (ii) feed the world population in an adequate way. The derivation of a planetary N boundary, in terms of anthropogenic fixation of di-nitrogen (N2) by growing legumes and production of N fertilizer, is illustrated by (i) identification of multiple threat N indicators and setting critical limits for them, (ii) back calculating critical N losses from critical limits for N indicators, while accounting for the spatial variability of indicators and their exceedance and (iii) back calculating critical N fixation rates from critical N losses. The derivation of the needed planetary N fixation is assessed from the global population, the recommended dietary N consumption per capita and the N use efficiency in the complete chain from N fixation to N consumption. Results of example applications show that the previously suggested planetary N boundary of 25% of the current value is too low in view of needed N fixation and also unnecessary in view of most environmental impacts. We also illustrate the impacts of changes in the N use efficiency on planetary boundaries in terms of critical N fixation rates.

  13. Impact of Preservation of Subsoil Water Act on Groundwater Depletion: The Case of Punjab, India

    NASA Astrophysics Data System (ADS)

    Tripathi, Amarnath; Mishra, Ashok K.; Verma, Geetanjali

    2016-07-01

    Indian states like Punjab and Haryana, epicenters of the Green Revolution, are facing severe groundwater shortages and falling water tables. Recognizing it as a serious concern, the Government of Punjab enacted the Punjab Preservation of Subsoil Water Act in 2009 (or the 2009 act) to slow groundwater depletion. The objective of this study is to assess the impact of this policy on groundwater depletion, using panel data from 1985 to 2011. Results from this study find a robust effect of the 2009 act on reducing groundwater depletion. Our models for pre-monsoon, post-monsoon, and overall periods of analysis find that since implementation of the 2009 act, groundwater tables have improved significantly. Second, our study reveals that higher shares of tube wells per total cropped area and increased population density have led to a significant decline in the groundwater tables. On the other hand, rainfall and the share of area irrigated by surface water have had an augmenting effect on groundwater resources. In the two models, pre-monsoon and post-monsoon, this study shows that seasonality plays a key role in determining the groundwater table in Punjab. Specifically, monsoon rainfall has a very prominent impact on groundwater.

  14. Assessment of groundwater quality in Puri City, India: an impact of anthropogenic activities.

    PubMed

    Vijay, Ritesh; Khobragade, Puja; Mohapatra, P K

    2011-06-01

    Puri City is situated on the east coast of India and receives water supply only from the groundwater sources demarcated as water fields. The objective of this paper is to assess and evaluate the groundwater quality due to impact of anthropogenic activities in the city. Groundwater samples were collected from the water fields, hand pumps, open wells, and open water bodies during post-monsoon 2006 and summer 2007. Groundwater quality was evaluated with drinking water standards as prescribed by Bureau of Indian Standards and Environmental Protection Agency to assess the suitability. The study indicated seasonal variation of water-quality parameters within the water fields and city area. Groundwater in the water fields was found to be suitable for drinking after disinfection. While in city area, groundwater quality was impacted by onsite sanitary conditions. The study revealed that groundwater quality was deteriorated due to the discharge of effluent from septic tanks, soak pits, pit latrines, discharges of domestic wastewater in leaky drains, and leachate from solid waste dumpsite. Based on observed groundwater quality, various mitigation measures were suggested to protect the water fields and further groundwater contamination in the city. PMID:20714928

  15. Assessment of groundwater quality in Puri City, India: an impact of anthropogenic activities.

    PubMed

    Vijay, Ritesh; Khobragade, Puja; Mohapatra, P K

    2011-06-01

    Puri City is situated on the east coast of India and receives water supply only from the groundwater sources demarcated as water fields. The objective of this paper is to assess and evaluate the groundwater quality due to impact of anthropogenic activities in the city. Groundwater samples were collected from the water fields, hand pumps, open wells, and open water bodies during post-monsoon 2006 and summer 2007. Groundwater quality was evaluated with drinking water standards as prescribed by Bureau of Indian Standards and Environmental Protection Agency to assess the suitability. The study indicated seasonal variation of water-quality parameters within the water fields and city area. Groundwater in the water fields was found to be suitable for drinking after disinfection. While in city area, groundwater quality was impacted by onsite sanitary conditions. The study revealed that groundwater quality was deteriorated due to the discharge of effluent from septic tanks, soak pits, pit latrines, discharges of domestic wastewater in leaky drains, and leachate from solid waste dumpsite. Based on observed groundwater quality, various mitigation measures were suggested to protect the water fields and further groundwater contamination in the city.

  16. Impact of Preservation of Subsoil Water Act on Groundwater Depletion: The Case of Punjab, India.

    PubMed

    Tripathi, Amarnath; Mishra, Ashok K; Verma, Geetanjali

    2016-07-01

    Indian states like Punjab and Haryana, epicenters of the Green Revolution, are facing severe groundwater shortages and falling water tables. Recognizing it as a serious concern, the Government of Punjab enacted the Punjab Preservation of Subsoil Water Act in 2009 (or the 2009 act) to slow groundwater depletion. The objective of this study is to assess the impact of this policy on groundwater depletion, using panel data from 1985 to 2011. Results from this study find a robust effect of the 2009 act on reducing groundwater depletion. Our models for pre-monsoon, post-monsoon, and overall periods of analysis find that since implementation of the 2009 act, groundwater tables have improved significantly. Second, our study reveals that higher shares of tube wells per total cropped area and increased population density have led to a significant decline in the groundwater tables. On the other hand, rainfall and the share of area irrigated by surface water have had an augmenting effect on groundwater resources. In the two models, pre-monsoon and post-monsoon, this study shows that seasonality plays a key role in determining the groundwater table in Punjab. Specifically, monsoon rainfall has a very prominent impact on groundwater.

  17. Impact of Preservation of Subsoil Water Act on Groundwater Depletion: The Case of Punjab, India.

    PubMed

    Tripathi, Amarnath; Mishra, Ashok K; Verma, Geetanjali

    2016-07-01

    Indian states like Punjab and Haryana, epicenters of the Green Revolution, are facing severe groundwater shortages and falling water tables. Recognizing it as a serious concern, the Government of Punjab enacted the Punjab Preservation of Subsoil Water Act in 2009 (or the 2009 act) to slow groundwater depletion. The objective of this study is to assess the impact of this policy on groundwater depletion, using panel data from 1985 to 2011. Results from this study find a robust effect of the 2009 act on reducing groundwater depletion. Our models for pre-monsoon, post-monsoon, and overall periods of analysis find that since implementation of the 2009 act, groundwater tables have improved significantly. Second, our study reveals that higher shares of tube wells per total cropped area and increased population density have led to a significant decline in the groundwater tables. On the other hand, rainfall and the share of area irrigated by surface water have had an augmenting effect on groundwater resources. In the two models, pre-monsoon and post-monsoon, this study shows that seasonality plays a key role in determining the groundwater table in Punjab. Specifically, monsoon rainfall has a very prominent impact on groundwater. PMID:27015967

  18. Evaluating impacts of subdivision density on shallow groundwater in Southeastern Wisconsin, USA

    USGS Publications Warehouse

    Rayne, T.W.; Bradbury, K.R.

    2011-01-01

    Using simple numerical groundwater flow models, we tested the impacts of suburban developments on groundwater levels and discharge to streams. We used lot sizes of 1, 3 and 5 acres (4000, 12,000 and 20,000 m2) with one domestic well per lot that pumped water from shallow aquifers. Our modelling showed that pumping had little impact on water levels and groundwater discharge to streams if the developed area is of a moderate size. However, domestic wells had the potential to impact local groundwater levels and baseflows in large developments. In township-wide development scenarios of 1-acre (4000 m2) lots, simulated drawdowns beneath developed areas ranged from 1 to 18 ft (0.3 to 5.5 m), and baseflow reductions ranged from 20 to 40%. Impacts generally were inversely proportional to lot size, recharge rate and hydraulic conductivity of the aquifer materials. Developments using individual domestic wells have the potential to impact local groundwater levels and surface water features. The impacts can range from negligible to severe, depending on local hydrogeologic conditions and on whether wastewater is recharged onsite or is removed from the basin. An assessment of groundwater impacts should be a part of the planning process for all suburban developments. ?? 2011 University of Newcastle upon Tyne.

  19. Salinity Impacts on Agriculture and Groundwater in Delta Regions

    NASA Astrophysics Data System (ADS)

    Clarke, D.; Salehin, M.; Jairuddin, M.; Saleh, A. F. M.; Rahman, M. M.; Parks, K. E.; Haque, M. A.; Lázár, A. N.; Payo, A.

    2015-12-01

    Delta regions are attractive for high intensity agriculture due to the availability of rich sedimentary soils and of fresh water. Many of the world's tropical deltas support high population densities which are reliant on irrigated agriculture. However environmental changes such as sea level rise, tidal inundation and reduced river flows have reduced the quantity and quality of water available for successful agriculture. Additionally, anthropogenic influences such as the over abstraction of ground water and the increased use of low quality water from river inlets has resulted in the accumulation of salts in the soils which diminishes crop productivity. Communities based in these regions are usually reliant on the same water for drinking and cooking because surface water is frequently contaminated by commercial and urban pollution. The expansion of shallow tube well systems for drinking water and agricultural use over the last few decades has resulted in mobilisation of salinity in the coastal and estuarine fringes. Sustainable development in delta regions is becoming constrained by water salinity. However salinity is often studied as an independent issue by specialists working in the fields of agriculture, community water supply and groundwater. The lack of interaction between these disciplines often results in corrective actions being applied to one sector without fully assessing the effects of these actions on other sectors. This paper describes a framework for indentifying the causes and impacts of salinity in delta regions based on the source-pathway-receptor framework. It uses examples and scenarios from the Ganges-Brahmaputra-Meghna delta in Bangladesh together with field measurements and observations made in vulnerable coastal communities. The paper demonstrates the importance of creating an holistic understanding of the development and management of water resources to reduce the impact of salinity in fresh water in delta regions.

  20. Impact of hurricanes storm surges on the groundwater resources

    USGS Publications Warehouse

    Van Biersel, T. P.; Carlson, D.A.; Milner, L.R.

    2007-01-01

    Ocean surges onto coastal lowlands caused by tropical and extra tropical storms, tsunamis, and sea level rise affect all coastal lowlands and present a threat to drinking water resources of many coastal residents. In 2005, two such storms, Hurricanes Katrina and Rita struck the Gulf Coast of the US. Since September 2005, water samples have been collected from water wells impacted by the hurricanes' storm surges along the north shore of Lake Pontchartrain in southeastern Louisiana. The private and public water wells tested were submerged by 0.6-4.5 m of surging saltwater for several hours. The wells' casing and/or the associated plumbing were severely damaged. Water samples were collected to determine if storm surge water inundated the well casing and, if so, its effect on water quality within the shallow aquifers of the Southern Hills Aquifer System. In addition, the samples were used to determine if the impact on water quality may have long-term implication for public health. Laboratory testing for several indicator parameters (Ca/Mg, Cl/Si, chloride, boron, specific conductance and bacteria) indicates that surge water entered water wells' casing and the screened aquifer. Analysis of the groundwater shows a decrease in the Ca/Mg ratio right after the storm and then a return toward pre-Katrina values. Chloride concentrations were elevated right after Katrina and Rita, and then decreased downward toward pre-Katrina values. From September 2005 to June 2006, the wells showed improvement in all the saltwater intrusion indicators. ?? 2007 Springer-Verlag.

  1. Cl/Br ratios and chlorine isotope evidences for groundwater salinization and its impact on groundwater arsenic, fluoride and iodine enrichment in the Datong basin, China.

    PubMed

    Li, Junxia; Wang, Yanxin; Xie, Xianjun

    2016-02-15

    In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250 mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000-10,000 mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ(37)Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility.

  2. Cl/Br ratios and chlorine isotope evidences for groundwater salinization and its impact on groundwater arsenic, fluoride and iodine enrichment in the Datong basin, China.

    PubMed

    Li, Junxia; Wang, Yanxin; Xie, Xianjun

    2016-02-15

    In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250 mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000-10,000 mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ(37)Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility. PMID:26657361

  3. Annual Research Review: Positive adjustment to adversity -Trajectories of minimal-impact resilience and emergent resilience

    PubMed Central

    Bonanno, George A.; Diminich, Erica D.

    2012-01-01

    Background Research on resilience in the aftermath of potentially traumatic life events is still evolving. For decades researchers have documented resilience in children exposed to corrosive early environments, such as poverty or chronic maltreatment. Relatively more recently the study of resilience has migrated to the investigation of isolated and potentially traumatic life events (PTE) in adults. Methods In this article we first consider some of the key differences in the conceptualization of resilience following chronic adversity versus resilience following single-incident traumas, and then describe some of the misunderstandings that have developed about these constructs. To organize our discussion we introduce the terms emergent resilience and minimal-impact resilience to represent trajectories positive adjustment in these two domains, respectively. Results We focused in particular on minimal-impact resilience, and reviewed recent advances in statistical modeling of latent trajectories that have informed the most recent research on minimal-impact resilience in both children and adults and the variables that predict it, including demographic variables, exposure, past and current stressors, resources, personality, positive emotion, coping and appraisal, and flexibility in coping and emotion regulation. Conclusions The research on minimal impact resilience is nascent. Further research is warranted with implications for a multiple levels of analysis approach to elucidate the processes that may mitigate or modify the impact of a PTE at different developmental stages. PMID:23215790

  4. Zonal management of multi-purposes groundwater utilization based on water quality and impact on the aquifer.

    PubMed

    Liang, Ching-Ping; Jang, Cheng-Shin; Chen, Ching-Fang; Chen, Jui-Sheng

    2016-07-01

    Groundwater is widely used for drinking, irrigation, and aquaculture in the Pingtung Plain, Southwestern Taiwan. The overexploitation and poor quality of groundwater in some areas of the Pingtung Plain pose great challenges for the safe use and sustainable management of groundwater resources. Thus, establishing an effective management plan for multi-purpose groundwater utilization in the Pingtung Plain is imperative. Considerations of the quality of the groundwater and potential impact on the aquifer of groundwater exploitation are paramount to multi-purpose groundwater utilization management. This study proposes a zonal management plan for the multi-purpose use of groundwater in the Pingtung Plain. The zonal management plan is developed by considering the spatial variability of the groundwater quality and the impact on the aquifer, which is defined as the ratio of the actual groundwater extraction rate to transmissivity. A geostatistical Kriging approach is used to spatially delineate the safe zones based on the water quality standards applied in the three groundwater utilization sectors. Suitable zones for the impact on the aquifer are then spatially determined. The evaluation results showing the safe water quality zones for the three types of utilization demands and suitable zones for the impact on aquifer are integrated to create a zonal management map for multi-purpose groundwater utilization which can help government administrators to establish a water resource management strategy for safe and sustainable use of groundwater to meet multi-purpose groundwater utilization requirements in the Pingtung Plain.

  5. Zonal management of multi-purposes groundwater utilization based on water quality and impact on the aquifer.

    PubMed

    Liang, Ching-Ping; Jang, Cheng-Shin; Chen, Ching-Fang; Chen, Jui-Sheng

    2016-07-01

    Groundwater is widely used for drinking, irrigation, and aquaculture in the Pingtung Plain, Southwestern Taiwan. The overexploitation and poor quality of groundwater in some areas of the Pingtung Plain pose great challenges for the safe use and sustainable management of groundwater resources. Thus, establishing an effective management plan for multi-purpose groundwater utilization in the Pingtung Plain is imperative. Considerations of the quality of the groundwater and potential impact on the aquifer of groundwater exploitation are paramount to multi-purpose groundwater utilization management. This study proposes a zonal management plan for the multi-purpose use of groundwater in the Pingtung Plain. The zonal management plan is developed by considering the spatial variability of the groundwater quality and the impact on the aquifer, which is defined as the ratio of the actual groundwater extraction rate to transmissivity. A geostatistical Kriging approach is used to spatially delineate the safe zones based on the water quality standards applied in the three groundwater utilization sectors. Suitable zones for the impact on the aquifer are then spatially determined. The evaluation results showing the safe water quality zones for the three types of utilization demands and suitable zones for the impact on aquifer are integrated to create a zonal management map for multi-purpose groundwater utilization which can help government administrators to establish a water resource management strategy for safe and sustainable use of groundwater to meet multi-purpose groundwater utilization requirements in the Pingtung Plain. PMID:27343131

  6. Climate change impact on shallow groundwater conditions in Hungary: Conclusions from a regional modelling study

    NASA Astrophysics Data System (ADS)

    Kovács, Attila; Marton, Annamária; Tóth, György; Szöcs, Teodóra

    2016-04-01

    A quantitative methodology has been developed for the calculation of groundwater table based on measured and simulated climate parameters. The aim of the study was to develop a toolset which can be used for the calculation of shallow groundwater conditions for various climate scenarios. This was done with the goal of facilitating the assessment of climate impact and vulnerability of shallow groundwater resources. The simulated groundwater table distributions are representative of groundwater conditions at the regional scale. The introduced methodology is valid for modelling purposes at various scales and thus represents a versatile tool for the assessment of climate vulnerability of shallow groundwater bodies. The calculation modules include the following: 1. A toolset to calculate climate zonation from climate parameter grids, 2. Delineation of recharge zones (Hydrological Response Units, HRUs) based on geology, landuse and slope conditions, 3. Calculation of percolation (recharge) rates using 1D analytical hydrological models, 4. Simulation of the groundwater table using numerical groundwater flow models. The applied methodology provides a quantitative link between climate conditions and shallow groundwater conditions, and thus can be used for assessing climate impacts. The climate data source applied in our calculation comprised interpolated daily climate data of the Central European CARPATCLIM database. Climate zones were determined making use of the Thorntwaite climate zonation scheme. Recharge zones (HRUs) were determined based on surface geology, landuse and slope conditions. The HELP hydrological model was used for the calculation of 1D water balance for hydrological response units. The MODFLOW numerical groundwater modelling code was used for the calculation of the water table. The developed methodology was demonstrated through the simulation of regional groundwater table using spatially averaged climate data and hydrogeological properties for various time

  7. Positive and negative impacts of five Austrian gravel pit lakes on groundwater quality.

    PubMed

    Muellegger, Christian; Weilhartner, Andreas; Battin, Tom J; Hofmann, Thilo

    2013-01-15

    Groundwater-fed gravel pit lakes (GPLs) affect the biological, organic, and inorganic parameters of inflowing groundwater through combined effects of bank filtration at the inflow, reactions within the lake, and bank filtration at the outflow. GPLs result from wet dredging for sand and gravel and may conflict with groundwater protection programs by removing the protective soil cover and exposing groundwater to the atmosphere. We have investigated the impact on groundwater of five GPLs with different sizes, ages, and mean residence times, and all having low post-excavation anthropogenic usage. The results revealed highly active biological systems within the lake water, in which primary producers significantly reduced inflowing nitrate concentrations. Decalcification also occurred in lake water, reducing water hardness, which could be beneficial for waterworks in hard groundwater areas. Downgradient groundwater nitrate and calcium concentrations were found to be stable, with only minor seasonal variations. Biological degradation of organic material and organic micropollutants was also observed in the GPLs. For young GPLs adequate sediment deposits may not yet have formed and degradation processes at the outflow may consequently not yet be well established. However, our results showed that within 5 years from the cessation of excavation a protective sediment layer is established that is sufficient to prevent the export of dissolved organic carbon to downgradient groundwater. GPLs can improve groundwater quality in anthropogenically (e.g., pesticides and nitrate) or geologically (e.g., hardness) challenging situations. However, post-excavation usage of GPLs is often dominated by human activities such as recreational activities, water sports, or fish farming. These activities will affect lake and groundwater quality and the risks involved are difficult to predict and monitor and can lead to overall negative impacts on groundwater quality. PMID:23178886

  8. Estimating impacts of land use on groundwater quality using trilinear analysis.

    PubMed

    Ouyang, Ying; Zhang, Jia En; Cui, Lihua

    2014-09-01

    Groundwater is connected to the landscape above and is thus affected by the overlaying land uses. This study evaluated the impacts of land uses upon groundwater quality using trilinear analysis. Trilinear analysis is a display of experimental data in a triangular graph. Groundwater quality data collected from agricultural, septic tank, forest, and wastewater land uses for a 6-year period were used for the analysis. Results showed that among the three nitrogen species (i.e., nitrate and nitrite (NO(x)), dissolved organic nitrogen (DON), and total organic nitrogen (TON)), NO(x) had a high percentage and was a dominant species in the groundwater beneath the septic tank lands, whereas TON was a major species in groundwater beneath the forest lands. Among the three phosphorus species, namely the particulate phosphorus (PP), dissolved ortho phosphorus (PO4(3-)) and dissolved organic phosphorus (DOP), there was a high percentage of PP in the groundwater beneath the septic tank, forest, and agricultural lands. In general, Ca was a dominant cation in the groundwater beneath the septic tank lands, whereas Na was a dominant cation in the groundwater beneath the forest lands. For the three major anions (i.e., F(-), Cl(-), and SO4(2-)), F(-) accounted for <1% of the total anions in the groundwater beneath the forest, wastewater, and agricultural lands. Impacts of land uses on groundwater Cd and Cr distributions were not profound. This study suggests that trilinear analysis is a useful technique to characterize the relationship between land use and groundwater quality.

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

    PubMed

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

    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. PMID:26745299

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

    PubMed

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

    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.

  11. Impact of groundwater use as heat energy on coastal ecosystem and fisheries

    NASA Astrophysics Data System (ADS)

    Taniguchi, Makoto

    2016-04-01

    Demands for groundwater as a heat energy source to melt snow is increasing in many coastal snowy areas in Japan because of the lack of laborers for snow removal and the abundance of groundwater resources. The temperature of groundwater is relatively higher in winter than that of the air and river water, therefore it is a useful heat source to melt snow. However, groundwater is also beneficial for the coastal ecosystem and fishery production because of the nutrient discharge by submarine groundwater discharge (SGD), which is one of the water and dissolved material pathways from land to the ocean. Therefore, groundwater is involved in the tradeoff and management conflict existing between energy and food (fisheries). In this study, the impact of groundwater, used as a heat energy source for the melting of snow accumulated on roads, on the coastal ecosystem and fisheries has been analyzed in the snowy areas of Obama City, Fukui Prefecture, Japan. Positive correlation has been found between primary production rates in Obama Bay and radon concentrations which show the magnitude of the submarine groundwater discharge. Therefore, the increase in groundwater pumping on land reduces fishery production in the ocean. Results of 3D numerical simulations of the basin scale groundwater model show a reduction of SGD by 5 percent due to an increase in groundwater pumping by 1.5 times. This reduction of SGD caused a 3.7 ton decrease in fishery production under the aforementioned assumptions. The groundwater-energy-fishery nexus was found in Obama Bay, Japan and the tradeoff between water and food was evaluated.

  12. Evaluation of groundwater chemistry and its impact on drinking and irrigation water quality in the eastern part of the Central Arabian graben and trough system, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Zaidi, Faisal K.; Mogren, Saad; Mukhopadhyay, Manoj; Ibrahim, Elkhedr

    2016-08-01

    The present study deals with the assessment of groundwater with respect to the main hydrological processes controlling its chemistry and its subsequent impact on groundwater quality for drinking and irrigation purposes in the eastern part of the Central Arabian graben and trough system. Groundwater samples were collected from 73 bore wells tapping the Cretaceous Biyadh and Wasia sandstone aquifers. The main groundwater facies in the area belong to the mixed Casbnd Mgsbnd SO4/Cl type and the SO4sbnd Cl type. Prolonged rock water interaction has resulted in high TDS (average of 2131 mg/l) and high EC (average of 2725 μS/cm) of the groundwater. The average nitrate (56.38 mg/l) value in the area is higher than the WHO prescribed limits of 50 mg/l in drinking water and is attributed to agricultural activities. The Drinking Water Quality Index (DWQI) shows that 33% of the water samples fall within the excellent to good category whereas the remaining samples fall in the poor to unsuitable for drinking category. In terms of Sodium Adsorption Ratio (SAR), Sodium percentage (Na %) and Residual Sodium Carbonate (RSC) the groundwater is suitable for irrigation however the high salinity values can adversely affect the plant physiology.

  13. Evaluation of groundwater chemistry and its impact on drinking and irrigation water quality in the eastern part of the Central Arabian graben and trough system, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Zaidi, Faisal K.; Mogren, Saad; Mukhopadhyay, Manoj; Ibrahim, Elkhedr

    2016-08-01

    The present study deals with the assessment of groundwater with respect to the main hydrological processes controlling its chemistry and its subsequent impact on groundwater quality for drinking and irrigation purposes in the eastern part of the Central Arabian graben and trough system. Groundwater samples were collected from 73 bore wells tapping the Cretaceous Biyadh and Wasia sandstone aquifers. The main groundwater facies in the area belong to the mixed Casbnd Mgsbnd SO4/Cl type and the SO4sbnd Cl type. Prolonged rock water interaction has resulted in high TDS (average of 2131 mg/l) and high EC (average of 2725 μS/cm) of the groundwater. The average nitrate (56.38 mg/l) value in the area is higher than the WHO prescribed limits of 50 mg/l in drinking water and is attributed to agricultural activities. The Drinking Water Quality Index (DWQI) shows that 33% of the water samples fall within the excellent to good category whereas the remaining samples fall in the poor to unsuitable for drinking category. In terms of Sodium Adsorption Ratio (SAR), Sodium percentage (Na %) and Residual Sodium Carbonate (RSC) the groundwater is suitable for irrigation however the high salinity values can adversely affect the plant physiology.

  14. Hydrochemistry of urban groundwater, Seoul, Korea: The impact of subway tunnels on groundwater quality

    NASA Astrophysics Data System (ADS)

    Chae, Gi-Tak; Yun, Seong-Taek; Choi, Byoung-Young; Yu, Soon-Young; Jo, Ho-Young; Mayer, Bernhard; Kim, Yun-Jong; Lee, Jin-Yong

    2008-10-01

    Hydrogeologic and hydrochemical data for subway tunnel seepage waters in Seoul (Republic of Korea) were examined to understand the effect of underground tunnels on the degradation of urban groundwater. A very large quantity of groundwater (up to 63 million m 3 year - 1 ) is discharged into subway tunnels with a total length of 287 km, resulting in a significant drop of the local groundwater table and the abandonment of groundwater wells. For the tunnel seepage water samples ( n = 72) collected from 43 subway stations, at least one parameter among pathogenic microbes (total coliform, heterotrophic bacteria), dissolved Mn and Fe, NH 4+, NO 3-, turbidity, and color exceeded the Korean Drinking Water Standards. Locally, tunnel seepage water was enriched in dissolved Mn (avg. 0.70 mg L - 1 , max. 5.58 mg L - 1 ), in addition to dissolved Fe, NH 4+, and pathogenic microbes, likely due to significant inflow of sewage water from broken or leaking sewer pipes. Geochemical modeling of redox reactions was conducted to simulate the characteristic hydrochemistry of subway tunnel seepage. The results show that variations in the reducing conditions occur in urban groundwater, dependent upon the amount of organic matter-rich municipal sewage contaminating the aquifer. The organic matter facilitates the reduction and dissolution of Mn- and Fe-bearing solids in aquifers and/or tunnel construction materials, resulting in the successive increase of dissolved Mn and Fe. The present study clearly demonstrates that locally significant deterioration of urban groundwater is caused by a series of interlinked hydrogeologic and hydrochemical changes induced by underground tunnels.

  15. Hydrochemistry of urban groundwater, Seoul, Korea: the impact of subway tunnels on groundwater quality.

    PubMed

    Chae, Gi-Tak; Yun, Seong-Taek; Choi, Byoung-Young; Yu, Soon-Young; Jo, Ho-Young; Mayer, Bernhard; Kim, Yun-Jong; Lee, Jin-Yong

    2008-10-23

    Hydrogeologic and hydrochemical data for subway tunnel seepage waters in Seoul (Republic of Korea) were examined to understand the effect of underground tunnels on the degradation of urban groundwater. A very large quantity of groundwater (up to 63 million m3 year(-1)) is discharged into subway tunnels with a total length of 287 km, resulting in a significant drop of the local groundwater table and the abandonment of groundwater wells. For the tunnel seepage water samples (n = 72) collected from 43 subway stations, at least one parameter among pathogenic microbes (total coliform, heterotrophic bacteria), dissolved Mn and Fe, NH4+, NO3(-), turbidity, and color exceeded the Korean Drinking Water Standards. Locally, tunnel seepage water was enriched in dissolved Mn (avg. 0.70 mg L(-1), max. 5.58 mg L(-1)), in addition to dissolved Fe, NH4+, and pathogenic microbes, likely due to significant inflow of sewage water from broken or leaking sewer pipes. Geochemical modeling of redox reactions was conducted to simulate the characteristic hydrochemistry of subway tunnel seepage. The results show that variations in the reducing conditions occur in urban groundwater, dependent upon the amount of organic matter-rich municipal sewage contaminating the aquifer. The organic matter facilitates the reduction and dissolution of Mn- and Fe-bearing solids in aquifers and/or tunnel construction materials, resulting in the successive increase of dissolved Mn and Fe. The present study clearly demonstrates that locally significant deterioration of urban groundwater is caused by a series of interlinked hydrogeologic and hydrochemical changes induced by underground tunnels. PMID:18725171

  16. Hydrochemistry of urban groundwater, Seoul, Korea: the impact of subway tunnels on groundwater quality.

    PubMed

    Chae, Gi-Tak; Yun, Seong-Taek; Choi, Byoung-Young; Yu, Soon-Young; Jo, Ho-Young; Mayer, Bernhard; Kim, Yun-Jong; Lee, Jin-Yong

    2008-10-23

    Hydrogeologic and hydrochemical data for subway tunnel seepage waters in Seoul (Republic of Korea) were examined to understand the effect of underground tunnels on the degradation of urban groundwater. A very large quantity of groundwater (up to 63 million m3 year(-1)) is discharged into subway tunnels with a total length of 287 km, resulting in a significant drop of the local groundwater table and the abandonment of groundwater wells. For the tunnel seepage water samples (n = 72) collected from 43 subway stations, at least one parameter among pathogenic microbes (total coliform, heterotrophic bacteria), dissolved Mn and Fe, NH4+, NO3(-), turbidity, and color exceeded the Korean Drinking Water Standards. Locally, tunnel seepage water was enriched in dissolved Mn (avg. 0.70 mg L(-1), max. 5.58 mg L(-1)), in addition to dissolved Fe, NH4+, and pathogenic microbes, likely due to significant inflow of sewage water from broken or leaking sewer pipes. Geochemical modeling of redox reactions was conducted to simulate the characteristic hydrochemistry of subway tunnel seepage. The results show that variations in the reducing conditions occur in urban groundwater, dependent upon the amount of organic matter-rich municipal sewage contaminating the aquifer. The organic matter facilitates the reduction and dissolution of Mn- and Fe-bearing solids in aquifers and/or tunnel construction materials, resulting in the successive increase of dissolved Mn and Fe. The present study clearly demonstrates that locally significant deterioration of urban groundwater is caused by a series of interlinked hydrogeologic and hydrochemical changes induced by underground tunnels.

  17. Impact of climate on groundwater recharge in the crystalline basement rocks aquifer of Northern Ghana

    NASA Astrophysics Data System (ADS)

    Koffi, K. V.

    2015-12-01

    Water is the cornerstone of human life and for all economic developments. West Africa and specifically Ghana are no exception to this reality.Northern Ghana is characterized by a semi-arid climate, with prolonged dry season (7 months of very few rainfall) leading to the drying up of many rivers and streams. In addition, rainfall is highly variable in space and time. Therefore, surface water is unreliable and insufficient to meet the water demands for socio-economic development in this area. As a result, the area is heavily dependent on groundwater for domestic water supply as well as for dry season irrigation of vegetables (cash crops).However, aquifers in northern Ghana are dominantly the hard rock type (Crystalline basement rock). This aquifer has no primary porosity and may not be able to sustain the increasing demand on the resource. Further, climate change may worsen the situation as recharge is dependent on rainfall in northern Ghana. Therefore, it is important to understand exactly how climate change will impact on recharge to the groundwater for sustainable development and management of the resource.Previous groundwater studies in Northern Ghana barely analyzed the combined impacts of Climate change on the recharge to the groundwater. This research is aimed at determining the current relationship between groundwater recharge and rainfall and to use the relationships to determine the impacts of changes in climate on the groundwater recharge. The results will inform plans and strategies for sustainably managing groundwater resources in Ghana and the Volta basin.

  18. [Medication adverse events: Impact of pharmaceutical consultations during the hospitalization of patients].

    PubMed

    Santucci, R; Levêque, D; Herbrecht, R; Fischbach, M; Gérout, A C; Untereiner, C; Bouayad-Agha, K; Couturier, F

    2014-11-01

    The medication iatrogenic events are responsible for nearly one iatrogenic event in five. The main purpose of this prospective multicenter study is to determine the effect of pharmaceutical consultations on the occurrence of medication adverse events during hospitalization (MAE). The other objectives are to study the impact of age, of the number of medications and pharmaceutical consultations on the risk of MAE. The pharmaceutical consultation is associated to a complete reassessment done by both a physician and a pharmacist for the home medication, the hospital treatment (3days after admission), the treatment during chemotherapy, and/or, the treatment when the patient goes back home. All MAE are subject to an advice for the patient, additional clinical-biological monitoring and/or prescription changes. Among the 318 patients, 217 (68%) had 1 or more clinically important MAE (89% drug-drug interaction, 8% dosing error, 2% indication error, 1% risk behavior). The patients have had 1121 pharmaceutical consultations (3.2±1.4/patient). Thus, the pharmaceutical consultations divided by 2.34 the risk of MAE (unadjusted incidence ratio, P≤0.05). Each consultation decreased by 24% the risk of MAE. Moreover, adding one medication increases from 14 to 30% as a risk of MAE on the population. Pharmaceutical consultations during the hospital stay could reduce significantly the number of medication adverse effects. PMID:25438655

  19. The impact of glacial fluctuations on the shallow proglacial groundwater systems of two SE Icelandic glaciers.

    NASA Astrophysics Data System (ADS)

    Levy, A.; Robinson, Z.; Krause, S.; Waller, R.

    2012-04-01

    Groundwater represents a key component of the complex hydrological processes of glaciated basins, where models project significant changes in glacial extent and mass balance. Exchange fluxes between groundwater and surface water can significantly impact discharge and stream level dynamics, biogeochemical cycling and aquifer and river habitat conditions. Understanding the spatial patterns and temporal dynamics of groundwater - surface water exchange fluxes is important for effective water resources management, especially considering the increasing pressures on groundwater and surface water systems resulting from environmental changes. This study investigates the shallow groundwater systems at two proglacial locations in SE Iceland. Impacted by the interaction between volcanic activity and glaciers, Skeiðarársandur is the world's largest active proglacial outwash plain (sandur). Skeiðarársandur contains an extensive unconfined aquifer whose thickness varies between 100-250m. Skaftafellsjökull, the second site of investigation, is a temperate valley glacier. This site is dominated by moraines and confined channels. Vegetation cover is higher than on the sandur. Groundwater seepage at both sites have potential impacts on eco-hydrological habitat conditions. Automated groundwater monitoring took place between July - mid August 2011. Preliminary results suggest strong coupling between rivers and the aquifer. This was illustrated by an increase in groundwater level following high, episodic increases in the discharge of the river Súla, western Skeiðarársandur. Results from the Skaftafellsjökull margin also suggest high river-aquifer coupling. A strong diurnal signal was detected in a well located between a large groundwater-fed lake and the glacial-fed river Skaftafellsà. Fluctuations in groundwater level, temperature and EC suggest strong response of the aquifer to changes in river level. This was illustrated during a flood event, in which an increase in

  20. The impact of food and agricultural policies on groundwater use in Syria

    NASA Astrophysics Data System (ADS)

    Aw-Hassan, Aden; Rida, Fadel; Telleria, Roberto; Bruggeman, Adriana

    2014-05-01

    During the last three decades, the expansion of irrigation using both surface water and groundwater resources has had an important positive impact on Syria’s agricultural production. It is an example of success in achieving food policy objectives, but it has also introduced the challenge of groundwater sustainability. This paper examines the trends in groundwater abstraction for irrigation and the effect of government policies, including input subsidies - such as the diesel fuel subsidy and the crop procurement price support. The fuel subsidy is an important driving force in groundwater depletion and over-abstraction. This analysis examines the interaction between policy signals and the use and allocation of water by farmers. The rapid decline in groundwater resources shows the limitations of this agricultural development strategy and questions its sustainability unless policies change and the rate of abstraction is changed so as not exceed the recharge rate.

  1. Precipitation and Air Temperature Impact on Seasonal Variations of Groundwater Levels

    NASA Astrophysics Data System (ADS)

    Vitola, Ilva; Vircavs, Valdis; Abramenko, Kaspars; Lauva, Didzis; Veinbergs, Arturs

    2012-12-01

    The aim of this study is to clarify seasonal effects of precipitation and temperature on groundwater level changes in monitoring stations of the Latvia University of Agriculture - Mellupīte, Bērze and Auce. Groundwater regime and level fluctuations depend on climatic conditions such as precipitation intensity, evapotranspiration, surface runoff and drainage, as well as other hydrological factors. The relationship between precipitation, air temperature and groundwater level fluctuations could also lead and give different perspective of possible changes in groundwater quality. Using mathematical statistics and graphic-analytic methods it is concluded that autumn and winter precipitation has the dominant impact on groundwater level fluctuations, whereas spring and summer season fluctuations are more dependent on the air temperature.

  2. Surrogate species selection for assessing potential adverse environmental impacts of genetically engineered plants on non-target organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most regulatory authorities require that developers of genetically engineered insect-resistant (GEIR) crops evaluate the potential for these crops to have adverse impacts on valued non-target organisms (NTOs), i.e., organisms not intended to be controlled by the trait. In many cases, impacts to NTOs...

  3. Do Verbal Interactions with Infants during Electronic Media Exposure Mitigate Adverse Impacts on Their Language Development as Toddlers?

    ERIC Educational Resources Information Center

    Mendelsohn, Alan L.; Brockmeyer, Carolyn A.; Dreyer, Benard P.; Fierman, Arthur H.; Berkule-Silberman, Samantha B.; Tomopoulos, Suzy

    2010-01-01

    The goal of this study was to determine whether verbal interactions between mothers and their 6-month-old infants during media exposure ("media verbal interactions") might have direct positive impacts, or mitigate any potential adverse impacts of media exposure, on language development at 14 months. For 253 low-income mother-infant dyads…

  4. Explaining the black-white gap in cognitive test scores: Toward a theory of adverse impact.

    PubMed

    Cottrell, Jonathan M; Newman, Daniel A; Roisman, Glenn I

    2015-11-01

    In understanding the causes of adverse impact, a key parameter is the Black-White difference in cognitive test scores. To advance theory on why Black-White cognitive ability/knowledge test score gaps exist, and on how these gaps develop over time, the current article proposes an inductive explanatory model derived from past empirical findings. According to this theoretical model, Black-White group mean differences in cognitive test scores arise from the following racially disparate conditions: family income, maternal education, maternal verbal ability/knowledge, learning materials in the home, parenting factors (maternal sensitivity, maternal warmth and acceptance, and safe physical environment), child birth order, and child birth weight. Results from a 5-wave longitudinal growth model estimated on children in the NICHD Study of Early Child Care and Youth Development from ages 4 through 15 years show significant Black-White cognitive test score gaps throughout early development that did not grow significantly over time (i.e., significant intercept differences, but not slope differences). Importantly, the racially disparate conditions listed above can account for the relation between race and cognitive test scores. We propose a parsimonious 3-Step Model that explains how cognitive test score gaps arise, in which race relates to maternal disadvantage, which in turn relates to parenting factors, which in turn relate to cognitive test scores. This model and results offer to fill a need for theory on the etiology of the Black-White ethnic group gap in cognitive test scores, and attempt to address a missing link in the theory of adverse impact. PMID:25867168

  5. Climate change impact on freshwater resources in a deltaic environment: A groundwater modeling study

    NASA Astrophysics Data System (ADS)

    Matiatos, Ioannis; Alexopoulos, John D.; Panagopoulos, Andreas; Nastos, Panagiotis T.; Kotsopoulos, Spyros; Ghionis, George; Poulos, Serafim

    2016-04-01

    Climate change is expected to affect the hydrological cycle, altering seawater level and groundwater recharge to coastal aquifers with various other associated impacts on natural ecosystems and human activities. As the sustainable use of groundwater resources is a great challenge for many countries in the world, groundwater modeling has become a very useful and well established tool for studying groundwater management problems. This study investigates the impacts of climate change on the groundwater of the deltaic plain of River Pinios (Central Greece). Geophysical data processing indicates that the phreatic aquifer extends mainly in the central and northern parts of the region. A one-layer transient groundwater flow and contaminant mass transport model of the aquifer system is calibrated and validated. Impacts of climate change were evaluated by incorporating the estimated recharge input and sea level change of different future scenarios within the simulation models. The most noticeable and consistent result of the climate change impact simulations is a prominent sea water intrusion in the coastal aquifer mainly as a result of sea level change which underlines the need for a more effective planning of environmental measures.

  6. Impact of urbanization on the groundwater regime in a fast growing city in central India.

    PubMed

    Naik, Pradeep K; Tambe, Jivesh A; Dehury, Biranchi N; Tiwari, Arun N

    2008-11-01

    This paper describes the impact of urbanization on the groundwater regime in a fast growing city, Solapur, in central India, giving special emphasis on the management of the present and ultimate demand of water in 2,020 AD. The objective is to apprise the city planners and administrators of the effects of urbanization on the groundwater regime in a fast growing medium-sized city in a developing country where the infrastructure developments are not in conformity with the rapid growth in population. Solapur city with an area of 178.57 km2 receives a recharge of about 24 million m3 of groundwater from various sources annually. Reduction in recharge, as conventionally assumed due to the impact of urbanization, could not, however, be well established. Instead, there was a rise in recharge as water use in the city grew from time to time and more and more water was supplied to satisfy the human needs. Compared to mid-1970s, groundwater levels have increased within the main city area due to increased recharge and decreased groundwater abstraction. However, outside the main city area, there is a general decline in groundwater levels due to increased groundwater utilization for irrigation purposes. Groundwater quality deterioration has been highly localized. Water quality has deteriorated during the last 10 years, especially in dugwells, mainly due to misuse and disuse of these structures and poor circulation of groundwater. However, in case of borewells, comparison of the present water quality with that in mid-1970s and early 1980s does not show any perceptible change. Deeper groundwater tapped by borewells can still be used for drinking purposes with caution.

  7. Hydraulic characteristics of fault zones and their impact on groundwater flow

    NASA Astrophysics Data System (ADS)

    Banks, E.; Cook, P. G.

    2014-12-01

    An important source of groundwater recharge to sedimentary basin aquifers is from mountain block recharge and in many instances the rate and direction of groundwater flow is controlled by regional scale fault systems. Vertical faults may act as either barriers to horizontal groundwater flow perpendicular to the fault, conduits to horizontal flow along the fault or a combination of both. Faults can also provide conduits for vertical flow. There are very few evaluations of the impact of fault zones on groundwater flow. This study investigated groundwater flow characteristics across a fault zone between a fractured rock and sedimentary aquifer system. Hydrogeological and hydrogeophysical techniques were used to design a drilling program whereby multi-level observation wells were constructed at 3 field sites either side of the Willunga fault in the Willunga Basin, South Australia, up to 300 metres below ground level. The observed hydraulic gradients across the fault zone were very significant (2.5), with a head difference of 80 metres over a horizontal distance of less than 30 metres. Despite the high hydraulic gradient, calculating the groundwater flux across the fault was more complicated. A 3D numerical model was developed to determine the relative proportion of groundwater flow across the fault and flow parallel to the fault. This model was also used to assess the impact of the fault zone permeability on the hydraulic gradients across the fault and evaluate the mechanisms and behaviour of these conduit-barrier systems to groundwater flow. Groundwater age dating and hydrochemical analyses were conducted to examine and constrain the contributing end members of the different aquifer systems and trace groundwater movement and residence time across the fault zone.

  8. Groundwater quality and its health impact: An assessment of dental fluorosis in rural inhabitants of the Main Ethiopian Rift.

    PubMed

    Rango, Tewodros; Kravchenko, Julia; Atlaw, Behailu; McCornick, Peter G; Jeuland, Marc; Merola, Brittany; Vengosh, Avner

    2012-08-01

    This study aims to assess the link between fluoride content in groundwater and its impact on dental health in rural communities of the Ethiopian Rift. A total of 148 water samples were collected from two drainage basins within the Main Ethiopian Rift (MER). In the Ziway-Shala basin in particular, wells had high fluoride levels (mean: 9.4±10.5mg/L; range: 1.1 to 68 mg/L), with 48 of 50 exceeding the WHO drinking water guideline limit of 1.5mg/L. Total average daily intake of fluoride from drinking groundwater (calculated per weight unit) was also found to be six times higher than the No-Observed-Adverse-Effects-Level (NOAEL) value of 0.06 mg/kg/day. The highest fluoride levels were found in highly-alkaline (pH of 7 to 8.9) groundwater characterized by high salinity; high concentrations of sodium (Na⁺), bicarbonate (HCO₃⁻), and silica (SiO₂); and low concentrations of calcium (Ca²⁺). A progressive Ca²⁺ decrease along the groundwater flow path is associated with an increase of fluoride in the groundwater. The groundwater quality problem is also coupled with the presence of other toxic elements, such as arsenic (As) and uranium (U). The health impact of fluoride was evaluated based on clinical examination of dental fluorosis (DF) among local residents using the Thylstrup and Fejerskov index (TFI). In total, 200 rural inhabitants between the ages of 7 and 40 years old using water from 12 wells of fluoride range of 7.8-18 mg/L were examined. Signs of DF (TF score of ≥ 1) were observed in all individuals. Most of the teeth (52%) recorded TF scores of 5 and 6, followed by TF scores of 3 and 4 (30%), and 8.4% had TF scores of 7 or higher. Sixty percent of the teeth exhibited loss of the outermost enamel. Within the range of fluoride contents, we did not find any correlation between fluoride content and DF. Finally, preliminary data suggest that milk intake has contributed to reducing the severity of DF. The study highlights the apparent positive role of

  9. Groundwater quality and its health impact: An assessment of dental fluorosis in rural inhabitants of the Main Ethiopian Rift.

    PubMed

    Rango, Tewodros; Kravchenko, Julia; Atlaw, Behailu; McCornick, Peter G; Jeuland, Marc; Merola, Brittany; Vengosh, Avner

    2012-08-01

    This study aims to assess the link between fluoride content in groundwater and its impact on dental health in rural communities of the Ethiopian Rift. A total of 148 water samples were collected from two drainage basins within the Main Ethiopian Rift (MER). In the Ziway-Shala basin in particular, wells had high fluoride levels (mean: 9.4±10.5mg/L; range: 1.1 to 68 mg/L), with 48 of 50 exceeding the WHO drinking water guideline limit of 1.5mg/L. Total average daily intake of fluoride from drinking groundwater (calculated per weight unit) was also found to be six times higher than the No-Observed-Adverse-Effects-Level (NOAEL) value of 0.06 mg/kg/day. The highest fluoride levels were found in highly-alkaline (pH of 7 to 8.9) groundwater characterized by high salinity; high concentrations of sodium (Na⁺), bicarbonate (HCO₃⁻), and silica (SiO₂); and low concentrations of calcium (Ca²⁺). A progressive Ca²⁺ decrease along the groundwater flow path is associated with an increase of fluoride in the groundwater. The groundwater quality problem is also coupled with the presence of other toxic elements, such as arsenic (As) and uranium (U). The health impact of fluoride was evaluated based on clinical examination of dental fluorosis (DF) among local residents using the Thylstrup and Fejerskov index (TFI). In total, 200 rural inhabitants between the ages of 7 and 40 years old using water from 12 wells of fluoride range of 7.8-18 mg/L were examined. Signs of DF (TF score of ≥ 1) were observed in all individuals. Most of the teeth (52%) recorded TF scores of 5 and 6, followed by TF scores of 3 and 4 (30%), and 8.4% had TF scores of 7 or higher. Sixty percent of the teeth exhibited loss of the outermost enamel. Within the range of fluoride contents, we did not find any correlation between fluoride content and DF. Finally, preliminary data suggest that milk intake has contributed to reducing the severity of DF. The study highlights the apparent positive role of

  10. Trace elements in groundwater as indicators of anthropogenic impact

    NASA Astrophysics Data System (ADS)

    Levins, Igors; Gosk, Edmund

    2008-07-01

    The distribution of several minor and trace elements mainly in fresh (dominating TDS 160 400 mg/l) groundwater of Latvia have been investigated by the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) technique. An evaluation of results of about 700 analyses leads to the conclusion that concentrations of these elements is influenced by: pH Eh conditions, groundwater residence time and diffuse contamination, whereas the role of water-bearing sediments is of secondary importance. Most trace elements are characterised by low mobility under alkaline and reducing conditions; concentrations in confined aquifers are much smaller than the Maximum Permissible Values for drinking water. The strongest anomalies of REE, Al and P were found in shallow groundwater around the former agrochemical storehouses.

  11. Projected impacts of climate change on farmers' extraction of groundwater from crystalline aquifers in South India

    PubMed Central

    Ferrant, Sylvain; Caballero, Yvan; Perrin, Jérome; Gascoin, Simon; Dewandel, Benoit; Aulong, Stéphanie; Dazin, Fabrice; Ahmed, Shakeel; Maréchal, Jean-Christophe

    2014-01-01

    Local groundwater levels in South India are falling alarmingly. In the semi-arid crystalline Deccan plateau area, agricultural production relies on groundwater resources. Downscaled Global Climate Model (GCM) data are used to force a spatially distributed agro-hydrological model in order to evaluate Climate Change (CC) effects on local groundwater extraction (GWE). The slight increase of precipitation may alleviate current groundwater depletion on average, despite the increased evaporation due to warming. Nevertheless, projected climatic extremes create worse GWE shortages than for present climate. Local conditions may lead to opposing impacts on GWE, from increases to decreases (+/−20 mm/year), for a given spatially homogeneous CC forcing. Areas vulnerable to CC in terms of irrigation apportionment are thus identified. Our results emphasize the importance of accounting for local characteristics (water harvesting systems and maximal aquifer capacity versus GWE) in developing measures to cope with CC impacts in the South Indian region. PMID:24424295

  12. Projected impacts of climate change on farmers' extraction of groundwater from crystalline aquifers in South India.

    PubMed

    Ferrant, Sylvain; Caballero, Yvan; Perrin, Jérome; Gascoin, Simon; Dewandel, Benoit; Aulong, Stéphanie; Dazin, Fabrice; Ahmed, Shakeel; Maréchal, Jean-Christophe

    2014-01-15

    Local groundwater levels in South India are falling alarmingly. In the semi-arid crystalline Deccan plateau area, agricultural production relies on groundwater resources. Downscaled Global Climate Model (GCM) data are used to force a spatially distributed agro-hydrological model in order to evaluate Climate Change (CC) effects on local groundwater extraction (GWE). The slight increase of precipitation may alleviate current groundwater depletion on average, despite the increased evaporation due to warming. Nevertheless, projected climatic extremes create worse GWE shortages than for present climate. Local conditions may lead to opposing impacts on GWE, from increases to decreases (+/-20 mm/year), for a given spatially homogeneous CC forcing. Areas vulnerable to CC in terms of irrigation apportionment are thus identified. Our results emphasize the importance of accounting for local characteristics (water harvesting systems and maximal aquifer capacity versus GWE) in developing measures to cope with CC impacts in the South Indian region.

  13. Adverse childhood experiences: assessing the impact on health and school engagement and the mitigating role of resilience.

    PubMed

    Bethell, Christina D; Newacheck, Paul; Hawes, Eva; Halfon, Neal

    2014-12-01

    The ongoing longitudinal Adverse Childhood Experiences Study of adults has found significant associations between chronic conditions; quality of life and life expectancy in adulthood; and the trauma and stress associated with adverse childhood experiences, including physical or emotional abuse or neglect, deprivation, or exposure to violence. Less is known about the population-based epidemiology of adverse childhood experiences among US children. Using the 2011-12 National Survey of Children's Health, we assessed the prevalence of adverse childhood experiences and associations between them and factors affecting children's development and lifelong health. After we adjusted for confounding factors, we found lower rates of school engagement and higher rates of chronic disease among children with adverse childhood experiences. Our findings suggest that building resilience-defined in the survey as "staying calm and in control when faced with a challenge," for children ages 6-17-can ameliorate the negative impact of adverse childhood experiences. We found higher rates of school engagement among children with adverse childhood experiences who demonstrated resilience, as well as higher rates of resilience among children with such experiences who received care in a family-centered medical home. We recommend a coordinated effort to fill knowledge gaps and translate existing knowledge about adverse childhood experiences and resilience into national, state, and local policies, with a focus on addressing childhood trauma in health systems as they evolve during ongoing reform.

  14. Estimation of impacts on groundwater quality in an urban area of Ljubljana

    NASA Astrophysics Data System (ADS)

    Janža, Mitja; Prestor, Joerg; Pestotnik, Simona; Jamnik, Brigita

    2016-04-01

    Groundwater is a major source of drinking water supply in many cities worldwide. It is relatively stable and better-protected water resource compared to surface water and will have a vital role in assuring water-supply security in the future. In urbanized catchments numerous human activities (e.g. settling, industry, traffic, agriculture) take place which pose a threat to groundwater quality. For sustainable management of urban groundwater resources an integrated and adaptive approach based on continuous monitoring supported by modeling is needed. The aim of presented study was to develop a model of environmental pressures and impacts on Ljubljansko polje aquifer which is the main source exploited for the public drinking water supply of the city of Ljubljana. It is based on estimation of contaminants emissions from different sources, coupled with numerical transport modelling which is used to assess the impact on groundwater quality. The model was built up on detailed analysis of nitrogen mass balance and validated with monitoring data - concentration measurements of relevant chemical parameters. Based on the model simulations impacts of different sources of pollution on groundwater quality was estimated and priority of measures for improvement of chemical status of groundwater was defined.

  15. Impact of peatland drainage and restoration on esker groundwater resources: modeling future scenarios for management

    NASA Astrophysics Data System (ADS)

    Rossi, Pekka M.; Ala-aho, Pertti; Doherty, John; Kløve, Bjørn

    2014-08-01

    Esker aquifers are common groundwater bodies in Europe. Management of these aquifers should take account of the sustainability of groundwater-dependent ecosystems and land use in an integrated way. An unconfined esker aquifer in northern Finland was modelled with MODFLOW to determine how groundwater resources are impacted by the surrounding peatland drainage scheme and to simulate scenarios for possible drainage restoration. The impacts of groundwater abstraction and climate change were also simulated. A calibration-constrained Monte Carlo method was used to provide information on the uncertainties associated with model predictions. The results suggest that peatland drainage in the vicinity of eskers can have a significant role in lowering the water table, even though climate variability may mask these impacts. Drainage restoration by filling the ditches might have positive impacts on the aquifer water levels. Comparison of water-table changes caused by peatland drainage with the changes brought by water abstraction and climate variability helped to quantify impacts of different land-use scenarios and facilitated discussion with the local stakeholders. Based on this study, more attention should be devoted to peatland drainage schemes in integrated groundwater management of esker aquifers.

  16. Reducing the environmental impacts of reverse osmosis desalination by using brackish groundwater resources.

    PubMed

    Muñoz, Ivan; Fernández-Alba, Amadeo Rodríguez

    2008-02-01

    The aim of the present work is to find out whether or not, and to what extent, the environmental impacts of reverse osmosis desalination are reduced when brackish groundwater is used instead of sea water. In order to answer this question, the Life-Cycle Assessment (LCA) methodology is used, and two water production plants are compared. The brackish groundwater scenario is based on a plant located in Almería (southern Spain), while the sea water scenario is based on literature data. Four impact categories and two environmental indicators, one of them related to brine discharge, are included. The results show that the key life-cycle issue of brackish groundwater desalination is electricity consumption, and since this is substantially reduced with regard to using sea water, the life-cycle impacts are found to be almost 50% lower. An uncertainty analysis based on Monte-Carlo simulation shows that these environmental savings are significant for all impact categories. Potential local impacts provoked by brine discharge are also found to be lower, due to a reduced content of salts. It is concluded that, when and wherever possible, exploitation of brackish groundwater resources should be assigned priority to sea water resources as an input for reverse osmosis desalination, although it must be taken into account that groundwater, as opposed to sea water, is a limited resource.

  17. Forced distribution rating systems: when does "rank and yank" lead to adverse impact?

    PubMed

    Giumetti, Gary W; Schroeder, Amber N; Switzer, Fred S

    2015-01-01

    Despite widespread use of forced distribution rating systems (FDRSs), the potential for this performance appraisal method to lead to adverse impact (AI) in a layoff context has yet to be examined empirically. Thus, the current study uses a Monte Carlo simulation to examine the likelihood of encountering AI violations when an FDRS is used in the context of layoffs. The primary research questions included an examination of how AI violations change depending on the definition of the employment action (i.e., retention vs. layoff), the length of the repeated layoffs, and whether or not laid off employees are replaced each year. The current study also examined the impact of the size of the organization, the percentage of the workforce laid off, and the type of AI calculation method used on the likelihood of AI violations. Results suggest that defining the employment action as layoffs (rather than as retentions) may result in a greater likelihood of AI violations, and AI violations are likely to peak in the 1st year of use. Further, replacing laid off employees may result in higher levels of AI over time as compared with not replacing layoffs. Additionally, the greatest risk for AI occurs when the organization size is large (i.e., N = 10,000) and when certain AI calculation methods are used. Results are discussed in terms of their practical and legal implications for organizations.

  18. Autonomic and Climatic Impacts on the Dutch Coastal Groundwater System

    NASA Astrophysics Data System (ADS)

    van Baaren, E. S.; Oude Essink, G. H.

    2008-12-01

    Half of the Netherlands is located below sea level and still land subsidence is taking place. As saline groundwater is found within a couple of meters below ground surface, salinization of the freshwater resources is taking place. Above mentioned process together with anthropogenic activities like groundwater exploitation and differentiated water level management is called the autonomic process. As a consequence, salt seepage affects the quality of surface water and reduces the freshwater volume necessary for drinking, environmental, industrial and agricultural purposes. Apart from this autonomic process, the Dutch delta will be jeopardized by climate change due to two effects: sea level rise and a combination of changing precipitation and evapotranspiration. Calculations with a regional density dependent 3D model for the coastal province of Zuid-Holland show increasing piezometric heads for all implemented climate scenarios due to sea level rise. This will, however, only happen at areas less than 10-20 km from the coastline or large rivers. Up to 5 km from the coast, the piezometric heads will increase with more than 50% of the sea level rise. In the inland areas, land subsidence causes decreasing piezometric heads. Salinization of the groundwater system will take place in most parts of the Dutch delta. Around the islands of Zuid-Holland, the main cause for salinization is sea level rise. The autonomic process on the other hand dominates the salinization of the polders. Due to increasing piezometric heads and salinization, the salt seepage will increase up to 20% for inland polders and up to 75% for coastal polders. The effects of the changes in recharge and evapotranspiration are small in general and depend on the climate scenario and area. Adaptive and mitigative activities like land reclamation offshore and desalinization of saline groundwater show some positive effects on the chloride concentrations of the groundwater. Nevertheless, this cannot reverse the

  19. Impact of Groundwater Flow and Energy Load on Multiple Borehole Heat Exchangers.

    PubMed

    Dehkordi, S Emad; Schincariol, Robert A; Olofsson, Bo

    2015-01-01

    The effect of array configuration, that is, number, layout, and spacing, on the performance of multiple borehole heat exchangers (BHEs) is generally known under the assumption of fully conductive transport. The effect of groundwater flow on BHE performance is also well established, but most commonly for single BHEs. In multiple-BHE systems the effect of groundwater advection can be more complicated due to the induced thermal interference between the boreholes. To ascertain the influence of groundwater flow and borehole arrangement, this study investigates single- and multi-BHE systems of various configurations. Moreover, the influence of energy load balance is also examined. The results from corresponding cases with and without groundwater flow as well as balanced and unbalanced energy loads are cross-compared. The groundwater flux value, 10(-7) m/s, is chosen based on the findings of previous studies on groundwater flow interaction with BHEs and thermal response tests. It is observed that multi-BHE systems with balanced loads are less sensitive to array configuration attributes and groundwater flow, in the long-term. Conversely, multi-BHE systems with unbalanced loads are influenced by borehole array configuration as well as groundwater flow; these effects become more pronounced with time, unlike when the load is balanced. Groundwater flow has more influence on stabilizing loop temperatures, compared to array characteristics. Although borehole thermal energy storage (BTES) systems have a balanced energy load function, preliminary investigation on their efficiency shows a negative impact by groundwater which is due to their dependency on high temperature gradients between the boreholes and surroundings.

  20. Impact of Groundwater Flow and Energy Load on Multiple Borehole Heat Exchangers.

    PubMed

    Dehkordi, S Emad; Schincariol, Robert A; Olofsson, Bo

    2015-01-01

    The effect of array configuration, that is, number, layout, and spacing, on the performance of multiple borehole heat exchangers (BHEs) is generally known under the assumption of fully conductive transport. The effect of groundwater flow on BHE performance is also well established, but most commonly for single BHEs. In multiple-BHE systems the effect of groundwater advection can be more complicated due to the induced thermal interference between the boreholes. To ascertain the influence of groundwater flow and borehole arrangement, this study investigates single- and multi-BHE systems of various configurations. Moreover, the influence of energy load balance is also examined. The results from corresponding cases with and without groundwater flow as well as balanced and unbalanced energy loads are cross-compared. The groundwater flux value, 10(-7) m/s, is chosen based on the findings of previous studies on groundwater flow interaction with BHEs and thermal response tests. It is observed that multi-BHE systems with balanced loads are less sensitive to array configuration attributes and groundwater flow, in the long-term. Conversely, multi-BHE systems with unbalanced loads are influenced by borehole array configuration as well as groundwater flow; these effects become more pronounced with time, unlike when the load is balanced. Groundwater flow has more influence on stabilizing loop temperatures, compared to array characteristics. Although borehole thermal energy storage (BTES) systems have a balanced energy load function, preliminary investigation on their efficiency shows a negative impact by groundwater which is due to their dependency on high temperature gradients between the boreholes and surroundings. PMID:25227154

  1. The impact of glaciations and glacial processes on groundwater flow dynamics: a numerical investigation

    NASA Astrophysics Data System (ADS)

    Sterckx, A.; Lemieux, J. M.; Vaikmae, R.

