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

Science.gov (United States)

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

2016-12-01

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

Estimation of groundwater flow rate using the decay of 222Rn in a well

International Nuclear Information System (INIS)

Hamada, Hiromasa

1999-01-01

A method of estimating groundwater flow rate using the decay of 222 Rn in a well was investigated. Field application revealed that infiltrated water (i.e., precipitation, pond water and irrigation water) accelerated groundwater flow. In