    2015-12-01

    Numerical models are widely used to investigate the impact of glaciations on groundwater flow systems because they can simulate complex glacial processes. However, it isn't clear which of these processes are relevant to adequately capture groundwater flow dynamics. Given the complexity of representing these processes in a numerical model and the paucity of field data available for their validation, it is of prime interest to assess how they impact groundwater flow and if any of these processes could be neglected. In order to assess the specific impact of glacial processes on groundwater flow dynamics, those processes were included in the numerical model FEFLOW and simulations were conducted in a simple conceptual model representing a 21 ky glacial cycle in a sedimentary basin. The following processes have been simulated: subglacial recharge, linear and non-linear compaction of the porous medium under the weight of the ice, isostasy, proglacial lakes, as well as permafrost. Solute transport was simulated along with groundwater flow to track groundwater originating from the ice-sheet. To interpret the results, a base case scenario considering only subglacial recharge was selected and compared with the other scenarios, where individual glacial processes were simulated. When comparing the results at the end of the simulations, it appears that most of the aforementioned glacial processes don't lead to a significant difference in meltwater distribution with respect to the base case. Only hydromechanical coupling brings some noticeable change. Conversely, the type and the value of the boundary condition applied at the base of the ice-sheet play a major role in groundwater flow dynamics. The presence of confining hydrogeological units also seems to be a key to understand the long-term effect of glaciations. These results suggest that some of the glacial processes may be neglected for the simulation of groundwater flow dynamics during a glacial period.

  2. Impact of Water Withdrawals from Groundwater and Surface Water on Continental Water Storage Variations

    NASA Technical Reports Server (NTRS)

    Doell, Petra; Hoffmann-Dobrev, Heike; Portmann, Felix T.; Siebert, Stefan; Eicker, Annette; Rodell, Matthew; Strassberg, Gil

    2011-01-01

    Humans have strongly impacted the global water cycle, not only water flows but also water storage. We have performed a first global-scale analysis of the impact of water withdrawals on water storage variations, using the global water resources and use model WaterGAP. This required estimation of fractions of total water withdrawals from groundwater, considering five water use sectors. According to our assessment, the source of 35% of the water withdrawn worldwide (4300 cubic km/yr during 1998-2002) is groundwater. Groundwater contributes 42%, 36% and 27% of water used for irrigation, households and manufacturing, respectively, while we assume that only surface water is used for livestock and for cooling of thermal power plants. Consumptive water use was 1400 cubic km/yr during 1998-2002. It is the sum of the net abstraction of 250 cubic km/yr of groundwater (taking into account evapotranspiration and return flows of withdrawn surface water and groundwater) and the net abstraction of 1150 km3/yr of surface water. Computed net abstractions indicate, for the first time at the global scale, where and when human water withdrawals decrease or increase groundwater or surface water storage. In regions with extensive surface water irrigation, such as Southern China, net abstractions from groundwater are negative, i.e. groundwater is recharged by irrigation. The opposite is true for areas dominated by groundwater irrigation, such as in the High Plains aquifer of the central USA, where net abstraction of surface water is negative because return flow of withdrawn groundwater recharges the surface water compartments. In intensively irrigated areas, the amplitude of seasonal total water storage variations is generally increased due to human water use; however, in some areas, it is decreased. For the High Plains aquifer and the whole Mississippi basin, modeled groundwater and total water storage variations were compared with estimates of groundwater storage variations based on

  3. Key Factors for Determining Risk of Groundwater Impacts Due to Leakage from Geologic Carbon Sequestration Reservoirs

    SciTech Connect

    Carroll, Susan; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-01-06

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow underwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models,l referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could result from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which "no impact" to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur.

  4. Hydrogeochemical signatures and evolution of groundwater impacted by the Bayan Obo tailing pond in northwest China.

    PubMed

    Huang, Xiang; Deng, Hailin; Zheng, Chunmiao; Cao, Guoliang

    2016-02-01

    Uncontrolled leakage from mine tailing ponds can pose a serious environmental threat. Groundwater quality in a semi-arid region with extensive worries about the leakage from one of world's largest tailing ponds is studied herein through an integrated hydrogeochemical analysis and multivariate statistical analysis. Results show that elevated concentrations of NO2(-), B, Mn, NH4(+), F(-), and SO4(2-) in groundwater were probably caused by leakage from the tailing pond and transported with the regional groundwater flow towards downstream Yellow River. While NO2(-) contamination is only limited to areas close to the pond, high B concentrations persist within the contaminated plume originating from the tailing pond. Our current study shows that there is no geochemical evidence for U and Th contamination in groundwater due to leakage from the Bayan Obo tailing pond. Combining effects which includes regional variations, pond leaking and downstream mixing, mineral precipitation and dissolution, redox processes, ion exchange processes and agricultural activities, controlled groundwater hydrogeochemical signatures in the studied area. This study demonstrate that an increase in knowledge of evolution of groundwater quality by integrating field hydrochemical data and multivariate statistical analysis will help understand major water-rock interactions and provide a scientific basis for protection and rational utilization of groundwater resources in this and other tailing-impacted areas. PMID:26595403

  5. Hydrogeochemical signatures and evolution of groundwater impacted by the Bayan Obo tailing pond in northwest China.

    PubMed

    Huang, Xiang; Deng, Hailin; Zheng, Chunmiao; Cao, Guoliang

    2016-02-01

    Uncontrolled leakage from mine tailing ponds can pose a serious environmental threat. Groundwater quality in a semi-arid region with extensive worries about the leakage from one of world's largest tailing ponds is studied herein through an integrated hydrogeochemical analysis and multivariate statistical analysis. Results show that elevated concentrations of NO2(-), B, Mn, NH4(+), F(-), and SO4(2-) in groundwater were probably caused by leakage from the tailing pond and transported with the regional groundwater flow towards downstream Yellow River. While NO2(-) contamination is only limited to areas close to the pond, high B concentrations persist within the contaminated plume originating from the tailing pond. Our current study shows that there is no geochemical evidence for U and Th contamination in groundwater due to leakage from the Bayan Obo tailing pond. Combining effects which includes regional variations, pond leaking and downstream mixing, mineral precipitation and dissolution, redox processes, ion exchange processes and agricultural activities, controlled groundwater hydrogeochemical signatures in the studied area. This study demonstrate that an increase in knowledge of evolution of groundwater quality by integrating field hydrochemical data and multivariate statistical analysis will help understand major water-rock interactions and provide a scientific basis for protection and rational utilization of groundwater resources in this and other tailing-impacted areas.

  6. Impact of Water Resorts Development along Laguna de Bay on Groundwater Resources

    NASA Astrophysics Data System (ADS)

    Jago-on, K. A. B.; Reyes, Y. K.; Siringan, F. P.; Lloren, R. B.; Balangue, M. I. R. D.; Pena, M. A. Z.; Taniguchi, M.

    2014-12-01

    Rapid urbanization and land use changes in areas along Laguna de Bay, one of the largest freshwater lake in Southeast Asia, have resulted in increased economic activities and demand for groundwater resources from households, commerce and industries. One significant activity that can affect groundwater is the development of the water resorts industry, which includes hot springs spas. This study aims to determine the impact of the proliferation of these water resorts in Calamba and Los Banos, urban areas located at the southern coast of the lake on the groundwater as a resource. Calamba, being the "Hot Spring Capital of the Philippines", presently has more than 300 resorts, while Los Banos has at least 38 resorts. Results from an initial survey of resorts show that the swimming pools are drained/ changed on an average of 2-3 times a week or even daily during peak periods of tourist arrivals. This indicates a large demand on the groundwater. Monitoring of actual groundwater extraction is a challenge however, as most of these resorts operate without water use permits. The unrestrained exploitation of groundwater has resulted to drying up of older wells and decrease in hot spring water temperature. It is necessary to strengthen implementation of laws and policies, and enhance partnerships among government, private sector groups, civil society and communities to promote groundwater sustainability.

  7. Impacts on groundwater due to land application of sewage sludge

    SciTech Connect

    Higgins, A.J.

    1984-06-01

    The project was designed to demonstrate the potential benefits of utilizing sewage sludge as a soil conditioner and fertilizer on Sassafras sandy loam soil. Aerobically digested, liquid sewage sludge was applied to the soil at rates of 0, 22.4, and 44.8 Mg of dry solids/ha for three consecutive years between 1978 and 1981. Groundwater, soil, and crop contamination levels were monitored to establish the maximum sewage solids loading rate that could be applied without causing environmental deterioration. The results indicate that application of 22.4 Mg of dry solids/ha of sludge is the upper limit to ensure protection of the groundwater quality on the site studied. Application rates at or slightly below 22.4 Mg of dry solids/ha are sufficient for providing plant nutrients for the dent corn and rye cropping system utilized in the study.

  8. Plant transpiration and groundwater dynamics in water-limited climates: Impacts of hydraulic redistribution

    NASA Astrophysics Data System (ADS)

    Luo, Xiangyu; Liang, Xu; Lin, Jeen-Shang

    2016-06-01

    The role of groundwater in sustaining plant transpiration constitutes an important but not well-understood aspect of the interactions between groundwater, vegetation, the land surface, and the atmosphere. The effect of the hydraulic redistribution (HR) process by plant roots on the interplay between plant transpiration and groundwater dynamics under water-limited climates is investigated by using the Variable Infiltration Capacity Plus (VIC+) land surface model. Numerical experiments, with or without explicitly considering HR, are conducted on soil columns over a range of groundwater table depths (GWTDs) under different vegetative land covers, soil types, and precipitation conditions. When HR is not included, this study obtains transpiration-GWTD relationships consistent with those from watershed studies that do not include HR. When HR is included, the transpiration-GWTD relationships are modified. The modification introduced by HR is manifested in the soil moisture of the root zone. The mechanism of HR is explained by detailing the roles of the hydraulically redistributed water, the upward diffusion of soil water, and the daytime root uptake. We have found that HR is particularly important in water-limited climates under which plants have high transpiration demand. At the beginning stage of a dry period, HR modulates the severe impacts that climate has on plant transpiration. Only after a prolonged dry period, impacts of HR are lessened when the groundwater table drops below the depth of water uptake by roots and are diminished when plant transpiration is decoupled from groundwater dynamics.

  9. Groundwater salinity in a floodplain forest impacted by saltwater intrusion

    NASA Astrophysics Data System (ADS)

    Kaplan, David A.; Muñoz-Carpena, Rafael

    2014-11-01

    Coastal wetlands occupy a delicate position at the intersection of fresh and saline waters. Changing climate and watershed hydrology can lead to saltwater intrusion into historically freshwater systems, causing plant mortality and loss of freshwater habitat. Understanding the hydrological functioning of tidally influenced floodplain forests is essential for advancing ecosystem protection and restoration goals, however finding direct relationships between hydrological inputs and floodplain hydrology is complicated by interactions between surface water, groundwater, and atmospheric fluxes in variably saturated soils with heterogeneous vegetation and topography. Thus, an alternative method for identifying common trends and causal factors is required. Dynamic factor analysis (DFA), a time series dimension reduction technique, models temporal variation in observed data as linear combinations of common trends, which represent unexplained common variability, and explanatory variables. DFA was applied to model shallow groundwater salinity in the forested floodplain wetlands of the Loxahatchee River (Florida, USA), where altered watershed hydrology has led to changing hydroperiod and salinity regimes and undesired vegetative changes. Long-term, high-resolution groundwater salinity datasets revealed dynamics over seasonal and yearly time periods as well as over tidal cycles and storm events. DFA identified shared trends among salinity time series and a full dynamic factor model simulated observed series well (overall coefficient of efficiency, Ceff = 0.85; 0.52 ≤ Ceff ≤ 0.99). A reduced multilinear model based solely on explanatory variables identified in the DFA had fair to good results (Ceff = 0.58; 0.38 ≤ Ceff ≤ 0.75) and may be used to assess the effects of restoration and management scenarios on shallow groundwater salinity in the Loxahatchee River floodplain.

  10. Groundwater salinity in a floodplain forest impacted by saltwater intrusion.

    PubMed

    Kaplan, David A; Muñoz-Carpena, Rafael

    2014-11-15

    Coastal wetlands occupy a delicate position at the intersection of fresh and saline waters. Changing climate and watershed hydrology can lead to saltwater intrusion into historically freshwater systems, causing plant mortality and loss of freshwater habitat. Understanding the hydrological functioning of tidally influenced floodplain forests is essential for advancing ecosystem protection and restoration goals, however finding direct relationships between hydrological inputs and floodplain hydrology is complicated by interactions between surface water, groundwater, and atmospheric fluxes in variably saturated soils with heterogeneous vegetation and topography. Thus, an alternative method for identifying common trends and causal factors is required. Dynamic factor analysis (DFA), a time series dimension reduction technique, models temporal variation in observed data as linear combinations of common trends, which represent unexplained common variability, and explanatory variables. DFA was applied to model shallow groundwater salinity in the forested floodplain wetlands of the Loxahatchee River (Florida, USA), where altered watershed hydrology has led to changing hydroperiod and salinity regimes and undesired vegetative changes. Long-term, high-resolution groundwater salinity datasets revealed dynamics over seasonal and yearly time periods as well as over tidal cycles and storm events. DFA identified shared trends among salinity time series and a full dynamic factor model simulated observed series well (overall coefficient of efficiency, Ceff=0.85; 0.52≤Ceff≤0.99). A reduced multilinear model based solely on explanatory variables identified in the DFA had fair to good results (Ceff=0.58; 0.38≤Ceff≤0.75) and may be used to assess the effects of restoration and management scenarios on shallow groundwater salinity in the Loxahatchee River floodplain.

  11. Modeling the impacts of dryland agricultural reclamation on groundwater resources in Northern Egypt using sparse data

    NASA Astrophysics Data System (ADS)

    Switzman, Harris; Coulibaly, Paulin; Adeel, Zafar

    2015-01-01

    Demand for freshwater in many dryland environments is exerting negative impacts on the quality and availability of groundwater resources, particularly in areas where demand is high due to irrigation or industrial water requirements to support dryland agricultural reclamation. Often however, information available to diagnose the drivers of groundwater degradation and assess management options through modeling is sparse, particularly in low and middle-income countries. This study presents an approach for generating transient groundwater model inputs to assess the long-term impacts of dryland agricultural land reclamation on groundwater resources in a highly data-sparse context. The approach was applied to the area of Wadi El Natrun in Northern Egypt, where dryland reclamation and the associated water use has been aggressive since the 1960s. Statistical distributions of water use information were constructed from a variety of sparse field and literature estimates and then combined with remote sensing data in spatio-temporal infilling model to produce the groundwater model inputs of well-pumping and surface recharge. An ensemble of groundwater model inputs were generated and used in a 3D groundwater flow (MODFLOW) of Wadi El Natrun's multi-layer aquifer system to analyze trends in water levels and water budgets over time. Validation of results against monitoring records, and model performance statistics demonstrated that despite the extremely sparse data, the approach used in this study was capable of simulating the cumulative impacts of agricultural land reclamation reasonably well. The uncertainty associated with the groundwater model itself was greater than that associated with the ensemble of well-pumping and surface recharge estimates. Water budget analysis of the groundwater model output revealed that groundwater recharge has not changed significantly over time, while pumping has. As a result of these trends, groundwater was estimated to be in a deficit of

  12. Impact of Different Childhood Adversities on 1-Year Outcomes of Psychotic Disorder in the Genetics and Psychosis Study

    PubMed Central

    Trotta, Antonella; Murray, Robin M.; David, Anthony S.; Kolliakou, Anna; O’Connor, Jennifer; Di Forti, Marta; Dazzan, Paola; Mondelli, Valeria; Morgan, Craig; Fisher, Helen L.

    2016-01-01

    While the role of childhood adversity in increasing the risk of psychosis has been extensively investigated, it is not clear what the impact of early adverse experiences is on the outcomes of psychotic disorders. Therefore, we investigated associations between childhood adversity and 1-year outcomes in 285 first-presentation psychosis patients. Exposure to childhood adversity prior to 17 years of age was assessed using the Childhood Experience of Care and Abuse Questionnaire. Data on illness course, symptom remission, length of psychiatric hospitalization, compliance with medication, employment, and relationship status were extracted from clinical records for the year following first contact with mental health services for psychosis. Seventy-one percent of patients reported exposure to at least 1 type of childhood adversity (physical abuse, sexual abuse, parental separation, parental death, disrupted family arrangements, or being taken into care). No robust associations were found between childhood adversity and illness course or remission. However, childhood physical abuse was associated with almost 3-fold increased odds of not being in a relationship at 1-year follow-up compared to patients who did not report such adverse experiences. There was also evidence of a significant association between parental separation in childhood and longer admissions to psychiatric wards during 1-year follow-up and 2-fold increased odds of noncompliance with medication compared to those not separated from their parents. Therefore, our findings suggest that there may be some specificity in the impact of childhood adversity on service use and social functioning among psychosis patients over the first year following presentation to mental health services. PMID:26373540

  13. Comparative metagenomics reveals impact of contaminants on groundwater microbiomes

    SciTech Connect

    Hemme, Christopher L.; Tu, Qichao; Shi, Zhou; Qin, Yujia; Gao, Weimin; Deng, Ye; Nostrand, Joy D. Van; Wu, Liyou; He, Zhili; Chain, Patrick S. G.; Tringe, Susannah G.; Fields, Matthew W.; Rubin, Edward M.; Tiedje, James M.; Hazen, Terry C.; Arkin, Adam P.; Zhou, Jizhong

    2015-10-31

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

  14. Comparative metagenomics reveals impact of contaminants on groundwater microbiomes

    DOE PAGES

    Hemme, Christopher L.; Tu, Qichao; Shi, Zhou; Qin, Yujia; Gao, Weimin; Deng, Ye; Nostrand, Joy D. Van; Wu, Liyou; He, Zhili; Chain, Patrick S. G.; et al

    2015-10-31

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

  15. Comparative metagenomics reveals impact of contaminants on groundwater microbiomes

    PubMed Central

    Hemme, Christopher L.; Tu, Qichao; Shi, Zhou; Qin, Yujia; Gao, Weimin; Deng, Ye; Nostrand, Joy D. Van; Wu, Liyou; He, Zhili; Chain, Patrick S. G.; Tringe, Susannah G.; Fields, Matthew W.; Rubin, Edward M.; Tiedje, James M.; Hazen, Terry C.; Arkin, Adam P.; Zhou, Jizhong

    2015-01-01

    To understand patterns of geochemical cycling in pristine versus contaminated groundwater ecosystems, pristine shallow groundwater (FW301) and contaminated groundwater (FW106) samples from the Oak Ridge Integrated Field Research Center (OR-IFRC) were sequenced and compared to each other to determine phylogenetic and metabolic difference between the communities. Proteobacteria (e.g., Burkholderia, Pseudomonas) are the most abundant lineages in the pristine community, though a significant proportion ( >55%) of the community is composed of poorly characterized low abundance (individually <1%) lineages. The phylogenetic diversity of the pristine community contributed to a broader diversity of metabolic networks than the contaminated community. In addition, the pristine community encodes redundant and mostly complete geochemical cycles distributed over multiple lineages and appears capable of a wide range of metabolic activities. In contrast, many geochemical cycles in the contaminated community appear truncated or minimized due to decreased biodiversity and dominance by Rhodanobacter populations capable of surviving the combination of stresses at the site. These results indicate that the pristine site contains more robust and encodes more functional redundancy than the stressed community, which contributes to more efficient nutrient cycling and adaptability than the stressed community. PMID:26583008

  16. Potential approaches to the management of third-party impacts from groundwater transfers

    NASA Astrophysics Data System (ADS)

    Skurray, James H.; Pannell, David J.

    2012-08-01

    Groundwater extraction can have varied and diffuse effects. Negative external effects may include costs imposed on other groundwater users and on surrounding ecosystems. Environmental damages are commonly not reflected in market transactions. Groundwater transfers have the potential to cause spatial redistribution, concentration, and qualitative transformation of the impacts from pumping. An economically and environmentally sound groundwater transfer scheme would ensure that marginal costs from trades do not exceed marginal benefits, accounting for all third-party impacts, including those of a non-monetary nature as well as delayed effects. This paper proposes a menu of possible management strategies that would help preclude unacceptable impacts by restricting transfers with certain attributes, ideally ensuring that permitted transfers are at least welfare-neutral. Management tools would require that transfers limit or reduce environmental impacts, and provide for the compensation of financial impacts. Three management tools are described. While these tools can limit impacts from a given level of extraction, they cannot substitute for sustainable overall withdrawal limits. Careful implementation of transfer limits and exchange rates, and the strategic use of management area boundaries, may enable a transfer system to restrict negative externalities mainly to monetary costs. Provision for compensation of these costs could be built into the system.

  17. Groundwater impact assessment report for the 216-S-26 Crib, 200 West Area

    SciTech Connect

    Lindberg, J.W.; Evelo, S.D.; Alexander, D.J.

    1993-11-01

    This report assesses the impact of wastewater discharged to the 216-S-26 Crib on groundwater quality. The 216-S-26 Crib, located in the southern 200 West Area, has been in use since 1984 to dispose of liquid effluents from the 222-S Laboratory Complex. The 222-S Laboratory Complex effluent stream includes wastewater from four sources: the 222-S Laboratory, the 219-S Waste Storage Facility, the 222-SA Chemical Standards Laboratory, and the 291-S Exhaust Fan Control House and Stack. Based on assessment of groundwater chemistry and flow data, contaminant transport predictions, and groundwater chemistry data, the 216-S-26 Crib has minimal influence on groundwater contamination in the southern 200 West Area.

  18. Potential climate change impacts on groundwater resources of south-western Australia

    NASA Astrophysics Data System (ADS)

    Ali, Riasat; McFarlane, Don; Varma, Sunil; Dawes, Warrick; Emelyanova, Irina; Hodgson, Geoff; Charles, Steve

    2012-12-01

    use groundwater directly. In areas under dryland agriculture, projected groundwater levels continue to rise even under a drier future climate. The climate change effects on confined groundwater systems are expected to be modest. This is due to the longer times required for the changed recharge and water level conditions in the overlying aquifers to propagate to the confined aquifers. All water balance components are projected to be impacted by climate change to a greater or lesser extent. This has consequences for the amount of extractable water from both the unconfined and confined aquifers, changes the risk of sea-water intrusion, and has implications for the groundwater dependent ecosystems.

  19. Climate change impacts on the temperature and magnitude of groundwater discharge from shallow, unconfined aquifers

    NASA Astrophysics Data System (ADS)

    Kurylyk, Barret L.; MacQuarrie, Kerry T. B.; Voss, Clifford I.

    2014-04-01

    Cold groundwater discharge to streams and rivers can provide critical thermal refuge for threatened salmonids and other aquatic species during warm summer periods. Climate change may influence groundwater temperature and flow rates, which may in turn impact riverine ecosystems. This study evaluates the potential impact of climate change on the timing, magnitude, and temperature of groundwater discharge from small, unconfined aquifers that undergo seasonal freezing and thawing. Seven downscaled climate scenarios for 2046-2065 were utilized to drive surficial water and energy balance models (HELP3 and ForHyM2) to obtain future projections for daily ground surface temperature and groundwater recharge. These future surface conditions were then applied as boundary conditions to drive subsurface simulations of variably saturated groundwater flow and energy transport. The subsurface simulations were performed with the U.S. Geological Survey finite element model SUTRA that was recently modified to include the dynamic freeze-thaw process. The SUTRA simulations indicate a potential rise in the magnitude (up to 34%) and temperature (up to 3.6°C) of groundwater discharge to the adjacent river during the summer months due to projected increases in air temperature and precipitation. The thermal response of groundwater to climate change is shown to be strongly dependent on the aquifer dimensions. Thus, the simulations demonstrate that the thermal sensitivity of aquifers and baseflow-dominated streams to decadal climate change may be more complex than previously thought. Furthermore, the results indicate that the probability of exceeding critical temperature thresholds within groundwater-sourced thermal refugia may significantly increase under the most extreme climate scenarios.

  20. Climate change impacts on the temperature and magnitude of groundwater discharge from shallow, unconfined aquifers

    USGS Publications Warehouse

    Kurylyk, Barret L.; MacQuarrie, Kerry T.B; Voss, Clifford I.

    2014-01-01

    Cold groundwater discharge to streams and rivers can provide critical thermal refuge for threatened salmonids and other aquatic species during warm summer periods. Climate change may influence groundwater temperature and flow rates, which may in turn impact riverine ecosystems. This study evaluates the potential impact of climate change on the timing, magnitude, and temperature of groundwater discharge from small, unconfined aquifers that undergo seasonal freezing and thawing. Seven downscaled climate scenarios for 2046–2065 were utilized to drive surficial water and energy balance models (HELP3 and ForHyM2) to obtain future projections for daily ground surface temperature and groundwater recharge. These future surface conditions were then applied as boundary conditions to drive subsurface simulations of variably saturated groundwater flow and energy transport. The subsurface simulations were performed with the U.S. Geological Survey finite element model SUTRA that was recently modified to include the dynamic freeze-thaw process. The SUTRA simulations indicate a potential rise in the magnitude (up to 34%) and temperature (up to 3.6°C) of groundwater discharge to the adjacent river during the summer months due to projected increases in air temperature and precipitation. The thermal response of groundwater to climate change is shown to be strongly dependent on the aquifer dimensions. Thus, the simulations demonstrate that the thermal sensitivity of aquifers and baseflow-dominated streams to decadal climate change may be more complex than previously thought. Furthermore, the results indicate that the probability of exceeding critical temperature thresholds within groundwater-sourced thermal refugia may significantly increase under the most extreme climate scenarios.

  1. Impact of river restoration on groundwater - surface water - interactions

    NASA Astrophysics Data System (ADS)

    Kurth, Anne-Marie; Schirmer, Mario

    2014-05-01

    Since the end of the 19th century, flood protection was increasingly based on the construction of impermeable dams and side walls (BWG, 2003). In spite of providing flood protection, these measures also limited the connectivity between the river and the land, restricted the area available for flooding, and hampered the natural flow dynamics of the river. Apart from the debilitating effect on riverine ecosystems due to loss of habitats, these measures also limited bank filtration, inhibited the infiltration of storm water, and affected groundwater-surface water-interactions. This in turn had a profound effect on ecosystem health, as a lack of groundwater-surface water interactions led to decreased cycling of pollutants and nutrients in the hyporheic zone and limited the moderation of the water temperature (EA, 2009). In recent decades, it has become apparent that further damages to riverine ecosystems must be prohibited, as the damages to ecology, economy and society surmount any benefits gained from exploiting them. Nowadays, the restoration of rivers is a globally accepted means to restore ecosystem functioning, protect water resources and amend flood protection (Andrea et al., 2012; Palmer et al., 2005; Wortley et al., 2013). In spite of huge efforts regarding the restoration of rivers over the last 30 years, the question of its effectiveness remains, as river restorations often reconstruct a naturally looking rather than a naturally functioning stream (EA, 2009). We therefore focussed our research on the effectiveness of river restorations, represented by the groundwater-surface water-interactions. Given a sufficiently high groundwater level, a lack of groundwater-surface water-interactions after restoration may indicate that the vertical connectivity in the stream was not fully restored. In order to investigate groundwater-surface water-interactions we determined the thermal signature on the stream bed and in +/- 40 cm depth by using Distributed Temperature

  2. The Impact of Postnatal Depression and Associated Adversity on Early Mother-Infant Interactions and Later Infant Outcome.

    ERIC Educational Resources Information Center

    Murray, Lynne; And Others

    1996-01-01

    Examined the impact of maternal depression and adversity on mother-infant face-to-face interactions at 2 months, and on subsequent infant cognitive development and attachment. Disturbances in early mother-infant interactions were found to be predictive of poorer infant cognitive outcomes at 18 months. (MDM)

  3. Deterministic modelling of the cumulative impacts of underground structures on urban groundwater flow and the definition of a potential state of urban groundwater flow: example of Lyon, France

    NASA Astrophysics Data System (ADS)

    Attard, Guillaume; Rossier, Yvan; Winiarski, Thierry; Cuvillier, Loann; Eisenlohr, Laurent

    2016-08-01

    Underground structures have been shown to have a great influence on subsoil resources in urban aquifers. A methodology to assess the actual and the potential state of the groundwater flow in an urban area is proposed. The study develops a three-dimensional modeling approach to understand the cumulative impacts of underground infrastructures on urban groundwater flow, using a case in the city of Lyon (France). All known underground structures were integrated in the numerical model. Several simulations were run: the actual state of groundwater flow, the potential state of groundwater flow (without underground structures), an intermediate state (without impervious structures), and a transient simulation of the actual state of groundwater flow. The results show that underground structures fragment groundwater flow systems leading to a modification of the aquifer regime. For the case studied, the flow systems are shown to be stable over time with a transient simulation. Structures with drainage systems are shown to have a major impact on flow systems. The barrier effect of impervious structures was negligible because of the small hydraulic gradient of the area. The study demonstrates that the definition of a potential urban groundwater flow and the depiction of urban flow systems, which involves understanding the impact of underground structures, are important issues with respect to urban underground planning.

  4. Pathogens in Dairy Farming: Source Characterization and Groundwater Impacts

    NASA Astrophysics Data System (ADS)

    Atwill, E. R.; Watanabe, N.; Li, X.; Hou, L.; Harter, T.; Bergamaschi, B.

    2007-12-01

    Intense animal husbandry is of growing concern as a potential contamination source of enteric pathogens as well as antibiotics. To assess the public health risk from pathogens and their hydrologic pathways, we hypothesize that the animal farm is not a homogeneous diffuse source, but that pathogen loading to the soil and, therefore, to groundwater varies significantly between the various management units of a farm. A dairy farm, for example, may include an area with calf hutches, corrals for heifers of various ages, freestalls and exercise yards for milking cows, separate freestalls for dry cows, a hospital barn, a yard for collection of solid manure, a liquid manure storage lagoon, and fields receiving various amounts of liquid and solid manure. Pathogen shedding and, hence, therapeutic and preventive pharmaceutical treatments vary between these management units. We are implementing a field reconnaissance program to determine the occurrence of three different pathogens ( E. coli, Salmonella, Campylobacter) and one indicator organism ( Enterococcus) at the ground-surface and in shallow groundwater of seven different management units on each of two farms, and in each of four seasons (spring/dry season, summer/irrigation season, fall/dry season, winter/rainy season). Initial results indicate that significant differences exist in the occurrence of these pathogens between management units and between organisms. These differences are weakly reflected in their occurrence in groundwater, despite the similarity of the shallow geologic environment across these sites. Our results indicate the importance of differentiating sources within a dairy farm and the importance of understanding subsurface transport processes for these pathogens.

  5. IMPACT OF LEATHER PROCESSING INDUSTRIES ON CHROMIUM CONCENTRATION IN GROUNDWATER SOUTH OF CHENNAI CITY, INDIA

    NASA Astrophysics Data System (ADS)

    Elango, L.; Brindha, K.; G. Rajesh, V.

    2009-12-01

    The groundwater quality is under threat due to disposal of effluents from a number of industries. Poor practice of treatment of wastes from tanning industries or leather processing industries lead to pollution of groundwater. This study was carried out with the objective of assessing the impact of tanneries on groundwater quality in Chromepet area which is a part of the metropolitan area of Chennai, Tamil Nadu, India. This area serves as the home town for a number of small and large scale tanning industries. People in certain parts of this area depend on the groundwater for their domestic needs as there is no piped drinking water supply system. Topographically this region is generally flat with gentle slope towards east and north east. The charnockite rocks occur as basement at the depth of about 15m from the surface of this area. Weathered charnockite rock occurs at the depth from 7m to 15m from the ground surface. The upper layer consists of loamy soil. Groundwater occurs in the unconfined condition at a depth from 0.5m to 5m. Thirty six groundwater samples were collected during March 2008 and the groundwater samples were analysed for their heavy metal (chromium) content using atomic absorption spectrophotometer. Bureau of Indian Standards (BIS) recommended the maximum permissible limit of chromium in drinking water as 0.05 mg/l. Considering this, it was found that 86% of the groundwater samples possessed concentration of chromium above the maximum permissible limit recommended by BIS. The tanneries use chrome sulphate to strengthen the leather and make it water repellent. The excess of chromium gets washed off and remains in the wastewater. This wastewater is disposed into open uncovered drains either untreated or after partial treatment. Thus the chromium leaches through the soil and reaches the groundwater table. Apart from this, there is also huge quantity of solid waste resulting from the hides and skins which are dumped off without suitable treatment. The

  6. Impact of diffuse nitrate pollution sources on groundwater quality--some examples from Czechoslovakia.

    PubMed Central

    Benes, V; Pĕkný, V; Skorepa, J; Vrba, J

    1989-01-01

    In several regions of Czechoslovakia with intensive agricultural production, the correlation between the amount of nitrogen fertilizer applied and the nitrate content in groundwater has been recognized. Nitrate pollution of groundwater is considered to be the most serious source of nonpoint pollution in Czechoslovakia. A program of research into the effects of farming activities on groundwater quality in Czechoslovakia is under way on experimental fields (20 to 30 hectares) and, simultaneously, in regions in which shallow, vulnerable aquifers occur. The importance of the soil organic matter's stability for maintaining the groundwater quality is emphasized. Research based on nitrogen and organic carbon balance has shown that the restoration of a soil-groundwater system is a complicated process that usually requires changes in the extent and intensity of agricultural activities and consistent attention to the effects produced by natural conditions. Regional investigation of the impact of farming on shallow aquifers in the fluvial deposits of the Elbe River in Bohemia has proved the hydrochemical instability and vertical hydrochemical heterogeneity of these aquifers. The WASTEN deterministic model was used for modeling the transport and transformation of various types of inorganic fertilizers. The input data is based on laboratory and field measurements. Special topics are the verification of model calculations and the time and spatial variability of input data with respect to the unsaturated zone. The research results are being used for making regional and national agro-groundwater managerial schemes more precise, as well as for decision-making. PMID:2559844

  7. Impact of climate changes during the last 5 million years on groundwater in basement aquifers

    PubMed Central

    Aquilina, Luc; Vergnaud-Ayraud, Virginie; Les Landes, Antoine Armandine; Pauwels, Hélène; Davy, Philippe; Pételet-Giraud, Emmanuelle; Labasque, Thierry; Roques, Clément; Chatton, Eliot; Bour, Olivier; Ben Maamar, Sarah; Dufresne, Alexis; Khaska, Mahmoud; La Salle, Corinne Le Gal; Barbecot, Florent

    2015-01-01

    Climate change is thought to have major effects on groundwater resources. There is however a limited knowledge of the impacts of past climate changes such as warm or glacial periods on groundwater although marine or glacial fluids may have circulated in basements during these periods. Geochemical investigations of groundwater at shallow depth (80–400 m) in the Armorican basement (western France) revealed three major phases of evolution: (1) Mio-Pliocene transgressions led to marine water introduction in the whole rock porosity through density and then diffusion processes, (2) intensive and rapid recharge after the glacial maximum down to several hundred meters depths, (3) a present-day regime of groundwater circulation limited to shallow depth. This work identifies important constraints regarding the mechanisms responsible for both marine and glacial fluid migrations and their preservation within a basement. It defines the first clear time scales of these processes and thus provides a unique case for understanding the effects of climate changes on hydrogeology in basements. It reveals that glacial water is supplied in significant amounts to deep aquifers even in permafrosted zones. It also emphasizes the vulnerability of modern groundwater hydrosystems to climate change as groundwater active aquifers is restricted to shallow depths. PMID:26392383

  8. Impact of storm water on groundwater quality below retention/detention basins.

    PubMed

    Zubair, Arif; Hussain, Asif; Farooq, Mohammed A; Abbasi, Haq Nawaz

    2010-03-01

    Groundwater from 33 monitoring of peripheral wells of Karachi, Pakistan were evaluated in terms of pre- and post-monsoon seasons to find out the impact of storm water infiltration, as storm water infiltration by retention basin receives urban runoff water from the nearby areas. This may increase the risk of groundwater contamination for heavy metals, where the soil is sandy and water table is shallow. Concentration of dissolved oxygen is significantly low in groundwater beneath detention basin during pre-monsoon season, which effected the concentration of zinc and iron. The models of trace metals shown in basin groundwater reflect the land use served by the basins, while it differed from background concentration as storm water releases high concentration of certain trace metals such as copper and cadmium. Recharge by storm water infiltration decreases the concentration and detection frequency of iron, lead, and zinc in background groundwater; however, the study does not point a considerable risk for groundwater contamination due to storm water infiltration.

  9. Impact of climate changes during the last 5 million years on groundwater in basement aquifers.

    PubMed

    Aquilina, Luc; Vergnaud-Ayraud, Virginie; Les Landes, Antoine Armandine; Pauwels, Hélène; Davy, Philippe; Pételet-Giraud, Emmanuelle; Labasque, Thierry; Roques, Clément; Chatton, Eliot; Bour, Olivier; Ben Maamar, Sarah; Dufresne, Alexis; Khaska, Mahmoud; Le Gal La Salle, Corinne; Barbecot, Florent

    2015-01-01

    Climate change is thought to have major effects on groundwater resources. There is however a limited knowledge of the impacts of past climate changes such as warm or glacial periods on groundwater although marine or glacial fluids may have circulated in basements during these periods. Geochemical investigations of groundwater at shallow depth (80-400 m) in the Armorican basement (western France) revealed three major phases of evolution: (1) Mio-Pliocene transgressions led to marine water introduction in the whole rock porosity through density and then diffusion processes, (2) intensive and rapid recharge after the glacial maximum down to several hundred meters depths, (3) a present-day regime of groundwater circulation limited to shallow depth. This work identifies important constraints regarding the mechanisms responsible for both marine and glacial fluid migrations and their preservation within a basement. It defines the first clear time scales of these processes and thus provides a unique case for understanding the effects of climate changes on hydrogeology in basements. It reveals that glacial water is supplied in significant amounts to deep aquifers even in permafrosted zones. It also emphasizes the vulnerability of modern groundwater hydrosystems to climate change as groundwater active aquifers is restricted to shallow depths. PMID:26392383

  10. Impact of diffuse nitrate pollution sources on groundwater quality--some examples from Czechoslovakia.

    PubMed

    Benes, V; Pĕkný, V; Skorepa, J; Vrba, J

    1989-11-01

    In several regions of Czechoslovakia with intensive agricultural production, the correlation between the amount of nitrogen fertilizer applied and the nitrate content in groundwater has been recognized. Nitrate pollution of groundwater is considered to be the most serious source of nonpoint pollution in Czechoslovakia. A program of research into the effects of farming activities on groundwater quality in Czechoslovakia is under way on experimental fields (20 to 30 hectares) and, simultaneously, in regions in which shallow, vulnerable aquifers occur. The importance of the soil organic matter's stability for maintaining the groundwater quality is emphasized. Research based on nitrogen and organic carbon balance has shown that the restoration of a soil-groundwater system is a complicated process that usually requires changes in the extent and intensity of agricultural activities and consistent attention to the effects produced by natural conditions. Regional investigation of the impact of farming on shallow aquifers in the fluvial deposits of the Elbe River in Bohemia has proved the hydrochemical instability and vertical hydrochemical heterogeneity of these aquifers. The WASTEN deterministic model was used for modeling the transport and transformation of various types of inorganic fertilizers. The input data is based on laboratory and field measurements. Special topics are the verification of model calculations and the time and spatial variability of input data with respect to the unsaturated zone. The research results are being used for making regional and national agro-groundwater managerial schemes more precise, as well as for decision-making.

  11. Impacts of a large Sahelian city on groundwater hydrodynamics and quality: example of Niamey (Niger)

    NASA Astrophysics Data System (ADS)

    Hassane, Aïssata B.; Leduc, Christian; Favreau, Guillaume; Bekins, Barbara A.; Margueron, Thomas

    2016-03-01

    The management of groundwater resources is very important in the semiarid Sahel region, which is experiencing rapid urban development. Impacts of urbanization on groundwater resources were investigated in the unconfined aquifer of the Continental Terminal beneath the city of Niamey, Niger, using water level and chemical data. Hydrodynamic and chemical changes are best described by a combination of factors including the historical development of the city, current land use, water-table depth and topography. Seasonal groundwater recharge occurs with high spatial variability, as indicated by water-level monitoring in all wells, but there was no interannual trend over the 5-year study period. Groundwater salinity shows high spatial variability and a minor rising trend. The highest salinity is in the old city centre, with Na-NO3 dominant, and it increases seasonally with recharge. Salinity is much lower and more variable in the suburbs (Ca-HCO3, Ca-NO3, and Na-NO3 dominant). Nitrate is the main ionic contaminant and is seasonally or permanently above the international guidelines for drinking water quality in 36 % of sampled wells, with a peak value of 112 mg L-1 NO3-N (8 meq L-1). Comparison of urban and rural sites indicates a long-term increase in groundwater recharge and nitrate enrichment in the urban area with serious implications for groundwater management in the region.

  12. Review: Impact of underground structures on the flow of urban groundwater

    NASA Astrophysics Data System (ADS)

    Attard, Guillaume; Winiarski, Thierry; Rossier, Yvan; Eisenlohr, Laurent

    2016-02-01

    Property economics favours the vertical development of cities but flow of groundwater can be affected by the use of underground space in them. This review article presents the state of the art regarding the impact of disturbances caused by underground structures (tunnels, basements of buildings, deep foundations, etc.) on the groundwater flow in urban aquifers. The structures built in the underground levels of urban areas are presented and organised in terms of their impact on flow: obstacle to the flow or disturbance of the groundwater budget of the flow system. These two types of disturbance are described in relation to the structure area and the urban area. The work reviewed shows, on one hand, the individual impacts of different urban underground structures, and on the other, their cumulative impacts on flow, using real case studies. Lastly, the works are placed in perspective regarding the integration of underground structures with the aim of operational management of an urban aquifer. The literature presents deterministic numerical modelling as a tool capable of contributing to this aim, in that it helps to quantify the effect of an underground infrastructure project on groundwater flow, which is crucial for decision-making processes. It can also be an operational decision-aid tool for choosing construction techniques or for formulating strategies to manage the water resource.

  13. Perched-Water Analysis Related to Deep Vadose Zone Contaminant Transport and Impact to Groundwater

    SciTech Connect

    Oostrom, Martinus; Truex, Michael J.; Carroll, KC; Chronister, Glen B.

    2013-11-15

    Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located just a few meters above the water table beneath the B-complex at the Hanford Site. The perched water, containing elevated concentrations of uranium and technetium-99, is important to consider in evaluating the future flux of contaminated water into the groundwater. A study was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and, 3) associated groundwater impact. Based on the current vertical transport pathways and large areal extent of the perched system, the evaluation was conducted using a one-dimensional (1-D) analysis. Steady-state scoping calculations showed that the perching-layer hydraulic conductivity is likely to be up to two orders of magnitude less than the base case value obtained from Hanford site literature. Numerical flow and transport simulations provided both steady-state and transient system estimates of water and contaminant behavior and were used to further refine the range of conditions consistent with current observations of perched water height and to provide estimates of future water and contaminant flux to groundwater. With a recharge rate of 6 cm/yr, representative of current disturbed surface conditions, contaminant flux from the perched water occurs over a time interval of tens of years. However, if the recharge rate is 0.35 cm/yr, representative of returning recharge to pre-Hanford Site levels, the contaminant flux into the groundwater is spread over hundreds of years. It was also demonstrated that removal of perched water by pumping would reduce the flux of water (and associated contaminants) to the groundwater, thereby impacting the long-term rate of contaminant movement to the groundwater.

  14. Anammox Coupled With Nitrification Impacts a Saline, High Ammonia Groundwater

    NASA Astrophysics Data System (ADS)

    Figueroa, L. A.; Landkamer, L.; Peterson, D. M.; Metzler, D.

    2007-05-01

    High amounts of ammonia (130 to 2200 mg-N/l) in a saline environment (TDS = 10-20 g/l) are present in a groundwater plume adjacent to the Colorado River near Moab, Utah. Ammonia levels sufficient to affect aquatic life have been observed in limited sections of the river adjacent to the site, which has prompted interim treatment efforts. Microcosm studies were performed to assess the potential for microbial transformations of ammonia in the hyporheic zone sediment and the effect of ground/river-water mixing on transformations. Experiments were conducted using sub-riverbed sediment and mixtures of groundwater (290 mg-N/L ammonia) and river water (100%, 50% and 10% plume water) in anaerobic and aerobic environments. Aqueous NH4+, NO2-, NO3-, pH, dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were monitored over 38 days. Interestingly, the ammonia concentration decreased in all microcosms (29% to 100%) with the highest removal occurring in the oxic microcosms. Total nitrogen removal ranged from 27% to 83%. Three lines of evidence suggest that anammox occurred in the anaerobic microcosms: 1) NH4+ concentrations decreased, 2) little change in DOC occurred and 3) DIC decreased. DIC should increase if denitrification were the dominant process. It is possible that small amounts of O2 diffused into the microcosms, driving some nitrification that supplied NO2- for anammox. In the aerobic microcosms, denitrification or anammox occurred in addition to nitrification because nitrate did not accumulate in general. Again, we believe anammox occurred because of DOC and DIC trends. In the aerobic 10% groundwater microcosm, NO3- accumulated once the ammonia concentration became low and the nitrate level stabilized after the ammonia was gone. This also indicated that anammox was the dominant process because denitrification should not stop due to ammonia depletion. The aerobic microcosms were only agitated twice per week, which would allow the sediments to become

  15. The long-term impact of early adversity on late-life psychiatric disorders.

    PubMed

    Gershon, Anda; Sudheimer, Keith; Tirouvanziam, Rabindra; Williams, Leanne M; O'Hara, Ruth

    2013-04-01

    Early adversity is a strong and enduring predictor of psychiatric disorders including mood disorders, anxiety disorders, substance abuse or dependence, and posttraumatic stress disorder. However, the mechanisms of this effect are not well understood. The purpose of this review is to summarize and integrate the current research knowledge pertaining to the long-term effects of early adversity on psychiatric disorders, particularly in late life. We explore definitional considerations including key dimensions of the experience such as type, severity, and timing of adversity relative to development. We then review the potential biological and environmental mediators and moderators of the relationships between early adversity and psychiatric disorders. We conclude with clinical implications, methodological challenges and suggestions for future research. PMID:23443532

  16. Impact of Adverse Childhood Experiences on Psychotic-Like Symptoms and Stress Reactivity in Daily Life in Nonclinical Young Adults

    PubMed Central

    Ballespí, Sergi; Mitjavila, Mercè; Myin-Germeys, Inez; Kwapil, Thomas R.; Barrantes-Vidal, Neus

    2016-01-01

    Background There is increasing interest in elucidating the association of different childhood adversities with psychosis-spectrum symptoms as well as the mechanistic processes involved. This study used experience sampling methodology to examine (i) associations of a range of childhood adversities with psychosis symptom domains in daily life; (ii) whether associations of abuse and neglect with symptoms are consistent across self-report and interview methods of trauma assessment; and (iii) the role of different adversities in moderating affective, psychotic-like, and paranoid reactivity to situational and social stressors. Method A total of 206 nonclinical young adults were administered self-report and interview measures to assess childhood abuse, neglect, bullying, losses, and general traumatic events. Participants received personal digital assistants that signaled them randomly eight times daily for one week to complete questionnaires about current experiences, including symptoms, affect, and stress. Results Self-reported and interview-based abuse and neglect were associated with psychotic-like and paranoid symptoms, whereas only self-reported neglect was associated with negative-like symptoms. Bullying was associated with psychotic-like symptoms. Losses and general traumatic events were not directly associated with any of the symptom domains. All the childhood adversities were associated with stress reactivity in daily life. Interpersonal adversities (abuse, neglect, bullying, and losses) moderated psychotic-like and/or paranoid reactivity to situational and social stressors, whereas general traumatic events moderated psychotic-like reactivity to situational stress. Also, different interpersonal adversities exacerbated psychotic-like and/or paranoid symptoms in response to distinct social stressors. Discussion The present study provides a unique examination of how childhood adversities impact the expression of spectrum symptoms in the real world and lends support

  17. Analysis of the impacts of well yield and groundwater depth on irrigated agriculture

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    Previous research has found that irrigation water demand is relatively insensitive to water price, suggesting that increased pumping costs due to declining groundwater levels will have limited effects on agricultural water management practices. However, non-linear changes in well yields as aquifer saturated thickness is reduced may have large impacts on irrigated production that are currently neglected in projections of the long-term sustainability of groundwater-fed irrigation. We conduct empirical analysis of observation data and numerical simulations for case studies in Nebraska, USA, to compare the impacts of changes in well yield and groundwater depth on agricultural production. Our findings suggest that declining well pumping capacities reduce irrigated production areas and profits significantly, whereas increased pumping costs reduce profits but have minimal impacts on the intensity of groundwater-fed irrigation. We suggest, therefore, that management of the dynamic relationship between well yield and saturated thickness should be a core component of policies designed to enhance long-term food security and support adaptation to climate change.

  18. Tetracycline residues and tetracycline resistance genes in groundwater impacted by swine production facilities.

    PubMed

    Mackie, Roderick I; Koike, Satoshi; Krapac, Ivan; Chee-Sanford, Joanne; Maxwell, Scott; Aminov, Rustam I

    2006-01-01

    Antibiotics are used at therapeutic levels to treat disease; at slightly lower levels as prophylactics; and at low, subtherapeutic levels for growth promotion and improvement of feed efficiency. Over 88% of swine producers in the United States gave antimicrobials to grower/finisher pigs in feed as a growth promoter in 2000. It is estimated that ca. 75% of antibiotics are not absorbed by animals and are excreted in urine and feces. The extensive use of antibiotics in swine production has resulted in antibiotic resistance in many intestinal bacteria, which are also excreted in swine feces, resulting in dissemination of resistance genes into the environment. To assess the impact of manure management on groundwater quality, groundwater samples have been collected near two swine confinement facilities that use lagoons for manure storage and treatment. Several key contaminant indicators - including inorganic ions, antibiotics, and antibiotic resistance genes - were analyzed in groundwater collected from the monitoring wells. Chloride, ammonium, potassium, and sodium were predominant inorganic constituents in the manure samples and served as indicators of groundwater contamination. Based on these analyses, shallow groundwater has been impacted by lagoon seepage at both sites. Liquid chromatography-mass spectroscopy (LC-MS) was used to measure the dissolved concentrations of tetracycline, chlortetracycline, and oxytetracycline in groundwater and manure. Although tetracyclines were regularly used at both facilities, they were infrequently detected in manure samples and then at relatively trace concentrations. Concentrations of all tetracyclines and their breakdown products in the groundwater sampled were generally less than 0.5 microg/L. Bacterial tetracycline resistance genes served as distinct genotypic markers to indicate the dissemination and mobility of antibiotic resistance genes that originated from the lagoons. Applying PCR to genomic DNA extracted from the lagoon

  19. Tetracycline residues and tetracycline resistance genes in groundwater impacted by swine production facilities

    USGS Publications Warehouse

    Mackie, R.I.; Koike, S.; Krapac, I.; Chee-Sanford, J.; Maxwell, Susan; Aminov, R.I.

    2006-01-01

    Antibiotics are used at therapeutic levels to treat disease; at slightly lower levels as prophylactics; and at low, subtherapeutic levels for growth promotion and improvement of feed efficiency. Over 88% of swine producers in the United States gave antimicrobials to grower/finisher pigs in feed as a growth promoter in 2000. It is estimated that ca. 75% of antibiotics are not absorbed by animals and are excreted in urine and feces. The extensive use of antibiotics in swine production has resulted in antibiotic resistance in many intestinal bacteria, which are also excreted in swine feces, resulting in dissemination of resistance genes into the environment.To assess the impact of manure management on groundwater quality, groundwater samples have been collected near two swine confinement facilities that use lagoons for manure storage and treatment. Several key contaminant indicators-including inorganic ions, antibiotics, and antibiotic resistance genes-were analyzed in groundwater collected from the monitoring wells. Chloride, ammonium, potassium, and sodium were predominant inorganic constituents in the manure samples and served as indicators of groundwater contamination. Based on these analyses, shallow groundwater has been impacted by lagoon seepage at both sites. Liquid chromatography-mass spectroscopy (LC-MS) was used to measure the dissolved concentrations of tetracycline, chlortetracycline, and oxytetracycline in groundwater and manure. Although tetracyclines were regularly used at both facilities, they were infrequently detected in manure samples and then at relatively trace concentrations. Concentrations of all tetracyclines and their breakdown products in the groundwater sampled were generally less than 0.5 ??g/L.Bacterial tetracycline resistance genes served as distinct genotypic markers to indicate the dissemination and mobility of antibiotic resistance genes that originated from the lagoons. Applying PCR to genomic DNA extracted from the lagoon and

  20. The impact of on-site wastewater from high density cluster developments on groundwater quality

    NASA Astrophysics Data System (ADS)

    Morrissey, P. J.; Johnston, P. M.; Gill, L. W.

    2015-11-01

    The net impact on groundwater quality from high density clusters of unsewered housing across a range of hydro(geo)logical settings has been assessed. Four separate cluster development sites were selected, each representative of different aquifer vulnerability categories. Groundwater samples were collected on a monthly basis over a two year period for chemical and microbiological analysis from nested multi-horizon sampling boreholes upstream and downstream of the study sites. The field results showed no statistically significant difference between upstream and downstream water quality at any of the study areas, although there were higher breakthroughs in contaminants in the High and Extreme vulnerability sites linked to high intensity rainfall events; these however, could not be directly attributed to on-site effluent. Linked numerical models were then built for each site using HYDRUS 2D to simulate the attenuation of contaminants through the unsaturated zone from which the resulting hydraulic and contaminant fluxes at the water table were used as inputs into MODFLOW MT3D models to simulate the groundwater flows. The results of the simulations confirmed the field observations at each site, indicating that the existing clustered on-site wastewater discharges would only cause limited and very localised impacts on groundwater quality, with contaminant loads being quickly dispersed and diluted downstream due to the relatively high groundwater flow rates. Further simulations were then carried out using the calibrated models to assess the impact of increasing cluster densities revealing little impact at any of the study locations up to a density of 6 units/ha with the exception of the Extreme vulnerability site.

  1. The impact of on-site wastewater from high density cluster developments on groundwater quality.

    PubMed

    Morrissey, P J; Johnston, P M; Gill, L W

    2015-11-01

    The net impact on groundwater quality from high density clusters of unsewered housing across a range of hydro(geo)logical settings has been assessed. Four separate cluster development sites were selected, each representative of different aquifer vulnerability categories. Groundwater samples were collected on a monthly basis over a two year period for chemical and microbiological analysis from nested multi-horizon sampling boreholes upstream and downstream of the study sites. The field results showed no statistically significant difference between upstream and downstream water quality at any of the study areas, although there were higher breakthroughs in contaminants in the High and Extreme vulnerability sites linked to high intensity rainfall events; these however, could not be directly attributed to on-site effluent. Linked numerical models were then built for each site using HYDRUS 2D to simulate the attenuation of contaminants through the unsaturated zone from which the resulting hydraulic and contaminant fluxes at the water table were used as inputs into MODFLOW MT3D models to simulate the groundwater flows. The results of the simulations confirmed the field observations at each site, indicating that the existing clustered on-site wastewater discharges would only cause limited and very localised impacts on groundwater quality, with contaminant loads being quickly dispersed and diluted downstream due to the relatively high groundwater flow rates. Further simulations were then carried out using the calibrated models to assess the impact of increasing cluster densities revealing little impact at any of the study locations up to a density of 6 units/ha with the exception of the Extreme vulnerability site.

  2. Impact of long-term land application of biosolids on groundwater quality and surface soils

    SciTech Connect

    Surampalli, R.Y.; Lin, K.L.; Banerji, S.K.

    1995-11-01

    A study was conducted to evaluate the long-term land application of Biosolids and its potential impact on groundwater quality and surface soils. For this study, an existing site, that has been in operation for 8--15 years were selected for sampling and analyses. From this site sludge applied soil samples, background soil samples, and groundwater monitoring samples were obtained. The samples were analyzed for the following: pH, conductivity, total solids, fecal coliform, fecal streptococci, nitrate nitrogen, ammonia nitrogen, TKN, arsenic, cadmium, chromium, copper, nickel, lead, and zinc. The results of this study indicate that groundwater at this biosolids application site was not contaminated with heavy metals or pathogens. The bacteriological soil data also indicated that the levels of fecal coliform and fecal streptococci were close to background level with no evidence of contamination. The results also indicate that there is no heavy metals buildup in biosolids-amended soils.

  3. Iron Deficiency Anemia Coexists with Cancer Related Anemia and Adversely Impacts Quality of Life

    PubMed Central

    Kanuri, Giridhar; Sawhney, Ritica; Varghese, Jeeva; Britto, Madonna; Shet, Arun

    2016-01-01

    Cancer related anemia (CRA) adversely affects patient Quality of Life (QoL) and overall survival. We prospectively studied the prevalence, etiology and the impact of anemia on QoL in 218 Indian cancer patients attending a tertiary referral hospital. The study used the sTfR/log Ferritin index to detect iron deficiency anemia and assessed patient QoL using the Functional Assessment of Cancer Therapy-Anemia (FACT-An) tool, standardized for language. Mean patient age was 51±13 years and 60% were female. The prevalence of cancer related anemia in this setting was 64% (n = 139). As expected, plasma ferritin did not differ significantly between anemic (n = 121) and non-anemic cancer patients (n = 73). In contrast, plasma sTfR levels were significantly higher in anemic cancer patients compared to non-anemic cancer patients (31 nmol/L vs. 24 nmol/L, p = 0.002). Among anemic cancer patients, using the sTfR/log Ferritin index, we found that 60% (n = 83) had iron deficiency anemia (IDA). Interestingly, plasma sTfR levels were significantly higher in cancer patients with CRA+IDA (n = 83) compared with patients having CRA (n = 38) alone (39 nmol/L vs. 20 nmol/L, p<0.001). There was a significant linear correlation between Hb and QoL (Spearman ρ = 0.21; p = 0.001) and multivariate regression analysis revealed that every gram rise in Hb was accompanied by a 3.1 unit increase in the QoL score (95% CI = 0.19–5.33; p = 0.003). The high prevalence of anemia in cancer patients, a major portion of which is due to iron deficiency anemia, the availability of sensitive and specific biomarkers of iron status to detect IDA superimposed on anemia of inflammation, suggests an urgent need to diagnose and treat such patients. Despite the potential negative consequences of increasing metabolically available plasma iron in cancer, our clinical data suggest that detecting and treating IDA in anemic cancer patients will have important consequences to their QoL and overall survival. Clinical

  4. Impact of Groundwater Flow on Thermal Energy Storage and Borehole Thermal Interference

    NASA Astrophysics Data System (ADS)

    Emad Dehkordi, S.; Schincariol, Robert A.

    2013-04-01

    Borehole heat exchanger (BHE) systems are drawing increasing attention and popularity due to their potential energy efficiency and environmental sustainability, as well as their worldwide applicability. Consequently the concern for sustainable designs and proper implementation is rising too. Furthermore an improperly planned and executed system can be economically unjustifiable. To address these issues related design software and to some extent regulatory guidelines have been developed. Thermal input load function and interaction with the subsurface significantly affect thermal performance and sustainability of geothermal heat pump (GHP) systems. Of particular interest is the interaction of such systems with groundwater flow and its impacts. However the related guidelines and the design software do not seem to properly address this growing concern. Typically regulations do not distinguish between high and no groundwater flow conditions, nor do they specify a groundwater velocity threshold at which it becomes important. A further limitation is that most BHE design software used by industry assume a closed box approach discounting the heat transport in/out by the groundwater flow. To efficiently model grids of multiple BHEs, FEFLOW® 6 and the integrated BHE solution is used. Single and multiple borehole grids with U-tube heat exchanger are modeled and compared here. All boreholes are assigned equal heat extraction and flow rates; loop temperatures are then calculated over the system lifetime to compare the thermal efficiency and evaluate the thermal interference between boreholes. For the purpose of assessing the effect of groundwater flow on thermal storage as well as interference, multiple heat loads (balanced and unbalanced) are simulated. Groundwater velocity and borehole spacing are also varied to identify possible thresholds for each case. The study confirms the significance of groundwater flow in certain conditions. The results can be applied to improve the

  5. The long-term impact of adverse caregiving environments on epigenetic modifications and telomeres

    PubMed Central

    Blaze, Jennifer; Asok, Arun; Roth, Tania L.

    2015-01-01

    Early childhood is a sensitive period in which infant-caregiver experiences have profound effects on brain development and behavior. Clinical studies have demonstrated that infants who experience stress and adversity in the context of caregiving are at an increased risk for the development of psychiatric disorders. Animal models have helped to elucidate some molecular substrates of these risk factors, but a complete picture of the biological basis remains unknown. Studies continue to indicate that environmentally-driven epigenetic modifications may be an important mediator between adverse caregiving environments and psychopathology. Epigenetic modifications such as DNA methylation, which normally represses gene transcription, and microRNA processing, which interferes with both transcription and translation, show long-term changes throughout the brain and body following adverse caregiving. Recent evidence has also shown that telomeres (TTAGGG nucleotide repeats that cap the ends of DNA) exhibit long-term changes in the brain and in the periphery following exposure to adverse caregiving environments. Interestingly, telomeric enzymes and subtelomeric regions are subject to epigenetic modifications—a factor which may play an important role in regulating telomere length and contribute to future mental health. This review will focus on clinical and animal studies that highlight the long-term epigenetic and telomeric changes produced by adverse caregiving in early-life. PMID:25904853

  6. Implementing groundwater extraction in life cycle impact assessment: characterization factors based on plant species richness for The Netherlands.

    PubMed

    van Zelm, Rosalie; Schipper, Aafke M; Rombouts, Michiel; Snepvangers, Judith; Huijbregts, Mark A J

    2011-01-15

    An operational method to evaluate the environmental impacts associated with groundwater use is currently lacking in life cycle assessment (LCA). This paper outlines a method to calculate characterization factors that address the effects of groundwater extraction on the species richness of terrestrial vegetation. Characterization factors (CF) were derived for The Netherlands and consist of a fate and an effect part. The fate factor equals the change in drawdown due to a change in groundwater extraction and expresses the amount of time required for groundwater replenishment. It was obtained with a grid-specific steady-state groundwater flow model. Effect factors were obtained from groundwater level response curves of potential plant species richness, which was constructed based on the soil moisture requirements of 625 plant species. Depending on the initial groundwater level, effect factors range up to 9.2% loss of species per 10 cm of groundwater level decrease. The total Dutch CF for groundwater extraction depended on the value choices taken and ranged from 0.09 to 0.61 m(2)·yr/m(3). For tap water production, we showed that groundwater extraction can be responsible for up to 32% of the total terrestrial ecosystem damage. With the proposed approach, effects of groundwater extraction on terrestrial ecosystems can be systematically included in LCA.

  7. Impacts of human activity modes and climate on heavy metal "spread" in groundwater are biased.

    PubMed

    Chen, Ming; Qin, Xiaosheng; Zeng, Guangming; Li, Jian

    2016-06-01

    Groundwater quality deterioration has attracted world-wide concerns due to its importance for human water supply. Although more and more studies have shown that human activities and climate are changing the groundwater status, an investigation on how different groundwater heavy metals respond to human activity modes (e.g. mining, waste disposal, agriculture, sewage effluent and complex activity) in a varying climate has been lacking. Here, for each of six heavy metals (i.e. Fe, Zn, Mn, Pb, Cd and Cu) in groundwater, we use >330 data points together with mixed-effect models to indicate that (i) human activity modes significantly influence the Cu and Mn but not Zn, Fe, Pb and Cd levels, and (ii) annual mean temperature (AMT) only significantly influences Cu and Pb levels, while annual precipitation (AP) only significantly affects Fe, Cu and Mn levels. Given these differences, we suggest that the impacts of human activity modes and climate on heavy metal "spread" in groundwater are biased. PMID:27003366

  8. Impact of post-methanation distillery effluent irrigation on groundwater quality.

    PubMed

    Jain, N; Bhatia, A; Kaushik, R; Kumar, Sanjeev; Joshi, H C; Pathak, H

    2005-11-01

    Molasses-based distilleries generate large quantities of effluent, which is used for irrigation in many countries including India. The effluent is rich in organic and inorganic ions, which may leach down and pollute the groundwater. An on-farm experiment was conducted to assess the impact of long-term irrigation with post-methanation distillery effluent (PMDE) on nitrate, sulphate, chloride, sodium, potassium, and magnesium contents in the groundwater of two sites in northwest India. Electrical conductivity (EC), pH, total dissolved solids (TDS), sodium adsorption ratio (SAR) and colour were also determined to assess the chemical load in the groundwater. Nitrate content in the groundwater samples ranged from 16.95 mg L(-1) in the unamended fields to 59.81 mg L(-1) in the PMDE-amended fields during the 2-year study (2001-2002). Concentrations of TDS in water samples from tubewell of the amended field was higher by 40.4% over the tubewell water of the unamended field. Colour of the water samples of the amended fields was also darker than that of the unamended fields. The study indicated that the organic and inorganic ions added through the effluent could pose a serious threat to the groundwater quality if applied without proper monitoring. PMID:16308790

  9. Impacts of human activity modes and climate on heavy metal "spread" in groundwater are biased.

    PubMed

    Chen, Ming; Qin, Xiaosheng; Zeng, Guangming; Li, Jian

    2016-06-01

    Groundwater quality deterioration has attracted world-wide concerns due to its importance for human water supply. Although more and more studies have shown that human activities and climate are changing the groundwater status, an investigation on how different groundwater heavy metals respond to human activity modes (e.g. mining, waste disposal, agriculture, sewage effluent and complex activity) in a varying climate has been lacking. Here, for each of six heavy metals (i.e. Fe, Zn, Mn, Pb, Cd and Cu) in groundwater, we use >330 data points together with mixed-effect models to indicate that (i) human activity modes significantly influence the Cu and Mn but not Zn, Fe, Pb and Cd levels, and (ii) annual mean temperature (AMT) only significantly influences Cu and Pb levels, while annual precipitation (AP) only significantly affects Fe, Cu and Mn levels. Given these differences, we suggest that the impacts of human activity modes and climate on heavy metal "spread" in groundwater are biased.

  10. Quantification of anthropogenic impact on groundwater-dependent terrestrial ecosystem using geochemical and isotope tools combined with 3-D flow and transport modelling

    NASA Astrophysics Data System (ADS)

    Zurek, A. J.; Witczak, S.; Dulinski, M.; Wachniew, P.; Rozanski, K.; Kania, J.; Postawa, A.; Karczewski, J.; Moscicki, W. J.

    2015-02-01

    Groundwater-dependent ecosystems (GDEs) have important functions in all climatic zones as they contribute to biological and landscape diversity and provide important economic and social services. Steadily growing anthropogenic pressure on groundwater resources creates a conflict situation between nature and man which are competing for clean and safe sources of water. Such conflicts are particularly noticeable in GDEs located in densely populated regions. A dedicated study was launched in 2010 with the main aim to better understand the functioning of a groundwater-dependent terrestrial ecosystem (GDTE) located in southern Poland. The GDTE consists of a valuable forest stand (Niepolomice Forest) and associated wetland (Wielkie Błoto fen). It relies mostly on groundwater from the shallow Quaternary aquifer and possibly from the deeper Neogene (Bogucice Sands) aquifer. In July 2009 a cluster of new pumping wells abstracting water from the Neogene aquifer was set up 1 km to the northern border of the fen. A conceptual model of the Wielkie Błoto fen area for the natural, pre-exploitation state and for the envisaged future status resulting from intense abstraction of groundwater through the new well field was developed. The main aim of the reported study was to probe the validity of the conceptual model and to quantify the expected anthropogenic impact on the studied GDTE. A wide range of research tools was used. The results obtained through combined geologic, geophysical, geochemical, hydrometric and isotope investigations provide strong evidence for the existence of upward seepage of groundwater from the deeper Neogene aquifer to the shallow Quaternary aquifer supporting the studied GDTE. Simulations of the groundwater flow field in the study area with the aid of a 3-D flow and transport model developed for Bogucice Sands (Neogene) aquifer and calibrated using environmental tracer data and observations of hydraulic head in three different locations on the study area

  11. Monitoring ecological recovery in a stream impacted by contaminated groundwater

    SciTech Connect

    Southworth, G.R.; Cada, G.F.; Kszos, L.A.; Peterson, M.J.; Smith, J.G.

    1997-11-01

    Past in-ground disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. A biological monitoring program initiated in 1984 has evaluated the effectiveness of the extensive remedial actions undertaken to address contamination sources. Elements of the monitoring program included toxicity testing with fish and invertebrates, bioaccumulation monitoring, and instream monitoring of streambed invertebrate and fish communities. In the mid 1980`s, toxicity tests on stream water indicated that the headwaters of the stream were acutely toxic to fish and aquatic invertebrates as a result of infiltration of a metal-enriched groundwater from ponds used to dispose of acid wastes. Over a twelve year period, measurable toxicity in the headwaters decreased, first becoming non-toxic to larval fish but still toxic to invertebrates, then becoming intermittently toxic to invertebrates. By 1997, episodic toxicity was infrequent at the site that was acutely toxic at the start of the study. Recovery in the fish community followed the pattern of the toxicity tests. Initially, resident fish populations were absent from reaches where toxicity was measured, but as toxicity to fish larvae disappeared, the sites in upper Bear Creek were colonized by fish. The Tennessee dace, an uncommon species receiving special protection by the State of Tennessee, became a numerically important part of the fish population throughout the upper half of the creek, making Bear Creek one of the most significant habitats for this species in the region. Although by 1990 fish populations were comparable to those of similar size reference streams, episodic toxicity in the headwaters coincided with a recruitment failure in 1996. Bioaccumulation monitoring indicated the presence of PCBs and mercury in predatory fish in Bear Creek, and whole forage fish contained elevated levels of cadmium, lead, lithium, nickel, mercury, and uranium.

  12. Impact of land-surface elevation and riparian evapotranspiration seasonality on groundwater budget in MODFLOW models

    NASA Astrophysics Data System (ADS)

    Ajami, Hoori; Meixner, Thomas; Maddock, Thomas; Hogan, James F.; Guertin, D. Phillip

    2011-09-01

    Riparian groundwater evapotranspiration (ETg) constitutes a major component of the water balance especially in many arid and semi-arid environments. Although spatial and temporal variability of riparian ETg are controlled by climate, vegetation and subsurface characteristics, depth to water table (DTWT) is often considered the major controlling factor. Relationships between ETg rates and DTWT, referred to as ETg curves, are implemented in MODFLOW ETg packages (EVT, ETS1 and RIP-ET) with different functional forms. Here, the sensitivity of the groundwater budget in MODFLOW groundwater models to ETg parameters (including ETg curves, land-surface elevation and ETg seasonality) are investigated. A MODFLOW model of the hypothetical Dry Alkaline Valley in the Southwestern USA is used to show how spatial representation of riparian vegetation and digital elevation model (DEM) processing methods impact the water budget when RIPGIS-NET (a GIS-based ETg program) is used with MODFLOW's RIP-ET package, and results are compared with the EVT and ETS1 packages. Results show considerable impact on ETg and other groundwater budget components caused by spatial representation of riparian vegetation, vegetation type, fractional coverage areas and land-surface elevation. RIPGIS-NET enhances ETg estimation in MODFLOW by incorporating vegetation and land-surface parameters, providing a tool for ecohydrology studies, riparian ecosystem management and stream restoration.

  13. The Impact of Adverse Childhood Experiences on an Urban Pediatric Population

    ERIC Educational Resources Information Center

    Burke, Nadine J.; Hellman, Julia L.; Scott, Brandon G.; Weems, Carl F.; Carrion, Victor G.

    2011-01-01

    Objective: The goal of this study was to investigate the adverse childhood experiences (ACEs) in youth in a low-income, urban community. Study design: Data from a retrospective chart review of 701 subjects from the Bayview Child Health Center in San Francisco are presented. Medical chart documentation of ACEs as defined in previous studies were…

  14. The Noise from Wind Turbines: Potential Adverse Impacts on Children's Well-Being

    ERIC Educational Resources Information Center

    Bronzaft, Arline L.

    2011-01-01

    Research linking loud sounds to hearing loss in youngsters is now widespread, resulting in the issuance of warnings to protect children's hearing. However, studies attesting to the adverse effects of intrusive sounds and noise on children's overall mental and physical health and well-being have not received similar attention. This, despite the…

  15. Coupled Geochemical Impacts of Leaking CO2 and Contaminants from Subsurface Storage Reservoirs on Groundwater Quality.

    PubMed

    Shao, Hongbo; Qafoku, Nikolla P; Lawter, Amanda R; Bowden, Mark E; Brown, Christopher F

    2015-07-01

    The leakage of CO2 and the concomitant brine from deep storage reservoirs to overlying groundwater aquifers is considered one of the major potential risks associated with geologic CO2 sequestration (GCS). In this work both batch and column experiments were conducted to determine the fate of trace metals in groundwater in the scenarios of CO2 and metal-contaminated brine leakage. The sediments for this study were from an unconsolidated sand and gravel aquifer in Kansas, containing 0-4 wt % carbonates. Cd (114 μg/L) and As (40 μg/L) were spiked into the reaction system to represent potential contaminants from the reservoir brine. Through this research we demonstrated that Cd and As were adsorbed on the sediments, in spite of the lowered pH due to CO2 dissolution in the groundwater. Cd concentrations in the effluent were below the Cd MCL, even for sediments without detectable carbonate to buffer the pH. Arsenic concentrations in the effluent were also significantly lower than the influent concentration, suggesting that the sediments tested have the capacity to mitigate the coupled adverse effects of CO2 leakage and brine intrusion. The mitigation capacity of sediment is a function of its geochemical properties (e.g., the presence of carbonate minerals, adsorbed As, and phosphate).

  16. A holistic look at minimizing adverse environmental impact under Section 316(b) of the Clean Water Act.

    PubMed

    Veil, John A; Puder, Markus G; Littleton, Debra J; Johnson, Nancy

    2002-04-18

    Section 316(b) of the Clean Water Act (CWA) requires that "the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact." As the U.S. Environmental Protection Agency (EPA) develops new regulations to implement Section 316(b), much of the debate has centered on adverse impingement and entrainment impacts of cooling-water intake structures. Depending on the specific location and intake layout, once-through cooling systems withdrawing many millions of gallons of water per day can, to a varying degree, harm fish and other aquatic organisms in the water bodies from which the cooling water is withdrawn. Therefore, opponents of once-through cooling systems have encouraged the EPA to require wet or dry cooling tower systems as the best technology available (BTA), without considering site-specific conditions. However, within the context of the broader scope of the CWA mandate, this focus seems too narrow. Therefore, this article examines the phrase "minimizing adverse environmental impact" in a holistic light. Emphasis is placed on the analysis of the terms "environmental" and "minimizing." Congress chose "environmental" in lieu of other more narrowly focused terms like "impingement and entrainment," "water quality," or "aquatic life." In this light, BTA for cooling-water intake structures must minimize the entire suite of environmental impacts, as opposed to just those associated with impingement and entrainment. Wet and dry cooling tower systems work well to minimize entrainment and impingement, but they introduce other equally important impacts because they impose an energy penalty on the power output of the generating unit. The energy penalty results from a reduction in plant operating efficiency and an increase in internal power consumption. As a consequence of the energy penalty, power companies must generate additional electricity to achieve the same net output

  17. Hydrochemical Impacts of CO2 Leakage on Fresh Groundwater: a Field Scale Experiment

    NASA Astrophysics Data System (ADS)

    Lions, J.; Gal, F.; Gombert, P.; Lafortune, S.; Darmoul, Y.; Prevot, F.; Grellier, S.; Squarcioni, P.

    2013-12-01

    One of the questions related to the emerging technology for Carbon Geological Storage concerns the risk of CO2 migration beyond the geological storage formation. In the event of leakage toward the surface, the CO2 might affect resources in neighbouring formations (geothermal or mineral resources, groundwater) or even represent a hazard for human activities at the surface or in the subsurface. In view of the preservation of the groundwater resources mainly for human consumption, this project studies the potential hydrogeochemical impacts of CO2 leakage on fresh groundwater quality. One of the objectives is to characterize the bio-geochemical mechanisms that may impair the quality of fresh groundwater resources in case of CO2 leakage. To reach the above mentioned objectives, this project proposes a field experiment to characterize in situ the mechanisms that could impact the water quality, the CO2-water-rock interactions and also to improve the monitoring methodology by controlled CO2 leakage in shallow aquifer. The tests were carried out in an experimental site in the chalk formation of the Paris Basin. The site is equipped with an appropriate instrumentation and was previously characterized (8 piezometers, 25 m deep and 4 piezairs 11 m deep). The injection test was preceded by 6 months of monitoring in order to characterize hydrodynamics and geochemical baselines of the site (groundwater, vadose and soil). Leakage into groundwater is simulated via the injection of a small quantity of food-grade CO2 (~20 kg dissolved in 10 m3 of water) in the injection well at a depth of about 20 m. A plume of dissolved CO2 is formed and moves downward according to the direction of groundwater flow and probably by degassing in part to the surface. During the injection test, hydrochemical monitoring of the aquifer is done in situ and by sampling. The parameters monitored in the groundwater are the piezometric head, temperature, pH and electrical conductivity. Analysis on water

  18. A comparison of the extent and impacts of sewage contamination on urban groundwater in developed and developing countries.

    PubMed

    Barrett, M; Howard, G; Pedley, S; Taylor, R; Nalubega, M

    2000-01-01

    In much of the world urban groundwater is an important resource for domestic and industrial use. In many developing countries, groundwater taken directly (untreated) from individual springs and wells is the only option available to communities where comprehensive, reliable reticulated supply systems are absent. A common feature of urban groundwater in both developing and developed countries is contamination by sewage. Current and recent research is presented that shows sewer leakage impacts groundwater in developed countries whilst on-site sanitation contaminates groundwater in developing countries. In the latter case, the competing demands of sanitation and groundwater protection must be addressed. Limitations on the usefulness of accepted standard sewage indicator species in groundwater are also highlighted. As sewage contamination of groundwater is usually addressed only if an actual health risk is posed, it is vital both to developed and developing countries to understand the movement of actual pathogens in groundwater in the context of groundwater management. Further research is required on microbial survival and health risks posed by sewage contamination.

  19. Coupled Geochemical Impacts of Leaking CO2 and Contaminants from Subsurface Storage Reservoirs on Groundwater Quality

    SciTech Connect

    Shao, Hongbo; Qafoku, Nikolla; Lawter, Amanda R.; Bowden, Mark E.; Brown, Christopher F.

    2015-07-07

    The leakage of CO2 and the concomitant saline solutions from deep storage reservoirs to overlying groundwater aquifers is considered one of the major potential risks associated with geologic CO2 sequestration (GCS). Batch and column experiments were conducted to determine the fate of trace metals in groundwater in the scenarios of CO2 and metal contaminated brine leakage. The sediments used in this work were collected from an unconsolidated sand and gravel aquifer in Kansas, and contained 0-4 wt% carbonates. Cd and As were spiked into the reaction system to represent potential contaminants from the reservoir brine that could intrude into groundwater aquifers with leaking CO2 at initial concentrations of 114 and 40 ppb, respectively. Through this research we demonstrated that Cd and As were adsorbed on the sediments, in spite of the lowered pH due to CO2 dissolution in the groundwater. Cd concentrations were well below its MCL in both batch and column studies, even for sediment samples without detectable carbonate to buffer the pH. Arsenic concentrations in the effluent were also significantly lower than influent concentration, suggesting that the sediments tested have the capacity to mitigate the coupled adverse effects of CO2 leakage and brine intrusion. However, the mitigation capacity of sediment is a function of its geochemical properties [e.g., the calcite content; the presence of adsorbed As(III); and the presence of P in the natural sediment]. The competitive adsorption between phosphate and arsenate may result in higher concentrations of As in the aqueous phase.

  20. Bioattenuation in groundwater impacted by landfill leachate traced with δ13C.

    PubMed

    Mohammadzadeh, Hossein; Clark, Ian

    2011-01-01

    The impact on groundwater imparted by the infiltration of high dissolved organic carbon (DOC) leachate from capped, unlined landfills can be attenuated by biogeochemical reactions beyond the waste source, although such reactive loss in the aquifer is difficult to distinguish from conservative advective dispersion. Compound-specific measurement of δ(13)C in carbon species, including CH(4), dissolved inorganic carbon (DIC), and the major DOC compounds (acetate, humic acid, and fulvic acid) provides a constraint in this assessment that can assist in exercises of modeling and prediction of leachate transport. The Trail Road municipal landfill near Ottawa, Ontario, Canada, hosts an unlined sector which produces a highly enriched leachate (DOC >4500 mg/L) that provides a good site to examine reactive attenuation within the receptor aquifer. Acetate, a sentinel component of leachate DOC (~1000 mg C/L), is absent in impacted groundwater. Mass balance calculations together with reaction modeling suggest continued acetate fermentation with calcite control on DIC and δ(13)C(DIC) evolution. In groundwater within 50 m of the landfill, methane concentrations are elevated (~10 mg/L), consistent with acetate fermentation, whereas δ(13)C(CH4) measurements in deeper groundwater range down to -51‰ compared with -60‰ in the landfill demonstrating oxidative loss. DOC in the deep aquifer is remarkably depleted to values less than -40‰ suggesting methanotrophic bacteria selectively consume isotopically light CH(4) to fix carbon. Continued reaction of leachate DOC in groundwater is demonstrated by evolution away from conservative mixing lines on diagrams of δ(13)C vs. concentrations of DIC and DOC. PMID:21306357

  1. Impacts of the 2004 tsunami on groundwater resources in Sri Lanka

    USGS Publications Warehouse

    Illangasekare, T.; Tyler, S.W.; Clement, T.P.; Villholth, K.G.; Perera, A.P.G.R.L.; Obeysekera, J.; Gunatilaka, A.; Panabokke, C.R.; Hyndman, D.W.; Cunningham, K.J.; Kaluarachchi, J.J.; Yeh, W.W.-G.; Van Genuchten, M. T.; Jensen, K.

    2006-01-01

    The 26 December 2004 tsunami caused widespread destruction and contamination of coastal aquifers across southern Asia. Seawater filled domestic open dug wells and also entered the aquifers via direct infiltration during the first flooding waves and later as ponded seawater infiltrated through the permeable sands that are typical of coastal aquifers. In Sri Lanka alone, it is estimated that over 40,000 drinking water wells were either destroyed or contaminated. From February through September 2005, a team of United States, Sri Lankan, and Danish water resource scientists and engineers surveyed the coastal groundwater resources of Sri Lanka to develop an understanding of the impacts of the tsunami and to provide recommendations for the future of coastal water resources in south Asia. In the tsunami-affected areas, seawater was found to have infiltrated and mixed with fresh groundwater lenses as indicated by the elevated groundwater salinity levels. Seawater infiltrated through the shallow vadose zone as well as entered aquifers directly through flooded open wells. Our preliminary transport analysis demonstrates that the intruded seawater has vertically mixed in the aquifers because of both forced and free convection. Widespread pumping of wells to remove seawater was effective in some areas, but overpumping has led to upconing of the saltwater interface and rising salinity. We estimate that groundwater recharge from several monsoon seasons will reduce salinity of many sandy Sri Lankan coastal aquifers. However, the continued sustainability of these small and fragile aquifers for potable water will be difficult because of the rapid growth of human activities that results in more intensive groundwater pumping and increased pollution. Long-term sustainability of coastal aquifers is also impacted by the decrease in sand replenishment of the beaches due to sand mining and erosion. Copyright 2006 by the American Geophysical Union.

  2. Impact of early adversity on glucocorticoid regulation and later mental disorders.

    PubMed

    Strüber, Nicole; Strüber, Daniel; Roth, Gerhard

    2014-01-01

    Early adverse experiences such as abuse or neglect can influence brain development and consequently bring forth a predisposition toward mental and behavioral disorders. Many authors suggest that long-term changes in the functionality of the HPA axis might be involved in mediating this relationship. The direction of change and its consequences have not been clarified though: Do early adverse experiences yield a stable glucocorticoid hyperfunction or a long-term glucocorticoid hypofunction, and how is this change of functionality associated with mental or behavioral disorders? This review summarizes correlative findings and illustrates inconsistencies of current research literature. It focuses on the specific neurochemical milieu accompanying early adverse experiences and discusses possible interactions of the glucocorticoid system with oxytocin and components of the serotonergic system. On the basis of this physiological view, a novel two-pathway model is presented, according to which specific early experiences are associated with characteristic early changes in the functionality of these systems and result in a predisposition to distinct mental and behavioral disorders. PMID:24216122

  3. A Holistic Look at Minimizing Adverse Environmental Impact Under Section 316(b) of the Clean Water Act

    DOE PAGES

    Veil, John A.; Puder, Markus G.; Littleton, Debra J.; Johnson, Nancy

    2002-01-01

    Section 316(b) of the Clean Water Act (CWA) requires that “the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.” As the U.S. Environmental Protection Agency (EPA) develops new regulations to implement Section 316(b), much of the debate has centered on adverse impingement and entrainment impacts of cooling-water intake structures. Depending on the specific location and intake layout, once-through cooling systems withdrawing many millions of gallons of water per day can, to a varying degree, harm fish and other aquatic organisms in the water bodies from which the coolingmore » water is withdrawn. Therefore, opponents of once-through cooling systems have encouraged the EPA to require wet or dry cooling tower systems as the best technology available (BTA), without considering site-specific conditions. However, within the context of the broader scope of the CWA mandate, this focus seems too narrow. Therefore, this article examines the phrase “minimizing adverse environmental impact” in a holistic light. Emphasis is placed on the analysis of the terms “environmental” and “minimizing.” Congress chose “environmental” in lieu of other more narrowly focused terms like “impingement and entrainment,” “water quality,” or “aquatic life.” In this light, BTA for cooling-water intake structures must minimize the entire suite of environmental impacts, as opposed to just those associated with impingement and entrainment. Wet and dry cooling tower systems work well to minimize entrainment and impingement, but they introduce other equally important impacts because they impose an energy penalty on the power output of the generating unit. The energy penalty results from a reduction in plant operating efficiency and an increase in internal power consumption. As a consequence of the energy penalty, power companies must generate additional

  4. Altered Landscapes and Groundwater Sustainability — Exploring Impacts with Induced Polarization, DC Resistivity, and Thermal Tracing

    NASA Astrophysics Data System (ADS)

    Eddy-Miller, C.; Caldwell, R.; Wheeler, J.; McCarthy, P.; Binley, A. M.; Constantz, J. E.; Stonestrom, D. A.

    2009-12-01

    Anthropogenically impacted landscapes constitute rising proportions of the Earth’s surface that are characterized by generally elevated nutrient and sediment loadings concurrent with increased consumptive water withdrawals. In recent years a growing number of hydraulically engineered riparian habitat restoration projects have attempted to ameliorate negative impacts of land use on groundwater-surface water systems resulting, e.g., from agricultural practices and urban development. Often the nature of groundwater-surface water interactions in pre- and minimally altered systems is poorly known, making it difficult to assess the impacts of land use and restoration projects on groundwater sustainability. Traditional assessments of surface water parameters (flow, temperature, dissolved oxygen, biotic composition, etc.) can be complemented by hydraulic and thermal measurements to better understand the important role played by groundwater-surface water interactions. Hydraulic and thermal measurements are usually limited to point samples, however, making non-invasive and spatially extensive geophysical characterizations an attractive additional tool. Groundwater-surface water interactions along the Smith River, a tributary to the Missouri River in Montana, and Fish Creek and Flat Creek, tributaries to the Snake River in Wyoming, are being examined using a combination of hydraulic measurements, thermal tracing, and electrical-property imaging. Ninety-two direct-current (DC) resistivity and induced polarization cross sections were obtained at stream transects covering a wide variety of hydrogeologic settings ranging from shallow bedrock to thick alluvial sequences, nature of groundwater-surface water interactions (always gaining, always losing, or seasonally varying) and anthropogenic impacts (minimal low-intensity agriculture to major landscape engineering, including channel reconstruction). DC resistivity and induced polarization delineated mutually distinct features

  5. Uncertainty of climate change impact on groundwater reserves - Application to a chalk aquifer

    NASA Astrophysics Data System (ADS)

    Goderniaux, Pascal; Brouyère, Serge; Wildemeersch, Samuel; Therrien, René; Dassargues, Alain

    2015-09-01

    Recent studies have evaluated the impact of climate change on groundwater resources for different geographical and climatic contexts. However, most studies have either not estimated the uncertainty around projected impacts or have limited the analysis to the uncertainty related to climate models. In this study, the uncertainties around impact projections from several sources (climate models, natural variability of the weather, hydrological model calibration) are calculated and compared for the Geer catchment (465 km2) in Belgium. We use a surface-subsurface integrated model implemented using the finite element code HydroGeoSphere, coupled with climate change scenarios (2010-2085) and the UCODE_2005 inverse model, to assess the uncertainty related to the calibration of the hydrological model. This integrated model provides a more realistic representation of the water exchanges between surface and subsurface domains and constrains more the calibration with the use of both surface and subsurface observed data. Sensitivity and uncertainty analyses were performed on predictions. The linear uncertainty analysis is approximate for this nonlinear system, but it provides some measure of uncertainty for computationally demanding models. Results show that, for the Geer catchment, the most important uncertainty is related to calibration of the hydrological model. The total uncertainty associated with the prediction of groundwater levels remains large. By the end of the century, however, the uncertainty becomes smaller than the predicted decline in groundwater levels.

  6. Quantifying the impact of groundwater depth on evapotranspiration in a semi-arid grassland region

    NASA Astrophysics Data System (ADS)

    Soylu, M. E.; Istanbulluoglu, E.; Lenters, J. D.; Wang, T.

    2011-03-01

    Interactions between shallow groundwater and land surface processes play an important role in the ecohydrology of riparian zones. Some recent land surface models (LSMs) incorporate groundwater-land surface interactions using parameterizations at varying levels of detail. In this paper, we examine the sensitivity of land surface evapotranspiration (ET) to water table depth, soil texture, and two commonly used soil hydraulic parameter datasets using four models with varying levels of complexity. The selected models are Hydrus-1D, which solves the pressure-based Richards equation, the Integrated Biosphere Simulator (IBIS), which simulates interactions among multiple soil layers using a (water-content) variant of the Richards equation, and two forms of a steady-state capillary flux model coupled with a single-bucket soil moisture model. These models are first evaluated using field observations of climate, soil moisture, and groundwater levels at a semi-arid site in south-central Nebraska, USA. All four models are found to compare reasonably well with observations, particularly when the effects of groundwater are included. We then examine the sensitivity of modelled ET to water table depth for various model formulations, node spacings, and soil textures (using soil hydraulic parameter values from two different sources, namely Rawls and Clapp-Hornberger). The results indicate a strong influence of soil texture and water table depth on groundwater contributions to ET. Furthermore, differences in texture-specific, class-averaged soil parameters obtained from the two literature sources lead to large differences in the simulated depth and thickness of the "critical zone" (i.e., the zone within which variations in water table depth strongly impact surface ET). Depending on the depth-to-groundwater, this can also lead to large discrepancies in simulated ET (in some cases by more than a factor of two). When the Clapp-Hornberger soil parameter dataset is used, the critical zone

  7. Human Health Impact of Fluoride in Groundwater in the Chiang Mai Basin

    NASA Astrophysics Data System (ADS)

    Matsui, Y.; Takizawa, S.; Wattanachira, S.; Wongrueng, A.; Ibaraki, M.

    2005-12-01

    Chiang Mai Basin, in Northern Thailand, is known as a fluorotic area. Groundwater of the Chiang Mai Basin has been gradually replaced by contaminated surface water since the 1980's. People have been exposed to fluoride contaminated groundwater since that time. As a result, harmful health effects on dental and skeletal growth were observed in the 90's. These include dental and skeletal fluorosis. Dental fluorosis is characterized by yellow or white spots on teeth and pitting or mottled enamel, consequently causing the teeth to look unsightly. Skeletal fluorosis leads to changes in bone structure, making them extremely weak and brittle. The most severe form of this is known as ``crippling skeletal fluorosis,'' a condition that can cause immobility, muscle wasting, and neurological problems related to spinal cord compression. This study focuses on the problematic issue of the Chiang Mai Basin's groundwater from the viewpoint of fluoride occurrence and current health impacts. Chiang Mai and Lamphun Provinces comprise the Chiang Mai Basin. Fluoride rich granites or fluorite deposits are scattered across the mountainside of the Lamphun Province. Tropical savanna climate conditions with seasonal monsoons bring more than 1,000 mm of annual precipitation, which can prompt weathering of minerals containing fluoride. The Ping River dominates the Basin, and the main eastern tributary of the Ping River runs through the Lamphun Province. The Basin has geological units composed of lower semi-consolidated Tertiary fluvial and upper unconsolidated Quaternary alluvium deposits. The main aquifers are in the upper unconsolidated unit. High fluoride concentrations tend to be observed in the aquifer located in lower part of this unconsolidated unit. We have been investigating two areas in the Basin. These two locations are similar with respect to geological and hydrological settings. However, one area in which groundwater is Ca-bicarbonate dominant has a low fluoride occurrence

  8. Climate change impact on groundwater levels in the Guarani Aquifer outcrop zone

    NASA Astrophysics Data System (ADS)

    Melo, D. D.; Wendland, E.

    2013-12-01

    The unsustainable use of groundwater in many countries might cause water availability restrictions in the future. Such issue is likely to worsen due to predicted climate changes for the incoming decades. As numerous studies suggest, aquifers recharge rates will be affected as a result of climate change. The Guarani Aquifer System (GAS) is one of the most important transboundary aquifer in the world, providing drinkable water for millions of people in four South American countries (Brazil, Argentina, Uruguay and Paraguay). Considering the GAS relevance and how its recharge rates might be altered by climatic conditions anomalies, the objective of this work is to assess possible climate changes impacts on groundwater levels in this aquifer outcrop zone. Global Climate Models' (GCM) outputs were used as inputs in a transient flux groundwater model created using the software SPA (Simulation of Process in Aquifers), enabling groundwater table fluctuation to be evaluated under distinct climatic scenarios. Six monitoring wells, located in a representative basin (Ribeirão da Onça basin) inside a GAS outcrop zone (ROB), provided water table measurements between 2004 and 2011 to calibrate the groundwater model. Using observed climatic data, a water budget method was applied to estimate recharge in different types of land uses. Statistically downscaled future climate scenarios were used as inputs for that same recharge model, which provided data for running SPA under those scenarios. The results show that most of the GCMs used here predict temperature arises over 275,15 K and major monthly rainfall mean changes to take place in the dry season. During wet seasons, those means might experience around 50% decrease. The transient model results indicate that water table variations, derived from around 70% of the climate scenarios, would vary below those measured between 2004 and 2011. Among the thirteen GCMs considered in this work, only four of them predicted more extreme

  9. Reservoir Removal and Legacy Sediment Impacts on Upstream Surface Water - Groundwater Communication

    NASA Astrophysics Data System (ADS)

    Gerecht, K.; Gooseff, M. N.; Singha, K.

    2011-12-01

    Pennsylvania alone there are 1,546 dams, of which 75% are ruled to be at a significant to high hazard potential for failure (USACE National Inventory of Dams, 2009). Understanding the impacts of dam and reservoir removal on upstream hydrologic systems, especially in the headwaters, is critical to understanding the anthropogenic impacts of deposited legacy sediments on stream-groundwater communication.

  10. Microbial processes influencing the transport, fate and groundwater impacts of fuel ethanol releases.

    PubMed

    Ma, Jie; Rixey, William G; Alvarez, Pedro J J

    2013-06-01

    Fuel releases that impact groundwater are a common occurrence, and the growing use of ethanol as a transportation biofuel is increasing the likelihood of encountering ethanol in such releases. Microorganisms play a critical role in the fate of ethanol-blended fuel releases, often determining their region of influence and potential impacts. This review summarizes current understanding on the biogeochemical footprint of such releases and the factors that influence their natural attenuation. Implications for site investigation, risk assessment and remediation strategies are also addressed along with research priorities.

  11. 25 CFR 170.109 - How do the Secretaries prevent discrimination or adverse impacts?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... impacts? In administering the IRR Program, the Secretaries ensure that nondiscrimination and environmental justice principles are integral program elements. The Secretaries consult with tribes early in the...

  12. 25 CFR 170.109 - How do the Secretaries prevent discrimination or adverse impacts?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... impacts? In administering the IRR Program, the Secretaries ensure that nondiscrimination and environmental justice principles are integral program elements. The Secretaries consult with tribes early in the...

  13. 25 CFR 170.109 - How do the Secretaries prevent discrimination or adverse impacts?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... impacts? In administering the IRR Program, the Secretaries ensure that nondiscrimination and environmental justice principles are integral program elements. The Secretaries consult with tribes early in the...

  14. 25 CFR 170.109 - How do the Secretaries prevent discrimination or adverse impacts?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... impacts? In administering the IRR Program, the Secretaries ensure that nondiscrimination and environmental justice principles are integral program elements. The Secretaries consult with tribes early in the...

  15. Assessing the impact of dairy waste lagoons on groundwater quality using a spatial analysis of vadose zone and groundwater information in a coastal phreatic aquifer.

    PubMed

    Baram, S; Kurtzman, D; Ronen, Z; Peeters, A; Dahan, O

    2014-01-01

    Dairy waste lagoons are considered to be point sources of groundwater contamination by chloride (Cl(-)), different nitrogen-species and pathogens/microorganisms. The objective of this work is to introduce a methodology to assess the past and future impacts of such lagoons on regional groundwater quality. The method is based on a spatial statistical analysis of Cl(-) and total nitrogen (TN) concentration distributions in the saturated and the vadose (unsaturated) zones. The method provides quantitative data on the relation between the locations of dairy lagoons and the spatial variability in Cl(-) and TN concentrations in groundwater. The method was applied to the Beer-Tuvia region, Israel, where intensive dairy farming has been practiced for over 50 years above the local phreatic aquifer. Mass balance calculations accounted for the various groundwater recharge and abstraction sources and sinks in the entire region. The mass balances showed that despite the small surface area covered by the dairy lagoons in this region (0.8%), leachates from lagoons have contributed 6.0% and 12.6% of the total mass of Cl(-) and TN (mainly as NO3(-)-N) added to the aquifer. The chemical composition of the aquifer and vadose zone water suggested that irrigated agricultural activity in the region is the main contributor of Cl(-) and TN to the groundwater. A low spatial correlation between the Cl(-) and NO3(-)-N concentrations in the groundwater and the on-land location of the dairy farms strengthened this assumption, despite the dairy waste lagoon being a point source for groundwater contamination by Cl(-) and NO3(-)-N. Mass balance calculations, for the vadose zone of the entire region, indicated that drying of the lagoons would decrease the regional groundwater salinization process (11% of the total Cl(-) load is stored under lagoons). A more considerable reduction in the groundwater contamination by NO3(-)-N is expected (25% of the NO3(-)-N load is stored under lagoons). Results

  16. Assessing the impact of dairy waste lagoons on groundwater quality using a spatial analysis of vadose zone and groundwater information in a coastal phreatic aquifer.

    PubMed

    Baram, S; Kurtzman, D; Ronen, Z; Peeters, A; Dahan, O

    2014-01-01

    Dairy waste lagoons are considered to be point sources of groundwater contamination by chloride (Cl(-)), different nitrogen-species and pathogens/microorganisms. The objective of this work is to introduce a methodology to assess the past and future impacts of such lagoons on regional groundwater quality. The method is based on a spatial statistical analysis of Cl(-) and total nitrogen (TN) concentration distributions in the saturated and the vadose (unsaturated) zones. The method provides quantitative data on the relation between the locations of dairy lagoons and the spatial variability in Cl(-) and TN concentrations in groundwater. The method was applied to the Beer-Tuvia region, Israel, where intensive dairy farming has been practiced for over 50 years above the local phreatic aquifer. Mass balance calculations accounted for the various groundwater recharge and abstraction sources and sinks in the entire region. The mass balances showed that despite the small surface area covered by the dairy lagoons in this region (0.8%), leachates from lagoons have contributed 6.0% and 12.6% of the total mass of Cl(-) and TN (mainly as NO3(-)-N) added to the aquifer. The chemical composition of the aquifer and vadose zone water suggested that irrigated agricultural activity in the region is the main contributor of Cl(-) and TN to the groundwater. A low spatial correlation between the Cl(-) and NO3(-)-N concentrations in the groundwater and the on-land location of the dairy farms strengthened this assumption, despite the dairy waste lagoon being a point source for groundwater contamination by Cl(-) and NO3(-)-N. Mass balance calculations, for the vadose zone of the entire region, indicated that drying of the lagoons would decrease the regional groundwater salinization process (11% of the total Cl(-) load is stored under lagoons). A more considerable reduction in the groundwater contamination by NO3(-)-N is expected (25% of the NO3(-)-N load is stored under lagoons). Results

  17. Key factors for determining groundwater impacts due to leakage from geologic carbon sequestration reservoirs

    SciTech Connect

    Carroll, Susan A.; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenxue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-09-07

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow groundwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models, referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could result from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which no impact to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur. To facilitate this, multi-phase flow and reactive transport simulations and emulations were developed for two classes of aquifers, considering uncertainty in leakage source terms and aquifer hydrogeology. We targeted an unconfined fractured carbonate aquifer based on the Edwards aquifer in Texas and a confined alluvium aquifer based on the High Plains Aquifer in Kansas, which share characteristics typical of many drinking water aquifers in the United States. The hypothetical leakage scenarios centered on the notion that wellbores

  18. Key factors for determining groundwater impacts due to leakage from geologic carbon sequestration reservoirs

    DOE PAGES

    Carroll, Susan A.; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenxue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-09-07

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow groundwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models, referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could resultmore » from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which no impact to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur. To facilitate this, multi-phase flow and reactive transport simulations and emulations were developed for two classes of aquifers, considering uncertainty in leakage source terms and aquifer hydrogeology. We targeted an unconfined fractured carbonate aquifer based on the Edwards aquifer in Texas and a confined alluvium aquifer based on the High Plains Aquifer in Kansas, which share characteristics typical of many drinking water aquifers in the United States. The hypothetical leakage scenarios centered on the notion that wellbores are the most likely

  19. Impacts of soil and groundwater salinization on tree crop performance in post-tsunami Aceh Barat, Indonesia

    NASA Astrophysics Data System (ADS)

    Marohn, C.; Distel, A.; Dercon, G.; Wahyunto; Tomlinson, R.; Noordwijk, M. v.; Cadisch, G.

    2012-09-01

    The Indian Ocean tsunami of December 2004 had far reaching consequences for agriculture in Aceh province, Indonesia, and particularly in Aceh Barat district, 150 km from the seaquake epicentre. In this study, the spatial distribution and temporal dynamics of soil and groundwater salinity and their impact on tree crops were monitored in Aceh Barat from 2006 to 2008. On 48 sampling points along ten transects, covering 40 km of coastline, soil and groundwater salinity were measured and related to mortality and yield depression of the locally most important tree crops. Given a yearly rainfall of over 3000 mm, initial groundwater salinity declined rapidly from over 10 to less than 2 mS cm-1 within two years. On the other hand, seasonal dynamics of the groundwater table in combination with intrusion of saline water into the groundwater body led to recurring elevated salinity, sufficient to affect crops. Tree mortality and yield depression in the flooded area varied considerably between tree species. Damage to coconut (65% trees damaged) was related to tsunami run-up height, while rubber (50% trees damaged) was mainly affected by groundwater salinity. Coconut yields (-35% in average) were constrained by groundwater Ca2+ and Mg2+, while rubber yields (-65% on average) were related to groundwater chloride, pH and soil sodium. These findings have implications on planting deep-rooted tree crops as growth will be constrained by ongoing oscillations of the groundwater table and salinity.

  20. Identification and prioritization of relationships between environmental stressor and adverse human health impacts

    EPA Science Inventory

    AbstractBackground: There are over 80,000 chemicals in commerce with little data available describing their impacts on human health. Biomonitoring surveys, such as the NHANES, offer one route to identifying possible relationships between environmental chemicals and health impacts...

  1. Adverse Impact of Racial Isolation on Student Performance: A Study in North Carolina

    ERIC Educational Resources Information Center

    Sharma, Andy; Joyner, Ann Moss; Osment, Ashley

    2014-01-01

    This study examines the impact of racial isolation on high school student performance in North Carolina, a state in the southeast United States. Our research goal is to investigate if increased isolation negatively impacts Black students' academic performance. Employing the North Carolina State Department of Public Instruction (NCDPI)…

  2. Assessing the impact of future climate change on groundwater recharge in Galicia-Costa, Spain

    NASA Astrophysics Data System (ADS)

    Raposo, Juan Ramón; Dafonte, Jorge; Molinero, Jorge

    2013-03-01

    Climate change can impact the hydrological processes of a watershed and may result in problems with future water supply for large sections of the population. Results from the FP5 PRUDENCE project suggest significant changes in temperature and precipitation over Europe. In this study, the Soil and Water Assessment Tool (SWAT) model was used to assess the potential impacts of climate change on groundwater recharge in the hydrological district of Galicia-Costa, Spain. Climate projections from two general circulation models and eight different regional climate models were used for the assessment and two climate-change scenarios were evaluated. Calibration and validation of the model were performed using a daily time-step in four representative catchments in the district. The effects on modeled mean annual groundwater recharge are small, partly due to the greater stomatal efficiency of plants in response to increased CO2 concentration. However, climate change strongly influences the temporal variability of modeled groundwater recharge. Recharge may concentrate in the winter season and dramatically decrease in the summer-autumn season. As a result, the dry-season duration may be increased on average by almost 30 % for the A2 emission scenario, exacerbating the current problems in water supply.

  3. The impact of industrial-scale cartridge filtration on the native microbial communities from groundwater.

    PubMed

    Wang, Yingying; Hammes, Frederik; Egli, Thomas

    2008-10-01

    Groundwater is a major source for bottled water, which is increasingly consumed all over the world. Some categories of bottled water can be subjected to treatments such as disinfection prior to bottling. In the current study, we present the quantitative impact of industrial-scale micro-filtration (0.22 microm pore size) on native microbial communities of groundwater and evaluate subsequent microbial growth after bottling. Two separate groundwater aquifers were tested. Flow-cytometric total cell concentration (TCC) and total adenosine tri-phosphate (ATP) analysis were used to quantify microbial abundance. The TCC of the native microbial community in both aquifers was in the range of 10(3)-10(4) cells/ml. Up to 10% of the native microbial community was able to pass through the cartridge filtration units installed at both aquifers. In addition, all samples (either with or without 0.22 microm filtration) showed significant growth after bottling and storage, reaching average final concentrations of 1-3 x 10(5) cells/ml. However, less growth was observed in carbon-free glassware than in standard polyethylene terephthalate (PET) bottles. Furthermore, our results showed that filtration and bottling can alter the microbial community patterns as observed with flow cytometry. The current study established that industrial-scale micro-filtration cannot serve as an absolute barrier for the native microbial community and provided significant insight to the impact of filtration and bottling on microbial concentrations in bottled water.

  4. Groundwater resources in Brazil: a review of possible impacts caused by climate change.

    PubMed

    Hirata, Ricardo; Conicelli, Bruno P

    2012-06-01

    Groundwater has a strategic role in times of climate change mainly because aquifers can provide water for long periods, even during very long and severe drought. The reduction and/or changes on the precipitation pattern can diminish the recharge mainly in unconfined aquifer, causing available groundwater restriction. The expected impact of long-term climate changes on the Brazilian aquifers for 2050 will lead to a severe reduction in 70% of recharge in the Northeast region aquifers (comparing to 2010 values), varying from 30% to 70% in the North region. Data referring to the South and Southeast regions are more favorable, with an increase in the relative recharge values from 30% to 100%. Another expected impact is the increase in demand and the decrease in the surface water availability that will make the population turn to aquifers as its main source of water for public or private uses in many regions of the country. Thus, an integrated use of surface and groundwater must therefore be considered in the water use planning. The solution of water scarcity is based on three factors: society growth awareness, better knowledge on the characteristics of hydraulic and chemical aquifers and effective management actions.

  5. Climate change impacts on groundwater recharge- uncertainty, shortcomings, and the way forward?

    NASA Astrophysics Data System (ADS)

    Holman, I. P.

    2006-06-01

    An integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge is described from East Anglia, UK. Many factors affect future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment, and changes in cropping and rotations. Important sources of uncertainty and shortcomings in recharge estimation are discussed in the light of the results. The uncertainty in, and importance of, socio-economic scenarios in exploring the consequences of unknown future changes are highlighted. Changes to soil properties are occurring over a range of time scales, such that the soils of the future may not have the same infiltration properties as existing soils. The potential implications involved in assuming unchanging soil properties are described. To focus on the direct impacts of climate change is to neglect the potentially important role of policy, societal values and economic processes in shaping the landscape above aquifers. If the likely consequences of future changes of groundwater recharge, resulting from both climate and socio-economic change, are to be assessed, hydrogeologists must increasingly work with researchers from other disciplines, such as socio-economists, agricultural modellers and soil scientists.

  6. Impact of blasting on groundwater composition in a fracture in Canada's Underground Research Laboratory

    NASA Astrophysics Data System (ADS)

    Thomas, David A.; Gascoyne, Mel

    1997-01-01

    Groundwater composition in a discrete, water-bearing fracture in granitic rock at the Underground Research Laboratory, Manitoba, was monitored during a period of underground excavation of adjacent rock to determine the impact of conventional blasting techniques and rock fracturing on the concentration of dissolved constituents. This work has relevance to the study of hydrogeochemical anomalies associated with seismic activity. Short-lived anomalies such as decreases in dissolved anion (Cl,F,Br,SO4) and gas (He,Rn) concentrations and concurrent increases in NO3 and O2 concentrations were seen shortly after two blasts located opposite the groundwater sampling site. A third blast downstream of the site resulted in variability in dissolved gases concentrations but showed no impact on dissolved anion concentrations. The results are compared with various models used to account for hydrogeochemical fluctuations associated with earthquakes. The data best fit a general form of the aquifer breaching/fluid mixing model in which hydrochemical responses are caused by localized changes in hydraulic conductivity along the plane of a fracture which, in turn, cause changes in mixing ratio of groundwater at the monitoring site.

  7. Using Bayesian methods to predict climate impacts on groundwater availability and agricultural production in Punjab, India

    NASA Astrophysics Data System (ADS)

    Russo, T. A.; Devineni, N.; Lall, U.

    2015-12-01

    Lasting success of the Green Revolution in Punjab, India relies on continued availability of local water resources. Supplying primarily rice and wheat for the rest of India, Punjab supports crop irrigation with a canal system and groundwater, which is vastly over-exploited. The detailed data required to physically model future impacts on water supplies agricultural production is not readily available for this region, therefore we use Bayesian methods to estimate hydrologic properties and irrigation requirements for an under-constrained mass balance model. Using measured values of historical precipitation, total canal water delivery, crop yield, and water table elevation, we present a method using a Markov chain Monte Carlo (MCMC) algorithm to solve for a distribution of values for each unknown parameter in a conceptual mass balance model. Due to heterogeneity across the state, and the resolution of input data, we estimate model parameters at the district-scale using spatial pooling. The resulting model is used to predict the impact of precipitation change scenarios on groundwater availability under multiple cropping options. Predicted groundwater declines vary across the state, suggesting that crop selection and water management strategies should be determined at a local scale. This computational method can be applied in data-scarce regions across the world, where water resource management is required to resolve competition between food security and available resources in a changing climate.

  8. Treatment of landfill leachate-impacted groundwater using cascade aeration and constructed wetlands

    SciTech Connect

    Loer, J.; O`Flanagan, B.; Fellows, W.

    1995-12-31

    At an unlined municipal solid waste landfill, heavy metal and toxic organic compounds present in leachate have impacted groundwater, necessitating extraction and treatment of the contaminated groundwater. A remedial design relying on a natural systems engineering approach will take advantage of existing contours (gravity flow) and surroundings (wetlands), and will limit energy inputs and eliminate chemical inputs. Impacted groundwater will be extracted, and aerated via a cascade constructed of polypropylene sheets fabricated into {open_quotes}step{close_quotes} sections and set into a side slope of the landfill. Volatilization of organics and oxidation of iron and heavy metals to insoluble compounds will occur during cascading and will continue within a sedimentation basin where settling of iron precipitates will induce co-settling of heavy metal precipitates. Following the sedimentation basin, a constructed wetland containing both aerobic zones and anaerobic zones will provide additional treatment of remaining solids and heavy metals, before surface discharge. Use of a natural systems approach significantly reduces operating costs compared to a mechanical-aeration, chemical-precipitation system, and is more aesthetically pleasing and suited to the remote locale. The system is under construction and seasonal operation will begin in spring 1996.

  9. Impact of the December 2004 tsunami on soil, groundwater and vegetation in the Nagapattinam District, India.

    PubMed

    Kume, Takashi; Umetsu, Chieko; Palanisami, K

    2009-07-01

    The tsunami of 26 December 2004 struck the Nagapattinam District, Tamil Nadu, India. Sea water inundation from the tsunami caused salinization problems for soil and groundwater in coastal areas of the district, and also induced salt injuries in crops. To document the recovery of the agricultural environment from the tsunami, we conducted observations of the soil, groundwater, and vegetation. Soil electrical conductivity increased sharply after the tsunami, but returned to pre-tsunami levels the following year. Groundwater salinity returned to pre-tsunami levels by 2006. These rapid rates of recovery were due to the monsoon rainfall leaching salt from the highly permeable soils in the area. MODIS NDVI values measured before and after the tsunami showed that vegetation damaged by the tsunami recovered to its pre-tsunami state by the next rice cropping season, called samba, which starts from August to February. From these results, we conclude that the agricultural environment of the district has now fully recovered from the tsunami. Based on the results, we have also identified important management implications for soil, groundwater, and vegetation as follows: 1) due to the heavy monsoon rainfall and the high permeability of soils in this region, anthropogenic inputs like fertilizers should be applied carefully to minimize pollution, and the use of green manure is recommended; 2) areas that were contaminated by sea water extended up to 1000 m from the sea shore and over pumping of groundwater should be carefully avoided to prevent inducing sea water intrusion; and 3) data from a moderate resolution sensor of 250 m, such as MODIS, can be applied to impact assessment in widespread paddy field areas like the Nagapattinam District.

  10. Virus in Groundwater: Characterization of transport mechanisms and impacts on an agricultural area in Uruguay

    NASA Astrophysics Data System (ADS)

    Gamazo, P. A.; Colina, R.; Victoria, M.; Alvareda, E.; Burutaran, L.; Ramos, J.; Lopez, F.; Soler, J.

    2014-12-01

    In many areas of Uruguay groundwater is the only source of water for human consumption and for industrial-agricultural economic activities. Traditionally considered as a safe source, due to the "natural filter" that occurs in porous media, groundwater is commonly used without any treatment. The Uruguayan law requires bacteriological analysis for most water uses, but virological analyses are not mentioned in the legislation. In the Salto district, where groundwater is used for human consumption and for agricultural activities, bacterial contamination has been detected in several wells but no viruses analysis have been performed. The Republic University (UDELAR), with the support of the National Agency for Research and Innovation (ANII), is studying the incidence of virus in groundwater on an intensive agriculture area of the Salto district. In this area water is pumped from the "Salto Aquifer", a free sedimentary aquifer. Below this sedimentary deposit is the "Arapey" basaltic formation, which is also exploited for water productions on its fractured zones. A screening campaign has been performed searching for bacterial and viral contamination. Total and fecal coliforms have been found on several wells and Rotavirus and Adenovirus have been detected. A subgroup of the screening wells has been selected for an annual survey. On this subgroup, besides bacteria and viruses analysis, a standard physical and chemical characterization was performed. Results show a significant seasonal variation on microbiological contamination. In addition to field studies, rotavirus circulation experiments on columns are being performed. The objective of this experiments is to determinate the parameters that control virus transport in porous media. The results of the study are expected to provide an insight into the impacts of groundwater on Salto's viral gastroenterocolitis outbreaks.

  11. Impact of pesticides used in agriculture and vineyards to surface and groundwater quality (North Spain).

    PubMed

    Hildebrandt, Alain; Guillamón, Míriam; Lacorte, Sílvia; Tauler, Romà; Barceló, Damià

    2008-07-01

    An environmental monitoring program was carried out to determine the impact of eight pesticides on the surface and groundwater quality of agricultural areas within the Ebro, Duero and Miño river basins. Three triazines and their desethyl degradation products, metolachlor and metalaxyl, were monitored during 18 months in 63 sites. Solid-phase extraction (SPE) using OASIS HLB 60 mg cartridges and gas chromatography-mass spectrometry (GC-EI-MS) provided good analytical quality parameters and limits of quantification of 0.01 microg/L. Environmental data were assessed using descriptive statistical analysis and multivariate data analysis with principal component analysis (PCA) to elucidate the relevant contamination patterns and provide a description of their seasonal trends, according to the pesticide application timing. Duero was the site with the highest frequency of detection and highest concentration levels, followed by the Ebro and Miño basins. The frequency of detection of the studied compounds, considering all surface and groundwater samples, was atrazine>desethylatrazine>simazine>desethylsimazine>metolachlor>desethylterbuthylazine>terbuthylazine>metalaxyl. Over all results, and taking into consideration the European Union (EU) maximum residual limit of pesticides in groundwater, only 12% of the results exceeded the 0.1 microg/L limit. However, sporadic high levels up to 2.46 mug/L in groundwater and 0.63 microg/L in surface water were detected. PCA permitted to state that Duero and Ebro river basins were especially affected by a contamination pattern dominated by atrazine, the Ebro river basin being occasionally affected by a contamination pattern dominated by simazine. Only trace levels were rarely detected in the Miño river basin. Groundwater levels were higher than surface water levels for the studied pesticides.

  12. Impact of stormwater infiltration basins on groundwater quality, Perth metropolitan region, Western Australia

    NASA Astrophysics Data System (ADS)

    Appleyard, S. J.

    1993-08-01

    Twelve bores were sunk adjacent to three stormwater infiltration basins in the Perth metropolitan area to examine the impact of runoff from a light industrial area, a medium-density residential area, and a major arterial road on groundwater quality, and to examine the hydrological response of the aquifer to runoff recharge. Automatic and manual water level monitoring between April and November 1990 indicated that groundwater levels responded within minutes to recharge from the infiltration basins. Peak water levels of up to 2.5 m above rest levels occurred 6 24 h after the commencement of ponding in the infiltration basins. There was a marked reduction in salinity and increase in dissolved oxygen concentrations in the upper part of the aquifer downgradient of the infiltration basins. Concentrations of toxic metals, nutrients, pesticides, and phenolic compounds in groundwater near the infiltration basins were low and generally well within Australian drinking water guidelines. However, sediment in the base of an infiltration basin draining a major road contained in excess of 3500 ppm of lead. Phthalates, which are US EPA priority pollutants, were detected in all but one bore near the infiltration basins. Their detection may be a sampling artifact, but they may also be derived from the plastic litter that accumulates in the infiltration basins. The concentration of iron in groundwater near the infiltration basins appears to be controlled by dissolved oxygen concentrations, with high iron concentrations occurring where dissolved oxygen concentrations are low. Pumping bores located near infiltration basins may suffer from iron encrustation problems caused by the mixing of shallow, oxygenated groundwater with water containing higher concentrations of iron from deeper in the aquifer.

  13. Modeled impacts of predicted climate change on recharge and groundwater levels

    NASA Astrophysics Data System (ADS)

    Scibek, J.; Allen, D. M.

    2006-11-01

    A methodology is developed for linking climate models and groundwater models to investigate future impacts of climate change on groundwater resources. An unconfined aquifer, situated near Grand Forks in south central British Columbia, Canada, is used to test the methodology. Climate change scenarios from the Canadian Global Coupled Model 1 (CGCM1) model runs are downscaled to local conditions using Statistical Downscaling Model (SDSM), and the change factors are extracted and applied in LARS-WG stochastic weather generator and then input to the recharge model. The recharge model simulated the direct recharge to the aquifer from infiltration of precipitation and consisted of spatially distributed recharge zones, represented in the Hydrologic Evaluation of Landfill Performance (HELP) hydrologic model linked to a geographic information system (GIS). A three-dimensional transient groundwater flow model, implemented in MODFLOW, is then used to simulate four climate scenarios in 1-year runs (1961-1999 present, 2010-2039, 2040-2069, and 2070-2099) and compare groundwater levels to present. The effect of spatial distribution of recharge on groundwater levels, compared to that of a single uniform recharge zone, is much larger than that of temporal variation in recharge, compared to a mean annual recharge representation. The predicted future climate for the Grand Forks area from the downscaled CGCM1 model will result in more recharge to the unconfined aquifer from spring to the summer season. However, the overall effect of recharge on the water balance is small because of dominant river-aquifer interactions and river water recharge.

  14. Reactive transport controls on sandy acid sulfate soils and impacts on shallow groundwater quality

    NASA Astrophysics Data System (ADS)

    Salmon, S. Ursula; Rate, Andrew W.; Rengel, Zed; Appleyard, Steven; Prommer, Henning; Hinz, Christoph

    2014-06-01

    Disturbance or drainage of potential acid sulfate soils (PASS) can result in the release of acidity and degradation of infrastructure, water resources, and the environment. Soil processes affecting shallow groundwater quality have been investigated using a numerical code that integrates (bio)geochemical processes with water, solute, and gas transport. The patterns of severe and persistent acidification (pH < 4) in the sandy, carbonate-depleted podzols of a coastal plain could be reproduced without calibration, based on oxidation of microcrystalline pyrite after groundwater level decrease and/or residual groundwater acidity, due to slow vertical solute transport rates. The rate of acidification was limited by gas phase diffusion of oxygen and hence was sensitive to soil water retention properties and in some cases also to oxygen consumption by organic matter mineralization. Despite diffusion limitation, the rate of oxidation in sandy soils was rapid once pyrite-bearing horizons were exposed, even to a depth of 7.5 m. Groundwater level movement was thus identified as an important control on acidification, as well as the initial pyrite content. Increase in the rate of Fe(II) oxidation lead to slightly lower pH and greater accumulation of Fe(III) phases, but had little effect on the overall amount of pyrite oxidized. Aluminosilicate (kaolinite) dissolution had a small pH-buffering effect but lead to the release of Al and associated acidity. Simulated dewatering scenarios highlighted the potential of the model for risk assessment of (bio)geochemical impacts on soil and groundwater over a range of temporal and spatial scales.

  15. Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review

    PubMed Central

    Polizzotto, Matthew L.

    2013-01-01

    Background: Pit latrines are one of the most common human excreta disposal systems in low-income countries, and their use is on the rise as countries aim to meet the sanitation-related target of the Millennium Development Goals. There is concern, however, that discharges of chemical and microbial contaminants from pit latrines to groundwater may negatively affect human health. Objectives: Our goals were to a) calculate global pit latrine coverage, b) systematically review empirical studies of the impacts of pit latrines on groundwater quality, c) evaluate latrine siting standards, and d) identify knowledge gaps regarding the potential for and consequences of groundwater contamination by latrines. Methods: We used existing survey and population data to calculate global pit latrine coverage. We reviewed the scientific literature on the occurrence of contaminants originating from pit latrines and considered the factors affecting transport of these contaminants. Data were extracted from peer-reviewed articles, books, and reports identified using Web of ScienceSM, PubMed, Google, and document reference lists. Discussion: We estimated that approximately 1.77 billion people use pit latrines as their primary means of sanitation. Studies of pit latrines and groundwater are limited and have generally focused on only a few indicator contaminants. Although groundwater contamination is frequently observed downstream of latrines, contaminant transport distances, recommendations based on empirical studies, and siting guidelines are variable and not well aligned with one another. Conclusions: In order to improve environmental and human health, future research should examine a larger set of contextual variables, improve measurement approaches, and develop better criteria for siting pit latrines. PMID:23518813

  16. Road impacts on the Baca National Wildlife Refuge, Colorado, with emphasis on effects to surface- and shallow ground-water hydrology - A literature review

    USGS Publications Warehouse

    Andersen, Douglas C.

    2007-01-01

    A review of published research on unpaved road effects on surface-water and shallow ground-water hydrology was undertaken to assist the Baca National Wildlife Refuge, Colorado, in understanding factors potentially influencing refuge ecology. Few studies were found that addressed hydrological effects of roads on a comparable area of shallow slope in a semiarid region. No study dealt with road effects on surface- and ground-water supplies to ephemeral wetlands, which on the refuge are sustained by seasonal snowmelt in neighboring mountains. Road surfaces increase runoff, reduce infiltration, and serve as a sediment source. Roadbeds can interfere with normal surface- and ground-water flows and thereby influence the quantity, timing, and duration of water movement both across landscapes and through the soil. Hydrologic effects can be localized near the road as well as widespread and distant. The number, arrangement, and effectiveness of road-drainage structures (culverts and other devices) largely determine the level of hydrologic alteration produced by a road. Undesirable changes to natural hydrologic patterns can be minimized by considering potential impacts during road design, construction, and maintenance. Road removal as a means to restore desirable hydrologic conditions to landscapes adversely affected by roads has yet to be rigorously evaluated.

  17. Sources and impact of sulphate on groundwaters of Triassic carbonate aquifers, Upper Silesia, Poland

    NASA Astrophysics Data System (ADS)

    Samborska, Katarzyna; Halas, Stanislaw; Bottrell, Simon H.

    2013-04-01

    SummaryGroundwater within the unconfined or semi-confined parts of Triassic carbonate aquifers in Upper Silesia (Poland) contains high concentrations of sulphate (up to 290 mg/L), sometimes in excess of drinking water limits (>250 mg/L). To assess the influence of different possible sulphate sources, isotopic analyses of S and O were performed on groundwater sulphate and potential sulphate sources and combined with literature data. Three dominant sources of sulphate were delineated, based on the geological and literature study and supported by the mixing relations between inverse concentration of sulphate and its isotopic compositions. These sources are: (i) sulphate from rainfall; (ii) weathering of sulphide minerals in ore deposits in the aquifer-forming carbonate rocks; (iii) dissolution of sulphate evaporites in the Triassic sequence. Fortunately these three sources have distinctive S and O isotope compositions and thus their contributions to the total dissolved sulphate could be estimated. The application of linear mixing models for three sources in the dual isotope system allowed the impact of the three different sulphate sources on particular parts of the aquifers to be calculated. The average isotopic composition of sulphate in abstracted groundwater indicates that the most important source of sulphate is sulphide weathering, contributing about 50% of total sulphate. The second most significant source of sulphate input is rainfall and it is characterised by a mean contribution of 30%. Application of Monte Carlo analysis that incorporates the full variability in distributions of isotopic compositions for the three sources and all mixing fractions between them gave the most probable ranges of the dissolved in groundwater sulphate. This analysis indicated that the proportion of sulphate derived by sulphide oxidation is comparable with the estimations based on linear models. This study has shown that the water quality of these important groundwater resources is

  18. Mitigating agricultural impacts on groundwater using distributed managed aquifer recharge ponds

    NASA Astrophysics Data System (ADS)

    Schmidt, C. M.; Russo, T. A.; Fisher, A. T.; Racz, A. J.; Wheat, C. G.; Los Huertos, M.; Lockwood, B. S.

    2010-12-01

    small-scale MAR ponds could be a useful strategy for improving groundwater conditions in this basin. Although the efficiency of small recharge ponds can be high, numerous projects would be needed to impact the overall water balance of a basin such as ours. We are applying a GIS-based approach to assess how small-scale MAR systems could be distributed to achieve significant benefit. This analysis involves determining where topography, soil type, land ownership, groundwater conditions, and cropping practices are the most favorable for locating recharge systems. Results of this work should be applicable to other basins facing similar challenges, ultimately helping to improve the sustainability of groundwater supplies.

  19. Seismically-triggered Release of Shallow Groundwater Caused by the Hale Impact, Mars

    NASA Astrophysics Data System (ADS)

    Harrison, T. N.; Kennedy, M. R.

    2010-12-01

    Channels originating at or near the margins of the continuous ejecta blanket of the youthful (Late Hesperian/Early Amazonian) 140 km-diameter Hale Crater have previously been attributed to melting of ice in the target material by superheated impact melt or remobilization of saturated ejecta. However, the presence of channels in the vicinity of Hale that do not originate on or at the margins of the ejecta blanket but are similar in morphology to those that do may suggest that channel formation at Hale was triggered by seismic energy from the impact. A key example lies at 33.0°S, 39.7°W, ~250 km northwest of Hale, where a small scabland (e.g. morphologies similar to the Channeled Scabland of the Columbia River Plateau, Washington) is observed. The scabland is located too far from the Hale impact to be explained by thermal melting of subsurface ice during the impact event. The channels are not associated with the Hale ejecta blanket, and are therefore not related to dewatering processes. The channels appear to be geologically young, with few superposed craters. Distinct depositional facies are observed; the channels terminate in a topographic depression in which the channel deposits have ponded. These deposits also have very few superposed craters. Aeolian bedforms are observed atop the deposits, potentially a lag of coarse-grained sand from within the deposits. These bedforms are confined to the deposit surface and are not observed elsewhere in the area. We propose that this “mini-scabland” was formed by the release of shallow groundwater due to seismic energy from the Hale impact. Seismic energy from earthquakes can lead to groundwater release via ejection of confined groundwater and/or upwelling of an unconfined shallow water table. In the former case, the water is confined by an impermeable layer and is typically released by jetting or spouting, resulting in fissures and/or mounds referred to as mud volcanoes. The latter case produces widespread non

  20. Surface-Water to Groundwater Transport of Pharmaceuticals in a Wastewater-Impacted Stream in the U.S.

    NASA Astrophysics Data System (ADS)

    Bradley, P. M.; Barber, L. B.; Duris, J. W.; Foreman, W. T.; Furlong, E. T.; Hubbard, L. E.; Hutchinson, K. J.; Keefe, S. H.; Kolpin, D. W.

    2014-12-01

    Wastewater pharmaceutical contamination of shallow groundwater is a substantial concern in effluent-dominated streams, due to aqueous mobility and designed bioactivity of pharmaceuticals and due to effluent-driven hydraulic gradients. Improved understanding of the environmental fate and transport of wastewater-derived pharmaceuticals is essential for effective protection of vital aquatic ecosystem services, environmental health, and drinking-water supplies. Substantial longitudinal (downstream) transport of pharmaceutical contaminants has been documented in effluent-impacted streams. The comparative lack of information on vertical and lateral transport (infiltration) of wastewater contaminants from surface-water to hyporheic and shallow groundwater compartments is a critical scientific data gap, given the potential for contamination of groundwater supplies in effluent-impacted systems. Growing dependencies on bank filtration and artificial recharge applications for release of wastewater to the environment and for pretreatment of poor-quality surface-water for drinking water emphasize the critical need to better understand the exchange of wastewater contaminants, like pharmaceuticals, between surface-water and groundwater compartments. The potential transport of effluent-derived pharmaceutical contaminants from surface-water to hyporheic-water and shallow groundwater compartments was examined in a wastewater-treatment-facility (WWTF) impacted stream in Ankeny, Iowa under effluent-dominated (71-99% of downstream flow) conditions. Strong hydraulic gradients and hydrologic connectivity were evident between surface-water and shallow-groundwater compartments in the vicinity of the WWTF outfall. Carbamazepine, sulfamethoxazole, and immunologically-related compounds were detected in groundwater 10-20 meters from the stream bank. Direct aqueous-injection HPLC-MS/MS revealed high percentage detections of pharmaceuticals (110 total analytes) in surface-water and groundwater

  1. Impact of climate change on groundwater recharge in dry areas: An ecohydrology approach

    NASA Astrophysics Data System (ADS)

    Liu, Hui-Hai

    2011-09-01

    SummaryThis work proposes an ecohydrology-based approach to study the impact of climate change on groundwater recharge in dry areas. It is largely based on a concept that in dry areas, vegetation community can be divided into two different groups, shallow- and deep-rooted vegetation, with the growing-season average of root-zone soil water saturation tending to be at its optimum value for the growth of deep-rooted vegetation. The concept is supported by data sets collected from different dry areas. Analytical results of soil water dynamics developed in previous studies are adapted here for investigating the impact of climate change. Because the conceptual model allows deep-zone soil-water saturation, averaged over growing seasons, to remain fixed during different climate conditions, we can construct a relationship among groundwater recharge, the coverage of deep-rooted vegetation, and climate. As an illustrative example, we apply the developed approach to the Yucca Mountain area. Our estimated recharge value under the current climate and the vegetation coverage is generally consistent with results estimated from other methods or observed from the site. We also evaluate how the recharge will change under several assumed future climate scenarios. The results show that both groundwater recharge and deep-rooted vegetation coverage increase with decreasing rainfall frequency (for a given amount of annual rainfall), with increasing average rainfall depth per rainfall event (for a fixed frequency) and with increasing frequency (for a fixed rainfall depth per rainfall event). The latter indicates a relatively large degree of buffering effects of vegetation on changes in groundwater recharge.

  2. Numerical investigation for the impact of CO2 geologic sequestration on regional groundwater flow

    SciTech Connect

    Yamamoto, H.; Zhang, K.; Karasaki, K.; Marui, A.; Uehara, H.; Nishikawa, N.

    2009-04-15

    Large-scale storage of carbon dioxide in saline aquifers may cause considerable pressure perturbation and brine migration in deep rock formations, which may have a significant influence on the regional groundwater system. With the help of parallel computing techniques, we conducted a comprehensive, large-scale numerical simulation of CO{sub 2} geologic storage that predicts not only CO{sub 2} migration, but also its impact on regional groundwater flow. As a case study, a hypothetical industrial-scale CO{sub 2} injection in Tokyo Bay, which is surrounded by the most heavily industrialized area in Japan, was considered, and the impact of CO{sub 2} injection on near-surface aquifers was investigated, assuming relatively high seal-layer permeability (higher than 10 microdarcy). A regional hydrogeological model with an area of about 60 km x 70 km around Tokyo Bay was discretized into about 10 million gridblocks. To solve the high-resolution model efficiently, we used a parallelized multiphase flow simulator TOUGH2-MP/ECO2N on a world-class high performance supercomputer in Japan, the Earth Simulator. In this simulation, CO{sub 2} was injected into a storage aquifer at about 1 km depth under Tokyo Bay from 10 wells, at a total rate of 10 million tons/year for 100 years. Through the model, we can examine regional groundwater pressure buildup and groundwater migration to the land surface. The results suggest that even if containment of CO{sub 2} plume is ensured, pressure buildup on the order of a few bars can occur in the shallow confined aquifers over extensive regions, including urban inlands.

  3. Chronic exposure of arsenic via drinking water and its adverse health impacts on humans.

    PubMed

    Rahman, Mohammad Mahmudur; Ng, Jack C; Naidu, Ravi

    2009-04-01

    Worldwide chronic arsenic (As) toxicity has become a human health threat. Arsenic exposure to humans mainly occurs from the ingestion of As contaminated water and food. This communication presents a review of current research conducted on the adverse health effects on humans exposed to As-contaminated water. Chronic exposure of As via drinking water causes various types of skin lesions such as melanosis, leucomelanosis, and keratosis. Other manifestations include neurological effects, obstetric problems, high blood pressure, diabetes mellitus, diseases of the respiratory system and of blood vessels including cardiovascular, and cancers typically involving the skin, lung, and bladder. The skin seems to be quite susceptible to the effects of As. Arsenic-induced skin lesions seem to be the most common and initial symptoms of arsenicosis. More systematic studies are needed to determine the link between As exposure and its related cancer and noncancer end points.

  4. Tracing man's impact on groundwater dependent ecosystem using geochemical an isotope tools combined with 3D flow and transport modeling: case study from southern Poland

    NASA Astrophysics Data System (ADS)

    Zurek, Anna; Witczak, Stanislaw; Kania, Jaroslaw; Wachniew, Przemyslaw; Rozanski, Kazimierz; Dulinski, Marek; Jench, Olga

    2013-04-01

    Thorough understanding of the link between terrestrial ecosystems and underlying groundwater reservoirs is an important element of sustainable management of groundwater resources in the light of ever growing anthropogenic pressure on groundwater reserves, both with respect to quantity and quality of this vital resource. While association of terrestrial ecosystems with surface water (rivers, streams, lakes, etc.) is visible and recognized, their link to underground components of the hydrological cycle is often forgotten and not appreciated. The presented study was aimed at investigating possible adverse effects of intensive exploitation of porous sandy aquifer on groundwater dependent terrestrial ecosystem (GDTE) consisting of a valuable forest stand and associated wetlands. The Bogucice Sands aquifer and the associated GDTE (Niepolomice Forest) are located in the south of Poland. The principal economic role of the aquifer, consisting of two water-bearing strata is to provide potable water for public and private users. Eastern part of the shallow phreatic aquifer is occupied by Niepolomice Forest. The Niepolomice Forest is a lowland forest covering around 110 km2. It is protected as a Natura 2000 Special Protection Area "Puszcza Niepołomicka" (PLB120002) which supports bird populations of European importance. Additionally, a fen in the western part of the forest comprises a separate Natura 2000 area "Torfowisko Wielkie Bloto" (PLH120080), a significant habitat of endangered butterfly species associated with wet meadows. Dependence of the Niepolomice Forest stands on groundwater is enhanced by low available water capacity and low capillary rise of soils. Groundwater conditions in the Niepolomice Forest, including Wielkie Bloto fen have been affected by meliorations carried out mostly after the Second World War and by forest management. In September 2009 a cluster of new pumping wells (Wola Batorska well-field) has been set up close to the northern boundary of

  5. Factors influencing adverse skin responses in rats receiving repeated subcutaneous injections and potential impact on neurobehavior

    PubMed Central

    Levoe, S. Nikki; Flannery, Brenna M.; Brignolo, Laurie; Imai, Denise M.; Koehne, Amanda; Austin, Adam T.; Bruun, Donald A.; Tancredi, Daniel J.; Lein, Pamela J.

    2015-01-01

    Repeated subcutaneous (s.c.) injection is a common route of administration in chronic studies of neuroactive compounds. However, in a pilot study we noted a significant incidence of skin abnormalities in adult male Long-Evans rats receiving daily s.c. injections of peanut oil (1.0 ml/kg) in the subscapular region for 21 d. Histopathological analyses of the lesions were consistent with a foreign body reaction. Subsequent studies were conducted to determine factors that influenced the incidence or severity of skin abnormalities, and whether these adverse skin reactions influenced a specific neurobehavioral outcome. Rats injected daily for 21 d with food grade peanut oil had an earlier onset and greater incidence of skin abnormalities relative to rats receiving an equal volume (1.0 ml/kg/d) of reagent grade peanut oil or triglyceride of coconut oil. Skin abnormalities in animals injected daily with peanut oil were increased in animals housed on corncob versus paper bedding. Comparison of animals obtained from different barrier facilities exposed to the same injection paradigm (reagent grade peanut oil, 1.0 ml/kg/d s.c.) revealed significant differences in the severity of skin abnormalities. However, animals from different barrier facilities did not perform differently in a Pavlovian fear conditioning task. Collectively, these data suggest that environmental factors influence the incidence and severity of skin abnormalities following repeated s.c. injections, but that these adverse skin responses do not significantly influence performance in at least one test of learning and memory. PMID:25705100

  6. Reduced order models for prediction of groundwater quality impacts from CO₂ and brine leakage

    SciTech Connect

    Zheng, Liange; Carroll, Susan; Bianchi, Marco; Mansoor, Kayyum; Sun, Yunwei; Birkholzer, Jens

    2014-12-31

    A careful assessment of the risk associated with geologic CO₂ storage is critical to the deployment of large-scale storage projects. A potential risk is the deterioration of groundwater quality caused by the leakage of CO₂ and brine leakage from deep subsurface reservoirs. In probabilistic risk assessment studies, numerical modeling is the primary tool employed to assess risk. However, the application of traditional numerical models to fully evaluate the impact of CO₂ leakage on groundwater can be computationally complex, demanding large processing times and resources, and involving large uncertainties. As an alternative, reduced order models (ROMs) can be used as highly efficient surrogates for the complex process-based numerical models. In this study, we represent the complex hydrogeological and geochemical conditions in a heterogeneous aquifer and subsequent risk by developing and using two separate ROMs. The first ROM is derived from a model that accounts for the heterogeneous flow and transport conditions in the presence of complex leakage functions for CO₂ and brine. The second ROM is obtained from models that feature similar, but simplified flow and transport conditions, and allow for a more complex representation of all relevant geochemical reactions. To quantify possible impacts to groundwater aquifers, the basic risk metric is taken as the aquifer volume in which the water quality of the aquifer may be affected by an underlying CO₂ storage project. The integration of the two ROMs provides an estimate of the impacted aquifer volume taking into account uncertainties in flow, transport and chemical conditions. These two ROMs can be linked in a comprehensive system level model for quantitative risk assessment of the deep storage reservoir, wellbore leakage, and shallow aquifer impacts to assess the collective risk of CO₂ storage projects.

  7. Reduced order models for prediction of groundwater quality impacts from CO₂ and brine leakage

    DOE PAGES

    Zheng, Liange; Carroll, Susan; Bianchi, Marco; Mansoor, Kayyum; Sun, Yunwei; Birkholzer, Jens

    2014-12-31

    A careful assessment of the risk associated with geologic CO₂ storage is critical to the deployment of large-scale storage projects. A potential risk is the deterioration of groundwater quality caused by the leakage of CO₂ and brine leakage from deep subsurface reservoirs. In probabilistic risk assessment studies, numerical modeling is the primary tool employed to assess risk. However, the application of traditional numerical models to fully evaluate the impact of CO₂ leakage on groundwater can be computationally complex, demanding large processing times and resources, and involving large uncertainties. As an alternative, reduced order models (ROMs) can be used as highlymore » efficient surrogates for the complex process-based numerical models. In this study, we represent the complex hydrogeological and geochemical conditions in a heterogeneous aquifer and subsequent risk by developing and using two separate ROMs. The first ROM is derived from a model that accounts for the heterogeneous flow and transport conditions in the presence of complex leakage functions for CO₂ and brine. The second ROM is obtained from models that feature similar, but simplified flow and transport conditions, and allow for a more complex representation of all relevant geochemical reactions. To quantify possible impacts to groundwater aquifers, the basic risk metric is taken as the aquifer volume in which the water quality of the aquifer may be affected by an underlying CO₂ storage project. The integration of the two ROMs provides an estimate of the impacted aquifer volume taking into account uncertainties in flow, transport and chemical conditions. These two ROMs can be linked in a comprehensive system level model for quantitative risk assessment of the deep storage reservoir, wellbore leakage, and shallow aquifer impacts to assess the collective risk of CO₂ storage projects.« less

  8. Protecting the nation's groundwater from contamination

    SciTech Connect

    LeVeen, E.P.

    1985-05-01

    Since groundwater provides approximately half of the nations drinking water, national concern has been focused on the depletion of groundwater. Today, however, the concern is shifting increasingly to the problem of contamination from toxic wastes. Contamination is more serious than depletion, for contamination can suddenly render a water supply worthless, thus causing unexpected and potentially enormous costs of substitute water supplies for home use, adverse impacts on the health of humans and livestock, and dislocation in regional economic activity. This paper reviews a report ''Protecting the Nation's Groundwater from Contamination'' issued by the US Congress Office of Technology Assessment.

  9. Infrastructure design integration to optimize structures and minimize groundwater impacts. Case of a bottom slab and groundwater by-pass integration in La Sagrera railway station, Spain.

    NASA Astrophysics Data System (ADS)

    Serrano Juan, Alejandro; Vázquez-Suñè, Enric; Pujades, Estanislao; Velasco, Violeta; Criollo, Rotman; Jurado, Anna

    2016-04-01

    Underground constructions search the most efficient solutions to increase safety, reduce impacts in both underground construction (such as bottom slab water pressures) and groundwater (such as groundwater barrier effect), reduce future maintenance processes and ensure that everything is implemented by the minimum cost. Even being all the previous solutions directly related to groundwater, independent solutions are usually designed to independently deal with each problem. This paper shows how with a groundwater by-pass design that enables the groundwater flow through the structure it is possible to provide an homogeneous distribution of the water pressures under the bottom slab and reduce the barrier effect produced by the structure. The new integrated design has been applied to the largest infrastructure of Barcelona: La Sagrera railway station. Through a hydrogeological model has been possible to test the project and the integrated designs in three different scenarios. This new solution resolves the barrier effect produced by the structure and optimizes the bottom slab, reducing considerably the costs and increasing safety during the construction phase.

  10. Assessing the impact of VOC-contaminated groundwater on surface water at the city scale.

    PubMed

    Ellis, Paul A; Rivett, Michael O

    2007-04-01

    This study is believed to be one of the first to assess the impact of urban VOC-(volatile organic compound) contaminated groundwater on river-water quality at the city scale. A network of riverbed piezometers was used to study the 7.4-km urbanised reach of the River Tame that flows across the groundwater-effluent unconfined Triassic sandstone aquifer underlying the city of Birmingham (UK). Aquifer groundwater contained significant chlorinated VOC contamination due to the city's industrial heritage. Chlorinated VOC-contaminated baseflow was widespread along the reach with trichloroethene (TCE) dominant. VOC concentrations in riverbed piezometers were in the range 0.1-100 microg/l with typical regulatory limits occasionally exceeded by an order of magnitude. Although anaerobic biodegradation products such as cis-dichloroethene were widespread, they were unlikely to have formed in the generally aerobic riverbed. The lack of anaerobic conditions was ascribed to insufficient accumulation of low-permeability, organic-carbon rich riverbed sediments in this medium-high energy river. Assumptions a priori that natural attenuation of chlorinated VOCs will occur via reductive dechlorination in urban riverbeds are likely in error, particularly where deposits of medium-high permeability exist transmitting much of the baseflow. Surface-water quality impacts were nevertheless still low with in-river TCE increasing by just 2 microg/l over the 7.4-km reach. Agreement of baseflow contaminant flux estimates based on five flow-concentration product methods was achieved to within an order of magnitude with 22-200 kg/yr of TCE estimated to discharge to the 7.4-km reach (equivalent to 0.8-7.5 mg/d/m2 of riverbed). Such uncertainty was not regarded as unreasonable when the large measurement scale and geological and chemical heterogeneities are considered. Improved flux estimation methods and greater monitoring densities are nevertheless warranted. Considering Birmingham's long industrial

  11. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species.

    PubMed

    Flousek, Jiří; Telenský, Tomáš; Hanzelka, Jan; Reif, Jiří

    2015-01-01

    Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše), where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta). It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory.

  12. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species

    PubMed Central

    Flousek, Jiří; Telenský, Tomáš; Hanzelka, Jan; Reif, Jiří

    2015-01-01

    Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše), where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta). It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory. PMID:26426901

  13. Urinary catheterization may not adversely impact quality of life in multiple sclerosis patients.

    PubMed

    James, Rebecca; Frasure, Heidi E; Mahajan, Sangeeta T

    2014-01-01

    Background. Multiple sclerosis (MS) healthcare providers (HCP) have undergone considerable educational efforts regarding the importance of evaluating and treating pelvic floor disorders, specifically, urinary dysfunction. However, limited data are available to determine the impact of catheterization on patient quality of life (QoL). Objectives. To describe the use of urinary catheterization among MS patients and determine the differences between those who report positive versus negative impact of this treatment on QoL. Methods. Patients were queried as part of the 2010 North American Research Committee On Multiple Sclerosis survey; topics included 1) urinary/bladder, bowel, or sexual problems; 2) current urine leakage; 3) current catheter use; 4) catheterizing and QoL. Results. Respondents with current urine leakage were 5143 (54.7%), of which 1201 reported current catheter use (12.8%). The types of catheters (intermittent self-catheterization and Foley catheter (indwelling and suprapubic)) did not differ significantly. Of the current catheter users, 304 (25.35%) respondents reported catheterization negatively impacting QoL, 629 (52.4%) reported a positive impact on QoL, and 223 (18.6%) reported neutral QoL. Conclusions. A large proportion of catheterized MS patients report negative or positive changes in QoL associated with urinary catheterization. Urinary catheterization does not appear to have a universally negative impact on patient QoL. PMID:25006498

  14. Groundwater Impacts on Urban Surface Water Quality in the Lowland Polder Catchments of the Amsterdam City Area

    NASA Astrophysics Data System (ADS)

    Rozemeijer, J.; Yu, L.; Van Breukelen, B. M.; Broers, H. P.

    2015-12-01

    Surface water quality in the Amsterdam area is suffering from high nutrient levels. The sources and transport mechanisms of these nutrients are unclear due to the complex hydrology of the highly manipulated urban and sub-urban polder catchments. This study aimed at identifying the impact of groundwater on surface water quality in the polder catchments of the greater Amsterdam city area. Therefore, we exploited the dense groundwater and surface water monitoring networks to explain spatial patterns in surface water chemistry and their relations with landscape characteristics and groundwater impact. We selected and statistically analyzed 23 variables for 144 polders, covering a total area of 700 km2. Our dataset includes concentrations of total-N, total-P, ammonium, nitrate, bicarbonate, sulfate, calcium, and chloride in surface water and groundwater, seepage rate, elevation, paved area percentage, surface water area percentage, and soil type (calcite, humus and clay percentages). Our results show that nutrient levels in groundwater were generally much higher than in surface water and often exceeded the surface water Environmental Quality Standards (EQSs). This indicates that groundwater is a large potential source of nutrients in surface water. High correlations (R2 up to 0.88) between solutes in both water compartments and close similarities in their spatial patterns confirmed the large impact of groundwater on surface water quality. Groundwater appeared to be a major source of chloride, bicarbonate and calcium in surface water and for N and P, leading to exceeding of EQSs in surface waters. In dry periods, the artificial redistribution of excess seepage water from deep polders to supply water to infiltrating polders further distributes the N and P loads delivered by groundwater over the area.

  15. Understanding the Effects of Groundwater Pumping on Streamflow: Human-Feedback Analysis on Downstream Impacts and Relevance to Reservoir Management

    NASA Astrophysics Data System (ADS)

    Seo, S. B.; Kumar, M.; Mahinthakumar, K.; Arumugam, S.

    2015-12-01

    To reduce the vulnerability of the surface water supply system from extreme drought, groundwater withdrawal has always been considered as an additional source for water supply. Since surface water process and groundwater are inter-connected, groundwater withdrawal reduces the amount of streamflow resulting in depletion downstream. Hence, a conjunctive management of surface water and groundwater resources is important to support the sustainable use of water resources. We propose a modeling framework that captures the conjunctive management on surface and groundwater resources for promoting freshwater sustainability. A fully coupled hydrologic model, Penn State Integrated Hydrologic Model (PIHM), has been applied to assess the effects of groundwater pumping on streamflow. The impact of groundwater pumping on streamflow during historic drought events has been evaluated to quantify the resiliency and vulnerability of the target watershed, the Haw (located in NC) and Verde River basin (located in AZ). Further, the groundwater pumping model is combined with a reservoir, Lake Jordan, model for developing optimal pumping strategies during droughts. The proposed conjunctive management model could also be used for assessing instream water quality due to pumping in local watersheds

  16. An Auxiliary Method To Reduce Potential Adverse Impacts Of Projected Land Developments: Subwatershed Prioritization

    EPA Science Inventory

    An index based method is developed that ranks the subwatersheds of a watershed based on their relative impacts on watershed response to anticipated land developments, and then applied to an urbanizing watershed in Eastern Pennsylvania. Simulations with a semi-distributed hydrolo...

  17. Building associations between markers of environmental stressors and adverse human health impacts using frequent itemset mining

    EPA Science Inventory

    Building associations between markers of exposure and effect using frequent itemset mining The human-health impact of environmental contaminant exposures is unclear. While some exposure-effect relationships are well studied, health effects are unknown for the vast majority of the...

  18. Quantifying the Impact of a Transboundary Streamflow Agreement on Groundwater Resources in the US High Plains Aquifer

    NASA Astrophysics Data System (ADS)

    Deines, J.; Hyndman, D. W.; Kendall, A. D.

    2015-12-01

    Many groundwater aquifers in important agricultural areas are exploited beyond their sustainable limits. Groundwater overuse can reduce streamflow across political boundaries, leading to transboundary management challenges. Although conflicts over transboundary water resources do arise, these conflicts can also prompt improved aquifer management. Portions of the Republican River Basin, which overlies the High Plains Aquifer in the central United States, have been under court-ordered groundwater restrictions to meet interstate streamflow requirements since 2004, following the 2002 Kansas v. Nebraska and Colorado Supreme Court case. We examined the impacts of these restrictions on groundwater levels, pumping volume, agricultural productivity, and streamflow in the Nebraska portion of the basin to assess how transboundary agreements can affect groundwater sustainability in agricultural systems. We synthesized available data for 1990-2014 to analyze trends before and after restrictions went into effect in 2004. After controlling for climate covariates, we found that restrictions reduced pumping volumes in the study area, resulting in increased streamflow across the Nebraska-Kansas border. Furthermore, restrictions appear to have reversed the declining trend in groundwater storage. Notably, this reversal contrasts with continuing decline in the unrestricted Kansas portion of the basin, suggesting the court-ordered restrictions have altered the sustainability trajectory of this region. The impacts of pumping restrictions on regional agricultural yields and productivity are examined. Our analysis of this system suggests that by setting external limits on resource use, enforceable transboundary water agreements can stimulate sustainable groundwater management and counter local incentives for overextraction.

  19. A stream-based methane monitoring approach for evaluating groundwater impacts associated with unconventional gas development.

    PubMed

    Heilweil, Victor M; Stolp, Bert J; Kimball, Briant A; Susong, David D; Marston, Thomas M; Gardner, Philip M

    2013-01-01

    Gaining streams can provide an integrated signal of relatively large groundwater capture areas. In contrast to the point-specific nature of monitoring wells, gaining streams coalesce multiple flow paths. Impacts on groundwater quality from unconventional gas development may be evaluated at the watershed scale by the sampling of dissolved methane (CH4 ) along such streams. This paper describes a method for using stream CH4 concentrations, along with measurements of groundwater inflow and gas transfer velocity interpreted by 1-D stream transport modeling, to determine groundwater methane fluxes. While dissolved ionic tracers remain in the stream for long distances, the persistence of methane is not well documented. To test this method and evaluate CH4 persistence in a stream, a combined bromide (Br) and CH4 tracer injection was conducted on Nine-Mile Creek, a gaining stream in a gas development area in central Utah. A 35% gain in streamflow was determined from dilution of the Br tracer. The injected CH4 resulted in a fivefold increase in stream CH4 immediately below the injection site. CH4 and δ(13) CCH4 sampling showed it was not immediately lost to the atmosphere, but remained in the stream for more than 2000 m. A 1-D stream transport model simulating the decline in CH4 yielded an apparent gas transfer velocity of 4.5 m/d, describing the rate of loss to the atmosphere (possibly including some microbial consumption). The transport model was then calibrated to background stream CH4 in Nine-Mile Creek (prior to CH4 injection) in order to evaluate groundwater CH4 contributions. The total estimated CH4 load discharging to the stream along the study reach was 190 g/d, although using geochemical fingerprinting to determine its source was beyond the scope of the current study. This demonstrates the utility of stream-gas sampling as a reconnaissance tool for evaluating both natural and anthropogenic CH4 leakage from gas reservoirs into groundwater and surface water.

  20. Impact of cemeteries on groundwater contamination by bacteria and viruses - a review.

    PubMed

    Żychowski, Józef; Bryndal, Tomasz

    2015-06-01

    In the process of decomposition of a human body, 0.4-0.6 litres of leachate is produced per 1 kg of body weight. The leachate contains pathogenic bacteria and viruses that may contaminate the groundwater and cause disease when it is used for drinking. So far, this topic has been investigated in several regions of the world (mainly Brazil, Australia, the Republic of South Africa, Portugal, the United Kingdom and Poland). However, recently more and more attention has been focused on this issue. This study reviews the results of investigations related to the impact of cemeteries on groundwater bacteriology and virology. This topic was mainly discussed in the context of the quantities and qualities of changes in types of microorganisms causing groundwater contamination. In some cases, these changes were related to the environmental setting of a place, where a cemetery was located. The review is completed by a list of recommendations. Their implementation aims to protect the local environment, employees of funeral homes and the residents living in the vicinity of cemeteries. In this form, this review aims to familiarize the reader with the results of this topic, and provide practical guidance for decision-makers in the context of expansion and management of cemeteries, as well as the location of new ones. PMID:26042963

  1. Impact of cemeteries on groundwater contamination by bacteria and viruses - a review.

    PubMed

    Żychowski, Józef; Bryndal, Tomasz

    2015-06-01

    In the process of decomposition of a human body, 0.4-0.6 litres of leachate is produced per 1 kg of body weight. The leachate contains pathogenic bacteria and viruses that may contaminate the groundwater and cause disease when it is used for drinking. So far, this topic has been investigated in several regions of the world (mainly Brazil, Australia, the Republic of South Africa, Portugal, the United Kingdom and Poland). However, recently more and more attention has been focused on this issue. This study reviews the results of investigations related to the impact of cemeteries on groundwater bacteriology and virology. This topic was mainly discussed in the context of the quantities and qualities of changes in types of microorganisms causing groundwater contamination. In some cases, these changes were related to the environmental setting of a place, where a cemetery was located. The review is completed by a list of recommendations. Their implementation aims to protect the local environment, employees of funeral homes and the residents living in the vicinity of cemeteries. In this form, this review aims to familiarize the reader with the results of this topic, and provide practical guidance for decision-makers in the context of expansion and management of cemeteries, as well as the location of new ones.

  2. Attributing a Value Onto Groundwater Resources: The Impact of Environmental Cost on Monitoring Decisions

    NASA Astrophysics Data System (ADS)

    Paleologos, E.

    2009-04-01

    European and U.S. regulations mandate a minimum number of wells in order to monitor for groundwater pollution from landfills. The optimum number and location of a network of wells is assessed by conducting numerical flow and transport simulations, which account for the heterogeneity of aquifers, and a decision-making analysis, which accounts for the probability of failure, the cost of monitoring measures, and the cost of remediation. An optimal monitoring network seeks to maximize the probability of detection, minimize the extent of polluted area, and minimize the cost of a system. The current work focuses on the decision-making part and specifically on the impact of the environmental cost on the selection of an optimal network. The results of a stochastic analysis by Yenigul et al. are utilized to determine the optimal configuration of wells subject to the above three objectives. When the standard practice is followed to set the remediation cost as a substitute of the environmental cost the optimal decision on monitoring network coincides with the minimum-mandated number of wells. A broader definition of environmental cost is proposed here that considers that the full value of groundwater resources is not recovered after remediation. The lost value of groundwater is defined as the value change from drinking water, before a pollution event, to irrigation water, which is returned after remediation. When this expanded notion of environmental cost is utilized higher monitoring standards are seen to be optimal.

  3. Impact of landfill leachate on the groundwater quality: A case study in Egypt.

    PubMed

    Abd El-Salam, Magda M; I Abu-Zuid, Gaber

    2015-07-01

    Alexandria Governorate contracted an international company in the field of municipal solid waste management for the collection, transport and disposal of municipal solid waste. Construction and operation of the sanitary landfill sites were also included in the contract for the safe final disposal of solid waste. To evaluate the environmental impacts associated with solid waste landfilling, leachate and groundwater quality near the landfills were analyzed. The results of physico-chemical analyses of leachate confirmed that its characteristics were highly variable with severe contamination of organics, salts and heavy metals. The BOD5/COD ratio (0.69) indicated that the leachate was biodegradable and un-stabilized. It was also found that groundwater in the vicinity of the landfills did not have severe contamination, although certain parameters exceeded the WHO and EPA limits. These parameters included conductivity, total dissolved solids, chlorides, sulfates, Mn and Fe. The results suggested the need for adjusting factors enhancing anaerobic biodegradation that lead to leachate stabilization in addition to continuous monitoring of the groundwater and leachate treatment processes.

  4. Impact of intensive horticulture practices on groundwater content of nitrates, sodium, potassium, and pesticides.

    PubMed

    Melo, Armindo; Pinto, Edgar; Aguiar, Ana; Mansilha, Catarina; Pinho, Olívia; Ferreira, Isabel M P L V O

    2012-07-01

    A monitoring program of nitrate, nitrite, potassium, sodium, and pesticides was carried out in water samples from an intensive horticulture area in a vulnerable zone from north of Portugal. Eight collecting points were selected and water-analyzed in five sampling campaigns, during 1 year. Chemometric techniques, such as cluster analysis, principal component analysis (PCA), and discriminant analysis, were used in order to understand the impact of intensive horticulture practices on dug and drilled wells groundwater and to study variations in the hydrochemistry of groundwater. PCA performed on pesticide data matrix yielded seven significant PCs explaining 77.67% of the data variance. Although PCA rendered considerable data reduction, it could not clearly group and distinguish the sample types. However, a visible differentiation between the water samples was obtained. Cluster and discriminant analysis grouped the eight collecting points into three clusters of similar characteristics pertaining to water contamination, indicating that it is necessary to improve the use of water, fertilizers, and pesticides. Inorganic fertilizers such as potassium nitrate were suspected to be the most important factors for nitrate contamination since highly significant Pearson correlation (r = 0.691, P < 0.01) was obtained between groundwater nitrate and potassium contents. Water from dug wells is especially prone to contamination from the grower and their closer neighbor's practices. Water from drilled wells is also contaminated from distant practices.

  5. Impact of landfill leachate on the groundwater quality: A case study in Egypt

    PubMed Central

    Abd El-Salam, Magda M.; I. Abu-Zuid, Gaber

    2014-01-01

    Alexandria Governorate contracted an international company in the field of municipal solid waste management for the collection, transport and disposal of municipal solid waste. Construction and operation of the sanitary landfill sites were also included in the contract for the safe final disposal of solid waste. To evaluate the environmental impacts associated with solid waste landfilling, leachate and groundwater quality near the landfills were analyzed. The results of physico-chemical analyses of leachate confirmed that its characteristics were highly variable with severe contamination of organics, salts and heavy metals. The BOD5/COD ratio (0.69) indicated that the leachate was biodegradable and un-stabilized. It was also found that groundwater in the vicinity of the landfills did not have severe contamination, although certain parameters exceeded the WHO and EPA limits. These parameters included conductivity, total dissolved solids, chlorides, sulfates, Mn and Fe. The results suggested the need for adjusting factors enhancing anaerobic biodegradation that lead to leachate stabilization in addition to continuous monitoring of the groundwater and leachate treatment processes. PMID:26199748

  6. Modeling climate change impacts on groundwater resources using transient stochastic climatic scenarios

    NASA Astrophysics Data System (ADS)

    Goderniaux, Pascal; BrouyèRe, Serge; Blenkinsop, Stephen; Burton, Aidan; Fowler, Hayley J.; Orban, Philippe; Dassargues, Alain

    2011-12-01

    Several studies have highlighted the potential negative impact of climate change on groundwater reserves, but additional work is required to help water managers plan for future changes. In particular, existing studies provide projections for a stationary climate representative of the end of the century, although information is demanded for the near future. Such time-slice experiments fail to account for the transient nature of climatic changes over the century. Moreover, uncertainty linked to natural climate variability is not explicitly considered in previous studies. In this study we substantially improve upon the state-of-the-art by using a sophisticated transient weather generator in combination with an integrated surface-subsurface hydrological model (Geer basin, Belgium) developed with the finite element modeling software "HydroGeoSphere." This version of the weather generator enables the stochastic generation of large numbers of equiprobable climatic time series, representing transient climate change, and used to assess impacts in a probabilistic way. For the Geer basin, 30 equiprobable climate change scenarios from 2010 to 2085 have been generated for each of six different regional climate models (RCMs). Results show that although the 95% confidence intervals calculated around projected groundwater levels remain large, the climate change signal becomes stronger than that of natural climate variability by 2085. Additionally, the weather generator's ability to simulate transient climate change enabled the assessment of the likely time scale and associated uncertainty of a specific impact, providing managers with additional information when planning further investment. This methodology constitutes a real improvement in the field of groundwater projections under climate change conditions.

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

    PubMed

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

    2016-02-15

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

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

    PubMed

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

    2016-02-15

    In the last decade, there has been an extensive use of shallow geothermal exploitations in urban environments. Although the thermal interference between exploitations has been recently studied, there is a lack of knowledge regarding the geochemical impacts of those systems on the aquifers where they are installed. Groundwater flow line scale and well-doublet scale research work has been conducted at city scale to quantify the geochemical interaction of shallow geothermal exploitations with the environment. A comprehensive analysis was conducted on data obtained from a monitoring network specifically designed to control and develop aquifer policies related to thermal management of the aquifer. The geochemical impacts were evaluated from a thermodynamic point of view by means of saturation index (SI) calculations with respect to the different mineral species considered in the system. The results obtained indicate limited geochemical interaction with the urban environment in most of the situations. However, there are some cases where the interaction of the groundwater heat pump installations with the evaporitic bedrock resulted in the total disablement of the exploitation system operation wells. The application of the tool proposed proved to be pragmatic in the evaluation of geochemical impacts. Injection of water into the aquifer can trigger an important bedrock gypsum and halite dissolution process that is partly responsible for scaling in well casing pipes and collapse of the terrain in the vicinity of injection wells. PMID:26657381

  9. Multivariate analysis of groundwater quality and modeling impact of ground heat pump system

    NASA Astrophysics Data System (ADS)

    Thuyet, D. Q.; Saito, H.; Muto, H.; Saito, T.; Hamamoto, S.; Komatsu, T.

    2013-12-01

    The ground source heat pump system (GSHP) has recently become a popular building heating or cooling method, especially in North America, Western Europe, and Asia, due to advantages in reducing energy consumption and greenhouse gas emission. Because of the stability of the ground temperature, GSHP can effectively exchange the excess or demand heat of the building to the ground during the building air conditioning in the different seasons. The extensive use of GSHP can potentially disturb subsurface soil temperature and thus the groundwater quality. Therefore the assessment of subsurface thermal and environmental impacts from the GSHP operations is necessary to ensure sustainable use of GSHP system as well as the safe use of groundwater resources. This study aims to monitor groundwater quality during GSHP operation and to develop a numerical model to assess changes in subsurface soil temperature and in groundwater quality as affected by GSHP operation. A GSHP system was installed in Fuchu city, Tokyo, and consists of two closed double U-tubes (50-m length) buried vertically in the ground with a distance of 7.3 m from each U-tube located outside a building. An anti-freezing solution was circulated inside the U-tube for exchanging the heat between the building and the ground. The temperature at every 5-m depth and the groundwater quality including concentrations of 16 trace elements, pH, EC, Eh and DO in the shallow aquifer (32-m depth) and the deep aquifer (44-m depth) were monitored monthly since 2012, in an observation well installed 3 m from the center of the two U-tubes.Temporal variations of each element were evaluated using multivariate analysis and geostatistics. A three-dimensional heat exchange model was developed in COMSOL Multiphysics4.3b to simulate the heat exchange processes in subsurface soils. Results showed the difference in groundwater quality between the shallow and deep aquifers to be significant for some element concentrations and DO, but

  10. Environmental impacts on soil and groundwater at airports: origin, contaminants of concern and environmental risks.

    PubMed

    Nunes, L M; Zhu, Y-G; Stigter, T Y; Monteiro, J P; Teixeira, M R

    2011-11-01

    Environmental impacts of airports are similar to those of many industries, though their operations expand over a very large area. Most international impact assessment studies and environmental management programmes have been giving less focus on the impacts to soil and groundwater than desirable. This may be the result of the large attention given to air and noise pollution, relegating other environmental descriptors to a second role, even when the first are comparatively less relevant. One reason that contributes to such "biased" evaluation is the lack of systematic information about impacts to soil and groundwater from airport activities, something the present study intends to help correct. Results presented here include the review of over seven hundred documents and online databases, with the objective of obtaining the following information to support environmental studies: (i) which operations are responsible for chemical releases?; (ii) where are these releases located?; (iii) which contaminants of concern are released?; (iv) what are the associated environmental risks? Results showed that the main impacts occur as a result of fuel storage, stormwater runoff and drainage systems, fuel hydrant systems, fuel transport and refuelling, atmospheric deposition, rescue and fire fighting training areas, winter operations, electrical substations, storage of chemical products by airport owners or tenants, and maintenance of green areas. A new method for ranking environmental risks of organic substances, based on chemical properties, is proposed and applied. Results show that the contaminants with the highest risks are the perfluorochemicals, benzene, trichloroethylene and CCl(4). The obtained information provides a basis for establishing the planning and checking phases of environmental management systems, and may also help in the best design of pollution prevention measures in order to avoid or reduce significant environmental impacts from airports.

  11. Groundwater impact assessment report for the 216-Z-20 Crib, 200 West Area

    SciTech Connect

    Johnson, V.G.

    1993-10-01

    As required by the Hanford Federal Facility Agreement and Consent Order ([Tri-Party Agreement] Milestone M-17-00A), this report assesses the impact of wastewater discharges to the 216-Z-20 Crib on groundwater quality. The assessment reported herein extends the initial analysis conducted from 1989 through 1990 for the Liquid Effluent Study Final Project Report. Three primary issues are addressed in response to regulator concerns with the initial analysis: The magnitude and status of the soil column transuranic inventory. Potential interactions of wastewater with carbon tetrachloride from adjacent facilities. Preferential pathways created by unsealed monitoring wells.

  12. Climate change impacts on risks of groundwater pollution by herbicides: a regional scale assessment

    NASA Astrophysics Data System (ADS)

    Steffens, Karin; Moeys, Julien; Lindström, Bodil; Kreuger, Jenny; Lewan, Elisabet; Jarvis, Nick

    2014-05-01

    Groundwater contributes nearly half of the Swedish drinking water supply, which therefore needs to be protected both under present and future climate conditions. Pesticides are sometimes found in Swedish groundwater in concentrations exceeding the EU-drinking water limit and thus constitute a threat. The aim of this study was to assess the present and future risks of groundwater pollution at the regional scale by currently approved herbicides. We identified representative combinations of major crop types and their specific herbicide usage (product, dose and application timing) based on long-term monitoring data from two agricultural catchments in the South-West of Sweden. All these combinations were simulated with the regional version of the pesticide fate model MACRO (called MACRO-SE) for the periods 1970-1999 and 2070-2099 for a major crop production region in South West Sweden. To represent the uncertainty in future climate data, we applied a five-member ensemble based on different climate model projections downscaled with the RCA3-model (Swedish Meteorological and Hydrological Institute). In addition to the direct impacts of changes in the climate, the risks of herbicide leaching in the future will also be affected by likely changes in weed pressure and land use and management practices (e.g. changes in crop rotations and application timings). To assess the relative importance of such factors we performed a preliminary sensitivity analysis which provided us with a hierarchical structure for constructing future herbicide use scenarios for the regional scale model runs. The regional scale analysis gave average concentrations of herbicides leaching to groundwater for a large number of combinations of soils, crops and compounds. The results showed that future scenarios for herbicide use (more autumn-sown crops, more frequent multiple applications on one crop, and a shift from grassland to arable crops such as maize) imply significantly greater risks of herbicide

  13. Study of Impact of Groundwater Cascading on Bio-Geochemical Parameters of Lake Michigan

    NASA Astrophysics Data System (ADS)

    Kontar, Y. A.; Stumpf, A.

    2010-12-01

    Groundwater Cascading (GC) is a specific type of thermohaline circulation, in which dense water formed over the continental shelf descends down the continental slope to a greater depth. This process is a major component of ventilation of intermediate and abyssal waters, hence affecting thermohaline circulation and global climate. The resulting flows produce an irreversible exchange of oceanic and shelf waters and takes an important role in bio-geochemical cycles by removal of phytoplankton, carbon and chlorophyll from productive areas. Because it can take decades or more for the subducted water to re-surface, water cascades contribute to long term climatic variability. It is common to consider formation of dense water by cooling, evaporation or freezing in the surface layer. GC can provide an alternative mechanism of dense water formation on the shelf. We are working on the estimation of the impact of GC on the bio-geochemical parameters of Lake Michigan. GC and groundwater discharge (GD) through permeable sediments is an important pathway for fluid, solute, and energy transport including freshwater, nutrients, trace metals, bacteria, and other land based pollutants. Given the vast population, agriculture, and industry surrounding Lake Michigan including Chicago area, there is high potential that the groundwater exchange in this environment can significantly contribute dissolved nutrients, heavy metal contaminants and organic pollutants to the lake. These pollutants are likely to impact both water quality and ecosystem health and must be considered by area managers and ecosystem modelers in order to fully understand the water, nutrient, and metal budgets of the lake under influence of climate change. It is important to obtain reliable quantitative estimates of both in coming and outgoing fluxes of fresh cold waters. In situation that incoming groundwater is cold enough to occupy the lower part of the lake water column, transport processes in the bottom boundary

  14. Persistence of perfluoroalkyl acid precursors in AFFF-impacted groundwater and soil.

    PubMed

    Houtz, Erika F; Higgins, Christopher P; Field, Jennifer A; Sedlak, David L

    2013-08-01

    Several classes of polyfluorinated chemicals that are potential precursors to the perfluorinated carboxylates and sulfonates are present in aqueous film-forming foams (AFFF). To assess the persistence of these AFFF-derived precursors, groundwater, soil, and aquifer solids were obtained in 2011 from an unlined firefighter training area at a U.S. Air Force Base where AFFF was regularly used between 1970 and 1990. To measure the total concentration of perfluorinated carboxylate and sulfonate precursors in archived AFFF formulations and AFFF-impacted environmental samples, a previously developed assay that uses hydroxyl radical to oxidize precursors to perfluorinated carboxylates was adapted for these media. This assay was employed along with direct measurement of 22 precursors found in AFFF and a suite of other poly- and perfluoroalkyl substances (PFASs). On a molar basis, precursors accounted for 41-100% of the total concentration of PFASs in archived AFFF formulations. In the training area, precursors measured by the oxidation assay accounted for an average of 23% and 28% of total PFASs (i.e., precursors and perfluorinated carboxylates and sulfonates) in groundwater and solids samples, respectively. One precursor in AFFF, perfluorohexane sulfonamide amine, was observed on several highly contaminated soil and aquifer solids samples, but no other precursors present in AFFF formulations were detected in any samples at this field site. Suspected intermediate transformation products of precursors in AFFF that were directly measured accounted for approximately half of the total precursor concentration in samples from the training site. The fraction of PFASs consisting of perfluorinated carboxylates and sulfonates was greater in groundwater and solid samples than in any archived AFFF formulations, suggesting that much of the mass of precursors released at the site was converted to perfluorinated carboxylates and sulfonates. The precursors that have persisted at this site

  15. [Application of tiered approach to assess the impact of backfilling remediated soil on groundwater].

    PubMed

    Zhong, Mao-Sheng; Jiang, Lin; Yao, Jue-Jun; Fan, Yan-Ling; Xia, Tian-Xiang; Li, Ting-Ting; Tian, Mei-Ying

    2013-03-01

    The tiered approach for assessing the impact of backfilling treated contaminated soil on groundwater was presented in details with a case study. The soil was contaminated by 1,2-dicholorenthane and 9 other organic pollutants and had been remediated before backfilling to meet the pre-set remediation goals based on health risk assessment. The results from tiered I assessment indicate that the concentrations of 8 contaminants in the leachate of the backfilling soil layer would exceed the assessment standards probably leading to groundwater contamination. However, the results from tiered II assessment, in which the adsorption and retardation of vadose zone soil was taken into account and the concentrations of pollutants reaching the groundwater table were predicated, reveal that only the concentrations of 6 contaminants would exceed the assessment standards. Further, taking the dilution and mixing of the groundwater into consideration, tiered III assessment was adopted and the results reveal that only 4 contaminants were beyond the standards. Finally, tiered IV assessment, aiming at predicting the concentration at the target well downstream, was carried out by considering the retardation of contaminants in saturated layer, and the results indicate only 1 pollutant was above the assessment standard. Therefore, it can be seen that the predicted concentrations of the target pollutants at advanced assessment levels will be closer to those at the target drinking water well and the amount of contaminants whose initially-set remediation goals need to be modified will decrease correspondingly, indicating the reduction in pollution prevention cost, although more efforts should be made and more field data should be collected to implement the advance assessment level.

  16. Numerical modeling of geothermal heat pump system: evaluation of site specific groundwater thermal impact

    NASA Astrophysics Data System (ADS)

    Pedron, Roberto; Sottani, Andrea; Vettorello, Luca

    2014-05-01

    A pilot plant using a geothermal open-loop heat pump system has been realized in the city of Vicenza (Northern Italy), in order to meet the heating and cooling needs of the main monumental building in the historical center, the Palladian Basilica. The low enthalpy geothermal system consists of a pumping well and a reinjection well, both intercepting the same confined aquifer; three other monitoring wells have been drilled and then provided with water level and temperature dataloggers. After about 1 year and a half of activity, during a starting experimental period of three years, we have now the opportunity to analyze long term groundwater temperature data series and to evaluate the numerical modeling reliability about thermal impact prediction. The initial model, based on MODFLOW and SHEMAT finite difference codes, has been calibrated using pumping tests and other field investigations data, obtaining a valid and reliable groundwater flow simulation. But thermal parameters, such as thermal conductivity and volumetric heat capacity, didn't have a site specific direct estimation and therefore they have been assigned to model cells referring to bibliographic standards, usually derived from laboratory tests and barely representing real aquifer properties. Anyway preliminary heat transport results have been compared with observed temperature trends, showing an efficient representation of the thermal plume extension and shape. The ante operam simulation could not consider heat pump real utilization, that happened to be relevantly different from the expected project values; so the first numerical model could not properly simulate the groundwater temperature evolution. Consequently a second model has been implemented, in order to calibrate the mathematical simulation with monitored groundwater temperature datasets, trying to achieve higher levels of reliability in heat transport phenomena interpretation. This second step analysis focuses on aquifer thermal parameters

  17. Ozone exposure and systemic biomarkers: Evaluation of evidence for adverse cardiovascular health impacts.

    PubMed

    Goodman, Julie E; Prueitt, Robyn L; Sax, Sonja N; Pizzurro, Daniella M; Lynch, Heather N; Zu, Ke; Venditti, Ferdinand J

    2015-05-01

    The US Environmental Protection Agency (EPA) recently concluded that there is likely to be a causal relationship between short-term (< 30 days) ozone exposure and cardiovascular (CV) effects; however, biological mechanisms to link transient effects with chronic cardiovascular disease (CVD) have not been established. Some studies assessed changes in circulating levels of biomarkers associated with inflammation, oxidative stress, coagulation, vasoreactivity, lipidology, and glucose metabolism after ozone exposure to elucidate a biological mechanism. We conducted a weight-of-evidence (WoE) analysis to determine if there is evidence supporting an association between changes in these biomarkers and short-term ozone exposure that would indicate a biological mechanism for CVD below the ozone National Ambient Air Quality Standard (NAAQS) of 75 parts per billion (ppb). Epidemiology findings were mixed for all biomarker categories, with only a few studies reporting statistically significant changes and with no consistency in the direction of the reported effects. Controlled human exposure studies of 2 to 5 hours conducted at ozone concentrations above 75 ppb reported small elevations in biomarkers for inflammation and oxidative stress that were of uncertain clinical relevance. Experimental animal studies reported more consistent results among certain biomarkers, although these were also conducted at ozone exposures well above 75 ppb and provided limited information on ozone exposure-response relationships. Overall, the current WoE does not provide a convincing case for a causal relationship between short-term ozone exposure below the NAAQS and adverse changes in levels of biomarkers within and across categories, but, because of study limitations, they cannot not provide definitive evidence of a lack of causation.

  18. Ozone exposure and systemic biomarkers: Evaluation of evidence for adverse cardiovascular health impacts.

    PubMed

    Goodman, Julie E; Prueitt, Robyn L; Sax, Sonja N; Pizzurro, Daniella M; Lynch, Heather N; Zu, Ke; Venditti, Ferdinand J

    2015-05-01

    The US Environmental Protection Agency (EPA) recently concluded that there is likely to be a causal relationship between short-term (< 30 days) ozone exposure and cardiovascular (CV) effects; however, biological mechanisms to link transient effects with chronic cardiovascular disease (CVD) have not been established. Some studies assessed changes in circulating levels of biomarkers associated with inflammation, oxidative stress, coagulation, vasoreactivity, lipidology, and glucose metabolism after ozone exposure to elucidate a biological mechanism. We conducted a weight-of-evidence (WoE) analysis to determine if there is evidence supporting an association between changes in these biomarkers and short-term ozone exposure that would indicate a biological mechanism for CVD below the ozone National Ambient Air Quality Standard (NAAQS) of 75 parts per billion (ppb). Epidemiology findings were mixed for all biomarker categories, with only a few studies reporting statistically significant changes and with no consistency in the direction of the reported effects. Controlled human exposure studies of 2 to 5 hours conducted at ozone concentrations above 75 ppb reported small elevations in biomarkers for inflammation and oxidative stress that were of uncertain clinical relevance. Experimental animal studies reported more consistent results among certain biomarkers, although these were also conducted at ozone exposures well above 75 ppb and provided limited information on ozone exposure-response relationships. Overall, the current WoE does not provide a convincing case for a causal relationship between short-term ozone exposure below the NAAQS and adverse changes in levels of biomarkers within and across categories, but, because of study limitations, they cannot not provide definitive evidence of a lack of causation. PMID:25959700

  19. Assessment of Groundwater Supply Impacts for a Mine Site in Western Turkey

    NASA Astrophysics Data System (ADS)

    Agartan, E.; Yazicigil, H.

    2010-12-01

    A nickel mine located in Turgutlu town in Western Turkey requires 135 L/s of water for the mining processes. The initial studies pointed out that part of the supply will be met by pumping water from the Turgutlu-Salihli aquifer system. The purpose of this study is to assess the impacts associated with meeting groundwater supply requirements for the mine. Scope of the study involved development of the groundwater flow model of the Turgutlu-Salihli aquifer system, determination of the alternative groundwater pumping scenarios, assessment of the impacts associated with each scenario and selection of the most feasible scenario in the aspect of environmental and technical factors. Turgutlu town is located in one of the most tectonically active areas in Turkey which is characterized by an E-W trending Gediz Graben formed as a result of N-S directed extension. Gediz River as a major surface water resource in the study area flows from east to west, passes through Gediz Graben and is connected to the Turgutlu-Salihli aquifer system. Quaternary deposits and Neogene rocks, showing better aquifer properties than the other formations of the Gediz Graben, form the Turgutlu-Salihli aquifer system. Quaternary deposits form the principal aquifer, and Neogene rocks form the secondary aquifer in the study area. Therefore, a two layered groundwater flow model of the Turgutlu-Salihli aquifer system was established using MODFLOW. The model was calibrated under steady state conditions assuming that the conditions in 1991 prior to the significant development represented a pseudo-steady state in the aquifer system. Calibration was carried out for hydraulic conductivity, recharge and boundary conditions. To get today’s groundwater levels, wells being drilled after 1991 were added to the model. In the scope of this study, two potential scenarios were considered, and their effects on the aquifer systems were evaluated. The locations of the scenario wells were determined so that they will

  20. Sensitivity of mGROWA-simulated groundwater recharge to changes in soil and land use parameters in a Mediterranean environment and conclusions in view of ensemble-based climate impact simulations.

    PubMed

    Ehlers, L; Herrmann, F; Blaschek, M; Duttmann, R; Wendland, F

    2016-02-01

    This study examines the impact of changing climatic conditions on groundwater recharge in the Riu Mannu catchment in southern Sardinia. Based on an ensemble of four downscaled and bias corrected combinations of Global and Regional Climate Models (GCM-RCMs), the deterministic distributed water balance model mGROWA was used to simulate long-term mean annual groundwater recharge in the catchment for four 30-year periods between 1981 and 2100. The four employed GCM-RCM combinations project an adverse climatic development for the study area: by the period 2071-2100, annual rainfall will decrease considerably, while grass reference evapotranspiration will rise. Accordingly, ensemble results for our base scenario showed a climate-induced decrease in the median of annual groundwater recharge in areas covered by Macchia from 42-48mm/a to 25-35mm/a between the periods 1981-2010 and 2071-2100, corresponding to a reduction of 17-43%. To take into account the influence of additional plant available water storage in weathered bedrock on groundwater recharge generation, the model was extended by a regolith zone for regions covered by Mediterranean Macchia. In a set of model runs ("scenarios"), parameter values controlling the water storage capacity of this zone were increased step-wise and evaluated by comparison to the base scenario to analyze the sensitivity of the model outcome to these changes. The implementation of a regolith zone had a considerable impact on groundwater recharge and resulted in a decrease of the median in annual groundwater recharge: by 2071-2100, the 35% scenario (available water content in the regolith of 3.9 to 5.7vol.%) showed a reduction of 67-82% as compared to the period 1981-2010 in the base scenario. In addition, we also examined the influence of changes in the crop coefficients (Kc) as well as different soil texture distributions on simulated groundwater recharge. PMID:25980930

  1. Estimating the Impact of Vadose Zone Sources on Groundwater to Support Performance Assessment of Soil Vapor Extraction

    SciTech Connect

    Oostrom, Martinus; Truex, Michael J.; Rice, Amy K.; Johnson, Christian D.; Carroll, Kenneth C.; Becker, Dave; Simon, Michelle A.

    2014-03-13

    A generalized conceptual model approach was developed that can be used to estimate the impact of volatile contaminant sources in the vadose zone on groundwater for sites where soil vapor extraction (SVE) operations have diminished source strength. The model has the potential to be broadly applicable for sites where vapor-phase transport dominates. The primary target for this conceptual model and related numerical modeling estimate of groundwater impact is for sites where contaminants have been removed from readily accessible portions of the subsurface, but where contaminants may persist in localized portions of the vadose zone. This paper describes the conceptual model, uses numerical simulations to evaluate the parameters controlling impact to groundwater, and presents estimated results for a range of input conditions. Over the implied ranges, the compliance well concentrations showed (inverse) proportionality with source concentration, Henry’s Law constant, and well screen length. An increase in site recharge caused a linear response in well concentration, with slopes dependent on the groundwater velocity. All other tested parameters resulted in nonlinear responses. The functional relationship between dimensional and transport parameters and resulting groundwater concentrations provide a basis for establishing a structured approach to evaluating the potential risk to groundwater posed by a vadose zone source. This type of evaluation is particularly important to sites where SVE has been applied and reduced contaminant concentrations, but has reached a condition of diminishing returns such that a site must consider whether continuation of SVE, remedy modifications, or closure is warranted.

  2. Chase the direct impact of rainfall into groundwater in Mt. Fuji from multiple analyses including microbial DNA

    NASA Astrophysics Data System (ADS)

    Kato, Kenji; Sugiyama, Ayumi; Nagaosa, Kazuyo; Tsujimura, Maki

    2016-04-01

    A huge amount of groundwater is stored in subsurface environment of Mt. Fuji, the largest volcanic mountain in Japan. Based on the concept of piston flow transport of groundwater an apparent residence time was estimated to ca. 30 years by 36Cl/Cl ratio (Tosaki et al., 2011). However, this number represents an averaged value of the residence time of groundwater which had been mixed before it flushes out. We chased signatures of direct impact of rainfall into groundwater to elucidate the routes of groundwater, employing three different tracers; stable isotopic analysis (delta 18O), chemical analysis (concentration of silica) and microbial DNA analysis. Though chemical analysis of groundwater shows an averaged value of the examined water which was blended by various water with different sources and routes in subsurface environment, microbial DNA analysis may suggest the place where they originated, which may give information of the source and transport routes of the water examined. Throughout the in situ observation of four rainfall events showed that stable oxygen isotopic ratio of spring water and shallow groundwater obtained from 726m a.s.l. where the average recharge height of rainfall was between 1500 and 1800 m became higher than the values before a torrential rainfall, and the concentration of silica decreased after this event when rainfall exceeded 300 mm in precipitation of an event. In addition, the density of Prokaryotes in spring water apparently increased. Those changes did not appear when rainfall did not exceed 100 mm per event. Thus, findings shown above indicated a direct impact of rainfall into shallow groundwater, which appeared within a few weeks of torrential rainfall in the studied geological setting. In addition, increase in the density of Archaea observed at deep groundwater after the torrential rainfall suggested an enlargement of the strength of piston flow transport through the penetration of rainfall into deep groundwater. This finding was

  3. Impact of Adverse Childhood Experiences on Intimate Partner Violence Perpetration among Sri Lankan Men

    PubMed Central

    Fonseka, Ruvani W.; Minnis, Alexandra M.; Gomez, Anu Manchikanti

    2015-01-01

    In Sri Lanka, over one in three women experience intimate partner violence (IPV) victimization in their lifetime, making it a serious public health concern. Adverse childhood experiences (ACEs) such as child abuse and neglect, witnessing domestic violence, parental separation, and bullying are also widespread. Studies in Western settings have shown positive associations between ACEs and IPV perpetration in adulthood, but few have examined this relationship in a non-Western context. In the present study, we examined the association of ACEs with IPV perpetration among Sri Lankan men surveyed for the UN Multi-Country Study on Men and Violence in Asia and the Pacific. We found statistically significant positive associations between the number of ACE categories (ACE score) and emotional, financial, physical, and sexual IPV perpetration among Sri Lankan men. We analyzed the contributions of each ACE category and found that childhood abuse was strongly associated with perpetration of IPV in adulthood, with sexual abuse associated with the greatest increase in odds of perpetration (Adjusted odds ratio 2.36; 95% confidence interval: 1.69, 3.30). Witnessing abuse of one’s mother was associated with the greatest increase in the odds of perpetrating physical IPV (AOR 1.82; 95% CI: 1.29, 2.58), while lack of a male parental figure was not associated with physical IPV perpetration (AOR 0.76; 95% CI: 0.53, 1.09). These findings support a social learning theory of IPV perpetration, in which children who are exposed to violence learn to perpetrate IPV in adulthood. They also suggest that in Sri Lanka, being raised in a female-headed household does not increase the risk of IPV perpetration in adulthood compared to being raised in a household with a male parental figure. The relationship between being raised in a female-headed household (the number of which increased dramatically during Sri Lanka’s recent civil war) and perpetration of IPV warrants further study. Interventions

  4. Impact of Adverse Childhood Experiences on Intimate Partner Violence Perpetration among Sri Lankan Men.

    PubMed

    Fonseka, Ruvani W; Minnis, Alexandra M; Gomez, Anu Manchikanti

    2015-01-01

    In Sri Lanka, over one in three women experience intimate partner violence (IPV) victimization in their lifetime, making it a serious public health concern. Adverse childhood experiences (ACEs) such as child abuse and neglect, witnessing domestic violence, parental separation, and bullying are also widespread. Studies in Western settings have shown positive associations between ACEs and IPV perpetration in adulthood, but few have examined this relationship in a non-Western context. In the present study, we examined the association of ACEs with IPV perpetration among Sri Lankan men surveyed for the UN Multi-Country Study on Men and Violence in Asia and the Pacific. We found statistically significant positive associations between the number of ACE categories (ACE score) and emotional, financial, physical, and sexual IPV perpetration among Sri Lankan men. We analyzed the contributions of each ACE category and found that childhood abuse was strongly associated with perpetration of IPV in adulthood, with sexual abuse associated with the greatest increase in odds of perpetration (Adjusted odds ratio 2.36; 95% confidence interval: 1.69, 3.30). Witnessing abuse of one's mother was associated with the greatest increase in the odds of perpetrating physical IPV (AOR 1.82; 95% CI: 1.29, 2.58), while lack of a male parental figure was not associated with physical IPV perpetration (AOR 0.76; 95% CI: 0.53, 1.09). These findings support a social learning theory of IPV perpetration, in which children who are exposed to violence learn to perpetrate IPV in adulthood. They also suggest that in Sri Lanka, being raised in a female-headed household does not increase the risk of IPV perpetration in adulthood compared to being raised in a household with a male parental figure. The relationship between being raised in a female-headed household (the number of which increased dramatically during Sri Lanka's recent civil war) and perpetration of IPV warrants further study. Interventions that

  5. A Possible Paradigm for the Mitigation of the Adverse Impacts of Natural Hazards in the Developing Countries

    NASA Astrophysics Data System (ADS)

    Aswathanarayana, U.

    2001-05-01

    The proneness of a country or region to a given natural hazard depends upon its geographical location, physiography, geological and structural setting, landuse/landcover situation, and biophysical and socioeconomic environments (e.g. cyclones and floods in Bangladesh, earthquakes in Turkey, drought in Sub-Saharan Africa). While the natural hazards themselves cannot be prevented, it is possible to mitigate their adverse effects, by a knowledge-based, environmentally-sustainable approach, involving the stakeholder communities: (i) by being prepared: on the basis of the understanding of the land conditions which are prone to a given hazard and the processes which could culminate in damage to life and property (e.g. planting of dense-rooted vegetation belts to protect against landslides in the earthquake-prone areas), (ii) by avoiding improper anthropogenic activities that may exacerbate a hazard (e.g. deforestation accentuating the floods and droughts), and (iii) by putting a hazard to a beneficial use, where possible (groundwater recharging of flood waters), etc. Mitigation strategies need to be custom-made for each country/region by integrating the biophysical and socioeconomic components. The proposed paradigm is illustrated in respect of Extreme Weather Events (EWEs), which is based on the adoption of three approaches: (i) Typology approach, involving the interpretation of remotely sensed data, to predict (say) temporal and spatial distribution of precipitation, (ii) "black box" approach, whereby the potential environmental consequences of an EWE are projected on the basis of previously known case histories, and (iii) Information Technology approach, to translate advanced technical information in the form of "virtual" do-it-yourself steps understandable to lay public.

  6. Impact of dose intensity of ponatinib on selected adverse events: Multivariate analyses from a pooled population of clinical trial patients.

    PubMed

    Dorer, David J; Knickerbocker, Ronald K; Baccarani, Michele; Cortes, Jorge E; Hochhaus, Andreas; Talpaz, Moshe; Haluska, Frank G

    2016-09-01

    Ponatinib is approved for adults with refractory chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia, including those with the T315I BCR-ABL1 mutation. We pooled data from 3 clinical trials (N=671) to determine the impact of ponatinib dose intensity on the following adverse events: arterial occlusive events (cardiovascular, cerebrovascular, and peripheral vascular events), venous thromboembolic events, cardiac failure, thrombocytopenia, neutropenia, hypertension, pancreatitis, increased lipase, increased alanine aminotransferase, increased aspartate aminotransferase, rash, arthralgia, and hypertriglyceridemia. Multivariate analyses allowed adjustment for covariates potentially related to changes in dosing or an event. Logistic regression analysis identified significant associations between dose intensity and most events after adjusting for covariates. Pancreatitis, rash, and cardiac failure had the strongest associations with dose intensity (odds ratios >2). Time-to-event analyses showed significant associations between dose intensity and risk of arterial occlusive events and each subcategory. Further, these analyses suggested that a lag exists between a change in dose and the resulting change in event risk. No significant association between dose intensity and risk of venous thromboembolic events was evident. Collectively, these findings suggest a potential causal relationship between ponatinib dose and certain adverse events and support prospective investigations of approaches to lower average ponatinib dose intensity. PMID:27505637

  7. The Impact of Herbal Drug Use on Adverse Drug Reaction Profiles of Patients on Antiretroviral Therapy in Zimbabwe

    PubMed Central

    Mudzviti, Tinashe; Maponga, Charles C.; Khoza, Star; Ma, Qing; Morse, Gene D.

    2012-01-01

    Background. The main objective was to determine the impact of herbal drug use on adverse drug reactions in patients on antiretroviral therapy (ART). Methodology. Patients receiving first-line ART from the national roll-out program participated in this cross-sectional study. Participants were interviewed and a data collection sheet was used to collect information from the corresponding medical record. Results. The majority (98.2%) of participants were using at least one herbal drug together with ART. The most common herbal remedies used were Allium Sativum (72.7%), Bidens pilosa (66.0%), Eucalyptus globulus (52.3%), Moringa oleifera (44.1%), Lippia javanica (36.3%), and Peltoforum africanum (34.3%). Two indigenous herbs, Musakavakadzi (OR = 0.25; 95% CI 0.076–0.828) and Peltoforum africanum (OR = 0.495; 95% CI 0.292–0.839) reduced the occurrence of adverse drug events. Conclusions. The use of herbal drugs is high in the HIV-infected population and there is need for pharmacovigilance programs to recognize the role they play in altering ADR profiles. PMID:22506106

  8. The lasting impact of early-life adversity on individuals and their descendants: potential mechanisms and hope for intervention.

    PubMed

    Cowan, C S M; Callaghan, B L; Kan, J M; Richardson, R

    2016-01-01

    The adverse effects of early-life stress are pervasive, with well-established mental and physical health consequences for exposed individuals. The impact of early adverse experiences is also highly persistent, with documented increases in risk for mental illness across the life span that are accompanied by stable alterations in neural function and hormonal responses to stress. Here, we review some of these 'stress phenotypes', with a focus on intermediary factors that may signal risk for long-term mental health outcomes, such as altered development of the fear regulation system. Intriguingly, recent research suggests that such stress phenotypes may persist even beyond the life span of the individuals, with consequences for their offspring and grand-offspring. Phenotypic characteristics may be transmitted to future generations via either the matriline or the patriline, a phenomenon that has been demonstrated in both human and animal studies. In this review, we highlight behavioral and epigenetic factors that may contribute to this multigenerational transmission and discuss the potential of various treatment approaches that may halt the cycle of stress phenotypes. PMID:26482536

  9. Impact of dose intensity of ponatinib on selected adverse events: Multivariate analyses from a pooled population of clinical trial patients.

    PubMed

    Dorer, David J; Knickerbocker, Ronald K; Baccarani, Michele; Cortes, Jorge E; Hochhaus, Andreas; Talpaz, Moshe; Haluska, Frank G

    2016-09-01

    Ponatinib is approved for adults with refractory chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia, including those with the T315I BCR-ABL1 mutation. We pooled data from 3 clinical trials (N=671) to determine the impact of ponatinib dose intensity on the following adverse events: arterial occlusive events (cardiovascular, cerebrovascular, and peripheral vascular events), venous thromboembolic events, cardiac failure, thrombocytopenia, neutropenia, hypertension, pancreatitis, increased lipase, increased alanine aminotransferase, increased aspartate aminotransferase, rash, arthralgia, and hypertriglyceridemia. Multivariate analyses allowed adjustment for covariates potentially related to changes in dosing or an event. Logistic regression analysis identified significant associations between dose intensity and most events after adjusting for covariates. Pancreatitis, rash, and cardiac failure had the strongest associations with dose intensity (odds ratios >2). Time-to-event analyses showed significant associations between dose intensity and risk of arterial occlusive events and each subcategory. Further, these analyses suggested that a lag exists between a change in dose and the resulting change in event risk. No significant association between dose intensity and risk of venous thromboembolic events was evident. Collectively, these findings suggest a potential causal relationship between ponatinib dose and certain adverse events and support prospective investigations of approaches to lower average ponatinib dose intensity.

  10. Bioremediation of adverse impact of cadmium toxicity on Cassia italica Mill by arbuscular mycorrhizal fungi.

    PubMed

    Hashem, Abeer; Abd Allah, E F; Alqarawi, A A; Egamberdieva, Dilfuza

    2016-01-01

    Cassia italica Mill is an important medicinal plant within the family Fabaceae. Pot experiment was conducted to evaluate cadmium stress induced changes in physiological and biochemical attributes in C. italica with and without arbuscular mycorrhizal fungi (AMF). Cadmium stressed plant showed reduced chlorophyll pigment and protein content while AMF inoculation enhanced the chlorophyll and protein content considerably. AMF also ameliorated the cadmium stress induced reduction in total chlorophyll and protein contents by 19.30% and 38.29%, respectively. Cadmium stress enhanced lipid peroxidation while AMF inoculation reduced lipid peroxidation considerably. Increase in proline and phenol content was observed due to cadmium stress and AMF inoculation caused a further increase in proline and phenol content ensuring better growth under stressed conditions. AMF alone also enhanced proline and phenol content. Activity of antioxidant enzymes enhanced under cadmium treatment and AMF inoculation further enhanced their activity thereby strengthening the antioxidant system. Enhanced activities of antioxidants and increased accumulation of osmolytes help plants to avoid damaging impact of oxidative damage. The research has shown that AMF inoculation mitigated the negative impact of stress by reducing the lipid peroxidation and enhancing the antioxidant activity. The present study strongly supports employing AMF as the biological mean for enhancing the cadmium stress tolerance of C. italica. PMID:26858537

  11. Bioremediation of adverse impact of cadmium toxicity on Cassia italica Mill by arbuscular mycorrhizal fungi

    PubMed Central

    Hashem, Abeer; Abd_Allah, E.F.; Alqarawi, A.A.; Egamberdieva, Dilfuza

    2015-01-01

    Cassia italica Mill is an important medicinal plant within the family Fabaceae. Pot experiment was conducted to evaluate cadmium stress induced changes in physiological and biochemical attributes in C. italica with and without arbuscular mycorrhizal fungi (AMF). Cadmium stressed plant showed reduced chlorophyll pigment and protein content while AMF inoculation enhanced the chlorophyll and protein content considerably. AMF also ameliorated the cadmium stress induced reduction in total chlorophyll and protein contents by 19.30% and 38.29%, respectively. Cadmium stress enhanced lipid peroxidation while AMF inoculation reduced lipid peroxidation considerably. Increase in proline and phenol content was observed due to cadmium stress and AMF inoculation caused a further increase in proline and phenol content ensuring better growth under stressed conditions. AMF alone also enhanced proline and phenol content. Activity of antioxidant enzymes enhanced under cadmium treatment and AMF inoculation further enhanced their activity thereby strengthening the antioxidant system. Enhanced activities of antioxidants and increased accumulation of osmolytes help plants to avoid damaging impact of oxidative damage. The research has shown that AMF inoculation mitigated the negative impact of stress by reducing the lipid peroxidation and enhancing the antioxidant activity. The present study strongly supports employing AMF as the biological mean for enhancing the cadmium stress tolerance of C. italica. PMID:26858537

  12. Bioremediation of adverse impact of cadmium toxicity on Cassia italica Mill by arbuscular mycorrhizal fungi.

    PubMed

    Hashem, Abeer; Abd Allah, E F; Alqarawi, A A; Egamberdieva, Dilfuza

    2016-01-01

    Cassia italica Mill is an important medicinal plant within the family Fabaceae. Pot experiment was conducted to evaluate cadmium stress induced changes in physiological and biochemical attributes in C. italica with and without arbuscular mycorrhizal fungi (AMF). Cadmium stressed plant showed reduced chlorophyll pigment and protein content while AMF inoculation enhanced the chlorophyll and protein content considerably. AMF also ameliorated the cadmium stress induced reduction in total chlorophyll and protein contents by 19.30% and 38.29%, respectively. Cadmium stress enhanced lipid peroxidation while AMF inoculation reduced lipid peroxidation considerably. Increase in proline and phenol content was observed due to cadmium stress and AMF inoculation caused a further increase in proline and phenol content ensuring better growth under stressed conditions. AMF alone also enhanced proline and phenol content. Activity of antioxidant enzymes enhanced under cadmium treatment and AMF inoculation further enhanced their activity thereby strengthening the antioxidant system. Enhanced activities of antioxidants and increased accumulation of osmolytes help plants to avoid damaging impact of oxidative damage. The research has shown that AMF inoculation mitigated the negative impact of stress by reducing the lipid peroxidation and enhancing the antioxidant activity. The present study strongly supports employing AMF as the biological mean for enhancing the cadmium stress tolerance of C. italica.

  13. Modelling the Impact of Human Actors on Groundwater Resources under Conditions of Climate Change

    NASA Astrophysics Data System (ADS)

    Barthel, R.; Reichenau, T. G.; Krimly, T.; Dabbert, S.; Schneider, K.; Mauser, W.; Hennicker, R.

    2012-12-01

    Water resources, activities of human actors and climate change are related in many different and complex ways because of the existence of and strong interactions between various influencing factors, including those that are natural-environmental and socio-economic. The GLOWA-Danube research cooperation has developed the integrated simulation system DANUBIA to simulate water-related influences of global change in different spatial and temporal contexts. DANUBIA is a modular system comprised of 17 dynamically-coupled, process-based model components and a framework which controls the interaction of these components with respect to space and time. This contribution describes approaches and capabilities of DANUBIA with regard to the simulation of global change effects on human decisions in water related fields with a focus on agriculture and groundwater. In agriculture, market prices and legislation can be equally or even more important than water availability in determining farmers' behavior and thus in determining the agricultural impact on water resources quantity and quality. The DANUBIA simulation framework and the associated DeepActor-framework for simulation of decision-making by human actors are presented together with the model components which are most relevant to the interactions between agriculture and groundwater. The approach for developing combination climate and socio-economic scenarios is explained. Exemplary scenario results are shown for the Upper Danube Catchment in Southern Germany. References Barthel, R., Janisch, S., N. Schwarz, A. Trifkovic, D. Nickel, C. Schulz, W. Mauser (2008): An integrated modelling framework for simulating regional-scale actor responses to global change in the water domain. Environmental Modelling and Software, 23, 1095-1121 (doi:10.1016/j.envsoft.2008.02.004) Barthel, R., Reichenau T., Krimly, T., Dabbert, S., Schneider, K., Mauser, W. (2012) Integrated modeling of climate change impacts on agriculture and groundwater

  14. Use of stream response functions to determine impacts of replacing surface-water use with groundwater withdrawals

    NASA Astrophysics Data System (ADS)

    Pruneda, Erik B.; Barber, Michael E.; Allen, Diana M.; Wu, Joan Q.

    2010-08-01

    A regional-scale numerical groundwater model is used to study the impacts of replacing surface-water use with groundwater wells to improve low-flow stream conditions for endangered species within the Bertrand and Fishtrap watersheds, southern British Columbia, Canada and Washington, USA. Stream response functions ranging from 0 to 1.0 were calculated for individual wells placed within a steady-state groundwater flow model at varying distances from the streams to determine the impact that these replacement wells, operating under sustained pumping rates, would have on summer instream flows. Lower response ratios indicate groundwater pumping will have less of an impact on streamflow than taking an equivalent amount of water directly from a surface-water source. Results show that replacing surface-water use with groundwater withdrawals may be a viable alternative for increasing summer streamflows. Assuming combined response factors should be ≤0.5 for irrigators to undergo the expense of installing new wells, ~57% of the land area within 0.8 km of Bertrand Creek would be suitable for replacement wells. Similarly, 70% of the land area within 0.8 km of Fishtrap Creek was found to be appropriate. A visual analysis tool was developed using STELLA to allow stakeholders to quickly evaluate the impact associated with moving their water right.

  15. Early Psychosocial Neglect Adversely Impacts Developmental Trajectories of Brain Oscillations and Their Interactions.

    PubMed

    Stamoulis, Catherine; Vanderwert, Ross E; Zeanah, Charles H; Fox, Nathan A; Nelson, Charles A

    2015-12-01

    Rhythmicity is a fundamental property of neural activity at multiple spatiotemporal scales, and associated oscillations represent a critical mechanism for communication and transmission of information across brain regions. During development, these oscillations evolve dynamically as a function of neural maturation and may be modulated by early experiences, positive and/or negative. This study investigated the impact of psychosocial deprivation associated with institutional rearing in early life and the effects of subsequent foster care intervention on developmental trajectories of neural oscillations and their cross-frequency correlations. Longitudinally acquired nontask EEGs from three cohorts of children from the Bucharest Early Intervention Project were analyzed. These included abandoned children initially reared in institutions and subsequently randomized to be placed in foster care or receive care as usual (prolonged institutional rearing) and a group of never-institutionalized children. Oscillation trajectories were estimated from 42 to 96 months, that is, 1-3 years after all children in the intervention arm of the study had been placed in foster care. Significant differences between groups were estimated for the amplitude trajectories of cognitive-related gamma, beta, alpha, and theta oscillations. Similar differences were identified as a function of time spent in institutions, suggesting that increased time spent in psychosocial neglect may have profound and widespread effects on brain activity. Significant group differences in cross-frequency coupling were estimated longitudinally between gamma and lower frequencies as well as alpha and lower frequencies. Lower cross-gamma coupling was estimated at 96 months in the group of children that remained in institutions at that age compared to the other two groups, suggesting potentially impaired communication between local and long-distance brain networks in these children. In contrast, higher cross

  16. Early Psychosocial Neglect Adversely Impacts Developmental Trajectories of Brain Oscillations and Their Interactions.

    PubMed

    Stamoulis, Catherine; Vanderwert, Ross E; Zeanah, Charles H; Fox, Nathan A; Nelson, Charles A

    2015-12-01

    Rhythmicity is a fundamental property of neural activity at multiple spatiotemporal scales, and associated oscillations represent a critical mechanism for communication and transmission of information across brain regions. During development, these oscillations evolve dynamically as a function of neural maturation and may be modulated by early experiences, positive and/or negative. This study investigated the impact of psychosocial deprivation associated with institutional rearing in early life and the effects of subsequent foster care intervention on developmental trajectories of neural oscillations and their cross-frequency correlations. Longitudinally acquired nontask EEGs from three cohorts of children from the Bucharest Early Intervention Project were analyzed. These included abandoned children initially reared in institutions and subsequently randomized to be placed in foster care or receive care as usual (prolonged institutional rearing) and a group of never-institutionalized children. Oscillation trajectories were estimated from 42 to 96 months, that is, 1-3 years after all children in the intervention arm of the study had been placed in foster care. Significant differences between groups were estimated for the amplitude trajectories of cognitive-related gamma, beta, alpha, and theta oscillations. Similar differences were identified as a function of time spent in institutions, suggesting that increased time spent in psychosocial neglect may have profound and widespread effects on brain activity. Significant group differences in cross-frequency coupling were estimated longitudinally between gamma and lower frequencies as well as alpha and lower frequencies. Lower cross-gamma coupling was estimated at 96 months in the group of children that remained in institutions at that age compared to the other two groups, suggesting potentially impaired communication between local and long-distance brain networks in these children. In contrast, higher cross

  17. Adverse impact of feed channel spacers on the performance of pressure retarded osmosis.

    PubMed

    Kim, Yu Chang; Elimelech, Menachem

    2012-04-17

    This article analyzes the influence of feed channel spacers on the performance of pressure retarded osmosis (PRO). Unlike forward osmosis (FO), an important feature of PRO is the application of hydraulic pressure on the high salinity (draw solution) side to retard the permeating flow for energy conversion. We report the first observation of membrane deformation under the action of the high hydraulic pressure on the feed channel spacer and the resulting impact on membrane performance. Because of this observation, reverse osmosis and FO tests that are commonly used for measuring membrane transport properties (water and salt permeability coefficients, A and B, respectively) and the structural parameter (S) can no longer be considered appropriate for use in PRO analysis. To accurately predict the water flux as a function of applied hydraulic pressure difference and the resulting power density in PRO, we introduced a new experimental protocol that accounts for membrane deformation in a spacer-filled channel to determine the membrane properties (A, B, and S). PRO performance model predictions based on these determined A, B, and S values closely matched experimental data over a range of draw solution concentrations (0.5 to 2 M NaCl). We also showed that at high pressures feed spacers block the permeation of water through the membrane area in contact with the spacer, a phenomenon that we term the shadow effect, thereby reducing overall water flux. The implications of the results for power generation by PRO are evaluated and discussed.

  18. Adverse Impact of Electromagnetic Radiation on Urban Environment and Natural Resources using Optical Sensors

    NASA Astrophysics Data System (ADS)

    Kumar, Pawan; Katiyar, Swati; Rani, Meenu

    2016-07-01

    We are living in the age of a rapidly growing population and changing environmental conditions with an advance technical capacity.This has resulted in wide spread land cover change. One of the main causes for increasing urban heat is that more than half of the world's population lives in a rapidly growing urbanized environment. Satellite data can be highly useful to map change in land cover and other environmental phenomena with the passage of time. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The UHI for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment on climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The present paper describes the methodology and resolution dynamic urban heat island change on climate using the geospatial approach. NDVI were generated using day time LANDSAT ETM+ image of 1990, 2000 and 2013. Temperature of various land use and land cover categories was estimated. Keywords: NDVI, Surface temperature, Dynamic changes.

  19. Estimating the Impact of Vadose Zone Sources on Groundwater to Support Performance Assessment of Soil Vapor Extraction

    SciTech Connect

    Oostrom, Martinus; Truex, Michael J.; Rice, Amy K.; Johnson, Christian D.; Carroll, Kenneth C.; Becker, Dave; Simon, Michelle A.

    2014-03-13

    Soil vapor extraction (SVE) is a prevalent remediation approach for volatile contaminants in the vadose zone. To support selection of an appropriate endpoint for the SVE remedy, an evaluation is needed to determine whether vadose zone contamination has been diminished sufficiently to protect groundwater. When vapor-phase transport is an important component of the overall contaminant fate and transport from a vadose zone source, the contaminant concentration expected in groundwater is controlled by a limited set of parameters, including specific site dimensions, vadose zone properties, and source characteristics. An approach was developed for estimating the contaminant concentration in groundwater resulting from a contaminant source in the vadose zone based on pre-modeling contaminant transport for a matrix of parameter value combinations covering a range of potential site conditions. An interpolation and scaling process are then applied to estimate groundwater impact for site-specific conditions.

  20. Municipal Landfilling Practice And Its Impact On Groundwater Resources In And Around Urban Toronto, Canada

    NASA Astrophysics Data System (ADS)

    Howard, K. W. F.; Eyles, N.; Livingstone, S.

    1996-01-01

    The hazardous contents of municipal landfills are rarely documented and problems are usually not recognised until landfill leachate pollutes a well or surface-water body. By this time, the groundwater is often extensively contaminated with little opportunity for redress. Recent studies in southern Ontario have adopted a pro-active stance to this issue. The location, size, design and geologic setting of almost 1,200 active and inactive landfills have been documented; in addition, a contaminant-source audit has been performed for a representative region of urban Toronto, where 82 landfills sites are contained in an area of 700 km2. Groundwater flow modeling reveals that at half the sites groundwater travel time to major urban streams and Lake Ontario is less than 10 years, suggesting that chemically conservative chemicals released at these sites would have a rapid impact on surface-water quality. The sites are as large as 99 ha, and waste thickness normally ranges from 3-30 m. In the audited area, the sites contain an estimated 4.6×107 tons of material, consisting primarily of domestic waste, incinerator ashes, and construction and commercial debris; some sites are believed, however, to have received liquid waste from industrial sources. The chemical audit indicates that more than 1.3 million tons, or approximately 2.9 percent of the landfill waste, will enter the landfill leachate. About 99 percent of the leachable mass is composed of calcium, magnesium, sodium, nitrogen (as ammonia, nitrate, and nitrite), chloride, sulphate, and bicarbonate. However, the real potential damage must be measured by the degree of environmental degradation that would ensue if the leachate is released to the subsurface. Ignoring the possible effects of chemical biodegradation and volatilization within the aquifer, calculations indicate that 17 of the 39 leachate components investigated are individually capable of contaminating at least 2×1012 liters of water in excess of Provincial

  1. Climate Impact on Groundwater Recharge in Southeastern Louisiana and Southwestern Mississippi

    NASA Astrophysics Data System (ADS)

    Beigi, E.; Tsai, F. T.

    2012-12-01

    Increases of concentrations of CO2 and other greenhouse gases have a significant effect on global climate, precipitation and hydrology, which in turn influences recharge to aquifers. Groundwater recharge study is imperative to the sole source aquifer, for example the Southern Hills aquifer system in southeastern Louisiana and southwestern Mississippi, which provides more than 50 percent of the drinking water consumed in the area overlying the aquifer and has no substitute drinking water source(s). To trace the climate impact and its consequent groundwater availability, this study developed a GIS-based integrated framework to connect climate models to a high-resolution hydrologic model to quantify long-term groundwater recharge. We employed the Hydrologic Evaluation of Landfill Performance (HELP3) model as our hydrologic model to estimate spatial-temporal distribution of potential recharge for a regional scale. HELP3 model was especially suitable for our recharge study due to Louisiana humid climate and the use of a regional-scale water budget approach. Detailed surficial soil property and land cover were obtained from the NRCS and the USGS to derive maps of curve number for the HELP3 model. Wireline well logs and drillers logs were analyzed to determine stratigraphic lithology and the first major sand encountered beneath the soil layer. For a regional scale, we used global circulation model (GCM) downscaled daily precipitation and temperature obtained from USGS CASCaDE Project Climate Data as the forcing input to the HELP3 model. The emission scenarios considered in this study were A2, B1 and A1FI from Parallel Climate Model 1 (PCM) and from the NOAA Geophysical Fluid Dynamics Lab's GFDL CM2.1 model. We used the computed runoff from USGS WaterWatch along with the HELP3 model to calculate the recharge index (RI) and delineate the recharge index map for individual hydrologic units in terms of Hydrologic Unit Codes (HUCs). The recharge index was defined as the

  2. Evaluation of the impacts of urban development on groundwater storage at the regional scale

    NASA Astrophysics Data System (ADS)

    Bhaskar, A. S.; Welty, C.; Maxwell, R. M.; Miller, A. J.

    2013-12-01

    Urban development results in a myriad of changes to the natural environment; these changes can give rise to a range of effects on the groundwater system. We have used the integrated subsurface - surface - land surface hydrologic model ParFlow.CLM to evaluate and isolate the impacts of urban development on groundwater storage at the regional scale. We have applied the model to the 13,216 sq km Baltimore metropolitan area at a 500 m horizontal and 5 m vertical discretization, incorporating realistic estimates of anthropogenic fluxes (lawn watering, leakage from water supply pipes, infiltration into sewer pipes, withdrawals for water supply) as well as any available hydrogeologic data. We developed a base-case model, where all urban fluxes and features are incorporated, followed by model scenarios in which urban features were modified one-at-a time to evaluate the effects of each feature. The scenarios presented are: (1) the vegetated city, in which urban land is represented as natural vegetation mosaic in the land surface model; (2) the pervious city, in which low hydraulic conductivity values representing impervious surfaces are replaced with higher soil hydraulic conductivities; (3) the intact-sewer scenario, in which infiltration and inflow (I/I) of groundwater and stormwater into wastewater sewer pipes is removed; and (4) the no-anthropogenic- discharge-and-recharge scenario, in which all anthropogenic input and output fluxes are removed. We compared the subsurface storage of these scenarios to the base case model. We found that the pervious city subsurface storage was slightly greater than the subsurface storage in the base case, which is expected due to additional infiltration associated higher hydraulic conductivity values. The magnitude of this increase in subsurface storage was surprisingly small compared to changes found in other scenarios. The intact-sewer scenario eliminated the large quantity of groundwater infiltrating into wastewater pipes in the

  3. Impacts of varying agricultural intensification on crop yield and groundwater resources: comparison of the North China Plain and US High Plains

    NASA Astrophysics Data System (ADS)

    Pei, Hongwei; Scanlon, Bridget R.; Shen, Yanjun; Reedy, Robert C.; Long, Di; Liu, Changming

    2015-04-01

    Agricultural intensification is often considered the primary approach to meet rising food demand. Here we compare impacts of intensive cultivation on crop yield in the North China Plain (NCP) with less intensive cultivation in the US High Plains (USHP) and associated effects on water resources using spatial datasets. Average crop yield during the past decade from intensive double cropping of wheat and corn in the NCP was only 15% higher than the yield from less intensive single cropping of corn in the USHP, although nitrogen fertilizer application and percent of cropland that was irrigated were both ˜2 times greater in the NCP than in the USHP. Irrigation and fertilization in both regions have depleted groundwater storage and resulted in widespread groundwater nitrate contamination. The limited response to intensive management in the NCP is attributed in part to the two month shorter growing season for corn to accommodate winter wheat than that for corn in the USHP. Previous field and modeling studies of crop yield in the NCP highlight over application of N and water resulting in low nitrogen and water use efficiencies and indicate that cultivars, plant densities, soil fertility and other factors had a much greater impact on crop yields over the past few decades. The NCP-USHP comparison along with previous field and modeling studies underscores the need to weigh the yield returns from intensive management relative to the negative impacts on water resources. Future crop management should consider the many factors that contribute to yield along with optimal fertilization and irrigation to further increase crop yields while reducing adverse impacts on water resources.

  4. Assessment of the impact of landfill on groundwater quality: a case study of the Pirana site in western India.

    PubMed

    Singh, Umesh Kumar; Kumar, Manish; Chauhan, Rita; Jha, Pawan Kumar; Ramanathan, Al; Subramanian, V

    2008-06-01

    In present study focus has been given on estimating quality and toxicity of waste with respect to heavy metals and its impact on groundwater quality, using statistical and empirical relationships between different hydrochemical data, so that easy monitoring may be possible which in turn help the sustainable management of landfill site and municipal solid waste. Samples of solid waste, leachate and groundwater were analyzed to evaluate the impact of leachates on groundwater through the comparison of their hydrochemical nature. Results suggest the existence of an empirical relationship between some specific indicator parameters like heavy metals of all three above mentioned sample type. Further, K/Mg ratio also indicates three groundwater samples heavily impacted from leachate contamination. A good number of samples are also showing higher values for NO(3)(-) and Pb than that of World Health Organization (WHO) drinking water regulation. Predominance of Fe and Zn in both groundwater and solid waste samples may be due to metal plating industries in the area. Factor analysis is used as a tool to explain observed relation between numerous variables in term of simpler relation, which may help to deduce the strength of relation. Positive loading of most of the factors for heavy metal clearly shows landfill impact on ground water quality especially along the hydraulic gradient. Cluster analysis, further substantiates the impact of landfill. Two major groups of samples obtained from cluster analysis suggest that one group comprises samples that are severely under the influence of landfill and contaminated leachates along the groundwater flow direction while other assorted with samples without having such influence.

  5. Impact of irrigation with arsenic-rich groundwater on soils and crops.

    PubMed

    Moyano, A; Garcia-Sanchez, A; Mayorga, P; Anawar, H M; Alvarez-Ayuso, E

    2009-03-01

    The study was carried out in an intensively cultivated agricultural area of central Spain where high arsenic (As) concentrations in groundwater were previously reported. The concentrations and distribution of As in soils and crops (wheat, potato, sugar beet and carrot) were determined to know the effect of irrigation with As-rich groundwater in the agricultural fields, and to estimate its impact on the food chain contamination. Irrigation water shows high As concentrations ranging between 38 and 136 microg/l. Total As contents in the studied agricultural soils are higher than 10 mg/kg exceeding the As content in two control areas and the results of this study reflect that irrigation with As-rich groundwater led to the elevated As levels in the agricultural soils. Total As concentration in soils of a sugar beet plot (36 mg/kg) is higher than that found in soils of the less intensively watered field (11 mg/kg), and more than 3.5 times higher than that in the soils of the control area irrigated with uncontaminated water (<10 mg/kg). Water soluble As in soils ranges between 0.03 and 0.9 mg/kg exceeding the limit of 0.04 mg/kg for agricultural use and shows a significant correlation with total As and organic matter (OM) content in soils. Arsenic contents in potato tuber samples are 35 times higher than that measured in potato tuber of uncontaminated control sites (0.03 mg/kg). Elevated As contents (3.9-5.4 mg/kg DW) were also found in root samples of sugar beet. The As contents in vegetable samples are higher than As content (0.1 mg/kg DW) in plants of uncontaminated control areas, and the limits for foodstuffs (0.5-1 mg/kg DW) set by legislation of many countries reflecting the risk of food chain contamination by As in this study area.

  6. Impacts of Near-term Climate Change on Surface Water - Groundwater Availability in the Nueces River basin, TX

    NASA Astrophysics Data System (ADS)

    Sinha, T.; Kumar, M.

    2014-12-01

    In arid and semi-arid regions, sustainability of surface water and groundwater resources is highly uncertain in the face of climate change as well as under competing demands due to urbanization, population growth and water needs to support ecosystem services. Most studies on climate change impact assessment focus on either surface water or groundwater resources alone. In this study, we utilize a fully coupled surface water and groundwater model, Penn-State Integrated Hydrologic Model (PIHM), and recent climate change projections from Climate Models Inter-comparison Project-5 (CMIP5) to evaluate impacts of near-term climate change on water availability in the Nueces River basin, TX. After performing calibration and validation of PIHM over multiple sites, hindcast simulations will be performed over the 1981-2010 period using data from multiple General Circulation Models (GCMs) obtained from the CMIP5 Project. The results will be compared to the observed data to understand added utility of hindcasts in improving the estimation of surface water and groundwater resources. Finally, we will assess the impacts of climate change on both surface water and groundwater resources over the next 20-30 years, which is a relevant time period for water management decisions.

  7. The adverse aerodynamic impact of very small leading-edge ice (roughness) buildups on wings and tails

    NASA Technical Reports Server (NTRS)

    Lynch, Frank T.; Valarezo, Walter O.; Mcghee, Robert J.

    1991-01-01

    Systematic experimental studies were performed to establish the aerodynamic impact of very small leading-edge simulated ice (roughness) formations on lifting surfaces. The geometries studied include single element configurations (airfoil and 3-D tail) as well as multi-element high-lift airfoil geometries. Emphasis in these studies was placed on obtaining results at high Reynolds numbers to insure the applicability of the findings to full-scale situations. It was found that the well-known Brumby correlation for the adverse lift impact of discrete roughness elements at the leading edge is not appropriate for cases representative of initial ice build up (i.e., distributed roughness). It was also found that allowing initial ice formations of a size required for removal by presently proposed deicing systems could lead to maximum lift losses of approximately 40 percent for single-element airfoils. Losses in angle-of-attack margin to stall are equally substantial - as high as 6 degrees. Percentage losses for multi-element airfoils are not as severe as for single-element configurations, but degradations of the angle-of-attack-to-stall margin are the same for both.

  8. Evaluation of the potential impact of climate changes on groundwater recharge in Karkheh river basin (Khuzestan, Iran)

    NASA Astrophysics Data System (ADS)

    Abrishamchi, A.; Beigi, E.; Tajrishy, M.; Abrishamchi, A.

    2009-12-01

    Groundwater is an important natural resource for human beings and ecosystems, especially in arid semi arid regions with scarce water resources and high climate variability. This vital resource is under stress in terms of both quantity and quality due to increased demands as well as the drought. Wise groundwater management requires vulnerability and susceptibility assessment of groundwater resources to natural and anthropogenic phenomena such as drought, over-abstraction and quality deterioration both in the current climatic situation and in the context of climate change. There is enough evidence that climate change is expected to affect all elements of hydrologic cycle and have negative effects on water resources due to increased variability in extreme hydrologic events of droughts and floods. .In this study impact of climate change on groundwater recharge in Karkheh river basin in province of Khuzestan, Iran, has been investigated using a physically-based methodology that can be used for predicting both temporal and spatial varying groundwater recharge. To ensure the sustainability of the land and water resources developments, assessment of the possible impacts of climate change on hydrology and water resources in the basin is necessary. Quantifying groundwater recharge is essential for management of groundwater resources. Recharge was estimated by using the hydrological evaluation of landfill performance (HELP3) water budget model. Model’s parameters were calibrated and validated using observational data in 1990-1998. The impact of climate change was modeled using downscaled precipitation and temperature from runs of CGCM2 model. These data were derived from two scenarios, A2 and B2 for three periods: 2010-2039, 2040-2069, and 2070-2099. Results of the study indicate that due to global warming evapotranspiration rates will increase and winter-precipitation will fall, spring-snowmelt will shift toward winter and consequently it will cause recharge to increase

  9. Impact of nandrolone decanoate on gene expression in endocrine systems related to the adverse effects of anabolic androgenic steroids.

    PubMed

    Alsiö, Johan; Birgner, Carolina; Björkblom, Lars; Isaksson, Pernilla; Bergström, Lena; Schiöth, Helgi B; Lindblom, Jonas

    2009-11-01

    Elite athletes, body builders and adolescents misuse anabolic-androgenic steroids (AAS) in order to increase muscle mass or to enhance physical endurance and braveness. The high doses misused are associated with numerous adverse effects. The purpose of this study was to evaluate the impact of chronic supratherapeutic AAS treatment on circulating hormones and gene expression in peripheral tissues related to such adverse effects. Quantitative real-time PCR was used to measure expression levels of in total 37 genes (including peptide hormones, cell membrane receptors, nuclear receptors, steroid synthesising enzymes and other enzymes) in the pituitary, testes, adrenals, adipose tissue, kidneys and liver of male Sprague-Dawley rats after 14-day administration of the AAS nandrolone decanoate, 3 or 15 mg/kg. Plasma glucose and levels of adrenocorticotropic hormone (ACTH), adiponectin, corticosterone, ghrelin, insulin and leptin were also measured. We found several expected effects on the hypothalamic-pituitary-gonadal axis, while the treatment also caused a number of other not previously identified changes in circulating factors and gene transcription levels such as the dose-dependent reduction of the beta(3)-adrenergic receptor in adipose tissue, reduction of both circulating and mRNA levels of adiponectin, up-regulation of both hydroxymethylglutaryl-CoA-reductase, the rate-limiting enzyme in de novo synthesis of cholesterol, and the receptor for ACTH in the adrenals. The results provide evidence for wide ranging effects of AAS on the hypothalamic-pituitary-adrenal axis, adipose tissue and substrates of the renal control of blood pressure.

  10. Climate change impacts on groundwater resources: modelled deficits in a chalky aquifer, Geer basin, Belgium

    NASA Astrophysics Data System (ADS)

    Brouyère, Serge; Carabin, Guy; Dassargues, Alain

    An integrated hydrological model (MOHISE) was developed in order to study the impact of climate change on the hydrological cycle in representative water basins in Belgium. This model considers most hydrological processes in a physically consistent way, more particularly groundwater flows which are modelled using a spatially distributed, finite-element approach. Thanks to this accurate numerical tool, after detailed calibration and validation, quantitative interpretations can be drawn from the groundwater model results. Considering IPCC climate change scenarios, the integrated approach was applied to evaluate the impact of climate change on the water cycle in the Geer basin in Belgium. The groundwater model is described in detail, and results are discussed in terms of climate change impact on the evolution of groundwater levels and groundwater reserves. From the modelling application on the Geer basin, it appears that, on a pluri-annual basis, most tested scenarios predict a decrease in groundwater levels and reserves in relation to variations in climatic conditions. However, for this aquifer, the tested scenarios show no enhancement of the seasonal changes in groundwater levels. Un modèle hydrologique intégré (MOHISE) a été développé afin d'étudier l'impact du changement climatique sur le cycle hydrologique de bassins versants représentatifs de Belgique. Ce modèle prend en compte tous les processus hydrologiques d'une manière physiquement consistante, plus particulièrement les écoulements souterrains qui sont modélisés par une approche spatialement distribuée aux éléments finis. Grâce à cet outil numérique précis, après une calibration et une validation détaillées, des interprétations quantitatives peuvent être réalisées à partir des résultats du modèle de nappe. Considérant des scénarios de changements climatiques de l'IPCC, l'approche intégrée a été appliquée pour évaluer l'impact du changement climatique sur le cycle de l

  11. Groundwater impacts during water shortages in the south Florida water management district

    SciTech Connect

    Wedderburn, L.A.; Knapp, M.S.; Burns, W.S.

    1985-01-01

    South Florida has historically experienced periods of below normal rainfall, without significant impacts on groundwater availability. However, rapidly increasing demands due to urbanization, intensification of agricultural land use, and the proximity of many public water supply wellfields to coastal saline water have contributed to recent water shortages. Analysis of conditions in the Floridan, Intermediate, and Surficial aquifer systems at selected locations indicate that reductions in water levels, as a result of increased development, have caused locally unstable conditions. This combined with other factors cause certain areas to be prone to water shortage emergencies although adequate resources may be available in other areas. In coastal areas the landward migration of the saltwater front into the surficial aquifers has been documented, and is the major concern in restricting water use. Where aquifers of low productivity are utilized, falling water levels have forced curtailment of supply due to well failure and the threat of vertical or lateral saline water intrusion. In the deeper artesian aquifers, the reduction of flowing head limits the ability to obtain water through free flowing wells. Recommended strategies to maximize yields from these aquifers during droughts include: (1) development of alternate sources, (2) reduction of high quality water demand through the use of reclaimed water and water conservation, (3) protection of present and future wellfield sites and their recharge areas, (4) land use controls to protect water quality and quantity, and (5) augmentation of groundwater supplies through artificial recharge during periods when supplies are abundant.

  12. Integrated assessment of the impact of climate and land use changes on groundwater quantity and quality in Mancha Oriental (Spain)

    NASA Astrophysics Data System (ADS)

    Pulido-Velazquez, M.; Peña-Haro, S.; Garcia-Prats, A.; Mocholi-Almudever, A. F.; Henriquez-Dole, L.; Macian-Sorribes, H.; Lopez-Nicolas, A.

    2014-09-01

    Climate and land use change (global change) impacts on groundwater systems cannot be studied in isolation, as various and complex interactions in the hydrological cycle take part. Land-use and land-cover (LULC) changes have a great impact on the water cycle and contaminant production and transport. Groundwater flow and storage are changing in response not only to climatic changes but also to human impacts on land uses and demands (global change). Changes in future climate and land uses will alter the hydrologic cycles and subsequently impact the quantity and quality of regional water systems. Predicting the behavior of recharge and discharge conditions under future climatic and land use changes is essential for integrated water management and adaptation. In the Mancha Oriental system in Spain, in the last decades the transformation from dry to irrigated lands has led to a significant drop of the groundwater table in one of the largest groundwater bodies in Spain, with the consequent effect on stream-aquifer interaction in the connected Jucar River. Streamflow depletion is compromising the related ecosystems and the supply to the downstream demands, provoking a complex management issue. The intense use of fertilizer in agriculture is also leading to locally high groundwater nitrate concentrations. Understanding the spatial and temporal distribution of water availability and water quality is essential for a proper management of the system. In this paper we analyze the potential impact of climate and land use change in the system by using an integrated modelling framework consisting of the sequentially coupling of a watershed agriculturally-based hydrological model (SWAT) with the ground-water model MODFLOW and mass-transport model MT3D. SWAT model outputs (mainly groundwater recharge and pumping, considering new irrigation needs under changing ET and precipitation) are used as MODFLOW inputs to simulate changes in groundwater flow and storage and impacts on stream

  13. Impact of anthropogenic development on coastal ground-water hydrology in southeastern Florida, 1900-2000

    USGS Publications Warehouse

    Renken, Robert A.; Dixon, Joann; Koehmstedt, John A.; Ishman, Scott; Lietz, A.C.; Marella, Richard L.; Telis, Pamela A.; Rodgers, Jeff; Memberg, Steven

    2005-01-01

    Southeastern Florida is an area that has been subject to widely conflicting anthropogenic stress to the Everglades and coastal ecosystems. This stress is a direct consequence of the 20th century economic competition for limited land and water resources needed to satisfy agricultural development and its expansion, its displacement by burgeoning urban development, and the accompanying growth of the limestone mining industry. The development of a highly controlled water-management system designed to reclaim land for urban and agricultural development has severely impacted the extent, character, and vitality of the historic Everglades and coastal ecosystems. An extensive conveyance system of canals, levees, impoundments, surface- water control structures, and numerous municipal well fields are used to sustain the present-day Everglades hydrologic system, prevent overland flow from moving eastward and flooding urban and agricultural areas, maintain water levels to prevent saltwater intrusion, and provide an adequate water supply. Extractive mining activities expanded considerably in the latter part of the 20th century, largely in response to urban construction needs. Much of the present-day urban-agricultural corridor of southeastern Florida lies within an area that is no more than 15 feet above NGVD 1929 and formerly characterized by freshwater marsh, upland, and saline coastal wetland ecosystems. Miami- Dade, Broward, and Palm Beach Counties have experienced explosive population growth, increasing from less than 4,000 inhabitants in 1900 to more than 5 million in 2000. Ground-water use, the principal source of municipal supply, has increased from about 65 Mgal/d (million gallons per day) obtained from 3 well fields in 1930 to more than 770 Mgal/d obtained from 65 well fields in 1995. Water use for agricultural supply increased from 505 Mgal/d in 1953 to nearly 1,150 Mgal/d in 1988, but has since declined to 764 Mgal/d in 1995, partly as a result of displacement of the

  14. The impact of river infiltration on the chemistry of shallow groundwater in a reclaimed water irrigation area

    NASA Astrophysics Data System (ADS)

    Yin, Shiyang; Wu, Wenyong; Liu, Honglu; Bao, Zhe

    2016-10-01

    Reclaimed water reuse is an effective method of alleviating agricultural water shortages, which entails some potential risks for groundwater. In this study, the impacts of wastewater reuse on groundwater were evaluated by combination of groundwater chemistry and isotopes. In reclaimed water infiltration, salt composition was affected not only by ion exchange and dissolution equilibrium but also by carbonic acid equilibrium. The dissolution and precipitation of calcites and dolomites as well as exchange and adsorption between Na and Ca/Mg were simultaneous, leading to significant changes in Na/Cl, (Ca + Mg)/Cl, electrical conductivity (EC) and sodium adsorption ratio (SAR). The reclaimed water was of the Na-Mg-Ca-HCO3-Cl type, and groundwater recharged by reclaimed water was of the Na-Mg-HCO3 and Mg-Na-HCO3 types. The hydrogeological conditions characterized by sand-clay alternation led to both total nitrogen (TN) and total phosphorus (TP) removal efficiencies > 95%, and there was no significant difference in those contents between aquifers recharged by precipitation and reclamation water. > 40 years of long-term infiltration and recharge from sewage and reclaimed water did not cause groundwater contamination by nitrogen, phosphorus and heavy metals. These results indicate that characteristics of the study area, such as the lithologic structure with sand-clay alternation, relatively thick clay layer, and relatively large groundwater depth have a significant role in the high vulnerability.

  15. Impact of human activity and natural processes on groundwater arsenic in an urbanized area (South China) using multivariate statistical techniques.

    PubMed

    Huang, Guanxing; Chen, Zongyu; Liu, Fan; Sun, Jichao; Wang, Jincui

    2014-11-01

    Anthropogenic factors resulted from the urbanization may affect the groundwater As in urbanized areas. Groundwater samples from the Guangzhou city (South China) were collected for As and other parameter analysis, in order to assess the impact of urbanization and natural processes on As distribution in aquifers. Nearly 25.5 % of groundwater samples were above the WHO drinking water standard for As, and the As concentrations in the granular aquifer (GA) were generally far higher than that in the fractured bedrock aquifer (FBA). Samples were classified into four clusters by using hierarchical cluster analysis. Cluster 1 is mainly located in the FBA and controlled by natural processes. Anthropogenic pollution resulted from the urbanization is responsible for high As concentrations identified in cluster 2. Clusters 3 and 4 are mainly located in the GA and controlled by both natural processes and anthropogenic factors. Three main mechanisms control the source and mobilization of groundwater As in the study area. Firstly, the interaction of water and calcareous rocks appears to be responsible for As release in the FBA. Secondly, reduction of Fe/Mn oxyhydroxides and decomposition of organic matter are probably responsible for high As concentrations in the GA. Thirdly, during the process of urbanization, the infiltration of wastewater/leachate with a high As content is likely to be the main source for groundwater As, while NO3 (-) contamination diminishes groundwater As.

  16. Scoping Calculations for Potential Groundwater Impacts from Operation of the APT Facility at SRS

    SciTech Connect

    Thibault, J.J.

    1999-10-07

    The purpose of this study was to determine the potential travel times and paths of the postulated activated groundwater beneath the facility and to examine the fate and transport of this activated groundwater.

  17. Resilience of Groundwater Impacted by Land Use and Climate Change in a Karst Aquifer, South China.

    PubMed

    Guo, Fang; Jiang, Guanghui; Polk, Jason S; Huang, Xiufeng; Huang, Siyu

    2015-11-01

    Changes of groundwater flow and quality were investigated in a subtropical karst aquifer to determine the driving mechanism. Decreases in groundwater flow are more distinct in discharge zones than those in recharge and runoff zones. Long-term measurement of the represented regional groundwater outlet reveals that groundwater discharge decrease by nearly 50% during the dry season. The hydrochemistry of groundwater in the runoff and discharge zones is of poorer quality than in the recharge zone. Indications of intensive land resource exploitation and changes in land use patterns were attributed to changes in groundwater conditions since 1990, but the influence of climate change was likely from 2001, because the water temperature exhibited increasing trends at a mean rate of 0.02 °C/yr even though groundwater depth was high in the aquifer. These conclusions imply the need for further groundwater monitoring and reevaluation to understand the resilience of aquifer during urbanization and development. PMID:26564587

  18. Resilience of Groundwater Impacted by Land Use and Climate Change in a Karst Aquifer, South China.

    PubMed

    Guo, Fang; Jiang, Guanghui; Polk, Jason S; Huang, Xiufeng; Huang, Siyu

    2015-11-01

    Changes of groundwater flow and quality were investigated in a subtropical karst aquifer to determine the driving mechanism. Decreases in groundwater flow are more distinct in discharge zones than those in recharge and runoff zones. Long-term measurement of the represented regional groundwater outlet reveals that groundwater discharge decrease by nearly 50% during the dry season. The hydrochemistry of groundwater in the runoff and discharge zones is of poorer quality than in the recharge zone. Indications of intensive land resource exploitation and changes in land use patterns were attributed to changes in groundwater conditions since 1990, but the influence of climate change was likely from 2001, because the water temperature exhibited increasing trends at a mean rate of 0.02 °C/yr even though groundwater depth was high in the aquifer. These conclusions imply the need for further groundwater monitoring and reevaluation to understand the resilience of aquifer during urbanization and development.

  19. Biosolids and distillery effluent amendment to Irish Miscanthus ×giganteus plantations: impacts on groundwater and soil.

    PubMed

    Galbally, P; Fagan, C; Ryan, D; Finnan, J; Grant, J; McDonnell, K

    2012-01-01

    It is necessary to determine the risk of water pollution arising from amendment of organic by-products (OBs) to energy crops under Irish conditions. Therefore, the impact of landspreading two OBs on the quality of groundwater underlying plantations of Miscanthus X giganteus was assessed. Municipal biosolids and distillery effluent (DE) were spread annually (for 4 yr) on six 0.117-ha treatment plots at rates of 100, 50, and 0%. The 100% rate represented a maximum P load of 15 t ha(-1) as per Irish EPA regulation. Groundwater was sampled for 25 mo and tested for pH, electrical conductivity, NO(3)(-), orthophosphate (PO(4)(3-)), total soluble P, K(+), Cu, Cd, Cr, Pb, Ni, and Zn. Assessment of quality was based on comparison with Irish groundwater threshold values (GTVs). The study was limited to within-plot using a "well bottom" approach and did not investigate movement of groundwater plumes or vectors of percolation through the soil profile. Mean groundwater concentrations did not exceed GTVs during the sampling period for any species, with the exception of groundwater PO(4)(3-) in the 100% DE plot, which was almost double the GTV of 0.035 mg L(-1). There was no significant build-up of nutrients or heavy metals in groundwater (or soil) for any plot. Excessive PO(4)(3-) in the 100% DE plot groundwater is likely due to high background soil P, soil characteristics, and the occurrence of macropore/soil pore flow. These factors (particularly background soil P) should be assessed when determining suitable sites for land-spreading OBs.

  20. Underground pumped storage hydroelectricity using abandoned works (deep mines or open pits) and the impact on groundwater flow

    NASA Astrophysics Data System (ADS)

    Pujades, Estanislao; Willems, Thibault; Bodeux, Sarah; Orban, Philippe; Dassargues, Alain

    2016-09-01

    Underground pumped storage hydroelectricity (UPSH) plants using open-pit or deep mines can be used in flat regions to store the excess of electricity produced during low-demand energy periods. It is essential to consider the interaction between UPSH plants and the surrounding geological media. There has been little work on the assessment of associated groundwater flow impacts. The impacts on groundwater flow are determined numerically using a simplified numerical model which is assumed to be representative of open-pit and deep mines. The main impact consists of oscillation of the piezometric head, and its magnitude depends on the characteristics of the aquifer/geological medium, the mine and the pumping and injection intervals. If an average piezometric head is considered, it drops at early times after the start of the UPSH plant activity and then recovers progressively. The most favorable hydrogeological conditions to minimize impacts are evaluated by comparing several scenarios. The impact magnitude will be lower in geological media with low hydraulic diffusivity; however, the parameter that plays the more important role is the volume of water stored in the mine. Its variation modifies considerably the groundwater flow impacts. Finally, the problem is studied analytically and some solutions are proposed to approximate the impacts, allowing a quick screening of favorable locations for future UPSH plants.

  1. Impacts of an ethanol-blended fuel release on groundwater and fate of produced methane: Simulation of field observations

    EPA Science Inventory

    In a field experiment at Vandenberg Air Force Base (VAFB) designed to mimic the impact of a small-volume release of E10, two plumes were created by injecting extracted groundwater spiked with benzene, toluene, and o-xylene, abbreviated BToX (No-Ethanol Lane) and BToX plus ethanol...

  2. The impact on climate of groundwater induced soil moisture memory : a study with a fully coupled WRF-LEAFHYDRO system

    NASA Astrophysics Data System (ADS)

    Miguez-Macho, Gonzalo; Gómez, Breogán; Martínez-de la Torre, Alberto

    2014-05-01

    Groundwater dynamics and its interactions with the land-atmosphere system are increasingly being taking into consideration in climate and ecosystem modeling studies. A shallow water table slows down drainage and affects soil moisture and potentially evapotranspiration (ET) and climate, particularly in water-limited environments. Our area of interest, the Iberian Peninsula, with a typical Mediterranean climate of dry growing season, is one of such regions where ET is largely constrained by water availability. We investigate how the induced memory on soil moisture by groundwater affects spring precipitation and summer temperatures there using a fully coupled WRF-LEAFHYDRO system. The LEAFHYDRO Land Surface Model includes groundwater dynamics with a realistic water table validated with hundreds of observations over Spain and Portugal. We perform two sets of long-term offline simulations, with and without groundwater forced by ERA-Interim and detailed precipitation analyses for the Iberian Peninsula. The corresponding fully coupled simulations with the Weather Research and Forecasting model (WRF), using exactly the same grid, take initial conditions from the off-line simulations at the end of the winter and are run for spring and summer, when we expect the impact of ET on climate to be largest. After a dry winter, in the run with groundwater soils are considerably wetter in regions with shallow water table and WRF results indicate that during spring the impact on precipitation can be sizeable when synoptic conditions are favorable for convection. Increased ET in the summer due also to more moisture availability in the run with groundwater leads in general to cooler temperatures. These preliminary results highlight the important role of groundwater on climate and the advantages of a fully coupled hydrology-atmospheric modeling system.

  3. Where to locate a tree plantation within a low rainfall catchment to minimise impacts on groundwater resources

    NASA Astrophysics Data System (ADS)

    Dean, J. F.; Webb, J. A.; Jacobsen, G. E.; Chisari, R.; Dresel, P. E.

    2014-08-01

    Despite the fact that there are many studies that consider the impacts of plantation forestry on water resources, and others that explore the spatial heterogeneity of groundwater recharge in dry regions, there is little marriage of the two subjects in forestry management guidelines and legislation. Here we carry out an in-depth analysis of the groundwater and surface water regime in a low rainfall, high evapotranspiration paired catchment study to examine the impact of reforestation, using water table fluctuations and chloride mass balance methods to estimate groundwater recharge. Recharge estimations using the chloride mass balance method were shown to be more likely representative of groundwater recharge regimes prior to the planting of the trees, and most likely prior to widespread land clearance by European settlers. These estimations were complicated by large amounts of recharge occurring as a result of runoff and streamflow in the lower parts of the catchment. Water table fluctuation method estimations of recharge verified that groundwater recharge occurs predominantly in the lowland areas of the study catchment. This leads to the conclusion that spatial variations in recharge are important considerations for locating tree plantations with respect to conserving water resources for downstream users. For dry regions, this means planting trees in the upland parts of the catchments, as recharge is shown to occur predominantly in the lowland areas.

  4. Thermal Removal of Tritium from Concrete and Soil to Reduce Groundwater Impacts - 13197

    SciTech Connect

    Jackson, Dennis G.; Blount, Gerald C.; Wells, Leslie H.; Cardoso, Joao E.; Kmetz, Thomas F.; Reed, Misty L.

    2013-07-01

    Legacy heavy-water moderator operations at the Savannah River Site (SRS) have resulted in the contamination of equipment pads, building slabs, and surrounding soil with tritium. At the time of discovery the tritium had impacted the shallow (< 3-m) groundwater at the facility. While tritium was present in the groundwater, characterization efforts determined that a significant source remained in a concrete slab at the surface and within the associated vadose zone soils. To prevent continued long-term impacts to the shallow groundwater a CERCLA non-time critical removal action for these source materials was conducted to reduce the leaching of tritium from the vadose zone soils and concrete slabs. In order to minimize transportation and disposal costs, an on-site thermal treatment process was designed, tested, and implemented. The on-site treatment consisted of thermal detritiation of the concrete rubble and soil. During this process concrete rubble was heated to a temperature of 815 deg. C (1,500 deg. F) resulting in the dehydration and removal of water bound tritium. During heating, tritium contaminated soil was used to provide thermal insulation during which it's temperature exceeded 100 deg. C (212 deg. F), causing drying and removal of tritium. The thermal treatment process volatiles the water bound tritium and releases it to the atmosphere. The released tritium was considered insignificant based upon Clean Air Act Compliance Package (CAP88) analysis and did not exceed exposure thresholds. A treatability study evaluated the effectiveness of this thermal configuration and viability as a decontamination method for tritium in concrete and soil materials. Post treatment sampling confirmed the effectiveness at reducing tritium to acceptable waste site specific levels. With American Recovery and Reinvestment Act (ARRA) funding three additional treatment cells were assembled utilizing commercial heating equipment and common construction materials. This provided a total

  5. Thermal Removal Of Tritium From Concrete And Soil To Reduce Groundwater Impacts

    SciTech Connect

    Jackson, Dennis G.; Blount, Gerald C.; Wells, Leslie H.; Cardoso-Neto, Joao E.; Kmetz, Thomas F.; Reed, Misty L.

    2012-12-04

    Legacy heavy-water moderator operations at the Savannah River Site (SRS) have resulted in the contamination of equipment pads, building slabs, and surrounding soil with tritium. At the time of discovery the tritium had impacted the shallow (< 3-m) groundwater at the facility. While tritium was present in the groundwater, characterization efforts determined that a significant source remained in a concrete slab at the surface and within the associated vadose zone soils. To prevent continued long-term impacts to the shallow groundwater a CERCLA non-time critical removal action for these source materials was conducted to reduce the leaching of tritium from the vadose zone soils and concrete slabs. In order to minimize transportation and disposal costs, an on-site thermal treatment process was designed, tested, and implemented. The on-site treatment consisted of thermal detritiation of the concrete rubble and soil. During this process concrete rubble was heated to a temperature of 815 deg C (1,500 deg F) resulting in the dehydration and removal of water bound tritium. During heating, tritium contaminated soil was used to provide thermal insulation during which it's temperature exceeded 100 deg C (212 deg F), causing drying and removal of tritium. The thermal treatment process volatiles the water bound tritium and releases it to the atmosphere. The released tritium was considered insignificant based upon Clean Air Act Compliance Package (CAP88) analysis and did not exceed exposure thresholds. A treatability study evaluated the effectiveness of this thermal configuration and viability as a decontamination method for tritium in concrete and soil materials. Post treatment sampling confirmed the effectiveness at reducing tritium to acceptable waste site specific levels. With American Recovery and Reinvestment Act (ARRA) funding three additional treatment cells were assembled utilizing commercial heating equipment and common construction materials. This provided a total of

  6. Climate change impact assessment in Veneto and Friuli Plain groundwater. Part II: a spatially resolved regional risk assessment.

    PubMed

    Pasini, S; Torresan, S; Rizzi, J; Zabeo, A; Critto, A; Marcomini, A

    2012-12-01

    Climate change impact assessment on water resources has received high international attention over the last two decades, due to the observed global warming and its consequences at the global to local scale. In particular, climate-related risks for groundwater and related ecosystems pose a great concern to scientists and water authorities involved in the protection of these valuable resources. The close link of global warming with water cycle alterations encourages research to deepen current knowledge on relationships between climate trends and status of water systems, and to develop predictive tools for their sustainable management, copying with key principles of EU water policy. Within the European project Life+ TRUST (Tool for Regional-scale assessment of groundwater Storage improvement in adaptation to climaTe change), a Regional Risk Assessment (RRA) methodology was developed in order to identify impacts from climate change on groundwater and associated ecosystems (e.g. surface waters, agricultural areas, natural environments) and to rank areas and receptors at risk in the high and middle Veneto and Friuli Plain (Italy). Based on an integrated analysis of impacts, vulnerability and risks linked to climate change at the regional scale, a RRA framework complying with the Sources-Pathway-Receptor-Consequence (SPRC) approach was defined. Relevant impacts on groundwater and surface waters (i.e. groundwater level variations, changes in nitrate infiltration processes, changes in water availability for irrigation) were selected and analyzed through hazard scenario, exposure, susceptibility and risk assessment. The RRA methodology used hazard scenarios constructed through global and high resolution model simulations for the 2071-2100 period, according to IPCC A1B emission scenario in order to produce useful indications for future risk prioritization and to support the addressing of adaptation measures, primarily Managed Artificial Recharge (MAR) techniques. Relevant

  7. Climate change impact assessment in Veneto and Friuli Plain groundwater. Part II: a spatially resolved regional risk assessment.

    PubMed

    Pasini, S; Torresan, S; Rizzi, J; Zabeo, A; Critto, A; Marcomini, A

    2012-12-01

    Climate change impact assessment on water resources has received high international attention over the last two decades, due to the observed global warming and its consequences at the global to local scale. In particular, climate-related risks for groundwater and related ecosystems pose a great concern to scientists and water authorities involved in the protection of these valuable resources. The close link of global warming with water cycle alterations encourages research to deepen current knowledge on relationships between climate trends and status of water systems, and to develop predictive tools for their sustainable management, copying with key principles of EU water policy. Within the European project Life+ TRUST (Tool for Regional-scale assessment of groundwater Storage improvement in adaptation to climaTe change), a Regional Risk Assessment (RRA) methodology was developed in order to identify impacts from climate change on groundwater and associated ecosystems (e.g. surface waters, agricultural areas, natural environments) and to rank areas and receptors at risk in the high and middle Veneto and Friuli Plain (Italy). Based on an integrated analysis of impacts, vulnerability and risks linked to climate change at the regional scale, a RRA framework complying with the Sources-Pathway-Receptor-Consequence (SPRC) approach was defined. Relevant impacts on groundwater and surface waters (i.e. groundwater level variations, changes in nitrate infiltration processes, changes in water availability for irrigation) were selected and analyzed through hazard scenario, exposure, susceptibility and risk assessment. The RRA methodology used hazard scenarios constructed through global and high resolution model simulations for the 2071-2100 period, according to IPCC A1B emission scenario in order to produce useful indications for future risk prioritization and to support the addressing of adaptation measures, primarily Managed Artificial Recharge (MAR) techniques. Relevant

  8. Simulating the impact of future land-use change on the groundwater system, a case study in Belgium

    NASA Astrophysics Data System (ADS)

    Dams, J.; Woldeamlak, S. T.; Batelaan, O.

    2009-04-01

    Groundwater is a major source of drinking water across the world and plays a vital role in maintaining the ecological value of many areas. However, in many places the quantity and quality of groundwater is jeopardized due to increasing human activity. Assessing the impact of human-induced factors influencing the groundwater system and predicting the magnitude of change in the future is therefore a major scientific challenge. The objective of this paper is to assess the impact of land-use changes, from 2000 until 2020, on the hydrological balance and in particular on groundwater quantity, as results from a case study in the Kleine Nete basin, Belgium. Four future land-use scenarios (A1, A2, B1 and B2) based on the Special Report on Emission Scenarios (SRES) indicate the area of land-use change in the studied basin. The novelty of this study is the successful coupling of a land-use change allocation model (CLUE-S) with a groundwater flow model as alternative to relying on expert judgment for the spatial distribution of the land-use changes in the basin. The CLUE-S model dynamically allocates land-use changes based on a combination of empirical and spatial analyses. Water balance components, groundwater level and baseflow are simulated using the distributed WetSpass model in conjunction with a steady-state MODFLOW groundwater flow model. The applied methodology allows an improved estimation of the range and spatial distribution of the effects of future land-use change on the groundwater system. Results show that the average recharge decreases with 2.9, 1.6, 1.8 and 0.8% for scenario A1, A2, B1 and B2, respectively, over the 20 covered years. The predicted reduction in recharge results in a small decrease of the average groundwater level in the basin, ranging from 2.5 cm for scenario A1 to 0.9 cm for scenario B2, and a reduction of the baseflow with maximum 2.3% and minimum 0.7% for scenario A1 and B2, respectively. Although these averages appear to indicate small

  9. Impact of water overstock on groundwater quality of the Bassee plain area (France)

    NASA Astrophysics Data System (ADS)

    Gourcy, L.; Pettenati, M.; Baran, N.; Durand, P. Y.

    2009-04-01

    The project, inspired by the structural flood plain management measures of the Rhine River, consists in the temporal removal of a maximum amount of water from the Seine River in order to leave priority to the water from the River Yonne. Yonne River and the Seine are presenting their maximum water flow usually at a same time. The space located between Bray-sur-Seine and Montereau-Fault-Yonne corresponding to the La Bassée plain (agricultural area of 23 km2) is well adapted to this project of temporary and artificial flood. The objective of the project financed by the Institution Interdépartementale des barrages Réservoirs du Bassin de la Seine (IIBRBS), the BRGM, the Seine-Normandie Water Agency, the European Communauty through the Interreg IIIB SAND project is the evaluation, at a local scale, of the impact on groundwater quality of the temporal Seine water storage. Indeed, the water over storage i) changes hydraulic conditions and therefore modify water and pollutants transfers through the unsaturated and saturated zones and ii) bring at soil surface a water (Seine River) potentially containing contaminants that may move to groundwater and consequently changed physico-chemicals conditions (redox) of groundwater. The estimation of the vulnerability of groundwater to changes and loads needs hydraulic and geochemical modelling of transfer through the unsaturated zone as well as the study of pollutants fate in static conditions. Retention properties of some metals (Pb, Ni, Cu, Cr, Zn) in soils and materials of the unsaturated zone by chemical processes were performed determining adsorption coefficient (Kd) by laboratory experiments. These experiments are showing that nickel mobility is lower in the argillous layers than in the sandy part of the unsaturated zone. Ni mobility is controlled by iron hydroxides and precipitation of other secondary minerals. Its complexation on organic ligands increases its mobility in soils. Copper concentration is influenced by CaCO3

  10. Impact of anthropogenic and natural processes on the evolution of groundwater chemistry in a rapidly urbanized coastal area, South China.

    PubMed

    Huang, Guanxing; Sun, Jichao; Zhang, Ying; Chen, Zongyu; Liu, Fan

    2013-10-01

    The moving of manufacturing industry from developed countries to Dongguan, China, promoted the semi-urbanization and rural industrialization in this area. It is urgent to acquire the impact of the enhanced anthropogenic pressure on the evolution of groundwater chemistry in this area. The objectives, in this study, were to understand the evolution of groundwater chemistry in Dongguan area based on the comparison of hydrochemical data variations and land use changes during the urbanization, to distinguish the impact of natural processes and anthropogenic activities on the groundwater chemistry by using principal components analysis (PCA) and hierarchical cluster analysis (HCA), and to discuss the origins of trace elements in groundwater. Eighteen physico-chemical parameters were investigated at 73 groundwater sites during July 2006. By analyzing the hydrochemical data, it shows that lateral flow from rivers and agricultural irrigation are the mechanisms controlling the groundwater chemistry in the river network area where the cation exchange of Na(+) in sediments taken up by the exchanger Ca(2+) occurs. Seawater intrusion is the mechanism controlling the groundwater chemistry in the coast area where the cation exchange of Ca(2+) in sediments taken up by the exchanger Na(+) occurs. The ion exchange reaction for fissured aquifer is weak in the study area. In addition, the comparison of hydrochemical data between in 2006 and in 1980 shows that anthropogenic activities such as excessive application of agricultural fertilizers, inappropriate emissions of domestic sewage and excessive emissions of SO2 are responsible for the occurrences of groundwater with NO3(-), SO4(2-) and Mg(2+) types. Four principal components (PCs) were extracted from PCA, which explain 80.86% of the total parameters in water chemistry: PC1, the seawater intrusion and As contamination; PC2, the water-rock interaction, surface water recharge and acidic precipitation; PC3, heavy metal pollution from

  11. Assessment of sanitary landfill leachate characterizations and its impacts on groundwater at Alexandria.

    PubMed

    Hassan, Ahmed Hossam; Ramadan, Mohamed Hassan

    2005-01-01

    The total amount of solid waste generated in Alexandria is 2820 tons/d which increases to 3425 tons/day during summer. In the past, 77% of the collected solid wastes was open dumped. The open dumping sites did not have the minimum requirements for pollution control. Following the exacerbation of the problem, the Alexandria Governorate contracted a company to carry out the solid waste management. The contracted company transferred 75% of the daily generated solid wastes to a new constructed sanitary lanfill. The site receives a daily average of 1910 tons. The landfilling is performed by trench method in the form of cells. The produced leachate is discharged into two lined aerated lagoons. The biogas formed from biodegradation of landfilled solid wastes is burned and the produced heat is used for drying the lagoons leachate. The remaining residues are relandfilled. The study aims at assessment of the solid waste sanitary landfill leachate characterization and its impacts on the groundwater. The analysis of the collected data confirms that leachates from the landfill are severely contaminated with organics, salts, and heavy metals. The fluctuations in concentration levels of the different parameters were attributed to aging and thickness of waste layers, stage of decomposition, and re-landfilling of the concentrated residues from the drying lagoons. The concentrations of NH4-N (600 mg/l) indicated that the process of stabilization was still in the initial stages and attributed to the compaction process. The high BOD5 results (28,833 mg/l) indicated that the process of stabilization was in the initial stages which were very slow. The high COD results (45,240 mg/l) can be attributed to the compaction of the wastes which also retards the degradation of the solid wastes. The BOD and COD values indicated clearly severe contamination. The BOD5/COD ratio measured in the current study (0.64) indicated that the leachate of the present study was biodegradable and unstabilized

  12. Degradation of ground ice in a changing climate: the potential impact of groundwater flow

    NASA Astrophysics Data System (ADS)

    de Grandpré, I.; Fortier, D.; Stephani, E.

    2011-12-01

    topography, soil geotechnical properties, water table and preferential flow paths characterization, ground and water temperature and active layer and permafrost depth were collected to built seepage, heat transfer and coupled advecto-conductive models. Results indicated that advective heat transfer processes associated with groundwater flow can have a substantial impact on permafrost degradation. After one year, the active layer was 4 m deeper in the advecto-conductive heat transfer model than in the conductive heat transfer model and this was corroborated with measured field data. Groundwater flow processes should therefore be taken into account in permafrost evolution models and climate warming scenarios.

  13. The impact of a pulsing groundwater table on greenhouse gas emissions in riparian grey alder stands.

    PubMed

    Mander, Ülo; Maddison, Martin; Soosaar, Kaido; Teemusk, Alar; Kanal, Arno; Uri, Veiko; Truu, Jaak

    2015-02-01

    Floods control greenhouse gas (GHG) emissions in floodplains; however, there is a lack of data on the impact of short-term events on emissions. We studied the short-term effect of changing groundwater (GW) depth on the emission of (GHG) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in two riparian grey alder (Alnus incana) stands of different age in Kambja, southern Estonia, using the opaque static chamber (five replicates in each site) and gas chromatography methods. The average carbon and total nitrogen content in the soil of the old alder (OA) stand was significantly higher than in the young alder (YA) stand. In both stands, one part was chosen for water table manipulation (Manip) and another remained unchanged with a stable and deeper GW table. Groundwater table manipulation (flooding) significantly increases CH4 emission (average: YA-Dry 468, YA-Manip 8,374, OA-Dry 468, OA-Manip 4,187 μg C m(-2) h(-1)) and decreases both CO2 (average: OA-Dry 138, OA-Manip 80 mg C m(-2) h(-1)) and N2O emissions (average: OA-Dry 23.1, OA-Manip 11.8 μg N m(-2) h(-1)) in OA sites. There was no significant difference in CO2 and CH4 emissions between the OA and YA sites, whereas in OA sites with higher N concentration in the soil, the N2O emission was significantly higher than at the YA sites. The relative CO2 and CH4 emissions (the soil C stock-related share of gaseous losses) were higher in manipulated plots showing the highest values in the YA-Manip plot (0.03 and 0.0030 % C day(-1), respectively). The soil N stock-related N2O emission was very low achieving 0.000019 % N day(-1) in the OA-Dry plot. Methane emission shows a negative correlation with GW, whereas the 20 cm depth is a significant limit below which most of the produced CH4 is oxidized. In terms of CO2 and N2O, the deeper GW table significantly increases emission. In riparian zones of headwater streams, the short-term floods (e.g. those driven by extreme climate events) may significantly enhance

  14. Assessment of sanitary landfill leachate characterizations and its impacts on groundwater at Alexandria.

    PubMed

    Hassan, Ahmed Hossam; Ramadan, Mohamed Hassan

    2005-01-01

    The total amount of solid waste generated in Alexandria is 2820 tons/d which increases to 3425 tons/day during summer. In the past, 77% of the collected solid wastes was open dumped. The open dumping sites did not have the minimum requirements for pollution control. Following the exacerbation of the problem, the Alexandria Governorate contracted a company to carry out the solid waste management. The contracted company transferred 75% of the daily generated solid wastes to a new constructed sanitary lanfill. The site receives a daily average of 1910 tons. The landfilling is performed by trench method in the form of cells. The produced leachate is discharged into two lined aerated lagoons. The biogas formed from biodegradation of landfilled solid wastes is burned and the produced heat is used for drying the lagoons leachate. The remaining residues are relandfilled. The study aims at assessment of the solid waste sanitary landfill leachate characterization and its impacts on the groundwater. The analysis of the collected data confirms that leachates from the landfill are severely contaminated with organics, salts, and heavy metals. The fluctuations in concentration levels of the different parameters were attributed to aging and thickness of waste layers, stage of decomposition, and re-landfilling of the concentrated residues from the drying lagoons. The concentrations of NH4-N (600 mg/l) indicated that the process of stabilization was still in the initial stages and attributed to the compaction process. The high BOD5 results (28,833 mg/l) indicated that the process of stabilization was in the initial stages which were very slow. The high COD results (45,240 mg/l) can be attributed to the compaction of the wastes which also retards the degradation of the solid wastes. The BOD and COD values indicated clearly severe contamination. The BOD5/COD ratio measured in the current study (0.64) indicated that the leachate of the present study was biodegradable and unstabilized

  15. The impact of a pulsing groundwater table on greenhouse gas emissions in riparian grey alder stands.

    PubMed

    Mander, Ülo; Maddison, Martin; Soosaar, Kaido; Teemusk, Alar; Kanal, Arno; Uri, Veiko; Truu, Jaak

    2015-02-01

    Floods control greenhouse gas (GHG) emissions in floodplains; however, there is a lack of data on the impact of short-term events on emissions. We studied the short-term effect of changing groundwater (GW) depth on the emission of (GHG) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in two riparian grey alder (Alnus incana) stands of different age in Kambja, southern Estonia, using the opaque static chamber (five replicates in each site) and gas chromatography methods. The average carbon and total nitrogen content in the soil of the old alder (OA) stand was significantly higher than in the young alder (YA) stand. In both stands, one part was chosen for water table manipulation (Manip) and another remained unchanged with a stable and deeper GW table. Groundwater table manipulation (flooding) significantly increases CH4 emission (average: YA-Dry 468, YA-Manip 8,374, OA-Dry 468, OA-Manip 4,187 μg C m(-2) h(-1)) and decreases both CO2 (average: OA-Dry 138, OA-Manip 80 mg C m(-2) h(-1)) and N2O emissions (average: OA-Dry 23.1, OA-Manip 11.8 μg N m(-2) h(-1)) in OA sites. There was no significant difference in CO2 and CH4 emissions between the OA and YA sites, whereas in OA sites with higher N concentration in the soil, the N2O emission was significantly higher than at the YA sites. The relative CO2 and CH4 emissions (the soil C stock-related share of gaseous losses) were higher in manipulated plots showing the highest values in the YA-Manip plot (0.03 and 0.0030 % C day(-1), respectively). The soil N stock-related N2O emission was very low achieving 0.000019 % N day(-1) in the OA-Dry plot. Methane emission shows a negative correlation with GW, whereas the 20 cm depth is a significant limit below which most of the produced CH4 is oxidized. In terms of CO2 and N2O, the deeper GW table significantly increases emission. In riparian zones of headwater streams, the short-term floods (e.g. those driven by extreme climate events) may significantly enhance

  16. An Update of the Analytical Groundwater Modeling to Assess Water Resource Impacts at the Afton Solar Energy Zone

    SciTech Connect

    Quinn, John J.; Greer, Christopher B.; Carr, Adrianne E.

    2014-10-01

    The purpose of this study is to update a one-dimensional analytical groundwater flow model to examine the influence of potential groundwater withdrawal in support of utility-scale solar energy development at the Afton Solar Energy Zone (SEZ) as a part of the Bureau of Land Management’s (BLM’s) Solar Energy Program. This report describes the modeling for assessing the drawdown associated with SEZ groundwater pumping rates for a 20-year duration considering three categories of water demand (high, medium, and low) based on technology-specific considerations. The 2012 modeling effort published in the Final Programmatic Environmental Impact Statement for Solar Energy Development in Six Southwestern States (Solar PEIS; BLM and DOE 2012) has been refined based on additional information described below in an expanded hydrogeologic discussion.

  17. Fate and groundwater impacts of produced water releases at OSPER "B" site, Osage County, Oklahoma

    USGS Publications Warehouse

    Kharaka, Y.K.; Kakouros, E.; Thordsen, J.J.; Ambats, G.; Abbott, M.M.

    2007-01-01

    For the last 5 a, the authors have been investigating the transport, fate, natural attenuation and ecosystem impacts of inorganic and organic compounds in releases of produced water and associated hydrocarbons at the Osage-Skiatook Petroleum Environmental Research (OSPER) "A" and "B" sites, located in NE Oklahoma. Approximately 1.0 ha of land at OSPER "B", located within the active Branstetter lease, is visibly affected by salt scarring, tree kills, soil salinization, and brine and petroleum contamination. Site "B" includes an active production tank battery and adjacent large brine pit, two injection well sites, one with an adjacent small pit, and an abandoned brine pit and tank battery site. Oil production in this lease started in 1938, and currently there are 10 wells that produce 0.2-0.5 m3/d (1-3 bbl/d) oil, and 8-16 m3/d (50-100 bbl/d) brine. Geochemical data from nearby oil wells show that the produced water source is a Na-Ca-Cl brine (???150,000 mg/L TDS), with high Mg, but low SO4 and dissolved organic concentrations. Groundwater impacts are being investigated by detailed chemical analyses of water from repeated sampling of 41 boreholes, 1-71 m deep. The most important results at OSPER "B" are: (1) significant amounts of produced water from the two active brine pits percolate into the surficial rocks and flow towards the adjacent Skiatook reservoir, but only minor amounts of liquid petroleum leave the brine pits; (2) produced-water brine and minor dissolved organics have penetrated the thick (3-7 m) shale and siltstone units resulting in the formation of three interconnected plumes of high-salinity water (5000-30,000 mg/L TDS) that extend towards the Skiatook reservoir from the two active and one abandoned brine pits; and (3) groundwater from the deep section of only one well, BR-01 located 330 m upslope and west of the site, appear not to be impacted by petroleum operations. ?? 2007.

  18. Modeling the Surface Water-Groundwater Interaction in Arid and Semi-Arid Regions Impacted by Agricultural Activities

    NASA Astrophysics Data System (ADS)

    Tian, Y.; Wu, B.; Zheng, Y.

    2013-12-01

    In many semi-arid and arid regions, interaction between surface water and groundwater plays an important role in the eco-hydrological system. The interaction is often complicated by agricultural activities such as surface water diversion, groundwater pumping, and irrigation. In existing surface water-groundwater integrated models, simulation of the interaction is often simplified, which could introduce significant simulation uncertainty under certain circumstance. In this study, GSFLOW, a USGS model coupling PRMS and MODFLOW, was improved to better characterize the surface water-groundwater interaction. The practices of water diversion from rivers, groundwater pumping and irrigation are explicitly simulated. In addition, the original kinematic wave routing method was replaced by a dynamic wave routing method. The improved model was then applied in Zhangye Basin (the midstream part of Heihe River Baisn), China, where the famous 'Silk Road' came through. It is a typical semi-arid region of the western China, with extensive agriculture in its oasis. The model was established and calibrated using the data in 2000-2008. A series of numerical experiments were conducted to evaluate the effect of those improvements. It has been demonstrated that with the improvements, the observed streamflow and groundwater level were better reproduced by the model. The improvements have a significant impact on the simulation of multiple fluxes associated with the interaction, such as groundwater discharge, riverbed seepage, infiltration, etc. Human activities were proved to be key elements of the water cycle in the study area. The study results have important implications to the water resources modeling and management in semi-arid and arid basins.

  19. Linking Climate, Hydrology and Groundwater in High-Resolution Transient Groundwater Flow Models: a Case Study For a Climate Change Impacts Assessment in Grand Forks, BC

    NASA Astrophysics Data System (ADS)

    Scibek, J.; Allen, D. M.; Whitfield, P.; Wei, M.

    2004-05-01

    A case study of an unconfined aquifer in the Grand Forks valley in south-central BC was used to develop methodology for linking climate models, hydrologic models, and groundwater models to investigate future impacts of climate change on groundwater resources. A three dimensional groundwater flow model of variable spatial resolution (constrained by borehole spacing) was implemented in MODFLOW, and calibrated to observation well data. Multiple scenarios of the hydraulic conductivity fields were used in a sensitivity analysis. A new methodology was developed for generating spatially-distributed and temporally-varying recharge zonation for the surficial aquifer, using GIS linked to the one-dimensional HELP (USEPA) hydrologic model that estimates aquifer recharge. The recharge model accounts for soil distribution, vadose zone depth and hydraulic conductivity, extent of impermeable areas, surficial geology, and vadose zone thickness. Production well pumping and irrigation return flow during the summer season were included in recharge computations. Although recharge was computed as monthly averages per climate scenario, it is driven by physically-based daily weather inputs generated by a stochastic weather generator and calibrated to local observed climate. Four year long climate scenarios were run, each representing one typical year in the present and future (2020s, 2050s, and 2080s), by perturbing the historical weather according to the downscaled CGCM1 general circulation model results (Environment Canada). CGCM1 model outputs were calibrated for local conditions during the downscaling procedure. These include absolute and relative changes in precipitation; including indirect measures of precipitation intensity, dry and wet spell lengths, temperature, and solar radiation for the evapotranspiration model. CGCM1 downscaling was also used to predict basin-scale runoff for the Kettle River upstream of Grand Forks. This river exerts strong control on the groundwater levels

  20. BDNF Val 66 Met and 5-HTTLPR genotype moderate the impact of early psychosocial adversity on plasma brain-derived neurotrophic factor and depressive symptoms: a prospective study.

    PubMed

    Buchmann, Arlette F; Hellweg, Rainer; Rietschel, Marcella; Treutlein, Jens; Witt, Stephanie H; Zimmermann, Ulrich S; Schmidt, Martin H; Esser, Günter; Banaschewski, Tobias; Laucht, Manfred; Deuschle, Michael

    2013-08-01

    Recent studies have emphasized an important role for neurotrophins, such as brain-derived neurotrophic factor (BDNF), in regulating the plasticity of neural circuits involved in the pathophysiology of stress-related diseases. The aim of the present study was to examine the interplay of the BDNF Val⁶⁶Met and the serotonin transporter promoter (5-HTTLPR) polymorphisms in moderating the impact of early-life adversity on BDNF plasma concentration and depressive symptoms. Participants were taken from an epidemiological cohort study following the long-term outcome of early risk factors from birth into young adulthood. In 259 individuals (119 males, 140 females), genotyped for the BDNF Val⁶⁶Met and the 5-HTTLPR polymorphisms, plasma BDNF was assessed at the age of 19 years. In addition, participants completed the Beck Depression Inventory (BDI). Early adversity was determined according to a family adversity index assessed at 3 months of age. Results indicated that individuals homozygous for both the BDNF Val and the 5-HTTLPR L allele showed significantly reduced BDNF levels following exposure to high adversity. In contrast, BDNF levels appeared to be unaffected by early psychosocial adversity in carriers of the BDNF Met or the 5-HTTLPR S allele. While the former group appeared to be most susceptible to depressive symptoms, the impact of early adversity was less pronounced in the latter group. This is the first preliminary evidence indicating that early-life adverse experiences may have lasting sequelae for plasma BDNF levels in humans, highlighting that the susceptibility to this effect is moderated by BDNF Val⁶⁶Met and 5-HTTLPR genotype.

  1. Identification of nitrate sources in groundwater and potential impact on drinking water reservoir (Goczałkowice reservoir, Poland)

    NASA Astrophysics Data System (ADS)

    Czekaj, Joanna; Jakóbczyk-Karpierz, Sabina; Rubin, Hanna; Sitek, Sławomir; Witkowski, Andrzej J.

    2016-08-01

    Goczałkowice dammed reservoir (area - 26 km2) is a strategic object for flood control in the Upper Vistula River catchment and one of the most important source of drinking water in the Upper Silesian Industrial Region (Southern Poland). Main aims of the investigation were identification of sources of nitrate and assessment of their significance in potential risk to groundwater quality. In the catchment area monitoring network of 22 piezometers, included 14 nested, have been installed. The significant spatial and seasonal differences in chemical composition between northern and southern part of the catchment were indicated based on the groundwater sampling conducted twice - in autumn 2011 and spring 2012. Maximum observed concentrations of nitrate were identified in northern part of the study area 255 mg/L as a results of inappropriate sewage management and agriculture activity. Results, based on the combines multi-scale hydrogeological and hydrochemical field studies, groundwater flow and transport modelling, dual stable isotope approach and geochemical modelling indicate mainly agriculture and inappropriate sewage water management as a sources of NO3- contamination of groundwater which moreover is affected by geochemical processes. In general, contaminated groundwater does not impact surface water quality. However, due to high concentration of nitrate in northern part a continues measurements of nitrogen compounds should be continued and used for reducing uncertainty of the predictive scenarios of the mass transport modelling in the study area.

  2. Using self-report and adverse event measures to track health's impact on productivity in known groups.

    PubMed

    Allen, Harris M; Bunn, William B

    2003-09-01

    The use of survey data to measure and monitor health and productivity differences between groups is an issue of increasing importance. This article examines the capacity of productivity self-reports (derived from surveys) and adverse event measures (derived from administrative sources) to differentiate groups with a priori known characteristics. A replication strategy is used to test the contributions that productivity self-reports make, alone as well as above and beyond measures of adverse events, to the discrimination of 5 pairs of groups classified by clinical, job type, and demographic criteria. These tests are conducted on representative samples of the active, largely blue-collar employee population at International Truck and Engine Corporation. The results show that both productivity self-reports and adverse event measures differentiate and track known groups. Even in the presence of highly significant effects from adverse event measures, self-reports improve the assessment of productivity. We conclude that: 1) although the joint use of self-reports and adverse event measures is the better approach, practitioners can use self-reports with the expectation that this method will track group differences in health and productivity when adverse event measures are not available; and 2) survey self-reports make unique and independent contributions when adverse events measures are used.

  3. Business oriented EU human cell and tissue product legislation will adversely impact Member States' health care systems.

    PubMed

    Pirnay, Jean-Paul; Vanderkelen, Alain; De Vos, Daniel; Draye, Jean-Pierre; Rose, Thomas; Ceulemans, Carl; Ectors, Nadine; Huys, Isabelle; Jennes, Serge; Verbeken, Gilbert

    2013-12-01

    The transplantation of conventional human cell and tissue grafts, such as heart valve replacements and skin for severely burnt patients, has saved many lives over the last decades. The late eighties saw the emergence of tissue engineering with the focus on the development of biological substitutes that restore or improve tissue function. In the nineties, at the height of the tissue engineering hype, industry incited policymakers to create a European regulatory environment, which would facilitate the emergence of a strong single market for tissue engineered products and their starting materials (human cells and tissues). In this paper we analyze the elaboration process of this new European Union (EU) human cell and tissue product regulatory regime-i.e. the EU Cell and Tissue Directives (EUCTDs) and the Advanced Therapy Medicinal Product (ATMP) Regulation and evaluate its impact on Member States' health care systems. We demonstrate that the successful lobbying on key areas of regulatory and policy processes by industry, in congruence with Europe's risk aversion and urge to promote growth and jobs, led to excessively business oriented legislation. Expensive industry oriented requirements were introduced and contentious social and ethical issues were excluded. We found indications that this new EU safety and health legislation will adversely impact Member States' health care systems; since 30 December 2012 (the end of the ATMP transitional period) there is a clear threat to the sustainability of some lifesaving and established ATMPs that were provided by public health institutions and small and medium-sized enterprises under the frame of the EUCTDs. In the light of the current economic crisis it is not clear how social security systems will cope with the inflation of costs associated with this new regulatory regime and how priorities will be set with regard to reimbursement decisions. We argue that the ATMP Regulation should urgently be revised to focus on delivering

  4. Business oriented EU human cell and tissue product legislation will adversely impact Member States' health care systems.

    PubMed

    Pirnay, Jean-Paul; Vanderkelen, Alain; De Vos, Daniel; Draye, Jean-Pierre; Rose, Thomas; Ceulemans, Carl; Ectors, Nadine; Huys, Isabelle; Jennes, Serge; Verbeken, Gilbert

    2013-12-01

    The transplantation of conventional human cell and tissue grafts, such as heart valve replacements and skin for severely burnt patients, has saved many lives over the last decades. The late eighties saw the emergence of tissue engineering with the focus on the development of biological substitutes that restore or improve tissue function. In the nineties, at the height of the tissue engineering hype, industry incited policymakers to create a European regulatory environment, which would facilitate the emergence of a strong single market for tissue engineered products and their starting materials (human cells and tissues). In this paper we analyze the elaboration process of this new European Union (EU) human cell and tissue product regulatory regime-i.e. the EU Cell and Tissue Directives (EUCTDs) and the Advanced Therapy Medicinal Product (ATMP) Regulation and evaluate its impact on Member States' health care systems. We demonstrate that the successful lobbying on key areas of regulatory and policy processes by industry, in congruence with Europe's risk aversion and urge to promote growth and jobs, led to excessively business oriented legislation. Expensive industry oriented requirements were introduced and contentious social and ethical issues were excluded. We found indications that this new EU safety and health legislation will adversely impact Member States' health care systems; since 30 December 2012 (the end of the ATMP transitional period) there is a clear threat to the sustainability of some lifesaving and established ATMPs that were provided by public health institutions and small and medium-sized enterprises under the frame of the EUCTDs. In the light of the current economic crisis it is not clear how social security systems will cope with the inflation of costs associated with this new regulatory regime and how priorities will be set with regard to reimbursement decisions. We argue that the ATMP Regulation should urgently be revised to focus on delivering

  5. Understanding the hydrologic impacts of wastewater treatment plant discharge to shallow groundwater: before and after plant shutdown

    USGS Publications Warehouse

    Hubbard, Laura E.; Keefe, Steffanie H.; Kolpin, Dana W.; Barber, Larry B.; Duris, Joseph; Hutchinson, Kasey J.; Bradley, Paul M.

    2016-01-01

    Effluent-impacted surface water has the potential to transport not only water, but wastewater-derived contaminants to shallow groundwater systems. To better understand the effects of effluent discharge on in-stream and near-stream hydrologic conditions in wastewater-impacted systems, water-level changes were monitored in hyporheic-zone and shallow-groundwater piezometers in a reach of Fourmile Creek adjacent to and downstream of the Ankeny (Iowa, USA) wastewater treatment plant (WWTP). Water-level changes were monitored from approximately 1.5 months before to 0.5 months after WWTP closure. Diurnal patterns in WWTP discharge were closely mirrored in stream and shallow-groundwater levels immediately upstream and up to 3 km downstream of the outfall, indicating that such discharge was the primary control on water levels before shutdown. The hydrologic response to WWTP shutdown was immediately observed throughout the study reach, verifying the far-reaching hydraulic connectivity and associated contaminant transport risk. The movement of WWTP effluent into alluvial aquifers has implications for potential WWTP-derived contamination of shallow groundwater far removed from the WWTP outfall.

  6. Electrochemical treatment of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in groundwater impacted by aqueous film forming foams (AFFFs).

    PubMed

    Schaefer, Charles E; Andaya, Christina; Urtiaga, Ana; McKenzie, Erica R; Higgins, Christopher P

    2015-09-15

    Laboratory experiments were performed to evaluate the use of electrochemical treatment for the decomposition of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), as well as other perfluoroalkyl acids (PFAAs), in aqueous film forming foam (AFFF)-impacted groundwater collected from a former firefighter training area and PFAA-spiked synthetic groundwater. Using a commercially-produced Ti/RuO2 anode in a divided electrochemical cell, PFOA and PFOS decomposition was evaluated as a function of current density (0-20 mA/cm(2)). Decomposition of both PFOA and PFOS increased with increasing current density, although the decomposition of PFOS did not increase as the current density was increased above 2.5 mA/cm(2). At a current density of 10 mA/cm(2), the first-order rate constants, normalized for current density and treatment volume, for electrochemical treatment of both PFOA and PFOS were 46 × 10(-5) and 70 × 10(-5) [(min(-1)) (mA/cm(2))(-1) (L)], respectively. Defluorination was confirmed for both PFOA and PFOS, with 58% and 98% recovery as fluoride, respectively (based upon the mass of PFOA and PFOS degraded). Treatment of other PFAAs present in the groundwater also was observed, with shorter chain PFAAs generally being more recalcitrant. Results highlight the potential for electrochemical treatment of PFAAs, particularly PFOA and PFOS, in AFFF-impacted groundwater.

  7. Assessing Drought Impacts on Water Storage using GRACE Satellites and Regional Groundwater Modeling in the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Scanlon, B. R.; Zhang, Z.; Save, H.; Faunt, C. C.; Dettinger, M. D.

    2015-12-01

    Increasing concerns about drought impacts on water resources in California underscores the need to better understand effects of drought on water storage and coping strategies. Here we use a new GRACE mascons solution with high spatial resolution (1 degree) developed at the Univ. of Texas Center for Space Research (CSR) and output from the most recent regional groundwater model developed by the U.S. Geological Survey to evaluate changes in water storage in response to recent droughts. We also extend the analysis of drought impacts on water storage back to the 1980s using modeling and monitoring data. The drought has been intensifying since 2012 with almost 50% of the state and 100% of the Central Valley under exceptional drought in 2015. Total water storage from GRACE data declined sharply during the current drought, similar to the rate of depletion during the previous drought in 2007 - 2009. However, only 45% average recovery between the two droughts results in a much greater cumulative impact of both droughts. The CSR GRACE Mascons data offer unprecedented spatial resolution with no leakage to the oceans and no requirement for signal restoration. Snow and reservoir storage declines contribute to the total water storage depletion estimated by GRACE with the residuals attributed to groundwater storage. Rates of groundwater storage depletion are consistent with the results of regional groundwater modeling in the Central Valley. Traditional approaches to coping with these climate extremes has focused on surface water reservoir storage; however, increasing conjunctive use of surface water and groundwater and storing excess water from wet periods in depleted aquifers is increasing in the Central Valley.

  8. Evaluating the impact of groundwater on cotton growth and root zone water balance using Hydrus-ID coupled with a crop growth model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Groundwater is an important factor that needs to be considered when evaluating the water balance of the soil-plant-atmosphere system and the sustainable water management. However, the impact of shallow groundwater on the root zone water balance and cotton growth is not fully understood. In this stud...

  9. Geochemical Impacts of Leaking CO2 from Subsurface Storage Reservoirs on the Fate of Metal Contaminants in an Overlaying Groundwater Aquifer

    NASA Astrophysics Data System (ADS)

    Shao, H.; Qafoku, N. P.; Lawter, A.; Bowden, M. E.; Brown, C. F.

    2014-12-01

    The leakage of CO2 and the concomitant upward transport of brine solutions and contaminants from deep storage reservoirs to overlaying groundwater aquifers is considered one of the major risks associated with geologic carbon sequestration (GCS). A systematic understanding of how such leakage would impact the geochemistry of potable aquifers is crucial to the maintenance of environmental quality and the widespread acceptance of GCS. A series of batch and column experiments studies were conducted to understand the fate (mobilization and immobilization) of trace metals, such as Cd and As in the groundwater aquifer after the intrusion of CO2 gas and CO2-saturated fluids containing leached metals from deep subsurface storage reservoirs. Sediments from the High Plains aquifer in Kansas, United States, were used in this investigation, which is part of the National Risk Assessment Partnership Program sponsored by the US DOE. This aquifer was selected to be representative of consolidated sand and gravel/sandstone aquifers overlying potential CO2 sequestration repositories within the continental US. The experiments were conducted at room temperature and atmospheric pressure. The results demonstrated that Cd and As that intrude into groundwater aquifers with the leaking CO2 at initial concentrations of 40 and 114 mg/L, respectively, will be adsorbed on the sediments, in spite of the acidic pH (between 5 and 6) due to CO2 dissolution in the groundwater. Cd concentrations were well below its MCL in both the aqueous solution of the batch study and the effluent of the column study, even for one of the sediment samples which had undetectable amount of carbonate minerals to buffer the pH. Arsenic concentrations were also significantly lower than that in the influent, suggesting that natural sediments have the capacity to mitigate the adverse effects of the CO2 leakage. However, the mitigation capacity of sediments is influenced by its geochemical properties. When there are anions

  10. Modeling impacts of change in Landuse/ Landcover on groundwater system in Shiwaliks of Punjab using Remote Sensing and GIS

    NASA Astrophysics Data System (ADS)

    Singh, C. K.; Mukherjee, S.; Shashtri, S.

    2009-04-01

    increasing influence of green revolution is continuously being manifested in the form of escalating area under salinization; the total increase being registered is around 94%. The areas lying within the vicinity of river have shown concentrations of several heavy metals to be higher than the desirable limits. Impact of agriculture has also shown alarming increase in nitrate concentration in some of the areas. Thematic maps for geology, geomorphology, slope, drainage, lineament density, distance from the lineaments, soil type, were prepared using GIS platform and a suitability analysis was performed for quantitative variation of groundwater in the study area. Several water quality parameters were analyzed and to observe spatial variation of suitability of groundwater in terms of quality a water quality index (WQI) was generated. Parameters such as relative humidity, temperature and rainfall for the last two decades were also analyzed in relation to decline in level of groundwater.

  11. Impact of river-lake-groundwater interaction on boundless carbon cycle in continental basin

    NASA Astrophysics Data System (ADS)

    Nakayama, T.; Shankman, D.

    2012-12-01

    In the Changjiang River in south China, deforestation and land reclamation have induced serious soil erosion and increased floods. Although the Three Gorges Dam (TGD) will provide flood control, the aquatic environment might be changed by discharge control and pollutant loads caused by the deposition of large amounts of sediment in the upper dam (Yang et al., 2006). Some research implies that seepage of groundwater along the lower regions plays important role in maintaining stream flow and after TGD impounding by using natural radionuclides (Dai et al., 2010). It is effective to clarify complicated river-lake-groundwater interaction (Eltahir and Yeh, 1999; Dai et al., 2010), and to evaluate optimum amount of transferred water and environmental consequences in the basin. The authors have so far developed the process-based National Integrated Catchment-based Eco-hydrology (NICE) model (Nakayama, 2008a, 2008b, 2010, 2011a-b, 2012a-c; Nakayama and Fujita, 2010; Nakayama and Hashimoto, 2011; Nakayama and Watanabe, 2004, 2006, 2008a, 2008b; Nakayama et al., 2006, 2007, 2010, 2012), which includes complex interactions between the forest canopy, surface water, the unsaturated zone, aquifers, lakes, and rivers. The objective of this research is to estimate the impact of river-lake-groundwater interaction on hydrologic cycle and to predict the impact of TGD on the hydrologic change in the downstream Dongting and Poyang Lakes region by using a process-based model. Analysis of power spectra in river discharge also helps to understand its complex mechanism. This integrated system also throws some light on the improvement in boundless biogeochemical cycle along terrestrial-aquatic continuum (Cole et al., 2007). References; Cole, J.J. et al., Ecosystems, doi:10.1007/s10021-006-9013-8, 2007. Dai, Z. et al., Hydrogeol. J., 18, 359-369, 2010. Eltahir, E.A.B.& Yeh, P.J.-F., Water Resour. Res., 35(4), 1199-1217, 1999. Nakayama, T., Ecol. Model., doi:10.1016/j.ecolmodel.2008

  12. Incorporation of groundwater pumping in a global Land Surface Model with the representation of human impacts

    NASA Astrophysics Data System (ADS)

    Pokhrel, Yadu N.; Koirala, Sujan; Yeh, Pat J.-F.; Hanasaki, Naota; Longuevergne, Laurent; Kanae, Shinjiro; Oki, Taikan

    2015-01-01

    Observations indicate that groundwater levels are declining in many regions around the world. Simulating such depletion of groundwater at the global scale still remains a challenge because most global Land Surface Models (LSMs) lack the physical representation of groundwater dynamics in general and well pumping in particular. Here we present an integrated hydrologic model, which explicitly simulates groundwater dynamics and pumping within a global LSM that also accounts for human activities such as irrigation and reservoir operation. The model is used to simulate global water fluxes and storages with a particular focus on groundwater withdrawal and depletion in the High Plains Aquifer (HPA) and Central Valley Aquifer (CVA). Simulated global groundwater withdrawal and depletion for the year 2000 are 570 and 330 km3 yr-1, respectively; the depletion agrees better with observations than our previous model result without groundwater representation, but may still contain certain uncertainties and is on the higher side of other estimates. Groundwater withdrawals from the HPA and CVA are ˜22 and ˜9 km3 yr-1, respectively, which are also consistent with the observations of ˜24 and ˜13 km3 yr-1. The model simulates a significant decline in total terrestrial water storage in both regions as caused mainly by groundwater storage depletion. Groundwater table declined by ˜14 cm yr-1 in the HPA during 2003-2010; the rate is even higher (˜71 cm yr-1) in the CVA. These results demonstrate the potential of the developed model to study the dynamic relationship between human water use, groundwater storage, and the entire hydrologic cycle.

  13. Impact of climate Change on Groundwater Recharge in the Tiber River Basin (Central Italy) Using Regional Climate model Outputs

    NASA Astrophysics Data System (ADS)

    Muluneh, F. B.; Setegn, S. G.; Melesse, A. M.; Fiori, A.

    2011-12-01

    Quantification of the various components of hydrological processes in a watershed remains a challenging topic as the hydrological system is altered by many internal and external drivers. Changes in climate variables can affect the quantity and quality of various components of hydrological cycle. Among others, the local effects of climate change on groundwater resources were not fully studied in different part of the world as compared to the surface water. Moreover, understanding the potential impact of climate change on groundwater is more complex than surface water. The main objective of this study is to analyze the potential impact of climate change on Groundwater recharge in the Tiber River Basin using outputs from Regional Climate model. In this study, a physically-based watershed model called Soil Water Assessment Tool (SWAT) was used to estimate recharge characteristics and its response to climate change in Tiber River Basin (central Italy). The SWAT model was successfully calibrated and validated using observed weather and flow data for the period of 1963-1970 and 1971-1978 respectively. During calibration, the model was highly sensitivity to groundwater flow parameters. Dynamically downscaled rainfall and temperature datasets from ten Regional Climate Models (RCM) archived in 'Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects (PRUDENCE)' were used to force the model to assess the climate change impact on the study area. A quantile-mapping statistical correction procedure was applied to the RCM dataset to correct the inherent systematic biases. The climate change analysis indicated that by the end of 2080s the rainfall was found to decrease nearly up to 40% in dry period and there was an increase in temperature that could reach as high as 3 to 5 oC. By the end of 2080s the ground water recharge shows a decreasing trend as a response to changes in rainfall. However as the timing of both precipitation and

  14. Surrogate species selection for assessing potential adverse environmental impacts of genetically engineered insect-resistant plants on non-target organisms

    PubMed Central

    Carstens, Keri; Cayabyab, Bonifacio; De Schrijver, Adinda; Gadaleta, Patricia G; Hellmich, Richard L; Romeis, Jörg; Storer, Nicholas; Valicente, Fernando H; Wach, Michael

    2014-01-01

    Most regulatory authorities require that developers of genetically engineered insect-resistant (GEIR) crops evaluate the potential for these crops to have adverse impacts on valued non-target organisms (NTOs), i.e., organisms not intended to be controlled by the trait. In many cases, impacts to NTOs are assessed using surrogate species, and it is critical that the data derived from surrogates accurately predict any adverse impacts likely to be observed from the use of the crop in the agricultural context. The key is to select surrogate species that best represent the valued NTOs in the location where the crop is going to be introduced, but this selection process poses numerous challenges for the developers of GE crops who will perform the tests, as well as for the ecologists and regulators who will interpret the test results. These issues were the subject of a conference “Surrogate Species Selection for Assessing Potential Adverse Environmental Impacts of Genetically Engineered Plants on Non-Target Organisms” convened by the Center for Environmental Risk Assessment, ILSI Research Foundation. This report summarizes the proceedings of the conference, including the presentations, discussions and the points of consensus agreed to by the participants. PMID:24637519

  15. Surrogate species selection for assessing potential adverse environmental impacts of genetically engineered insect-resistant plants on non-target organisms.

    PubMed

    Carstens, Keri; Cayabyab, Bonifacio; De Schrijver, Adinda; Gadaleta, Patricia G; Hellmich, Richard L; Romeis, Jörg; Storer, Nicholas; Valicente, Fernando H; Wach, Michael

    2014-01-01

    Most regulatory authorities require that developers of genetically engineered insect-resistant (GEIR) crops evaluate the potential for these crops to have adverse impacts on valued non-target organisms (NTOs), i.e., organisms not intended to be controlled by the trait. In many cases, impacts to NTOs are assessed using surrogate species, and it is critical that the data derived from surrogates accurately predict any adverse impacts likely to be observed from the use of the crop in the agricultural context. The key is to select surrogate species that best represent the valued NTOs in the location where the crop is going to be introduced, but this selection process poses numerous challenges for the developers of GE crops who will perform the tests, as well as for the ecologists and regulators who will interpret the test results. These issues were the subject of a conference "Surrogate Species Selection for Assessing Potential Adverse Environmental Impacts of Genetically Engineered Plants on Non-Target Organisms" convened by the Center for Environmental Risk Assessment, ILSI Research Foundation. This report summarizes the proceedings of the conference, including the presentations, discussions and the points of consensus agreed to by the participants.

  16. Impacts on groundwater recharge areas of megacity pumping: analysis of potential contamination of Kolkata, India, water supply

    USGS Publications Warehouse

    Sahu, Paulami; Michael, Holly A.; Voss, Clifford I.; Sikdar, Pradip K.

    2013-01-01

    Water supply to the world's megacities is a problem of quantity and quality that will be a priority in the coming decades. Heavy pumping of groundwater beneath these urban centres, particularly in regions with low natural topographic gradients, such as deltas and floodplains, can fundamentally alter the hydrological system. These changes affect recharge area locations, which may shift closer to the city centre than before development, thereby increasing the potential for contamination. Hydrogeological simulation analysis allows evaluation of the impact on past, present and future pumping for the region of Kolkata, India, on recharge area locations in an aquifer that supplies water to over 13 million people. Relocated recharge areas are compared with known surface contamination sources, with a focus on sustainable management of this urban groundwater resource. The study highlights the impacts of pumping on water sources for long-term development of stressed city aquifers and for future water supply in deltaic and floodplain regions of the world.

  17. Predicting the impact of future land-use and climate change on the groundwater system, Kleine Nete basin, Belgium

    NASA Astrophysics Data System (ADS)

    Salvadore, E.; Dams, J.; Batelaan, O.; van Daele, T.

    2009-04-01

    Climate changes including global warming and changing air circulation patterns, along with anthropogenic land-cover/use changes are expected to significantly influence both surface and subsurface hydrology in the near future. To be able to plan mitigating or adaptive actions, there is a strong need to study the individual as well as the combined impact of climate and land-use changes on the river, groundwater and wetland system on regional and local scale. Wetlands are particularly sensitive to modifications in water conditions; therefore this study focuses on modeling the impact of climate and land-use changes on the groundwater system and how this will further affect the distribution of most highly valued vegetation types. The regional study area, the Kleine Nete basin, comprises 580 km2 and is located 65 km north-east of Brussels. Within the basin, the 5.4 km2 sized groundwater dependent nature reserve "Olensbroek" serves as local study area. Initially, the "current" condition of the groundwater system has been determined; meteorological and land-use data for the period 1960-1990 has been used as input in a transient fully distributed physically-based hydrological model, WetSpa, to calculate with a daily time step the two weekly groundwater recharge. These values have been used as input for a transient MODFLOW model of the basin to simulate the groundwater level, flow, drainage and to derive other ecohydrological relevant parameters as mean lowest and highest groundwater level in every location of the basin. Future meteorological conditions have been obtained from a joint collaboration between the Royal Meteorological Institute of Belgium, K.U. Leuven Hydraulics Laboratory and the Royal Meteorological Institute of the Netherlands. All scenarios are based on the hierarchy of Global Climate Model (GCM) output, high resolution nested Regional Climate Model (RCM) simulations, and empirical/statistical downscaling using local observations. Choosing the change in

  18. Mines as lower reservoir of an UPSH (Underground Pumping Storage Hydroelectricity): groundwater impacts and feasibility

    NASA Astrophysics Data System (ADS)

    Bodeux, Sarah; Pujades, Estanislao; Orban, Philippe; Dassargues, Alain

    2016-04-01

    The energy framework is currently characterized by an expanding use of renewable sources. However, their intermittence could not afford a stable production according to the energy demand. Pumped Storage Hydroelectricity (PSH) is an efficient possibility to store and release electricity according to the demand needs. Because of the topographic and environmental constraints of classical PSH, new potential suitable sites are rare in countries whose topography is weak or with a high population density. Nevertheless, an innovative alternative is to construct Underground Pumped Storage Hydroelectricity (UPSH) plants by using old underground mine works as lower reservoir. In that configuration, large amount of pumped or injected water in the underground cavities would impact the groundwater system. A representative UPSH facility is used to numerically determine the interactions with surrounding aquifers Different scenarios with varying parameters (hydrogeological and lower reservoir characteristics, boundaries conditions and pumping/injection time-sequence) are computed. Analysis of the computed piezometric heads around the reservoir allows assessing the magnitude of aquifer response and the required time to achieve a mean pseudo-steady state under cyclic solicitations. The efficiency of the plant is also evaluated taking the leakage into the cavity into account. Combining these two outcomes, some criterions are identified to assess the feasibility of this type of projects within potential old mine sites from a hydrogeological point of view.

  19. Modeling spatiotemporal impacts of hydroclimatic extremes on groundwater recharge at a Mediterranean karst aquifer

    NASA Astrophysics Data System (ADS)

    Hartmann, Andreas; Mudarra, Matías; Andreo, Bartolomé; Marín, Ana; Wagener, Thorsten; Lange, Jens

    2014-08-01

    Karst aquifers provide large parts of the water supply for Mediterranean countries, though climate change is expected to have a significant negative impact on water availability. Recharge is therefore a key variable that has to be known for sustainable groundwater use. In this study, we present a new approach that combines two independent methods for karst recharge estimation. The first method derives spatially distributed information of mean annual recharge patterns through GIS analysis. The second is a process-based karst model that provides spatially lumped but temporally distributed information about recharge. By combining both methods, we add a spatial reference to the lumped simulations of the process-based model. In this way, we are able to provide spatiotemporal information of recharge and subsurface flow dynamics also during varying hydroclimatic conditions. We find that there is a nonlinear relationship between precipitation and recharge rates resulting in strong decreases of recharge following even moderate decreases of precipitation. This is primarily due to almost constant actual evapotranspiration amounts despite varying hydroclimatic conditions. During the driest year in the record, almost the entire precipitation was consumed as actual evapotranspiration and only little diffuse recharge took place at the high altitudes of our study site. During wettest year, recharge constituted a much larger fraction of precipitation and occurred at the entire study site. Our new method and our findings are significant for decision makers in similar regions that want to prepare for possible changes of hydroclimatic conditions in the future.

  20. The influence of model structure on groundwater recharge rates in climate-change impact studies

    NASA Astrophysics Data System (ADS)

    Moeck, Christian; Brunner, Philip; Hunkeler, Daniel

    2016-08-01

    Numerous modeling approaches are available to provide insight into the relationship between climate change and groundwater recharge. However, several aspects of how hydrological model choice and structure affect recharge predictions have not been fully explored, unlike the well-established variability of climate model chains—combination of global climate models (GCM) and regional climate models (RCM). Furthermore, the influence on predictions related to subsoil parameterization and the variability of observation data employed during calibration remain unclear. This paper compares and quantifies these different sources of uncertainty in a systematic way. The described numerical experiment is based on a heterogeneous two-dimensional reference model. Four simpler models were calibrated against the output of the reference model, and recharge predictions of both reference and simpler models were compared to evaluate the effect of model structure on climate-change impact studies. The results highlight that model simplification leads to different recharge rates under climate change, especially under extreme conditions, although the different models performed similarly under historical climate conditions. Extreme weather conditions lead to model bias in the predictions and therefore must be considered. Consequently, the chosen calibration strategy is important and, if possible, the calibration data set should include climatic extremes in order to minimise model bias introduced by the calibration. The results strongly suggest that ensembles of climate projections should be coupled with ensembles of hydrogeological models to produce credible predictions of future recharge and with the associated uncertainties.

  1. Impact of groundwater surface storage on chlorination and disinfection by-product formation.

    PubMed

    Padhi, R K; Satpathy, K K; Subramanian, S

    2015-09-01

    The change in water quality arising from the open storage of groundwater (GW) and its impact on chlorination and chlorination by-product formation were investigated. Water quality descriptors, such as temperature, pH, chlorophyll, and dissolved oxygen contents of GW undergo substantial alteration when stored in a reservoir. Dissolved organic content (DOC) measured in the two water sources studied, i.e., GW and open reservoir water (RW), varied from 0.41 mg/L to 0.95 mg/L and 0.93 mg/L to 2.53 mg/L, respectively. Although DOC demonstrated wide variation, UV absorbance at 254 nm (UVA254) values for GW (0.022-0.067) and RW (0.037-0.077) did not display reciprocal variations. The chlorine demand (CD) of RW was always higher than that of GW for the corresponding sampling period. Average trihalomethane (THM) formation for RW was 50-80% higher compared to GW and thus poses an enhanced health risk. Appreciable amounts of bromide present in these water sources (0.15-0.26 mg/L in GW and 0.17-0.65 mg/L in RW) have resulted in the non-selective distribution of the four THM species. The formation of more toxic brominated THM due to chlorination of these near-coast drinking water sources must be regarded as a decisive factor for the choice of water disinfection regime.

  2. Potential hydrologic impacts of ground-water withdrawal from the Cape Cod National Seashore, Truro, Massachusetts

    USGS Publications Warehouse

    LeBlanc, Denis R.

    1982-01-01

    The hydrologic impacts of continuous ground-water withdrawals at 0.75, 1.0, and 1.24 Mgal/d (million gallons per day) from a test-well site in the Cape Cod National Seashore, Truro, Massachusetts, were evaluated with a three-dimensional finite-difference steady-state-flow digital model. The digital model was prepared during an earlier study and is only briefly described. Continuous withdrawal of more than 1.0 Mgal/d from a well screened from 10 to 40 feet below sea level at the test site will result in upward movement of the freshwater-saltwater interface, and most likely saltwater will eventually contaminate the well. Pumping from a shallower well will decrease the potential for the movement of saltwater into the well, but the water table may be drawn down to the well screen. It is unlikely that movement of the freshwater-saltwater interface in response to pumping from the test site at the simulated rates will result in saltwater contamination of the shallow domestic supply wells in Truro. For the simulated pumping schemes, the water-table decline below average (1963-76) levels did not exceed 0.6 foot except near the pumping wells. Continuous withdrawal at the average year-round rate and the average summer rate will decrease freshwater discharge to the wetland and ocean along the northeastern boundary of the aquifer. (USGS)

  3. Impacts of Urbanization on Groundwater Quality and Recharge in a Semi-arid Alluvial Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The management of groundwater resources is paramount in semi-arid regions experiencing urban development. In the southwestern United States, enhancing recharge of urban storm runoff has been identified as a strategy for augmenting groundwater resources. An understanding of how urbanization may impac...

  4. Impacts of Shallow Groundwater and Soil Texture on Agricultural Drought Resistance

    NASA Astrophysics Data System (ADS)

    Zipper, S. C.; Soylu, M. E.; Booth, E.; Steven, L. I.

    2015-12-01

    Meeting increasing global food demands while fostering environmental sustainability requires a detailed understanding of the drivers of yield sensitivity within agroecosystems. In this study, we untangle the roles of soil texture and shallow groundwater as simultaneous drivers of corn yield resistance to excessively wet and dry growing seasons. Specifically, we ask (1) does the presence of groundwater in or near the root zone increase/decrease yield?; and (2) how does yield response to water table depth interact with variability in soil texture and growing season weather conditions? We combine a multi-year field study at a commercial corn field in south-central Wisconsin with ecohydrological modeling using AgroIBIS-VSF to assess the yield response to a broad spectrum of groundwater, soil, and weather conditions. We find that shallow groundwater (<1 m) increases yield sensitivity to overly wet growing season conditions, but acts as a stable reservoir of water to increase drought resistance by providing a groundwater yield subsidy during dry years. Modeling results indicate that coarser soils receive a groundwater yield subsidy at shallower water table depths than finer-grained soils, and that the magnitude of the groundwater yield subsidy tends to be larger. We also find that crops growing on soils with different textures experience a comparable response to changes in growing season precipitation and evapotranspiration demands. Overall, we find that the benefits of shallow groundwater (drought resistance) outweigh the negatives (waterlogging and yield loss) at our study site.

  5. Impact of Early Life Adversity on Reward Processing in Young Adults: EEG-fMRI Results from a Prospective Study over 25 Years

    PubMed Central

    Boecker, Regina; Holz, Nathalie E.; Buchmann, Arlette F.; Blomeyer, Dorothea; Plichta, Michael M.; Wolf, Isabella; Baumeister, Sarah; Meyer-Lindenberg, Andreas; Banaschewski, Tobias

    2014-01-01

    Several lines of evidence have implicated the mesolimbic dopamine reward pathway in altered brain function resulting from exposure to early adversity. The present study examined the impact of early life adversity on different stages of neuronal reward processing later in life and their association with a related behavioral phenotype, i.e. attention deficit/hyperactivity disorder (ADHD). 162 healthy young adults (mean age = 24.4 years; 58% female) from an epidemiological cohort study followed since birth participated in a simultaneous EEG-fMRI study using a monetary incentive delay task. Early life adversity according to an early family adversity index (EFA) and lifetime ADHD symptoms were assessed using standardized parent interviews conducted at the offspring's age of 3 months and between 2 and 15 years, respectively. fMRI region-of-interest analysis revealed a significant effect of EFA during reward anticipation in reward-related areas (i.e. ventral striatum, putamen, thalamus), indicating decreased activation when EFA increased. EEG analysis demonstrated a similar effect for the contingent negative variation (CNV), with the CNV decreasing with the level of EFA. In contrast, during reward delivery, activation of the bilateral insula, right pallidum and bilateral putamen increased with EFA. There was a significant association of lifetime ADHD symptoms with lower activation in the left ventral striatum during reward anticipation and higher activation in the right insula during reward delivery. The present findings indicate a differential long-term impact of early life adversity on reward processing, implicating hyporesponsiveness during reward anticipation and hyperresponsiveness when receiving a reward. Moreover, a similar activation pattern related to lifetime ADHD suggests that the impact of early life stress on ADHD may possibly be mediated by a dysfunctional reward pathway. PMID:25118701

  6. Assessment of groundwater quality impacts due to use of coal combustion byproducts to control subsidence from underground mines.

    PubMed

    Singh, G; Paul, B C

    2001-06-01

    Coal combustion byproducts are to be placed in an underground coal mine to control subsidence. The materials were characterized to determine potential groundwater impacts. No problems were found with respect to heavy or toxic metals. Coal combustion byproduct leachates are high in dissolved solids and sulfates. Chloride and boron from fly ash may also leach in initially high concentrations. Because the demonstration site is located beneath deep tight brine-bearing aquifers, no problems are anticipated at the demonstration site. PMID:11485225

  7. The impact of groundwater depletion on spatial variations in sea level change during the past century

    NASA Astrophysics Data System (ADS)

    Veit, Emeline; Conrad, Clinton P.

    2016-04-01

    Continental groundwater loss during the past century has elevated sea level by up to ~25 mm. The mass unloading associated with this depletion locally uplifts Earth's solid surface and depresses the geoid, leading to slower relative sea level rise near areas of significant groundwater loss. We computed spatial variations in sea level using a model of the solid Earth's response to estimates of groundwater depletion during the past century and find large negative deviations of ~0.4 mm/yr along the coastlines of western North America and southern Asia. This approximately corresponds to the difference between rates of sea level rise measured by tide gauges in these regions since 1930 and average rates inferred from global reconstructions. Groundwater-induced regional variations in sea level can be larger than those due to postglacial rebound and interseismic deformation and should become increasingly important in the future as both groundwater depletion and sea level rise accelerate.

  8. Impact of land use and land cover change on groundwater recharge and quality in the southwestern US

    USGS Publications Warehouse

    Scanlon, B.R.; Reedy, R.C.; Stonestrom, D.A.; Prudic, D.E.; Dennehy, K.F.

    2005-01-01

    Humans have exerted large-scale changes on the terrestrial biosphere, primarily through agriculture; however, the impacts of such changes on the hydrologic cycle are poorly understood. The purpose of this study was to test the hypothesis that the conversion of natural rangeland ecosystems to agricultural ecosystems impacts the subsurface portion of the hydrologic cycle by changing groundwater recharge and flushing salts to underlying aquifers. The hypothesis was examined through point and areal studies investigating the effects of land use/land cover (LU/LC) changes on groundwater recharge and solute transport in the Amargosa Desert (AD) in Nevada and in the High Plains (HP) in Texas, US. Studies use the fact that matric (pore-water-pressure) potential and environmental-tracer profiles in thick unsaturated zones archive past changes in recharging fluxes. Results show that recharge is related to LU/LC as follows: Discharge through evapotranspiration (i.e., no recharge; upward fluxes <0.1 mm yr-1) in natural rangeland ecosystems (low matric potentials; high chloride and nitrate concentrations); moderate-to-high recharge in irrigated agricultural ecosystems (high matric potentials; low-to-moderate chloride and nitrate concentrations) (AD recharge: ??? 130-640 mm yr-1); and moderate recharge in nonirrigated (dryland) agricultural ecosystems (high matric potentials; low chloride and nitrate concentrations, and increasing groundwater levels) (HP recharge: ??? 9-32 mm yr-1). Replacement of rangeland with agriculture changed flow directions from upward (discharge) to downward (recharge). Recent replacement of rangeland with irrigated ecosystems was documented through downward displacement of chloride and nitrate fronts. Thick unsaturated zones contain a reservoir of salts that are readily mobilized under increased recharge related to LU/LC changes, potentially degrading groundwater quality. Sustainable land use requires quantitative knowledge of the linkages between

  9. The impact of biostimulation on the fate of sulfate and associated sulfur dynamics in groundwater.

    PubMed

    Miao, Ziheng; Carreón-Diazconti, Concepcion; Carroll, Kenneth C; Brusseau, Mark L

    2014-08-01

    The impact of electron-donor addition on sulfur dynamics for a groundwater system with low levels of metal contaminants was evaluated with a pilot-scale biostimulation test conducted at a former uranium mining site. Geochemical and stable-isotope data collected before, during, and after the test were analyzed to evaluate the sustainability of sulfate reducing conditions induced by the test, the fate of hydrogen sulfide, and the impact on aqueous geochemical conditions. The results of site characterization activities conducted prior to the test indicated the absence of measurable bacterial sulfate reduction. The injection of an electron donor (ethanol) induced bacterial sulfate reduction, as confirmed by an exponential decrease of sulfate concentration in concert with changes in oxidation-reduction potential, redox species, alkalinity, production of hydrogen sulfide, and fractionation of δ(34)S-sulfate. High, stoichiometrically-equivalent hydrogen sulfide concentrations were not observed until several months after the start of the test. It is hypothesized that hydrogen sulfide produced from sulfate reduction was initially sequestered in the form of iron sulfides until the exhaustion of readily reducible iron oxides within the sediment. The fractionation of δ(34)S for sulfate was atypical, wherein the enrichment declined in the latter half of the experiment. It was conjectured that mixing effects associated with the release of sulfate from sulfate minerals associated with the sediments, along with possible sulfide re-oxidation contributed to this behavior. The results of this study illustrate the biogeochemical complexity that is associated with in-situ biostimulation processes involving bacterial sulfate reduction.

  10. THE IMPACT OF BIOSTIMULATION ON THE FATE OF SULFATE AND ASSOCIATED SULFUR DYNAMICS IN GROUNDWATER

    PubMed Central

    Miao, Ziheng; Carreón-Diazconti, Concepcion; Carroll, Kenneth C.; Brusseau, Mark L.

    2014-01-01

    The impact of electron-donor addition on sulfur dynamics for a groundwater system with low levels of metal contaminants was evaluated with a pilot-scale biostimulation test conducted at a former uranium mining site. Geochemical and stable-isotope data collected before, during, and after the test were analyzed to evaluate the sustainability of sulfate reducing conditions induced by the test, the fate of hydrogen sulfide, and the impact on aqueous geochemical conditions. The results of site characterization activities conducted prior to the test indicated the absence of measurable bacterial sulfate reduction. The injection of an electron donor (ethanol) induced bacterial sulfate reduction, as confirmed by an exponential decrease of sulfate concentration in concert with changes in oxidation-reduction potential, redox species, alkalinity, production of hydrogen sulfide, and fractionation of δ34S-sulfate. High, stoichiometrically-equivalent hydrogen sulfide concentrations were not observed until several months after the start of the test. It is hypothesized that hydrogen sulfide produced from sulfate reduction was initially sequestered in the form of iron sulfides until the exhaustion of readily reducible iron oxides associated with the sediment. The fractionation of δ34S for sulfate was atypical, wherein the enrichment declined in the latter half of the experiment. It was conjectured that mixing effects associated with the release of sulfate from sulfate minerals associated with the sediments, along with possible sulfide re-oxidation contributed to this behavior. The results of this study illustrate the biogeochemical complexity that is associated with in-situ biostimulation processes involving bacterial sulfate reduction. PMID:25016586

  11. The impact of biostimulation on the fate of sulfate and associated sulfur dynamics in groundwater

    NASA Astrophysics Data System (ADS)

    Miao, Ziheng; Carreón-Diazconti, Concepcion; Carroll, Kenneth C.; Brusseau, Mark L.

    2014-08-01

    The impact of electron-donor addition on sulfur dynamics for a groundwater system with low levels of metal contaminants was evaluated with a pilot-scale biostimulation test conducted at a former uranium mining site. Geochemical and stable-isotope data collected before, during, and after the test were analyzed to evaluate the sustainability of sulfate reducing conditions induced by the test, the fate of hydrogen sulfide, and the impact on aqueous geochemical conditions. The results of site characterization activities conducted prior to the test indicated the absence of measurable bacterial sulfate reduction. The injection of an electron donor (ethanol) induced bacterial sulfate reduction, as confirmed by an exponential decrease of sulfate concentration in concert with changes in oxidation-reduction potential, redox species, alkalinity, production of hydrogen sulfide, and fractionation of δ34S-sulfate. High, stoichiometrically-equivalent hydrogen sulfide concentrations were not observed until several months after the start of the test. It is hypothesized that hydrogen sulfide produced from sulfate reduction was initially sequestered in the form of iron sulfides until the exhaustion of readily reducible iron oxides within the sediment. The fractionation of δ34S for sulfate was atypical, wherein the enrichment declined in the latter half of the experiment. It was conjectured that mixing effects associated with the release of sulfate from sulfate minerals associated with the sediments, along with possible sulfide re-oxidation contributed to this behavior. The results of this study illustrate the biogeochemical complexity that is associated with in-situ biostimulation processes involving bacterial sulfate reduction.

  12. Climate change impact assessment on Veneto and Friuli Plain groundwater. Part I: an integrated modeling approach for hazard scenario construction.

    PubMed

    Baruffi, F; Cisotto, A; Cimolino, A; Ferri, M; Monego, M; Norbiato, D; Cappelletto, M; Bisaglia, M; Pretner, A; Galli, A; Scarinci, A; Marsala, V; Panelli, C; Gualdi, S; Bucchignani, E; Torresan, S; Pasini, S; Critto, A; Marcomini, A

    2012-12-01

    Climate change impacts on water resources, particularly groundwater, is a highly debated topic worldwide, triggering international attention and interest from both researchers and policy makers due to its relevant link with European water policy directives (e.g. 2000/60/EC and 2007/118/EC) and related environmental objectives. The understanding of long-term impacts of climate variability and change is therefore a key challenge in order to address effective protection measures and to implement sustainable management of water resources. This paper presents the modeling approach adopted within the Life+ project TRUST (Tool for Regional-scale assessment of groUndwater Storage improvement in adaptation to climaTe change) in order to provide climate change hazard scenarios for the shallow groundwater of high Veneto and Friuli Plain, Northern Italy. Given the aim to evaluate potential impacts on water quantity and quality (e.g. groundwater level variation, decrease of water availability for irrigation, variations of nitrate infiltration processes), the modeling approach integrated an ensemble of climate, hydrologic and hydrogeologic models running from the global to the regional scale. Global and regional climate models and downscaling techniques were used to make climate simulations for the reference period 1961-1990 and the projection period 2010-2100. The simulation of the recent climate was performed using observed radiative forcings, whereas the projections have been done prescribing the radiative forcings according to the IPCC A1B emission scenario. The climate simulations and the downscaling, then, provided the precipitation, temperatures and evapo-transpiration fields used for the impact analysis. Based on downscaled climate projections, 3 reference scenarios for the period 2071-2100 (i.e. the driest, the wettest and the mild year) were selected and used to run a regional geomorphoclimatic and hydrogeological model. The final output of the model ensemble produced

  13. Moderating role of FKBP5 genotype in the impact of childhood adversity on cortisol stress response during adulthood.

    PubMed

    Buchmann, Arlette F; Holz, Nathalie; Boecker, Regina; Blomeyer, Dorothea; Rietschel, Marcella; Witt, Stephanie H; Schmidt, Martin H; Esser, Günter; Banaschewski, Tobias; Brandeis, Daniel; Zimmermann, Ulrich S; Laucht, Manfred

    2014-06-01

    Recent research suggests an important role of FKBP5, a glucocorticoid receptor regulating co-chaperone, in the development of stress-related diseases such as depression and anxiety disorders. The present study aimed to replicate and extend previous evidence indicating that FKBP5 polymorphisms moderate hypothalamus-pituitary-adrenal (HPA) function by examining whether FKBP5 rs1360780 genotype and different measures of childhood adversity interact to predict stress-induced cortisol secretion. At age 19 years, 195 young adults (90 males, 105 females) participating in an epidemiological cohort study completed the Trier Social Stress Test (TSST) to assess cortisol stress responsiveness and were genotyped for the FKBP5 rs1360780. Childhood adversity was assessed using the Childhood Trauma Questionnaire (CTQ) and by a standardized parent interview yielding an index of family adversity. A significant interaction between genotype and childhood adversity on cortisol response to stress was demonstrated for exposure to childhood maltreatment as assessed by retrospective self-report (CTQ), but not for prospectively ascertained objective family adversity. Severity of childhood maltreatment was significantly associated with attenuated cortisol levels among carriers of the rs1360780 CC genotype, while no such effect emerged in carriers of the T allele. These findings point towards the functional involvement of FKBP5 in long-term alterations of neuroendocrine stress regulation related to childhood maltreatment, which have been suggested to represent a premorbid risk or resilience factor in the context of stress-related disorders.

  14. Moderating role of FKBP5 genotype in the impact of childhood adversity on cortisol stress response during adulthood.

    PubMed

    Buchmann, Arlette F; Holz, Nathalie; Boecker, Regina; Blomeyer, Dorothea; Rietschel, Marcella; Witt, Stephanie H; Schmidt, Martin H; Esser, Günter; Banaschewski, Tobias; Brandeis, Daniel; Zimmermann, Ulrich S; Laucht, Manfred

    2014-06-01

    Recent research suggests an important role of FKBP5, a glucocorticoid receptor regulating co-chaperone, in the development of stress-related diseases such as depression and anxiety disorders. The present study aimed to replicate and extend previous evidence indicating that FKBP5 polymorphisms moderate hypothalamus-pituitary-adrenal (HPA) function by examining whether FKBP5 rs1360780 genotype and different measures of childhood adversity interact to predict stress-induced cortisol secretion. At age 19 years, 195 young adults (90 males, 105 females) participating in an epidemiological cohort study completed the Trier Social Stress Test (TSST) to assess cortisol stress responsiveness and were genotyped for the FKBP5 rs1360780. Childhood adversity was assessed using the Childhood Trauma Questionnaire (CTQ) and by a standardized parent interview yielding an index of family adversity. A significant interaction between genotype and childhood adversity on cortisol response to stress was demonstrated for exposure to childhood maltreatment as assessed by retrospective self-report (CTQ), but not for prospectively ascertained objective family adversity. Severity of childhood maltreatment was significantly associated with attenuated cortisol levels among carriers of the rs1360780 CC genotype, while no such effect emerged in carriers of the T allele. These findings point towards the functional involvement of FKBP5 in long-term alterations of neuroendocrine stress regulation related to childhood maltreatment, which have been suggested to represent a premorbid risk or resilience factor in the context of stress-related disorders. PMID:24411633

  15. Stream channel surface water - groundwater interactions in a fire impacted watershed

    NASA Astrophysics Data System (ADS)

    Russo, T. A.; Fisher, A. T.

    2010-12-01

    We are conducting a study of surface water - groundwater interactions within the Scott Creek watershed, a 4th order catchment of 76.6 km2 in central coastal California, to assess the impacts of fire on channel and riparian conditions. Scott Creek and its tributaries are valuable spawning habitat for Coho salmon and Steelhead trout. The Scott Creek watershed is located on the western (windward) side of the Santa Cruz Mountains, where the most intense precipitation falls from November to April, and includes a mixture of protected land and areas used for agriculture, grazing, and selective timber harvesting. 37% of the watershed was burned in a fire in August 2009, and we hypothesize that this could result in enhanced delivery of fine grained hill slope sediments to stream channels for several years post fire, reducing the extent of hyporheic exchange downstream of burned areas. This could reduce the survival rates of Coho and Steelhead redds (egg nests), which are dependent on surface water - groundwater exchange for regulation of water nutrient content and temperature. We are monitoring streambed seepage rates and hydraulic conductivity, and performing repeated tracer discharge experiments at three sites on Scott Creek, two within and one upstream of the area burned in the 2009 fire. Streambed seepage rates are calculated using a time series method applied to heat as a tracer, using naturally occurring diurnal changes in stream temperature, and extended to calculations of streambed hydraulic conductivity based on measured head gradients. Hyporheic exchange parameters are assessed using tracer breakthrough data, as fit by an optimized model of one-dimensional advection, dispersion and transient storage. Variations in hydrologic characteristics (e.g., transient storage area, exchange coefficient) over time at each site are being used to assess the magnitude and timing of channel modifications independent to, and associated with, the burning of catchment hill slopes

  16. Explaining disproportionately high rates of adverse birth outcomes among African Americans: the impact of stress, racism, and related factors in pregnancy.

    PubMed

    Giscombé, Cheryl L; Lobel, Marci

    2005-09-01

    Compared with European Americans, African American infants experience disproportionately high rates of low birth weight and preterm delivery and are more than twice as likely to die during their 1st year of life. The authors examine 5 explanations for these differences in rates of adverse birth outcomes: (a) ethnic differences in health behaviors and socioeconomic status; (b) higher levels of stress in African American women; (c) greater susceptibility to stress in African Americans; (d) the impact of racism acting either as a contributor to stress or as a factor that exacerbates stress effects; and (e) ethnic differences in stress-related neuroendocrine, vascular, and immunological processes. The review of literature indicates that each explanation has some merit, although none is sufficient to explain ethnic disparities in adverse birth outcomes. There is a lack of studies examining the impact of such factors jointly and interactively. Recommendations and cautions for future research are offered.

  17. Assessment of potential impacts of major groundwater contaminants to fall chinook salmon (Oncorhynchus tshawytscha) in the Hanford Reach, Columbia River

    SciTech Connect

    Geist, D.R.; Poston, T.M.; Dauble, D.D.

    1994-10-01

    Past operations of Hanford Site facilities have contaminated the groundwater adjacent to the Hanford Reach of the Columbia River, Washington, with various chemical and radiological constituents. The groundwater is hydraulically connected to the river and contains concentrations of contaminants that sometimes exceed federal and/or state drinking water standards or standards for the protection of aquatic life. For example, concentrations of chromium in shoreline seeps and springs at most 100 Area operable units exceed concentrations found to be toxic to fish. Nitrate and tritium concentrations in shoreline seeps are generally below drinking water standards and concentrations potentially toxic to aquatic life, but nitrate concentrations may be high enough to synergistically interact with and exacerbate chromium toxicity. The Hanford Reach also supports the largest run of fall chinook salmon (Oncorhynchus tshawytscha) in the Columbia River Basin. Numbers of fall chinook salmon returning to the Hanford Reach have increased relative to other mainstem populations during the last 30 years. Groundwater discharge appears to occur near some salmon spawning areas, but contaminants are generally not detectable in surface water samples. The concentration and potential toxicity of contaminants in the interstitial waters of the substrate where fall chinook salmon embryogenesis occurs are presently unknown. New tools are required to characterize the extent of groundwater contaminant discharge to the Hanford Reach and to resolve uncertainties associated with assessment of potential impacts to fall chinook salmon.

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

    PubMed

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

    2009-04-15

    The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes (deltaD, T, delta15N, delta18O, delta34S, and 87Sr/86Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes (deltaD and delta18O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The delta34S and delta15N of SO4(2-) and NO3- data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO4(2-) (>30 ppm as SO4(2-)) and NO3- (>20 ppm as NO3-) of groundwater. The 87Sr/86Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas.

  19. Subsurface Drip Irrigation As a Methold to Beneficiallly Use Coalbed Methane Produced Water: Initial Impacts to Groundwater, Soil Water, and Surface Water

    SciTech Connect

    Engle, M.A.: Bern, C: Healy, R: Sams, J: Zupancic, J.: Schroeder, K.

    2009-10-18

    Coalbed methane (CBM) currently accounts for >8% of US natural gas production. Compared to traditional sources, CBM co-produces large volumes of water. Of particular interest is CBM development in the Powder River Basin of Wyoming and Montana, the 2nd largest CBM production field in the US, where CBM produced waters exhibit low to moderate TDS and relatively high sodium-adsorption ratio (SAR) that could potentially impact the surface environment. Subsurface drip irrigation (SDI) is an emerging technology for beneficial use of pre-treated CBM waters (injectate) which are emitted into the root zone of an agricultural field to aid in irrigation. The method is designed to minimize environmental impacts by storing potentially detrimental salts in the vadose zone. Research objectives include tracking the transport and fate of the water and salts from the injected CBM produced waters at an SDI site on an alluvial terrace, adjacent to the Powder River, Johnson County, Wyoming. This research utilizes soil science, geochemical, and geophysical methods. Initial results from pre-SDI data collection and the first 6-months of post-SDI operation will be presented. Substantial ranges in conductivity (2732-9830 {micro}S/cm) and dominant cation chemistry (Ca-SO{sub 4} to Na-SO{sub 4}) have been identified in pre-SDI analyses of groundwater samples from the site. Ratios of average composition of local ground water to injectate demonstrate that the injectate contains lower concentrations of most constituents except for Cr, Zn, and Tl (all below national water quality standards) but exhibits a higher SAR. Composition of soil water varies markedly with depth and between sites, suggesting large impacts from local controls, including ion exchange and equilibrium with gypsum and carbonates. Changes in chemical composition and specific conductivity along surface water transects adjacent to the site are minimal, suggesting that discharge to the Powder River from groundwater underlying the

  20. Impact of Groundwater Table and Plateau Zokors (Myospalax baileyi) on Ecosystem Respiration in the Zoige Peatlands of China

    PubMed Central

    Grace, John; Yang, Meng; Lu, Cai; Geng, Xuemeng; Lei, Guangchun; Zhu, Wei; Deng, Yongfeng

    2014-01-01

    Peatlands contain large amount of carbon stock that is vulnerable to release into the atmosphere. Mostly because of human impact, the peatlands at Zoige Wetlands face severe degradation, and the groundwater table is now lower than before, which has increased the population of the plateau zokor, a burrowing rodent. However, the impact of these changes on ecosystem carbon flows has not been studied. To investigate how the plateau zokor and the groundwater level alter the ecosystem respiration of the Zoige peatlands, we sampled the CO2 flux of hummocks shaped by the zokors and compared it with the CO2 flux of undisturbed sites with different groundwater table levels. The soil organic carbon (SOC), soil water content (SWC) and soil temperature at 5 cm (T5) were measured. SOC showed no significant difference among the four sampling sites and did not correlate with the CO2 flux, while SWC was found to partly determine the CO2 flux. A linear equation could adequately describe the relationship between the natural logarithm of the ecosystem respiration and the soil temperature. It is demonstrated that descending groundwater table might accelerate ecosystem respiration and the CO2 flux from hummocks was higher than the CO2 flux from the control site in the non-growing season. With rising temperature, the CO2 flux from the control site accelerated faster than that from the hummocks. Our results show that ecosystem respiration was significantly lower from hummocks than at the control site in the growing season. The results on the impact of zokors on greenhouse gas emissions presented in this paper provide a useful reference to help properly manage not only this, but other litter-burrowing mammals at peatland sites. PMID:25542023

  1. Groundwater Governance in a Water-Starved Country: Public Policy, Farmers' Perceptions, and Drivers of Tubewell Adoption in Balochistan, Pakistan.

    PubMed

    Khair, Syed Mohammad; Mushtaq, Shahbaz; Reardon-Smith, Kathryn

    2015-01-01

    Pakistan faces the challenge of developing sustainable groundwater policies with the main focus on groundwater management rather than groundwater development and with appropriate governance arrangement to ensure benefits continue into the future. This article investigates groundwater policy, farmers' perceptions, and drivers of tubewell (groundwater bore) adoption and proposes possible pathways for improved groundwater management for Balochistan, Pakistan. Historical groundwater policies were mainly aimed at increasing agricultural production and reducing poverty, without consideration of adverse impact on groundwater availability. These groundwater policies and governance arrangements have resulted in a massive decline in groundwater tables. Tubewell owners' rankings of the drivers of groundwater decline suggest that rapid and widespread installation of tubewells, together with uncontrolled extraction due to lack of property rights, electricity subsidy policies, and ineffective governance, are key causes of groundwater decline in Balochistan. An empirical "tubewell adoption" model confirmed that the electricity subsidy significantly influenced tubewell adoption decisions. The article proposes a more rational electricity subsidy policy for sustaining groundwater levels in the short-run. However, in the long run a more comprehensive sustainable groundwater management policy, with strong institutional support and involvement of all stakeholders, is needed.

  2. Tourism impacts of Three Mile Island and other adverse events: Implications for Lincoln County and other rural counties bisected by radioactive wastes intended for Yucca Mountain

    SciTech Connect

    Himmelberger, J.J.; Ogneva-Himmelberger, Y.A.; Baughman, M.

    1995-11-01

    Whether the proposed Yucca Mountain nuclear waste repository system will adversely impact tourism in southern Nevada is an open question of particular importance to visitor-oriented rural counties bisected by planned waste transportation corridors (highway or rail). As part of one such county`s repository impact assessment program, tourism implications of Three Mile Island (TMI) and other major hazard events have been revisited to inform ongoing county-wide socioeconomic assessments and contingency planning efforts. This paper summarizes key research implications of such research as applied to Lincoln County, Nevada. Implications for other rural counties are discussed in light of the research findings. 29 refs., 3 figs., 1 tab.

  3. Tourism impacts of Three Mile Island and other adverse events: Implications for Lincoln County and other rural counties bisected by radioactive wastes intended for Yucca Mountain

    NASA Astrophysics Data System (ADS)

    Himmelberger, Jeffery J.; Baughman, Mike; Ogneva-Himmelberger, Yelena A.

    1995-11-01

    Whether the proposed Yucca Mountain nuclear waste repository system will adversely impact tourism in southern Nevada is an open question of particular importance to visitor-oriented rural counties bisected by planned waste transportatin corridors (highway or rail). As part of one such county's repository impact assessment program, tourism implications of Three Mile Island (TMI) and other major hazard events have beem revisited to inform ongoing county-wide socioeconomic assessments and contingency planning efforts. This paper summarizes key research implications of such research as applied to Lincoln County, Nevada. Implications for other rural counties are discussed in light of the research findings.

  4. Prevalence and Predictors of Adverse Events in Older Surgical Patients: Impact of the Present on Admission Indicator

    ERIC Educational Resources Information Center

    Kim, Hongsoo; Capezuti, Elizabeth; Kovner, Christine; Zhao, Zhonglin; Boockvar, Kenneth

    2010-01-01

    Purpose of the Study: To examine the effects of the present on admission (POA) indicator on the prevalence of and factors associated with postsurgical adverse events in older patients. Design and Methods: This is a secondary data analysis of 82,898 surgical patients aged 65 years or older in 252 acute care hospitals in California in 2004. Four…

  5. A review of seawater intrusion in the Nile Delta groundwater system - the basis for assessing impacts due to climate changes and water resources development

    NASA Astrophysics Data System (ADS)

    Mabrouk, M. B.; Jonoski, A.; Solomatine, D.; Uhlenbrook, S.

    2013-08-01

    Serious environmental problems are emerging in the River Nile basin and its groundwater resources. Recent years have brought scientific evidence of climate change and development-induced environmental impacts globally as well as over Egypt. Some impacts are subtle, like decline of the Nile River water levels, others are dramatic like the salinization of all coastal land in the Nile Delta - the agricultural engine of Egypt. These consequences have become a striking reality causing a set of interconnected groundwater management problems. Massive population increase that overwhelmed the Nile Delta region has amplified the problem. Many researchers have studied these problems from different perspectives using different methodologies, following different objectives and, consequently, arrived at different findings. However, they all confirmed that significant groundwater salinization has affected the Nile Delta and this is likely to become worse rapidly in the future. This article presents, categorizes and critically analyses and synthesizes the most relevant research regarding climate change and development challenges in relation to groundwater resources in the Nile Delta. It is shown that there is a gap in studies that focus on sustainable groundwater resources development and environmentally sound protection as an integrated regional process in Nile Delta. Moreover, there is also a knowledge gap related to the deterioration of groundwater quality. The article recommends further research that covers the groundwater resources and salinization in the whole Nile Delta based on integrated three-dimensional groundwater modelling of the Nile delta aquifer.

  6. Groundwater-fed irrigation impacts spatially distributed temporal scaling behavior of the natural system: a spatio-temporal framework for understanding water management impacts

    NASA Astrophysics Data System (ADS)

    Condon, Laura E.; Maxwell, Reed M.

    2014-03-01

    Regional scale water management analysis increasingly relies on integrated modeling tools. Much recent work has focused on groundwater-surface water interactions and feedbacks. However, to our knowledge, no study has explicitly considered impacts of management operations on the temporal dynamics of the natural system. Here, we simulate twenty years of hourly moisture dependent, groundwater-fed irrigation using a three-dimensional, fully integrated, hydrologic model (ParFlow-CLM). Results highlight interconnections between irrigation demand, groundwater oscillation frequency and latent heat flux variability not previously demonstrated. Additionally, the three-dimensional model used allows for novel consideration of spatial patterns in temporal dynamics. Latent heat flux and water table depth both display spatial organization in temporal scaling, an important finding given the spatial homogeneity and weak scaling observed in atmospheric forcings. Pumping and irrigation amplify high frequency (sub-annual) variability while attenuating low frequency (inter-annual) variability. Irrigation also intensifies scaling within irrigated areas, essentially increasing temporal memory in both the surface and the subsurface. These findings demonstrate management impacts that extend beyond traditional water balance considerations to the fundamental behavior of the system itself. This is an important step to better understanding groundwater’s role as a buffer for natural variability and the impact that water management has on this capacity.

  7. A structured analysis of uncertainty surrounding modeled impacts of groundwater-extraction rules

    NASA Astrophysics Data System (ADS)

    Guillaume, Joseph H. A.; Qureshi, M. Ejaz; Jakeman, Anthony J.

    2012-08-01

    Integrating economic and groundwater models for groundwater-management can help improve understanding of trade-offs involved between conflicting socioeconomic and biophysical objectives. However, there is significant uncertainty in most strategic decision-making situations, including in the models constructed to represent them. If not addressed, this uncertainty may be used to challenge the legitimacy of the models and decisions made using them. In this context, a preliminary uncertainty analysis was conducted of a dynamic coupled economic-groundwater model aimed at assessing groundwater extraction rules. The analysis demonstrates how a variety of uncertainties in such a model can be addressed. A number of methods are used including propagation of scenarios and bounds on parameters, multiple models, block bootstrap time-series sampling and robust linear regression for model calibration. These methods are described within the context of a theoretical uncertainty management framework, using a set of fundamental uncertainty management tasks and an uncertainty typology.

  8. Remedial Process Optimization and Green In-Situ Ozone Sparging for Treatment of Groundwater Impacted with Petroleum Hydrocarbons

    NASA Astrophysics Data System (ADS)

    Leu, J.

    2012-12-01

    A former natural gas processing station is impacted with TPH and BTEX in groundwater. Air sparging and soil vapor extraction (AS/AVE) remediation systems had previously been operated at the site. Currently, a groundwater extraction and treatment system is operated to remove the chemicals of concern (COC) and contain the groundwater plume from migrating offsite. A remedial process optimization (RPO) was conducted to evaluate the effectiveness of historic and current remedial activities and recommend an approach to optimize the remedial activities. The RPO concluded that both the AS/SVE system and the groundwater extraction system have reached the practical limits of COC mass removal and COC concentration reduction. The RPO recommended an in-situ chemical oxidation (ISCO) study to evaluate the best ISCO oxidant and approach. An ISCO bench test was conducted to evaluate COC removal efficiency and secondary impacts to recommend an application dosage. Ozone was selected among four oxidants based on implementability, effectiveness, safety, and media impacts. The bench test concluded that ozone demand was 8 to 12 mg ozone/mg TPH and secondary groundwater by-products of ISCO include hexavalent chromium and bromate. The pH also increased moderately during ozone sparging and the TDS increased by approximately 20% after 48 hours of ozone treatment. Prior to the ISCO pilot study, a capture zone analysis (CZA) was conducted to ensure containment of the injected oxidant within the existing groundwater extraction system. The CZA was conducted through a groundwater flow modeling using MODFLOW. The model indicated that 85%, 90%, and 95% of an injected oxidant could be captured when a well pair is injecting and extracting at 2, 5, and 10 gallons per minute, respectively. An ISCO pilot test using ozone was conducted to evaluate operation parameters for ozone delivery. The ozone sparging system consisted of an ozone generator capable of delivering 6 lbs/day ozone through two ozone

  9. The Impact of Groundwater Depletion on Spatial Variations in Sea Level Change During the Past Century

    NASA Astrophysics Data System (ADS)

    Conrad, C. P.; Veit, E.; Natarov, S.

    2015-12-01

    The loss of continental groundwater to the oceans during the past century has elevated sea level by ~25(±5) mm, and has caused ~0.7mm/yr of sea level rise since 2005. The mass unloading associated with this groundwater depletion induces elastic uplift of Earth's solid surface and depresses the gravitational equipotential surface that defines sea level. Together, these deflections should cause slower relative sea level rise near areas of continental groundwater loss. We estimated these variations in sea level change using a model of the solid Earth's response to estimates of groundwater depletion during the past century. We find large negative deviations in relative sea level near California, Western India, the western Yellow Sea and the eastern Mediterranean Sea. Relative sea level measured by tide gauges in these areas show slower sea level rise rates compared to global averages. For example, on the western coast of India (e.g., Karachi), groundwater-induced deviations from global average sea level rise can exceed -40 mm, and our model predicts ~1 mm/yr of sea level drop since 2005. Correcting tide gauge records for groundwater depletion using our model improves their fit to the global trend estimated by Church & White (2011), and further reduces the variation of rise rates observed among regional groups of stations. We reconstructed Global Mean Sea Level (GMSL) between 1930 and 2009 taking in account groundwater depletion corrections determined from our model. We found that including groundwater depletion increases our estimate of the global rate of change of GMSL from 1.81 to 1.88 mm/yr during this time period because the observed rise at some key stations is slowed by nearby groundwater depletion. For the past 20 years, including groundwater depletion increases GMSL from 3.32mm/yr to 3.46mm/yr. Quantifying the spatial variability of sea level associated with groundwater depletion is important for understanding the variety of factors that affect sea level, and

  10. Gulf of Mexico integrated science - Tampa Bay study, the impact of groundwater and contaminants on Tampa Bay

    USGS Publications Warehouse

    Swarzenski, Peter W.

    2005-01-01

    Despite the recreational and economic value of coastal bays and estuaries, these ecosystems are often among our most 'troubled' natural environments. Urbanization, agriculture, mining, and shipping are just a few activities that can have a profound and lasting impact on the coastal zone. In order to maintain a healthy coastal ecosystem, it is crucial to develop reasonable management practices around expert scientific information. We still have much to learn about the quantity and quality of groundwater being discharged into Tampa Bay, Florida. We also need to improve our knowledge of a wide range of contaminants entering the bay and must be able to determine where they accumulate in seafloor sediments. Such buried contaminants can potentially be harmful to biota if they are released to the water column. U.S. Geological Survey (USGS) scientists and research partners from the University of South Florida (USF), the University of Florida (UF), and the Florida Marine Research Institute (FMRI) are mapping sources of groundwater, measuring groundwater flow into Tampa Bay, and assessing the impact of contaminants and sediments on bay water quality and ecosystem health.

  11. Antibiotic-Resistant Enterococci and Fecal Indicators in Surface Water and Groundwater Impacted by a Concentrated Swine Feeding Operation

    PubMed Central

    Sapkota, Amy R.; Curriero, Frank C.; Gibson, Kristen E.; Schwab, Kellogg J.

    2007-01-01

    Background The nontherapeutic use of antibiotics in swine feed can select for antibiotic resistance in swine enteric bacteria. Leaking swine waste storage pits and the land-application of swine manure can result in the dispersion of resistant bacteria to water sources. However, there are few data comparing levels of resistant bacteria in swine manure–impacted water sources versus unaffected sources. Objectives The goal of this study was to analyze surface water and groundwater situated up and down gradient from a swine facility for antibiotic-resistant enterococci and other fecal indicators. Methods Surface water and groundwater samples (n = 28) were collected up and down gradient from a swine facility from 2002 to 2004. Fecal indicators were isolated by membrane filtration, and enterococci (n = 200) were tested for susceptibility to erythromycin, tetracycline, clindamycin, virginiamycin, and vancomycin. Results Median concentrations of enterococci, fecal coliforms, and Escherichia coli were 4- to 33-fold higher in down-gradient versus up-gradient surface water and groundwater. We observed higher minimal inhibitory concentrations for four antibiotics in enterococci isolated from down-gradient versus up-gradient surface water and groundwater. Elevated percentages of erythromycin- (p = 0.02) and tetracycline-resistant (p = 0.06) enterococci were detected in down-gradient surface waters, and higher percentages of tetracycline- (p = 0.07) and clindamycin-resistant (p < 0.001) enterococci were detected in down-gradient groundwater. Conclusions We detected elevated levels of fecal indicators and antibiotic-resistant enterococci in water sources situated down gradient from a swine facility compared with up-gradient sources. These findings provide additional evidence that water contaminated with swine manure could contribute to the spread of antibiotic resistance. PMID:17637920

  12. Invisible water, visible impact: groundwater use and Indian agriculture under climate change

    NASA Astrophysics Data System (ADS)

    Zaveri, Esha; Grogan, Danielle S.; Fisher-Vanden, Karen; Frolking, Steve; Lammers, Richard B.; Wrenn, Douglas H.; Prusevich, Alexander; Nicholas, Robert E.

    2016-08-01

    India is one of the world’s largest food producers, making the sustainability of its agricultural system of global significance. Groundwater irrigation underpins India’s agriculture, currently boosting crop production by enough to feed 170 million people. Groundwater overexploitation has led to drastic declines in groundwater levels, threatening to push this vital resource out of reach for millions of small-scale farmers who are the backbone of India’s food security. Historically, losing access to groundwater has decreased agricultural production and increased poverty. We take a multidisciplinary approach to assess climate change challenges facing India’s agricultural system, and to assess the effectiveness of large-scale water infrastructure projects designed to meet these challenges. We find that even in areas that experience climate change induced precipitation increases, expansion of irrigated agriculture will require increasing amounts of unsustainable groundwater. The large proposed national river linking project has limited capacity to alleviate groundwater stress. Thus, without intervention, poverty and food insecurity in rural India is likely to worsen.

  13. Submarine groundwater discharge to the Baltic coastal zone: Impacts on the meiofaunal community

    NASA Astrophysics Data System (ADS)

    Kotwicki, L.; Grzelak, K.; Czub, M.; Dellwig, O.; Gentz, T.; Szymczycha, B.; Böttcher, M. E.

    2014-01-01

    The discharge of groundwater into the sea affects surrounding environments by changing the salinity, temperature and nutrient regimes. This work reports the spatial effects of a submarine groundwater discharge (SGD) on the abundance and structure of the meiofaunal community in the shallow area of Puck Bay (Baltic Sea). Several field expeditions in the years 2009 and 2010 found that low-saline groundwater escapes into the bay from permeable, sandy, near-shore sediments. The SGD literature has grown rapidly during the current decade; however, the effects of this type of disturbance on the shallow sandy bottom fauna have thus far been little studied. We provide evidence that the discharge of groundwater has a clear effect on meiofaunal assemblages in the research area. This effect was reflected in a significant decline of certain meiofaunal taxa, mainly nematodes and harpacticoids, as well as in altered patterns of temporal distribution and small-scale (vertical) zonation of meiofaunal assemblages. Overlooking submarine groundwater discharge processes may lead to serious misinterpretations of ecological data. It is clear that groundwater discharge phenomena should be considered in future scientific studies.

  14. Impacts of Groundwater Constraints on Saudi Arabia's Low-Carbon Electricity Supply Strategy.

    PubMed

    Parkinson, Simon C; Djilali, Ned; Krey, Volker; Fricko, Oliver; Johnson, Nils; Khan, Zarrar; Sedraoui, Khaled; Almasoud, Abdulrahman H

    2016-02-16

    Balancing groundwater depletion, socioeconomic development and food security in Saudi Arabia will require policy that promotes expansion of unconventional freshwater supply options, such as wastewater recycling and desalination. As these processes consume more electricity than conventional freshwater supply technologies, Saudi Arabia's electricity system is vulnerable to groundwater conservation policy. This paper examines strategies for adapting to long-term groundwater constraints in Saudi Arabia's freshwater and electricity supply sectors with an integrated modeling framework. The approach combines electricity and freshwater supply planning models across provinces to provide an improved representation of coupled infrastructure systems. The tool is applied to study the interaction between policy aimed at a complete phase-out of nonrenewable groundwater extraction and concurrent policy aimed at achieving deep reductions in electricity sector carbon emissions. We find that transitioning away from nonrenewable groundwater use by the year 2050 could increase electricity demand by more than 40% relative to 2010 conditions, and require investments similar to strategies aimed at transitioning away from fossil fuels in the electricity sector. Higher electricity demands under groundwater constraints reduce flexibility of supply side options in the electricity sector to limit carbon emissions, making it more expensive to fulfill climate sustainability objectives. The results of this analysis underscore the importance of integrated long-term planning approaches for Saudi Arabia's electricity and freshwater supply systems.

  15. Impacts of Groundwater Constraints on Saudi Arabia's Low-Carbon Electricity Supply Strategy.

    PubMed

    Parkinson, Simon C; Djilali, Ned; Krey, Volker; Fricko, Oliver; Johnson, Nils; Khan, Zarrar; Sedraoui, Khaled; Almasoud, Abdulrahman H

    2016-02-16

    Balancing groundwater depletion, socioeconomic development and food security in Saudi Arabia will require policy that promotes expansion of unconventional freshwater supply options, such as wastewater recycling and desalination. As these processes consume more electricity than conventional freshwater supply technologies, Saudi Arabia's electricity system is vulnerable to groundwater conservation policy. This paper examines strategies for adapting to long-term groundwater constraints in Saudi Arabia's freshwater and electricity supply sectors with an integrated modeling framework. The approach combines electricity and freshwater supply planning models across provinces to provide an improved representation of coupled infrastructure systems. The tool is applied to study the interaction between policy aimed at a complete phase-out of nonrenewable groundwater extraction and concurrent policy aimed at achieving deep reductions in electricity sector carbon emissions. We find that transitioning away from nonrenewable groundwater use by the year 2050 could increase electricity demand by more than 40% relative to 2010 conditions, and require investments similar to strategies aimed at transitioning away from fossil fuels in the electricity sector. Higher electricity demands under groundwater constraints reduce flexibility of supply side options in the electricity sector to limit carbon emissions, making it more expensive to fulfill climate sustainability objectives. The results of this analysis underscore the importance of integrated long-term planning approaches for Saudi Arabia's electricity and freshwater supply systems. PMID:26807884

  16. Occurrence of steroid hormones and antibiotics in shallow groundwater impacted by livestock waste control facilities

    NASA Astrophysics Data System (ADS)

    Bartelt-Hunt, Shannon; Snow, Daniel D.; Damon-Powell, Teyona; Miesbach, David

    2011-04-01

    Wastewater impoundments at concentrated animal feeding operations (CAFOs) represent a potential source of veterinary pharmaceuticals and steroid hormone contamination to shallow groundwater. This study investigates the occurrence of seventeen veterinary pharmaceuticals and thirteen steroid hormones and hormone metabolites in lagoons and adjacent groundwater at operating swine and beef cattle facilities. These sites were chosen because subsurface geology and previous monitoring of nitrate, ammonia and chloride levels in shallow ground water strongly indicated direct infiltration, and as such represent worst cases for ground water contamination by waste water. Pharmaceutical compounds detected in samples obtained from cattle facilities include sulfamerazine; sulfamethazine; erythromycin; monensin; tiamulin; and sulfathiazole. Lincomycin; ractopamine; sulfamethazine; sulfathiazole; erythromycin; tiamulin and sulfadimethoxine were detected in wastewater samples obtained from swine facilities. Steroid hormones were detected less frequently than veterinary pharmaceuticals in this study. Estrone, testosterone, 4-androstenedione, and androsterone were detected in wastewater impoundments at concentrations ranging from 30 to 3600 ng/L, while only estrone and testosterone were detected in groundwater samples at concentrations up to 390 ng/L. The co-occurrence of veterinary pharmaceutical and steroid hormone contamination in groundwater at these locations and the correlation between pharmaceutical occurrence in lagoon wastewater and hydraulically downgradient groundwater indicates that groundwater underlying some livestock wastewater impoundments is susceptible to contamination by veterinary pharmaceuticals and steroid hormones originating in wastewater lagoons.

  17. Occurrence of steroid hormones and antibiotics in shallow groundwater impacted by livestock waste control facilities.

    PubMed

    Bartelt-Hunt, Shannon; Snow, Daniel D; Damon-Powell, Teyona; Miesbach, David

    2011-04-25

    Wastewater impoundments at concentrated animal feeding operations (CAFOs) represent a potential source of veterinary pharmaceuticals and steroid hormone contamination to shallow groundwater. This study investigates the occurrence of seventeen veterinary pharmaceuticals and thirteen steroid hormones and hormone metabolites in lagoons and adjacent groundwater at operating swine and beef cattle facilities. These sites were chosen because subsurface geology and previous monitoring of nitrate, ammonia and chloride levels in shallow ground water strongly indicated direct infiltration, and as such represent worst cases for ground water contamination by waste water. Pharmaceutical compounds detected in samples obtained from cattle facilities include sulfamerazine; sulfamethazine; erythromycin; monensin; tiamulin; and sulfathiazole. Lincomycin; ractopamine; sulfamethazine; sulfathiazole; erythromycin; tiamulin and sulfadimethoxine were detected in wastewater samples obtained from swine facilities. Steroid hormones were detected less frequently than veterinary pharmaceuticals in this study. Estrone, testosterone, 4-androstenedione, and androsterone were detected in wastewater impoundments at concentrations ranging from 30 to 3600ng/L, while only estrone and testosterone were detected in groundwater samples at concentrations up to 390ng/L. The co-occurrence of veterinary pharmaceutical and steroid hormone contamination in groundwater at these locations and the correlation between pharmaceutical occurrence in lagoon wastewater and hydraulically downgradient groundwater indicates that groundwater underlying some livestock wastewater impoundments is susceptible to contamination by veterinary pharmaceuticals and steroid hormones originating in wastewater lagoons.

  18. Closing the irrigation deficit in Cambodia: Implications for transboundary impacts on groundwater and Mekong River flow

    NASA Astrophysics Data System (ADS)

    Erban, Laura E.; Gorelick, Steven M.

    2016-04-01

    Rice production in Cambodia, essential to food security and exports, is largely limited to the wet season. The vast majority (96%) of land planted with rice during the wet season remains fallow during the dry season. This is in large part due to lack of irrigation capacity, increases in which would entail significant consequences for Cambodia and Vietnam, located downstream on the Mekong River. Here we quantify the extent of the dry season "deficit" area in the Cambodian Mekong River catchment, using a recent agricultural survey and our analysis of MODIS satellite data. Irrigation of this land for rice production would require a volume of water up to 31% of dry season Mekong River flow to Vietnam. However, the two countries share an aquifer system in the Mekong Delta, where irrigation demand is increasingly met by groundwater. We estimate expansion rates of groundwater-irrigated land to be >10% per year in the Cambodian Delta using LANDSAT satellite data and simulate the effects of future expansion on groundwater levels over a 25-year period. If groundwater irrigation continues to expand at current rates, the water table will drop below the lift limit of suction pump wells, used for domestic supply by >1.5 million people, throughout much of the area within 15 years. Extensive groundwater irrigation jeopardizes access for shallow domestic water supply wells, raises the costs of pumping for all groundwater users, and may exacerbate arsenic contamination and land subsidence that are already widespread hazards in the region.

  19. Impacts of Climate Changes on the Future Groundwater Storage in the High Plains Aquifer

    NASA Astrophysics Data System (ADS)

    Lo, M. H.; Wu, W. Y.; Wada, Y.; Reager, J. T., II; Famiglietti, J. S.; Yeh, P. J. F.; Ducharne, A.

    2015-12-01

    Groundwater contributes approximately 40% of global freshwater use, and it is critical for water supply and associated food production in arid or semi-arid areas during dry seasons. The increasing demand for water and finite water sources have led to long-term groundwater depletion, creating an obstacle to sustainability in several regions of the world under the pressures of population growth and climate change. The High Plains Aquifer System has an area of 450,000 km2, and is the most pumped aquifer and one of the most important agricultural areas in the United States. In this study, we use coupled climate-hydrological model simulations from the NCAR Community Earth System Model Large Ensemble Project to investigate the groundwater storage changes in the High Plains Aquifer under future climate changes and also to explore how such groundwater storage changes might in turn affect the climate through land-atmosphere coupling. Preliminary results indicate that not only the amount of groundwater recharge declines, but the seasonal variations of groundwater recharge also become smaller, resulting in widespread water table decline in a future warmer climate. We will explore how such variations associate to projected changes in precipitation and evapotranspiration, and feedback to the climate.

  20. Model analysis of the impact on ground-water conditions of the Muskegon County wastewater disposal system, Michigan

    USGS Publications Warehouse

    McDonald, Michael G.; Fleck, William B.

    1978-01-01

    A digital model was developed to study the impact on ground-water conditions of the Muskegon County, Mich., wastewater disposal system. At the disposal site, wastewater is stored in two 850-acre lagoons and then spray-irrigated on crop land. About 70 miles of drainage tile, which underlies the irrigated land, has caused the water table to be lowered substantially. The decline in water levels has been partially offset by irrigation and leakage from the lagoons; at some places the water table is higher than it was prior to construction. Predictive simulations by the model were used to study the effects of varying tile drainage, amount of irrigation water applied, lagoon leakage, and natural ground-water recharge. If the effectiveness of the tile to collect drainage is reduced by 75 percent, large areas within the wastewater site would become waterlogged. However, the effect outside of the wastewater site would be negligible. (Woodard-USGS)

  1. Assessing the Life Cycle Impact of Four Groundwater Remediation Technologies: P&T, EIB, PRB, and ISM

    NASA Astrophysics Data System (ADS)

    Hou, D.; Al-Tabbaa, A.

    2012-12-01

    As sustainable remediation draws attention from both industry and academia, there is growing interest in evaluating the environmental sustainability of various environmental remediation technologies. This study aims at assessing four groundwater remediation technologies from a life cycle impact perspective: pump and treat (P&T), enhanced in-situ bioremediation (EIB), permeable reactive barrier (PRB), and in-situ soil mixing (ISM). The technologies were compared under a variety of scenarios, with site location, plume dimension, hydrology, and chemistry and geochemistry parameters changing in a wide range. This life cycle assessment (LCA) has chosen chlorinated ethylene as the study subject because chlorinated solvents are the most prevalent organic contaminants in soil and groundwater. The USEPA TRACI method was used in the life cycle impact assessment (LCIA). A multi-criteria decision analysis (MCDA) score is used to rank the four remediation technologies. The assessment results indicated that P&T tended to have the highest life cycle impact under most scenarios. The other three technologies can all be the most desired technology (with lowest life cycle impact), under different distributional, hydrogeological, and chemical conditions: PRB was the most desired when treatment zone was long, hydraulic gradient or hydraulic conductivity was low, or contaminants degraded fast in the reactive media; ISM became the most desirable when hydraulic gradient or hydraulic conductivity was very high; and EIB was most desirable under most other conditions.

  2. Assessment of different doses of N applied to a melon crop in the quality of groundwater: environmental impact indexes.

    NASA Astrophysics Data System (ADS)

    Castellanos, M. T.; Cartagena, M. C.; Ribas, F.; Cabello, M. J.; Arce, A.; Tarquis, A. M.

    2010-05-01

    Provided that the intensive use of N in agricultural systems has negatively impacted environmental quality, because a higher fertilization requirements of the crop to make the nitrate leached into the aquifer contaminating, as well as increasing their presence on the ground resulting in a time of intercropping nitrates washing with the arrival of rains. It's necessary to know the N management to reduce the pollution risks and may lead the higher production with the fewer economic cost, environmental and health. The aim of this study was to asses how different doses of nitrogen applied to a melon crop affected the quality of groundwater. The doses of N applied ranged between 11 and 393 kg ha-1. Several indexes, based in N leaching consequence of the agricultural practice, were calculated and provided an essential tool for knowing the risks of groundwater pollution with the practices used. Drinking water impact, irrigation water management impact and environmental impact indexes were obtained during four years in a vulnerable area of the centre of Spain. Acknowledgements: This project has been supported by INIA-RTA04-111

  3. Evaluation of the impact of fuel hydrocarbons and oxygenates on groundwater resources.

    PubMed

    Shih, Tom; Rong, Yue; Harmon, Thomas; Suffet, Mel

    2004-01-01

    The environmental behavior of fuel oxygenates (other than methyl tert-butyl ether [MTBE]) is poorly understood because few data have been systematically collected and analyzed. This study evaluated the potential for groundwater resource contamination by fuel hydrocarbons (FHCs) and oxygenates (e.g., tert-butyl alcohol [TBA], tertamyl methyl ether [TAME], diisopropyl ether [DIPE], ethyl tert-butyl ether [ETBE], and MTBE) by examining their occurrence, distribution, and spatial extent in groundwater beneath leaking underground fuel tank (LUFT) facilities, focusing on data collected from over 7200 monitoring wells in 868 LUFT sites from the greater Los Angeles, CA, region. Excluding the composite measure total petroleum hydrocarbons as gasoline (TPHG), TBA has the greatestsite maximum (geometric mean) groundwater concentration among the study analytes; therefore, its presence needs to be confirmed at LUFT sites so that specific cleanup strategies can be developed. The alternative ether oxygenates (DIPE, TAME, and ETBE) are less likely to be detected in groundwater beneath LUFT facilities in the area of California studied and when detected are present at lower dissolved concentrations than MTBE, benzene, or TBA. Groundwater plume length was used as an initial indicator of the threat of contamination to drinking water resources. Approximately 500 LUFT sites were randomly selected and analyzed. The results demonstrate MTBE to pose the greatest problem, followed by TBA and benzene. The alternative ether oxygenates were relatively localized and indicated lesser potential for groundwater resource contamination. However, all indications suggest the alternative ether oxygenates would pose groundwater contamination threats similar to MTBE if their scale of usage is expanded. Plume length data suggest that in the absence of a completely new design and construction of the underground storage tank (UST) system, an effective management strategy may involve placing greater emphasis

  4. The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines

    USGS Publications Warehouse

    Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, A.; Bullen, T.D.; Mayer, B.; Polak, A.; Shavit, U.

    2007-01-01

    The chemical composition of groundwater in the Jordan Valley, along the section between the Sea of Galilee and the Dead Sea, is investigated in order to evaluate the origin of the groundwater resources and, in particular, to elucidate the role of deep brines on the chemical composition of the regional groundwater resources in the Jordan Valley. Samples were collected from shallow groundwater in research boreholes on two sites in the northern and southern parts of the Jordan Valley, adjacent to the Jordan River. Data is also compiled from previous published studies. Geochemical data (e.g., Br/Cl, Na/Cl and SO4/Cl ratios) and B, O, Sr and S isotopic compositions are used to define groundwater groups, to map their distribution in the Jordan valley, and to evaluate their origin. The combined geochemical tools enabled the delineation of three major sources of solutes that differentially affect the quality of groundwater in the Jordan Valley: (1) flow and mixing with hypersaline brines with high Br/Cl (>2 ?? 10-3) and low Na/Cl (<0.8) ratios; (2) dissolution of highly soluble salts (e.g., halite, gypsum) in the host sediments resulting in typically lower Br/Cl signal (<2 ?? 10-3); and (3) recharge of anthropogenic effluents, primarily derived from evaporated agricultural return flow that has interacted (e.g., base-exchange reactions) with the overlying soil. It is shown that shallow saline groundwaters influenced by brine mixing exhibit a north-south variation in their Br/Cl and Na/Cl ratios. This chemical trend was observed also in hypersaline brines in the Jordan valley, which suggests a local mixing process between the water bodies. ?? 2007 Elsevier Ltd. All rights reserved.

  5. Labile Organic Carbon in Recharge and its Impact on Groundwater Arsenic Concentrations in Bangladesh

    NASA Astrophysics Data System (ADS)

    Neumann, R. B.; Ashfaque, K. N.; Badruzzaman, A. M.; Ali, M.; Shoemaker, J. K.; Harvey, C. F.

    2009-12-01

    Researchers have puzzled over the origin of dissolved arsenic in the aquifers of the Ganges Delta since widespread arsenic poisoning from groundwater was publicized two decades ago. Previous work has concluded that biological oxidation of organic carbon drives geochemical transformations that mobilize arsenic from sediments; however, the source of the organic carbon that fuels these processes remains controversial. A combined hydrologic and biogeochemical analysis of a typical site in Bangladesh, where constructed ponds and groundwater-irrigated rice fields are the main sources of recharge, shows that only recharge through pond sediments provides the biologically degradable organic carbon that can drive arsenic mobilization. Numerical groundwater simulations as well as chemical and isotopic indicators suggest that contaminated groundwater originates from excavated ponds and that water originating from rice fields is low in arsenic. In fact, rice fields act as an arsenic sink. Irrigation moves arsenic-rich groundwater from the aquifers and deposits it on the rice fields. Most of the deposited arsenic does not return to the aquifers; it is sorbed by the field’s surface soil and bunds, and is swept away in the monsoon floods. The findings indicate that patterns of arsenic contamination in the shallow aquifer are due to recharge-source variation and complex three-dimensional flow.

  6. Impacts of thickening unsaturated zone on groundwater recharge in the North China Plain

    NASA Astrophysics Data System (ADS)

    Cao, Guoliang; Scanlon, Bridget R.; Han, Dongmei; Zheng, Chunmiao

    2016-06-01

    Unsustainable groundwater development shown by rapid groundwater depletion in the North China Plain (NCP) underscores the need to quantify spatiotemporal variability in groundwater recharge for improved management of the resource. The objective of this study was to assess spatiotemporal variability in recharge in response to thickening of the unsaturated zone in the NCP. Recharge was estimated by linking a soil water balance (SWB) model, on the basis of monthly meteorological data, irrigation applications, and soil moisture monitoring data (1993-2008), to the water table using a deep unsaturated zone flow model. The dynamic bottom boundary (water table) position was provided by the saturated zone flow component, which simulates regional pumping. The model results clearly indicate the effects of unsaturated zone thickening on both temporal distribution and magnitude of recharge: smoothing temporal variability in recharge, and increasing unsaturated storage and lag time between percolation and recharge. The thickening unsaturated zone can result in average recharge reduction of up to ∼70% in loam soils with water table declines ⩾30 m. Declining groundwater levels with irrigation sourced by groundwater converts percolation to unsaturated zone storage, averaging 14 mm equivalent water depth per year in mostly loam soil over the study period, accounting for ∼30% of the saturated groundwater storage depletion. This study demonstrates that, in thickening unsaturated zones, modeling approaches that directly equate deep drainage with recharge will overestimate the amount and underestimate the time lag between percolation and recharge, emphasizing the importance of more realistic simulation of the continuity of unsaturated and saturated storage to provide more reliable estimates of spatiotemporal variability in recharge.

  7. Impact of artificial recharge and drought in Tafilalet Oasis system: First investigation by GIS and groundwater modeling

    NASA Astrophysics Data System (ADS)

    Bouaamlat, I.; Larabi, A.; Faouzi, M.

    2013-12-01

    The geographical location of Tafilalet oasis system (TOS) in the south of the valley of Ziz (Morocco) offers him a particular advantage on the plane of water potential. The surface water which comes from humid regions of the High Atlas and intercepted by a dam then converged through the watercourse of Ziz towards the plain of the TOS, have created the conditions for the formation of a water table relatively rich with regard to the local climatic conditions (arid climate with recurrent drought). Because of this situation, the region has one of the largest palms of North Africa. Thus there is an agricultural activity that is practiced in a 21 irrigation areas whose size rarely exceeds 2,000 hectare. Given the role of the water table in the economic development of the region, a hydrogeological study was conducted to understand the impact of artificial recharge and recurrent droughts on the development of the groundwater reserves of TOS. In this study, a three-dimensional model of groundwater flow was developed for the Tafilalet oasis system aquifer, to assist the decision makers as a "management tool" in order to assess alternative schemes for development and exploitation of groundwater resources based on the variation of artificial recharge and drought, using for the first time the Modflow code. This study takes into account the most possible real hydrogeological conditions and using the geographical information system (GIS) for the organisation and treatment of data and applying a multidisciplinary approach combining geostatistical and hydrogeological modeling. The results from this numerical investigation of the TOS aquifer shows that the commissioning of the dam to control the flows of extreme flood and good management of water releases, has avoided the losses of irrigation water and consequently the non-overexploitation of the groundwater. So that with one or two water releases per year from the dam of flow rate more than 14 million m3/year it is possible to

  8. Impact of fertilizer application and urban wastes on the quality of groundwater in the Cambrai Chalk aquifer, Northern France

    NASA Astrophysics Data System (ADS)

    Serhal, Hani; Bernard, Daniel; Khattabi, Jamal El; Sabine, Bastin-Lacherez; Shahrour, Isam

    2009-06-01

    Since 1975, Europe sets up its policy to limit the degradation and the pollution of the aquatic environments through 30 directives and regulations. In the north of France, the nitrate concentrations measured in the groundwater exceed the water drinking limit fixed at 50 mg/L by the European framework directive in the field of water (2000/60/EC). This high concentration is due to intensive agriculture, industrialization and demographic growth. Several programs were launched in order to resolve this situation: “Ferti-better” or the use of fertilizer in moderation and installation and amelioration of wastewater collect and treatment systems. In order to estimate the influence of the anthropic activities on the quality of groundwater in the “Artois-Picardy” basin, a preliminary validation on parcel and district scale were necessary. The impact of these programs in the “Cambrai district” was evaluated using an integrated approach, which is based on the use of four numerical models: AgriFlux, VS2DT, Modflow and MT3D. The results illustrate an improvement due to the “Ferti-Better” program initiated in 1990 and punctual degradation under urbanized areas. Predictions (2015) show a spatial evolution of nitrates concentration varying with the thickness of unsaturated layer. The integrated model constitutes an efficient tool for predicting the evolution of the groundwater quality. This approach is important to control the application of the new European laws in the water field.

  9. Land application of domestic wastewater in Florida--statewide assessment of impact on ground-water quality

    USGS Publications Warehouse

    Franks, Bernard J.

    1981-01-01

    In Florida domestic waste water is being applied to the land for disposal and reuse. State and Federal regulations favor land-application methods over other advanced waste water treatment practices. Despite the increasing use of this alternative technology, little is known about localized effects on groundwater quality. This report documents the extent of land-application practices in Florida and summarizes case study information on some of the more adequately monitored site throughout the State. More than 2,500 sites in Florida are permitted by the Department of Environmental Regulation for applying domestic waste water to the land. The majority (more than 1,700 sites), classified as infiltration ponds, are concentrated in central and southern Florida. More than 560 sites classified as drainfields, and more than 250 sites classified as irrigation sites, are located primarily in central Florida. An estimated 150 million gallons per day of domestic waste water, after required secondary treatment, are applied to Florida soils. Despite the large numbers of sites and the considerable volume of waste water utilized, little is known about potential impact on groundwater quality. At the few sites where observation wells have been drilled and local groundwater quality monitored, no significant deterioration of water quality has been detected. (USGS)

  10. Thermal and visible remote sensing for estimation of evapotranspiration of rainfed agrosystems and its impact on groundwater in SE Australia

    NASA Astrophysics Data System (ADS)

    Roohi, Rakhshan; Webb, John A.

    2016-05-01

    Rainfed agrosystems are important components of the world's food production system and account for 65-95% of total agriculture. In contrast to irrigated production systems, relatively little attention has been paid to understanding the hydrological interactions between the components of rainfed agrosystems and their impact on water resources, especially groundwater. A new model, the Surface Energy Balance Algorithm for Rainfed Agriculture (SEBARA), has been developed to estimate the spatial pattern of evapotranspiration in these agrosystems using satellite images (thermal, infrared and visible spectra). The model was calibrated for two competing land uses (Eucalyptus globules tree plantations and pastures) in adjacent catchments in western Victoria, southeastern Australia. Using measurements from a flux tower in the pasture catchment and adjusted sapflow measurements in the plantation catchment, an estimation accuracy of 95% was achieved. The tree plantations had higher available net radiation, lower soil heat flux and higher latent heat flux, resulting in 15-20% higher evapotranspirative demand than the pasture, depending upon the age and canopy of plantations. The evapotranspiration rate of plantations declines where groundwater depth is >12m or where shallow groundwater is saline. The shallow root system of the pasture means that it relies solely on soil moisture to meet its water requirements and thus has lower evapotranspiration, which varies according to the pasture species.

  11. Assessing the impacts of future demand for saline groundwater on commercial deployment of CCS in the United States

    SciTech Connect

    Davidson, Casie L.; Dooley, James J.; Dahowski, Robert T.

    2009-04-20

    This paper provides a preliminary assessment of the potential impact that future demand for groundwater might have on the commercial deployment of carbon dioxide capture and storage (CCS) technologies within the United States. A number of regions within the U.S. have populations, agriculture and industries that are particularly dependent upon groundwater. Moreover, some key freshwater aquifers are already over-utilized or depleted, and others are likely to be moving toward depletion as demand grows. The need to meet future water demands may lead some parts of the nation to consider supplementing existing supplies with lower quality groundwater resources, including brackish waters that are currently not considered sources of drinking water but which could provide supplemental water via desalination. In some areas, these same deep saline-filled geologic formations also represent possible candidate carbon dioxide (CO2) storage reservoirs. The analysis presented here suggests that future constraints on CCS deployment due to potential needs to supplement conventional water supplies by desalinating deeper and more brackish waters are likely to be necessary only in limited regions across the country, particularly in areas that are already experiencing water stress.

  12. Impact of agriculture and land use on nitrate contamination in groundwater and running waters in central-west Poland.

    PubMed

    Lawniczak, Agnieszka Ewa; Zbierska, Janina; Nowak, Bogumił; Achtenberg, Krzysztof; Grześkowiak, Artur; Kanas, Krzysztof

    2016-03-01

    Protected areas due to their long-term protection are expected to be characterized by good water quality. However, in catchments where arable fields dominate, the impact of agriculture on water pollution is still problematic. In Poland, recently, the fertilization level has decreased, mostly for economic reasons. However, this applies primarily to phosphorus and potassium. In order to evaluate the impact of agriculture on water quality in a protected area with a high proportion of arable fields in the aspect of level and type of fertilization, complex monitoring has been applied. The present study was carried out in Wielkopolska National Park and its buffer zone, which are protected under Natura 2000 as Special Areas of Conservation and Special Protection Areas. The aim of the study were (1) to assess the impact of agriculture, with special attention on fertilization, on groundwater, and running water quality and (2) to designate priority areas for implementing nitrogen reduction measures in special attention on protected areas. In our study, high nitrogen concentrations in groundwater and surface waters were detected in the agricultural catchments. The results demonstrate that in the watersheds dominated by arable fields, high nitrogen concentrations in groundwater were measured in comparison to forestry catchments, where high ammonium concentrations were observed. The highest nitrogen concentrations were noted in spring after winter freezing, with a small cover of vegetation, and in the areas with a high level of nitrogen application. In the studied areas, both in the park and its buffer zone, unfavorable N:P and N:K ratios in supplied nutrients were detected. Severe shortage of phosphorus and potassium in applied fertilizers is one of the major factors causing leaching of nitrogen due to limited possibilities of its consumption by plants. PMID:26887311

  13. Impact of agriculture and land use on nitrate contamination in groundwater and running waters in central-west Poland.

    PubMed

    Lawniczak, Agnieszka Ewa; Zbierska, Janina; Nowak, Bogumił; Achtenberg, Krzysztof; Grześkowiak, Artur; Kanas, Krzysztof

    2016-03-01

    Protected areas due to their long-term protection are expected to be characterized by good water quality. However, in catchments where arable fields dominate, the impact of agriculture on water pollution is still problematic. In Poland, recently, the fertilization level has decreased, mostly for economic reasons. However, this applies primarily to phosphorus and potassium. In order to evaluate the impact of agriculture on water quality in a protected area with a high proportion of arable fields in the aspect of level and type of fertilization, complex monitoring has been applied. The present study was carried out in Wielkopolska National Park and its buffer zone, which are protected under Natura 2000 as Special Areas of Conservation and Special Protection Areas. The aim of the study were (1) to assess the impact of agriculture, with special attention on fertilization, on groundwater, and running water quality and (2) to designate priority areas for implementing nitrogen reduction measures in special attention on protected areas. In our study, high nitrogen concentrations in groundwater and surface waters were detected in the agricultural catchments. The results demonstrate that in the watersheds dominated by arable fields, high nitrogen concentrations in groundwater were measured in comparison to forestry catchments, where high ammonium concentrations were observed. The highest nitrogen concentrations were noted in spring after winter freezing, with a small cover of vegetation, and in the areas with a high level of nitrogen application. In the studied areas, both in the park and its buffer zone, unfavorable N:P and N:K ratios in supplied nutrients were detected. Severe shortage of phosphorus and potassium in applied fertilizers is one of the major factors causing leaching of nitrogen due to limited possibilities of its consumption by plants.

  14. Impact of fresh tailing deposition on the evolution of groundwater hydrogeochemistry at the abandoned Manitou mine site, Quebec, Canada.

    PubMed

    Maqsoud, Abdelkabir; Neculita, Carmen Mihaela; Bussière, Bruno; Benzaazoua, Mostafa; Dionne, Jean

    2016-05-01

    The abandoned Manitou mine site has produced acid mine drainage (AMD) for several decades. In order to limit the detrimental environmental impacts of AMD, different rehabilitation scenarios were proposed and analyzed. The selected rehabilitation scenario was to use fresh tailings from the neighboring Goldex gold mine as monolayer cover and to maintain an elevated water table. In order to assess the impact of the Goldex tailing deposition on the hydrogeochemistry of the Manitou mine site, a network of 30 piezometers was installed. These piezometers were used for continuous measurement of the groundwater level, as well as for water sampling campaigns for chemical quality monitoring, over a 3-year period. Hydrochemical data were analyzed using principal component analysis. Results clearly showed the benefic impact of fresh tailing deposition on the groundwater quality around the contaminated area. These findings were also confirmed by the evolution of electrical conductivity. In addition to the improvement of the physicochemical quality of water on the Manitou mine site, new tailing deposition induced an increase of water table level. However, at this time, the Manitou reactive tailings are not completely submerged and possible oxidation might still occur, especially after ceasing of the fresh tailing deposition. Therefore, complementary rehabilitation scenarios should still be considered. PMID:26832863

  15. Climate impacts on groundwater storage, hydrochemistry and residence time in geologically variable, snowmelt-dominated mountain catchments, Front Range, Colorado

    NASA Astrophysics Data System (ADS)

    Zeliff, M. M.; Williams, M. W.

    2012-12-01

    series plots of calcium (Ca2+), a predominately rock-derived solute, show annual minimum concentrations in early August, approximately two full months beyond final snowpack melt-out dates at the Saddle snowpit site. Nitrate (NO3-) has peak concentrations in June-July during snowmelt and also in winter months (November-March) perhaps due to the cessation of biological uptake of nitrogen. Time series plots of stable isotopes of water show a significant (p ≤ 0.05) isotopic depletion in groundwater at deep piezometers at the Saddle between 2006 and 2011 from a mean δ18O value of -15.64 ‰ (n = 38) to -16.05 ‰ (n = 74) but not in other locations. This trend may reflect the greater influence of snow over the study period which was characterized by successively increasing snow deposition since a major drought in 2002. These results indicate that climate has a large impact on the water table and water quality of groundwater in high elevation catchments.

  16. Transient Inverse Calibration of Hanford Site-Wide Groundwater Model to Hanford Operational Impacts - 1943 to 1996

    SciTech Connect

    Cole, Charles R.; Bergeron, Marcel P.; Wurstner, Signe K.; Thorne, Paul D.; Orr, Samuel; Mckinley, Mathew I.

    2001-05-31

    This report describes a new initiative to strengthen the technical defensibility of predictions made with the Hanford site-wide groundwater flow and transport model. The focus is on characterizing major uncertainties in the current model. PNNL will develop and implement a calibration approach and methodology that can be used to evaluate alternative conceptual models of the Hanford aquifer system. The calibration process will involve a three-dimensional transient inverse calibration of each numerical model to historical observations of hydraulic and water quality impacts to the unconfined aquifer system from Hanford operations since the mid-1940s.

  17. APPLICATION STRATEGIES AND DESIGN CRITERIA FOR IN SITU BIOREMEDIATION OF SOIL AND GROUNDWATER IMPACTED BY PAHS

    EPA Science Inventory

    Biotreatability studies conducted in our laboratory used soils from two former wood-treatment facilities to evaluate the use of in situ bioventing and biosparging applications for their potential ability to remediate soil and groundwater containing creosote. The combination of ph...

  18. Developing Rapid and Cost-Effective Tools for Assessing Groundwater Impacts on Contaminated Sediments

    EPA Science Inventory

    This research developed quick and inexpensive methods that can be useful in characterizing the interaction of water and solids within the GW/SW transition zone to explain processes that occur during physical contact between groundwater and sediments. The research used self-conta...

  19. Impacts of urbanization on groundwater hydrodynamics and hydrochemistry of the Toluca Valley aquifer (Mexico).

    PubMed

    Martín Del Campo, M A; Esteller, M V; Expósito, J L; Hirata, R

    2014-05-01

    The Toluca Valley is located on the high plains of Mexico, where there are significant industrial zones and large populations. Water needs are almost exclusively met by groundwater, which has brought about intense exploitation of the aquifer and indication of some contamination. The present study investigates the effect of urbanization, related to industrialization of the region, on groundwater in the central portion of the Toluca Valley aquifer--a zone with high population density and where the largest industrial park is located. A general decline in the groundwater level has been found over the years, at a rate of as much as 2.5 m/year. The appearance of a large drawdown cone was identified, indicating changes in the direction of groundwater flow. Also identified was the presence of several ground fissures, the location of which coincided with the drawdown cone. In hydrochemical terms, the water type is sodium-magnesium bicarbonate and this characteristic has not changed over time, although it has been possible to detect the presence of larger quantities of sulfates (up to 117 mg/L) and nitrates (up to 47 mg/L) in recent years, likely associated with contamination from industrial and urban wastewater. Factor analysis made it possible to identify ions that would characterize natural processes involving the acquisition of salts (HCO3 (-), Na(+), Mg(2+), and Si), as well as anthropic activities (SO4 (2-), NO3 (-), Cl(-), Ca(2+), and K(+)).

  20. Sea level periodic change and its impact on submarine groundwater discharge rate in coastal aquifer

    NASA Astrophysics Data System (ADS)

    Lee, Eunhee; Hyun, Yunjung; Lee, Kang-Kun

    2013-04-01

    This study focused on the interaction between groundwater and seawater and the effect of temporal scale of sea level fluctuation on submarine groundwater discharge (SGD) rate. The numerical code FEFLOW (Diersch, 2005) was used to evaluate the influence of periodic changes in sea level on an increase in SGD at various time scales from diurnal to glacial cycles. Simulation results showed that not only amplitude but also period of the sea level fluctuation controls total amount of SGD. The increase ratio of recirculated submarine groundwater discharge (RSGD) was found to generally be proportional to the amplitude of sea level and the square root of specific storage of an aquifer while inversely proportional to the square root of hydraulic conductivity of an aquifer and period of sea level fluctuation. A nondimensional number P∗ that incorporates combined effect of sea level oscillation and aquifer properties is used to represent the magnitude of periodic forcing from sea boundary into an aquifer as a mechanism for enhancement of RSGD. Simulation results demonstrate that increase ratios of RSGD are well fitted by an exponential curve as a function of P∗, and variations in RSGD occur only when P∗ exceeds a critical number. The dimensionless inland recharge rate, where recharge rate is divided by hydraulic conductivity, was shown to be important in determining the critical number. This implies that sea level fluctuation does not lead to enhancement of RSGD until the specified condition is reached, and groundwater recharge rate and aquifer hydraulic conductivity are the key factors controlling the increase of RSGD.

  1. A Review of Climate Change and Societal Impacts on Groundwater: Implications for a UNESCO Initiative

    NASA Astrophysics Data System (ADS)

    Taniguchi, M.; Green, T. R.; Aureli, A.

    2004-12-01

    Global change issues have gained widespread interests, but hydrologic studies of the effects have been largely limited to surface and very near-surface processes. Global climate change/variability and human activities may also have pronounced effects on groundwater systems, including groundwater storage and fluxes (recharge and discharge rates). A new initiative in collaboration with the UNESCO International Hydrological Programme (IHP) will address various subjects (groundwater fluxes, storage, and quality), methods (simulation, data analysis, remote sensing, and paleo-reconstruction), and regions of the world. The aim is to investigate a range of high-priority research areas, including: 1) spatial and temporal scaling issues; 2) quantitative plant physiology and succession for environmental stress responses; 3) hydrological boundary conditions, including sea-level and snow-pack changes; 4) coupled atmospheric-hydrologic-oceanographic processes and their feedbacks; and 5) feedbacks associated with societal adjustments in land/water resource management. In this presentation, we review published and ongoing investigations in these areas to identify knowledge gaps and potential for collaborative research under the umbrella of a proposed international project on Groundwater Resources Assessments under the Pressures of Humanity and Climate change (GRAPHiC).

  2. Impacts of Agriculture on Nitrates in Soil and Groundwater in the Southeastern Coastal Plain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) contamination of surface and groundwater is a health concern for both humans and animals. Excess N in surface water bodies may contribute to eutrophication. Elevated nitrate (NO3-N) concentrations in drinking water have caused infant death from the disease methemoglobinemia. Nitrates...

  3. Impacts of adverse childhood experiences on health, mental health, and substance use in early adulthood: A cohort study of an urban, minority sample in the U.S.

    PubMed Central

    Topitzes, J.; Reynolds, A.J.

    2014-01-01

    Research has shown that adverse childhood experiences (ACEs) increase the risk of poor health-related outcomes in later life. Less is known about the consequences of ACEs in early adulthood or among diverse samples. Therefore, we investigated the impacts of differential exposure to ACEs on an urban, minority sample of young adults. Health, mental health, and substance use outcomes were examined alone and in aggregate. Potential moderating effects of sex were also explored. Data were derived from the Chicago Longitudinal Study, a panel investigation of individuals who were born in 1979 or 1980. Main-effect analyses were conducted with multivariate logistic and OLS regression. Sex differences were explored with stratified analysis, followed by tests of interaction effects with the full sample. Results confirmed that there was a robust association between ACEs and poor outcomes in early adulthood. Greater levels of adversity were associated with poorer self-rated health and life satisfaction, as well as more frequent depressive symptoms, anxiety, tobacco use, alcohol use, and marijuana use. Cumulative adversity also was associated with cumulative effects across domains. For instance, compared to individuals without an ACE, individuals exposed to multiple ACEs were more likely to have three or more poor outcomes (OR range = 2.75–10.15) and four or more poor outcomes (OR range = 3.93–15.18). No significant differences between males and females were detected. Given that the consequences of ACEs in early adulthood may lead to later morbidity and mortality, increased investment in programs and policies that prevent ACEs and ameliorate their impacts is warranted. PMID:23978575

  4. Impacts of adverse childhood experiences on health, mental health, and substance use in early adulthood: a cohort study of an urban, minority sample in the U.S.

    PubMed

    Mersky, J P; Topitzes, J; Reynolds, A J

    2013-11-01

    Research has shown that adverse childhood experiences (ACEs) increase the risk of poor health-related outcomes in later life. Less is known about the consequences of ACEs in early adulthood or among diverse samples. Therefore, we investigated the impacts of differential exposure to ACEs on an urban, minority sample of young adults. Health, mental health, and substance use outcomes were examined alone and in aggregate. Potential moderating effects of sex were also explored. Data were derived from the Chicago Longitudinal Study, a panel investigation of individuals who were born in 1979 or 1980. Main-effect analyses were conducted with multivariate logistic and OLS regression. Sex differences were explored with stratified analysis, followed by tests of interaction effects with the full sample. Results confirmed that there was a robust association between ACEs and poor outcomes in early adulthood. Greater levels of adversity were associated with poorer self-rated health and life satisfaction, as well as more frequent depressive symptoms, anxiety, tobacco use, alcohol use, and marijuana use. Cumulative adversity also was associated with cumulative effects across domains. For instance, compared to individuals without an ACE, individuals exposed to multiple ACEs were more likely to have three or more poor outcomes (OR range=2.75-10.15) and four or more poor outcomes (OR range=3.93-15.18). No significant differences between males and females were detected. Given that the consequences of ACEs in early adulthood may lead to later morbidity and mortality, increased investment in programs and policies that prevent ACEs and ameliorate their impacts is warranted.

  5. The impact of point source pollution on shallow groundwater used for human consumption in a threshold country.

    PubMed

    Cruz, Mercedes Cecilia; Cacciabue, Dolores Gutiérrez; Gil, José F; Gamboni, Oscar; Vicente, María Soledad; Wuertz, Stefan; Gonzo, Elio; Rajal, Verónica B

    2012-09-01

    Many developing and threshold countries rely on shallow groundwater wells for their water supply whilst pit latrines are used for sanitation. We employed a unified strategy involving satellite images and environmental monitoring of 16 physico-chemical and microbiological water quality parameters to identify significant land uses that can lead to unacceptable deterioration of source water, in a region with a subtropical climate and seasonally restricted torrential rainfall in Northern Argentina. Agricultural and non-agricultural sources of nitrate were illustrated in satellite images and used to assess the organic load discharged. The estimated human organic load per year was 28.5 BOD(5) tons and the N load was 7.5 tons, while for poultry farms it was 9940-BOD(5) tons and 1037-N tons, respectively. Concentrations of nitrates and organics were significantly different between seasons in well water (p values of 0.026 and 0.039, respectively). The onset of the wet season had an extraordinarily negative impact on well water due in part to the high permeability of soils made up of fine gravels and coarse sand. Discriminant analysis showed that land uses had a pronounced seasonal influence on nitrates and introduced additional microbial contamination, causing nitrification and denitrification in shallow groundwater. P-well was highly impacted by a poultry farm while S-well was affected by anthropogenic pollution and background load, as revealed by Principal Component Analysis. The application of microbial source tracking techniques is recommended to corroborate local sources of human versus animal origin.

  6. Identifying Impacts of Hydropower Regulation on Salmonid Habitats to Guide River Restoration for Existing Schemes and Mitigate Adverse Effects of Future Developments

    NASA Astrophysics Data System (ADS)

    Buddendorf, B.; Geris, J.; Malcolm, I.; Wilkinson, M.; Soulsby, C.

    2015-12-01

    A decrease in longitudinal connectivity in riverine ecosystems resulting from the construction of transverse barriers has been identified as a major threat to biodiversity. For example, Atlantic Salmon (Salmo salar) have a seasonal variety of hydraulic habitat requirements for their different life stages. However, hydropower impoundments impact the spatial and temporal connectivity of natural habitat along many salmon rivers in ways that are not fully understood. Yet, these changes may affect the sustainability of habitat at local and regional scales and so ultimately the conservation of the species. Research is therefore needed both to aid the restoration and management of rivers impacted by previous hydropower development and guide new schemes to mitigate potentially adverse effects. To this end we assessed the effects of hydropower development on the flow related habitat conditions for different salmon life stages in Scottish rivers at different spatial scales. We used GIS techniques to map the changes in structural connectivity at regional scales, applying a weighting for habitat quality. Next, we used hydrological models to simulate past and present hydrologic conditions that in turn drive reach-scale hydraulic models to assess the impacts of regulation on habitat suitability in both space and time. Preliminary results indicate that: 1) impacts on connectivity depend on the location of the barrier within the river network; 2) multiple smaller barriers may have a potentially lower impact than a single larger barrier; 3) there is a relationship between habitat and connectivity where losing less but more suitable habitat potentially has a disproportionally large impact; 4) the impact of flow regulation can lead to a deterioration of habitat quality, though the effects are spatially variable and the extent of the impact depends on salmon life stage. This work can form a basis for using natural processes to perform targeted and cost-effective restoration of rivers.

  7. Impact of variable river water stage on the simulation of groundwater-river interactions over the Upper Rhine Graben hydrosystem

    NASA Astrophysics Data System (ADS)

    Habets, F.; Vergnes, J.

    2013-12-01

    The Upper Rhine alluvial aquifer is an important transboundary water resource which is particularly vulnerable to pollution from the rivers due to anthropogenic activities. A realistic simulation of the groundwater-river exchanges is therefore of crucial importance for effective management of water resources, and hence is the main topic of the NAPROM project financed by the French Ministry of Ecology. Characterization of these fluxes in term of quantity and spatio-temporal variability depends on the choice made to represent the river water stage in the model. Recently, a couple surface-subsurface model has been applied to the whole aquifer basin. The river stage was first chosen to be constant over the major part of the basin for the computation of the groundwater-river interactions. The present study aims to introduce a variable river water stage to better simulate these interactions and to quantify the impact of this process over the simulated hydrological variables. The general modeling strategy is based on the Eau-Dyssée modeling platform which couples existing specialized models to address water resources and quality in regional scale river basins. In this study, Eau-Dyssée includes the RAPID river routing model and the SAM hydrogeological model. The input data consist in runoff and infiltration coming from a simulation of the ISBA land surface scheme covering the 1986-2003 period. The QtoZ module allows to calculate river stage from simulated river discharges, which is then used to calculate the exchanges between aquifer units and river. Two approaches are compared. The first one uses rating curves derived from observed river discharges and river stages. The second one is based on the Manning's formula. Manning's parameters are defined with geomorphological parametrizations and topographic data based on Digital Elevation Model (DEM). First results show a relatively good agreement between observed and simulated river water height. Taking into account a

  8. Impact of leachate on groundwater pollution due to non-engineered municipal solid waste landfill sites of erode city, Tamil Nadu, India.

    PubMed

    Nagarajan, Rajkumar; Thirumalaisamy, Subramani; Lakshumanan, Elango

    2012-01-01

    Leachate and groundwater samples were collected from Vendipalayam, Semur and Vairapalayam landfill sites in Erode city, Tamil Nadu, India, to study the possible impact of leachate percolation on groundwater quality. Concentrations of various physicochemical parameters including heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Fe and Zn) were determined in leachate samples and are reported. The concentrations of Cl-, NO3-, SO42-, NH4+ were found to be in considerable levels in the groundwater samples particularly near to the landfill sites, likely indicating that groundwater quality is being significantly affected by leachate percolation. Further they were proved to be the tracers for groundwater contamination near Semur and Vendipalayam dumpyards. The presence of contaminants in groundwater particularly near the landfill sites warns its quality and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures are suggested to reduce further groundwater contamination via leachate percolation, the present study demands for the proper management of waste in Erode city.

  9. Impact assessment of on-site sanitation system on groundwater quality in alluvial settings: A case study from Lucknow city in North India.

    PubMed

    Jangam, Chandrakant; Ramya Sanam, S; Chaturvedi, M K; Padmakar, C; Pujari, Paras R; Labhasetwar, Pawan K

    2015-10-01

    The present case study has been undertaken to investigate the impact of on-site sanitation on groundwater quality in alluvial settings in Lucknow City in India. The groundwater samples have been collected in the areas of Lucknow City where the on-site sanitation systems have been implemented. The groundwater samples have been analyzed for the major physicochemical parameters and fecal coliform. The results of analysis reveal that none of the groundwater samples exceeded the Bureau of Indian Standards (BIS) limits for all the parameters. Fecal coliform was not found in majority of the samples including those samples which were very close to the septic tank. The study area has a thick alluvium cover as a top layer which acts as a natural barrier for groundwater contamination from the on-site sanitation system. The t test has been performed to assess the seasonal effect on groundwater quality. The statistical t test implies that there is a significant effect of season on groundwater quality in the study area.

  10. Impact of leachate on groundwater pollution due to non-engineered municipal solid waste landfill sites of erode city, Tamil Nadu, India

    PubMed Central

    2012-01-01

    Leachate and groundwater samples were collected from Vendipalayam, Semur and Vairapalayam landfill sites in Erode city, Tamil Nadu, India, to study the possible impact of leachate percolation on groundwater quality. Concentrations of various physicochemical parameters including heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Fe and Zn) were determined in leachate samples and are reported. The concentrations of Cl-, NO3-, SO42-, NH4+ were found to be in considerable levels in the groundwater samples particularly near to the landfill sites, likely indicating that groundwater quality is being significantly affected by leachate percolation. Further they were proved to be the tracers for groundwater contamination near Semur and Vendipalayam dumpyards. The presence of contaminants in groundwater particularly near the landfill sites warns its quality and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures are suggested to reduce further groundwater contamination via leachate percolation, the present study demands for the proper management of waste in Erode city. PMID:23369323

  11. Waste-water impacts on groundwater: Cl/Br ratios and implications for arsenic pollution of groundwater in the Bengal Basin and Red River Basin, Vietnam.

    PubMed

    McArthur, J M; Sikdar, P K; Hoque, M A; Ghosal, U

    2012-10-15

    Across West Bengal and Bangladesh, concentrations of Cl in much groundwater exceed the natural, upper limit of 10 mg/L. The Cl/Br mass ratios in groundwaters range up to 2500 and scatter along mixing lines between waste-water and dilute groundwater, with many falling near the mean end-member value for waste-water of 1561 at 126 mg/L Cl. Values of Cl/Br exceed the seawater ratio of 288 in uncommon NO(3)-bearing groundwaters, and in those containing measurable amounts of salt-corrected SO(4) (SO(4) corrected for marine salt). The data show that shallow groundwater tapped by tube-wells in the Bengal Basin has been widely contaminated by waste-water derived from pit latrines, septic tanks, and other methods of sanitary disposal, although reducing conditions in the aquifers have removed most evidence of NO(3) additions from these sources, and much evidence of their additions of SO(4). In groundwaters from wells in palaeo-channel settings, end-member modelling shows that >25% of wells yield water that comprises ≥10% of waste-water. In palaeo-interfluvial settings, only wells at the margins of the palaeo-interfluvial sequence contain detectable waste water. Settings are identifiable by well-colour survey, owner information, water composition, and drilling. Values of Cl/Br and faecal coliform counts are both inversely related to concentrations of pollutant As in groundwater, suggesting that waste-water contributions to groundwater in the near-field of septic-tanks and pit-latrines (within 30 m) suppress the mechanism of As-pollution and lessen the prevalence and severity of As pollution. In the far-field of such sources, organic matter in waste-water may increase groundwater pollution by As.

  12. Impact of the leaked CO2 from deep reservoirs on quality of shallow groundwater

    NASA Astrophysics Data System (ADS)

    Dai, Z.; Keating, E. H.; Viswanathan, H. S.; Pawar, R. J.; Bacon, D. H.; Carroll, S.

    2012-12-01

    One of the areas of concerns for geologic CO2 sequestration is the potential leakage of CO2 and brine from deeper storage reservoirs to shallow groundwater resources. This could lead to changes in shallow groundwater chemistry degrading water quality. As part of the National Risk Assessment Partnership (NRAP) for geologic CO2 sequestration project, we perform experimental and modeling studies to understand the mechanisms of the leaked CO2 and brine flow, transport and reaction with aquifer water and minerals. We have developed a 3-dimensional heterogeneous numerical model for an un-confined shallow aquifer that is being used to simulate the CO2 leakage and the associated geochemical interactions over 200 years. A Monte-Carlo analysis is performed to estimate the probability of plume sizes of the pH less than 6.5 and TDS larger than 500 ppm in the shallow aquifer. The metrics were chosen as proxies that indicate how groundwater quality is affected by leakage. The uncertain parameters in our study include five for describing geologic heterogeneity in the permeability (permeability mean, variance, integral range, anisotropic factor and porosity), one for lateral flow rate and five for defining the CO2 leakage rate in temporal and spatial domains. A global sensitivity analysis is conducted for three outputs (the amount of CO2 leaving the top of aquifer, the plume sizes of pH below 6.5 and TDS over 500 ppm). Finally, we derive one-, two- and three-dimensional response surfaces developed based on the 2000 process modeling results of CO2 and brine reactive transport models. These response surfaces have been incorporated into the system model CO2-PENS in order to calculate risk profiles that consider uncertainty in the sequestration reservoir, leaky wellbore and the shallow groundwater aquifer.

  13. Long-term impacts of pasture irrigation with treated sewage effluent on shallow groundwater quality.

    PubMed

    Gwenzi, W; Munondo, R

    2008-01-01

    The study investigated the effects of 26 years of effluent irrigation on chemical and bacteriological quality of shallow (<3.0 m) groundwater. Annual loading rates for N and P exceeded pasture requirements, while trace metals were either lower or higher than guideline limits. Effluent irrigation removed TN (44-71%), TP (80%), Cr (96%) and coliform bacteria (87-99.9%) while Zn, Cu and Cd removal was negligible probably due to their enhanced mobility. Analysis of groundwater samples from effluent-irrigated and non-irrigated control sites showed that effluent irrigation increased the levels of all measured parameters compared to the control. Average groundwater quality parameters from effluent-irrigated sites compared to the control were: pH (6.1 vs. 5.7), EC (0.71 vs. 0.53 dS m(-1)), concentrations (mg L(-1)) for TP (2.3 vs. 0.3), DP (1.0 vs. 0.1), TN (15.1 vs. 2.5), NH(4)-N (2.6 vs. 0.5), NO(3)-N (4.1 vs. 1.3), Zn (0.4 vs. 0.05), Cu (0.13 vs. 0.02), Cd (0.05 vs. 0.01) and Cr (0.06 vs. 0.03). Across effluent-irrigated sites, FC and TC were 25 and 288 cfu/100 ml, respectively, versus nil for the control. Overall, effluent irrigation led to groundwater contamination by N, P, trace metals and coliform bacteria, which could threaten the long-term sustainability of the practice.

  14. Groundwater flow near the Shoal Site, Sand Springs Range, Nevada: Impact of density-driven flow

    SciTech Connect

    Chapman, J.; Mihevc, T.; McKay, A.

    1994-09-01

    The nature of flow from a highland recharge area in a mountain range in north-central Nevada to discharge areas on either side of the range is evaluated to refine a conceptual model of contaminant transport from an underground nuclear test conducted beneath the range. The test, known as the Shoal event, was conducted in 1963 in granitic rocks of the Sand Springs Range. Sparse hydraulic head measurements from the early 1960s suggest flow from the shot location to the east to Fairview Valley, while hydrochemistry supports flow to salt pans in Fourmile Flat to the west. Chemical and isotopic data collected from water samples and during well-logging arc best explained by a reflux brine system on the west side of the Sand Springs Range, rather than a typical local flow system where all flow occurs from recharge areas in the highlands to a central discharge area in a playa. Instead, dense saline water from the playa is apparently being driven toward the range by density contrasts. The data collected between the range and Fourmile Flat suggest the groundwater is a mixture of younger, fresher recharge water with older brine. Chemical contrasts between groundwater in the east and west valleys reflect the absence of re-flux water in Fairview Valley because the regional discharge area is distant and thus there is no accumulation of salts. The refluxing hydraulic system probably developed after the end of the last pluvial period and differences between the location of the groundwater divide based on hydraulic and chemical indicators could reflect movement of the divide as the groundwater system adjusts to the new reflux condition.

  15. Assessing performance and closure for soil vapor extraction: integrating vapor discharge and impact to groundwater quality.

    PubMed

    Carroll, Kenneth C; Oostrom, Mart; Truex, Michael J; Rohay, Virginia J; Brusseau, Mark L

    2012-02-01

    Soil vapor extraction (SVE) is typically effective for removal of volatile contaminants from higher-permeability portions of the vadose zone. However, contamination in lower-permeability zones can persist due to mass transfer processes that limit the removal effectiveness. After SVE has been operated for a period of time and the remaining contamination is primarily located in lower-permeability zones, the remedy performance needs to be evaluated to determine whether the SVE system should be optimized, terminated, or transitioned to another technology to replace or augment SVE. Numerical modeling of vapor-phase contaminant transport was used to investigate the correlation between measured vapor-phase mass discharge, MF(r), from a persistent, vadose-zone contaminant source and the resulting groundwater contaminant concentrations. This relationship was shown to be linear, and was used to directly assess SVE remediation progress over time and to determine the level of remediation in the vadose zone necessary to protect groundwater. Although site properties and source characteristics must be specified to establish a unique relation between MF(r) and the groundwater contaminant concentration, this correlation provides insight into SVE performance and support for decisions to optimize or terminate the SVE operation or to transition to another type of treatment.

  16. Impact of industrialization on groundwater quality--a case study of Peenya industrial area, Bangalore, India.

    PubMed

    Shankar, B S; Balasubramanya, N; Maruthesha Reddy, M T

    2008-07-01

    The present study aims at identifying the groundwater contamination problems in Bangalore city in India. Groundwater samples from 30 different locations of the industrial area were collected. Analytical techniques as described in the Standard methods for the examination of water and wastewater were adopted for physico-chemical analysis of these samples and the results compared with the Bureau of Indian Standards (BIS) guideline values for potable water in the light of possible health hazards. The investigations reveal that most of the study area is highly contaminated due to the excessive concentrations of one or more water quality parameters such as Nitrates, Total Hardness, Calcium, Magnesium, Total dissolved solids, Sulphates and Fluorides, which have rendered nearly 77% of the water samples tested, non- potable. Discussions held by the authors with the local public as well as the Primary health centre authorities of the area revealed that a lot of people in the area are suffering from severe health problems on using this water. The findings show that there is a clear correlation between the ill health faced by the public and contamination of the said groundwaters.

  17. Impact of microforms on nitrate transport at the groundwater-surface water interface in gaining streams

    NASA Astrophysics Data System (ADS)

    Hu, Haizhu; Binley, Andrew; Heppell, Catherine M.; Lansdown, Katrina; Mao, Xiaomin

    2014-11-01

    Small streambed structures (or microforms, 0.01-1 m in length) exist ubiquitously in riverbed systems. Small-scale topography is potentially important in controlling hyporheic exchange flow and transport of conservative and reactive solutes at the groundwater-surface water interface. The role of microforms on NO3- transfer in a riffle-scale (macroforms of >1 m length) hyporheic zone within a gaining river setting is investigated using a 2-D flow and transport model which accounts for both nitrification and denitrification. Results show that the short pathlines caused by microforms lead to more NO3- discharge to the river compared with a macroform-only condition due to shortened residence times of both surface water and groundwater in mixing zones. Short hyporheic exchange flow pathways caused by microforms could remain oxic along their entire length or switch from nitrate producing to nitrate consuming as oxygen concentrations decline. Microforms affect net NO3- flux by the combined effect of introducing more stream mass flux and reducing their residence time in mixing zones under different hydrological and biogeochemical conditions. Our findings underscore that ignoring microforms in river beds may underestimate NO3- load to the river and have practical implications for pore water sampling strategies in groundwater-surface water studies.

  18. Modeling dropout from adverse event data: impact of dosing regimens across pregabalin trials in the treatment of generalized anxiety disorder.

    PubMed

    Lalovic, Bojan; Hutmacher, Matt; Frame, Bill; Miller, Raymond

    2011-05-01

    Dizziness represents a major determinant of dropout in the treatment of generalized anxiety disorder with pregabalin. Titration (dose escalation) regimens based on clinical judgment were implemented to mitigate this adverse event and reduce patient dropout across clinical trials. Dropout is an important treatment failure endpoint, which can be analyzed using time-to-event models that incorporate daily dosing or other time-varying information. A parametric discrete-time dropout model with daily dizziness severity score as a covariate afforded a systematic, model-based assessment of titration dosing strategies, with model predictions evaluated against corresponding nonparametric estimates. A Gompertz hazard function adequately described the decreasing dropout hazard over time for individuals with severe or moderate dizziness and a lower, constant hazard for individuals reporting no dizziness or mild dizziness. Predictive performance of the model was adequate based on external validation with an independent trial and other goodness-of-fit criteria. Prospective simulations highlight the utility of this approach in reducing dropout based on examination of untested titration scenarios for future generalized anxiety disorder or other trials.

  19. Assessment of Climate Change Impact: Use of a Groundwater and Surface Water Model in a Highly-Urbanized Catchment

    NASA Astrophysics Data System (ADS)

    Cochand, F.; Therrien, R.

    2013-12-01

    There is currently great interest in quantifying the impact of anticipated climate change on groundwater volumes and flow dynamics. Several studies have assessed the impact of future climatic conditions on groundwater but only a few have investigated the concurrent potential impact of future urbanization. The main objective of our research project is to assess the impact of future climatic conditions and urban development on groundwater resources by focusing on the highly-urbanized catchment of the Saint-Charles River, in Quebec City, Canada. The methodology proposed to reach this objective is divided in two steps. The first step is to develop and calibrate a numerical model that simulates the surface water and groundwater flow dynamics for the catchment, using the physically-based, fully integrated, variably-saturated 3-D surface-subsurface simulator HydroGeoSphere (HGS). In addition, this model includes functions for simulating snow accumulation (during winter), snow melting (during spring) and freezing/thawing dynamic of pore water near the surface, which have been applied to the catchment. The second step is to identify climate projections from general circulation models (GCMs) and downscale their input to the catchment scale, as well as to propose urbanisation scenarios. Using the calibrated model as a starting point, the output of the GCMs and urbanisation scenarios will then be used as boundary conditions in the numerical model for predictive simulations and to assess their effect on groundwater flow dynamics. This presentation mainly reports on the first step of the project, which is the development of the calibrated model. The geology of the catchment is complex because of successions of quaternary deposits, with highly-variable hydrogeological properties and a complex spatial distribution that lie on fractured bedrock. A 3D Quaternary geological model is available but due to its complex geometry, the integration of this model into the 3-D hydrogeological

  20. Impact of the climate change to shallow groundwater in Baltic artesian basin

    NASA Astrophysics Data System (ADS)

    Lauva, D.; Bethers, P.; Timuhins, A.; Sennikovs, J.

    2012-04-01

    The purpose of our work was to find the long term pattern of annual shallow ground water changes in region of Latvia, ground water level modelling for the contemporary climate and future climate scenarios and the model generalization to the Baltic artesian basin (BAB) region. Latvia is located in the middle part of BAB. It occupies about 65'000 square kilometers. BAB territory (480'000 square kilometres) also includes Lithuania, Estonia as well as parts of Poland, Russia, Belarus and the Baltic Sea. Territory of BAB is more than seven times bigger than Latvia. Precipitation and spring snow melt are the main sources of the ground water recharge in BAB territory. The long term pattern of annual shallow ground water changes was extracted from the data of 25 monitoring wells in the territory of Latvia. The main Latvian groundwater level fluctuation regime can be described as a function with two maximums (in spring and late autumn) and two minimums (in winter and late summer). The mathematical model METUL (developed by Latvian University of Agriculture) was chosen for the ground water modelling. It was calibrated on the observations in 25 gauging wells around Latvia. After the calibration we made calculations using data provided by an ensemble of regional climate models, yielding a continuous groundwater table time-series from 1961 to 2100, which were analysed and split into 3 time windows for further analysis: contemporary climate (1961-1990), near future (2021-2050) and far future (2071-2100). The daily average temperature, precipitation and humidity time series were used as METUL forcing parameters. The statistical downscaling method (Sennikovs and Bethers, 2009) was applied for the bias correction of RCM calculated and measured variables. The qualitative differences in future and contemporary annual groundwater regime are expected. The future Latvian annual groundwater cycle according to the RCM climate projection changes to curve with one peak and one drought point

  1. Using vadose zone data and spatial statistics to assess the impact of cultivated land and dairy waste lagoons on groundwater contamination

    NASA Astrophysics Data System (ADS)

    Baram, S.; Ronen, Z.; Kurtzman, D.; Peeters, A.; Dahan, O.

    2013-12-01

    Land cultivation and dairy waste lagoons are considered to be nonpoint and point sources of groundwater contamination by chloride (Cl-) and nitrate (NO3-). The objective of this work is to introduce a methodology to assess the past and future impacts of such agricultural activities on regional groundwater quality. The method is based on mass balances and on spatial statistical analysis of Cl- and NO3-concentration distributions in the saturated and unsaturated zones. The method enables quantitative analysis of the relation between the locations of pollution point sources and the spatial variability in Cl- and NO3- concentrations in groundwater. The method was applied to the Beer-Tuvia region, Israel, where intensive dairy farming along with land cultivation has been practiced for over 50 years above the local phreatic aquifer. Mass balance calculations accounted for the various groundwater recharge and abstraction sources and sinks in the entire region. The mass balances showed that leachates from lagoons and the cultivated land have contributed 6.0 and 89.4 % of the total mass of Cl- added to the aquifer and 12.6 and 77.4 % of the total mass of NO3-. The chemical composition of the aquifer and vadose zone water suggested that irrigated agricultural activity in the region is the main contributor of Cl- and NO3- to the groundwater. A low spatial correlation between the Cl- and NO3- concentrations in the groundwater and the on-land location of the dairy farms strengthened this assumption, despite the dairy waste lagoon being a point source for groundwater contamination by Cl- and NO3-. Results demonstrate that analyzing vadose zone and groundwater data by spatial statistical analysis methods can significantly contribute to the understanding of the relations between groundwater contaminating sources, and to assessing appropriate remediation steps.

  2. Adverse impact of fibrin clot inhibitors on intravesical bacillus Calmette-Guerin therapy for superficial bladder tumors.

    PubMed

    Hudson, M A; Yuan, J J; Catalona, W J; Ratliff, T L

    1990-12-01

    Although intravesical bacillus Calmette-Guerin therapy has proved to be efficacious in the treatment and prophylaxis against tumor recurrence of superficial bladder tumors, its mechanism of action has not been fully elucidated. Previous work has suggested that bacillus Calmette-Guerin organisms attach to the matrix protein, fibronectin, during fibrin clot formation at sites of urothelial disruption and that this attachment was required for the antitumor effect of bacillus Calmette-Guerin to be expressed. Furthermore, drugs inhibiting clot formation were found to abrogate the antitumor effect of intravesical bacillus Calmette-Guerin therapy in a murine bladder tumor model. To examine the effect of inhibitors of fibrin clot formation on the results of intravesical bacillus Calmette-Guerin therapy, a retrospective analysis of 149 evaluable patients receiving intravesical bacillus Calmette-Guerin for superficial bladder tumors was performed. The over-all response rate free of tumor for 29 patients who concomitantly received inhibitors of fibrin clot formation with bacillus Calmette-Guerin therapy was 48%, as compared with 67% for 120 patients who were not receiving these medications (p = 0.0655, chi-square). The most striking difference was noted for patients who failed with recurrent superficial disease. Of the patients who received fibrin clot inhibitors during intravesical bacillus Calmette-Guerin therapy 35% had recurrent superficial tumors compared to only 8% of those who did not receive these drugs during a mean followup of 29.8 plus or minus 11 months (p = 0.005, chi-square). Our study suggests that inhibitors of fibrin clot formation may have an adverse influence on the results of intravesical bacillus Calmette-Guerin therapy for superficial bladder tumors.

  3. Geophysical and hydrogeological characterisation of the impacts of on-site wastewater treatment discharge to groundwater in a poorly productive bedrock aquifer.

    PubMed

    Donohue, Shane; McCarthy, Valerie; Rafferty, Patrick; Orr, Alison; Flynn, Raymond

    2015-08-01

    Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar

  4. Geophysical and hydrogeological characterisation of the impacts of on-site wastewater treatment discharge to groundwater in a poorly productive bedrock aquifer.

    PubMed

    Donohue, Shane; McCarthy, Valerie; Rafferty, Patrick; Orr, Alison; Flynn, Raymond

    2015-08-01

    Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar

  5. Substantial nitrous oxide emissions from intertidal sediments and groundwater in anthropogenically-impacted West Falmouth Harbor, Massachusetts

    USGS Publications Warehouse

    Moseman-Valtierra, Serena; Kroeger, Kevin D.; Crusius, John; Baldwin, Sandy; Green, Adrian; Brooks, Thomas W.; Pugh, E.

    2015-01-01

    Large N2O emissions were observed from intertidal sediments in a coastal estuary, West Falmouth Harbor, MA, USA. Average N2O emission rates from 41 chambers during summer 2008 were 10.7 mol N2O m(-2) h(-1)±4.43 μmol N2O m(-2) h(-1) (standard error). Emissions were highest from sediments within a known wastewater plume, where a maximum N2O emission rate was 155 μmol N2O m(-2) h(-1). Intertidal N2O fluxes were positively related to porewater ammonium concentrations at 10 and 25 cm depths. In groundwater from 7 shoreline wells, dissolved N2O ranged from 488% of saturation (56 nM N2O) to more than 13000% of saturation (1529 nM N2O) and was positively related to nitrate concentrations. Fresh and brackish porewater underlying 14 chambers was also supersaturated in N2O, ranging from 2980% to 13175% of saturation. These observations support a relationship between anthropogenic nutrient loading and N2O emissions in West Falmouth Harbor, with both groundwater sources and also local N2O production within nutrient-rich, intertidal sediments in the groundwater seepage face. N2O emissions from intertidal "hotspot" in this harbor, together with estimated surface water emissions, constituted 2.4% of the average overall rate of nitrogen export from the watershed to the estuary. This suggests that N2O emissions factors from coastal ecosystems may be underestimated. Since anthropogenic nutrient loading affects estuaries worldwide, quantification of N2O dynamics is warranted in other anthropogenically-impacted coastal ecosystems.

  6. Preliminary report on coal pile, coal pile runoff basins, and ash basins at the Savannah River Site: effects on groundwater

    SciTech Connect

    Palmer, E.

    1997-04-28

    Coal storage piles, their associated coal pile runoff basins and ash basins could potentially have adverse environmental impacts, especially on groundwater. This report presents and summarizes SRS groundwater and soil data that have been compiled. Also, a result of research conducted on the subject topics, discussions from noted experts in the field are cited. Recommendations are made for additional monitor wells to be installed and site assessments to be conducted.

  7. Impact of global change on karst groundwater mineralization in the Jura Mountains.

    PubMed

    Jeannin, Pierre-Yves; Hessenauer, Marc; Malard, Arnauld; Chapuis, Valentin

    2016-01-15

    Chemistry of karst groundwater is related to conditions prevailing within the karst underground as well as at the land-surface within the recharge area. It is dominated by the dissolution of calcite and/or dolomite, which is strongly triggered by the presence of high pCO2 in soils at the top of the bedrock. Dissolution (water mineralization) is clearly influenced by soil pCO2, i.e. by global changes such as land-use, agriculture practices and climate change. However, the dissolution of carbonates is considered as a quite significant carbon sink for the Earth Atmosphere. Assessing the evolution of carbonate water mineralization can thus help characterizing the evolution of the carbon sink related to carbonate dissolution. The main goal of the study is to check the presence of trends with a high statistical relevance in groundwater quality data along the past 20 years. Causes potentially explaining the observed trends, such as land-use, agriculture practices and global warming are analyzed and discussed. The long term evolution of parameters related to carbonate dissolution are discussed and extrapolated as they may have consequences for the Global Carbon Cycle. The analysis is based on three independent data-sets stretching over more than 20 years each, coming from more than 40 sources. Statistical tests (Mann-Kendall trend test) indicate clear trends for compounds related to groundwater mineralization: increase in temperature (by about 0.5 °C/25 years), decrease in pH, increase in bicarbonate (by about 5%), and positive or negative trends for major ions directly related to human practices. Data and analysis suggest that carbonate dissolution is quickly increasing as a consequence of climate warming. Considering the largely accepted fact that carbonate dissolution acts as carbon sink for the atmosphere, it can be postulated that the observed increase could act as a negative feedback mechanism, tending to slow down the atmospheric increase in CO2. PMID:26473718

  8. Impact of global change on karst groundwater mineralization in the Jura Mountains.

    PubMed

    Jeannin, Pierre-Yves; Hessenauer, Marc; Malard, Arnauld; Chapuis, Valentin

    2016-01-15

    Chemistry of karst groundwater is related to conditions prevailing within the karst underground as well as at the land-surface within the recharge area. It is dominated by the dissolution of calcite and/or dolomite, which is strongly triggered by the presence of high pCO2 in soils at the top of the bedrock. Dissolution (water mineralization) is clearly influenced by soil pCO2, i.e. by global changes such as land-use, agriculture practices and climate change. However, the dissolution of carbonates is considered as a quite significant carbon sink for the Earth Atmosphere. Assessing the evolution of carbonate water mineralization can thus help characterizing the evolution of the carbon sink related to carbonate dissolution. The main goal of the study is to check the presence of trends with a high statistical relevance in groundwater quality data along the past 20 years. Causes potentially explaining the observed trends, such as land-use, agriculture practices and global warming are analyzed and discussed. The long term evolution of parameters related to carbonate dissolution are discussed and extrapolated as they may have consequences for the Global Carbon Cycle. The analysis is based on three independent data-sets stretching over more than 20 years each, coming from more than 40 sources. Statistical tests (Mann-Kendall trend test) indicate clear trends for compounds related to groundwater mineralization: increase in temperature (by about 0.5 °C/25 years), decrease in pH, increase in bicarbonate (by about 5%), and positive or negative trends for major ions directly related to human practices. Data and analysis suggest that carbonate dissolution is quickly increasing as a consequence of climate warming. Considering the largely accepted fact that carbonate dissolution acts as carbon sink for the atmosphere, it can be postulated that the observed increase could act as a negative feedback mechanism, tending to slow down the atmospheric increase in CO2.

  9. [Impact of mining wastes on the physicochemical and biological characteristics of groundwater in a mining area in Marrakech (Morocco)].

    PubMed

    El Adnani, M; Boughrous, A Ait; Khebiza, M Yacoubi; El Gharmali, A; Sbai, M L; Errouane, A S; Idrissi, L Loukili; Nejmeddine, A

    2007-01-01

    Metal sulphide tailings represent a potential risk basically for the environment and particularly for water resources, because of their natural oxidisability which leads to the production of acid/neutral mine drainage. The prospected site close to Marrakech includes zinc, lead and copper sulphide deposits. This site is located in an agricultural area where ground water is used both for irrigation and drinking. Eco-toxicological investigations have been undertaken in order to asses the tailings impact on water quality in nearby wells. These investigations include physico-chemical characterization of the groundwaters as well as faunistic population determination. As compared to standard wells, waters from the wells located downstream of the mining site, have high electrical conductivities and high major ions contents, which can reach: 755 mg l(-1) in SO4(2-), 1670 mg l(-1) in Ca2+, 528 mg l(-1) in Mg2+, 2289 mg I(-1) in Na+ and 14981 mg l(-1) in Cl-. The fauna distribution analysis carried out around the studied wells shows qualitative and quantitative differences according to the flow gradient of the groundwaters. Areas located upstream of the mine tailings site are richer in stygobite species (Type and quantity) than those located downstream or close to it. It is likely that these biological differences are due to water quality alteration induced by the mining activity.

  10. Impact of the geologic setting on the groundwater using geoelectrical sounding in the area southwest of Sohag - Upper Egypt

    NASA Astrophysics Data System (ADS)

    Mahmoud, Hussein Hosni; Tawfik, Mohamed Zaghloul

    2015-04-01

    A geoelectrical resistivity survey has been carried out in El Kawameil area which lies to the southwest of Sohag governorate, Upper Egypt with the purpose of delineating the geologic setting and its impact on the groundwater occurrence. The study involved measuring Vertical Electrical Sounding (VES) at twenty-four locations using the Schlumberger Array. The results showed that the geoelectrical succession in the study area consists of eleven geoelectric layers which were grouped into three main zones. The first zone consists of four geoelectric layers corresponding to the dry upper surface layers. The second one is composed of four geoelectric layers that constitute the Eocene limestone plateau at the western and northern parts of the study area. The third zone is consists of three geoelectric layers and corresponds to Pleistocene water bearing sand and gravel at the central and eastern parts of the study area. The area was found to be affected by a group of normal faults. The results showed, also, that the lateral lithological changes and thickness of the saturated zone have their effect on the groundwater potentiality in the study area. Moreover, the detected faults contribute to seepage of runoff water to recharge the water bearing zone and control the flow. Sites to drill new wells in the investigated area have been determined.

  11. Reactive transport modeling of thermal column experiments to investigate the impacts of aquifer thermal energy storage on groundwater quality.

    PubMed

    Bonte, Matthijs; Stuyfzand, Pieter J; Breukelen, Boris M van

    2014-10-21

    Aquifer thermal energy storage (ATES) systems are increasingly being used to acclimatize buildings and are often constructed in aquifers used for drinking water supply. This raises the question of potential groundwater quality impact. Here, we use laboratory column experiments to develop and calibrate a reactive transport model (PHREEQC) simulating the thermally induced (5-60 °C) water quality changes in anoxic sandy sediments. Temperature-dependent surface complexation, cation-exchange, and kinetic dissolution of K-feldspar were included in the model. Optimization results combined with an extensive literature survey showed surface complexation of (oxy)anions (As, B, and PO4) is consistently exothermic, whereas surface complexation of cations (Ca and Mg) and cationic heavy metals (Cd, Pb, and Zn) is endothermic. The calibrated model was applied to simulate arsenic mobility in an ATES system using a simple yet powerful mirrored axi-symmetrical grid. Results showed that ATES mobilizes arsenic toward the fringe of the warm water bubble and the center of the cold water bubble. This transient redistribution of arsenic causes its aqueous concentrations in the cold and warm groundwater bubbles to become similar through multiple heating cycles, with a final concentration depending on the average injection temperature of the warm and cold ATES wells.

  12. Increased biomass burning due to the economic crisis in Greece and its adverse impact on wintertime air quality in Thessaloniki.

    PubMed

    Saffari, Arian; Daher, Nancy; Samara, Constantini; Voutsa, Dimitra; Kouras, Athanasios; Manoli, Evangelia; Karagkiozidou, Olga; Vlachokostas, Christos; Moussiopoulos, Nicolas; Shafer, Martin M; Schauer, James J; Sioutas, Constantinos

    2013-01-01

    The recent economic crisis in Greece resulted in a serious wintertime air pollution episode in Thessaloniki. This air quality deterioration was mostly due to the increased price of fuel oil, conventionally used as a source of energy for domestic heating, which encouraged the residents to burn the less expensive wood/biomass during the cold season. A wintertime sampling campaign for fine particles (PM2.5) was conducted in Thessaloniki during the winters of 2012 and 2013 in an effort to quantify the extent to which the ambient air was impacted by the increased wood smoke emissions. The results indicated a 30% increase in the PM2.5 mass concentration as well as a 2-5-fold increase in the concentration of wood smoke tracers, including potassium, levoglucosan, mannosan, and galactosan. The concentrations of fuel oil tracers (e.g., Ni and V), on the other hand, declined by 20-30% during 2013 compared with 2012. Moreover, a distinct diurnal variation was observed for wood smoke tracers, with significantly higher concentrations in the evening period compared with the morning. Correlation analysis indicated a strong association between reactive oxygen species (ROS) activity and the concentrations of levoglucosan, galactosan, and potassium, underscoring the potential impact of wood smoke on PM-induced toxicity during the winter months in Thessaloniki.

  13. Integrated assessment of the impact of climate and land use changes on groundwater quantity and quality in the Mancha Oriental system (Spain)

    NASA Astrophysics Data System (ADS)

    Pulido-Velazquez, M.; Peña-Haro, S.; García-Prats, A.; Mocholi-Almudever, A. F.; Henriquez-Dole, L.; Macian-Sorribes, H.; Lopez-Nicolas, A.

    2015-04-01

    Climate and land use change (global change) impacts on groundwater systems cannot be studied in isolation. Land use and land cover (LULC) changes have a great impact on the water cycle and contaminant production and transport. Groundwater flow and storage are changing in response not only to climatic changes but also to human impacts on land uses and demands, which will alter the hydrologic cycle and subsequently impact the quantity and quality of regional water systems. Predicting groundwater recharge and discharge conditions under future climate and land use changes is essential for integrated water management and adaptation. In the Mancha Oriental system (MOS), one of the largest groundwater bodies in Spain, the transformation from dry to irrigated lands during the last decades has led to a significant drop of the groundwater table, with the consequent effect on stream-aquifer interaction in the connected Jucar River. Understanding the spatial and temporal distribution of water quantity and water quality is essential for a proper management of the system. On the one hand, streamflow depletion is compromising the dependent ecosystems and the supply to the downstream demands, provoking a complex management issue. On the other hand, the intense use of fertilizer in agriculture is leading to locally high groundwater nitrate concentrations. In this paper we analyze the potential impacts of climate and land use change in the system by using an integrated modeling framework that consists in sequentially coupling a watershed agriculturally based hydrological model (Soil and Water Assessment Tool, SWAT) with a groundwater flow model developed in MODFLOW, and with a nitrate mass-transport model in MT3DMS. SWAT model outputs (mainly groundwater recharge and pumping, considering new irrigation needs under changing evapotranspiration (ET) and precipitation) are used as MODFLOW inputs to simulate changes in groundwater flow and storage and impacts on stream

  14. Microbial Indicators, Pathogens, and Antibiotic Resistance in Groundwater Impacted by Animal Farming: Field Scale to Basin Scale

    NASA Astrophysics Data System (ADS)

    Harter, T.; Li, X.; Atwill, E. R.; Packman, A. I.

    2015-12-01

    Several surveys of microbial indicators and pathogens were conducted to determine the impact of confined animal farming operations (CAFOs) on shallow, local, and regional groundwater quality in the Central Valley aquifer system, California. The aquifer system consists of highly heterogeneous, alluvial, unconsolidated coarse- to fine-grained sediments and is among the largest aquifers in the U.S.. Overlying landuse includes 3 million ha of irrigated agriculture and 1.7 million mature dairy cows in nearly 1,500 CAFOs. A multi-scale survey of water-borne indicator pathogens (Enterococcus spp. and generic E. coli) and of three water-borne pathogens (Campylobacter, Salmonella, and E. coli O157:H7) was conducted at five different spatial scales, increasing with distance from animal sources of these enteric microbial organisms: moist surfaces within individual CAFO sub-systems (calf-hutches, heifer corrals, mature cow stalls, hospital barn etc.), first encountered (shallow) groundwater immediately below these sub-systems, production aquifer below CAFOs, production aquifer near CAFOs, and production aquifer away from CAFOs. Where found, indicator pathogens were tested for antibiotic resistance. Hundreds of samples were collected at each scale: continuously during irrigation events and seasonally over a multi-year period at the three smaller site-scales; and in a one-time survey at the two l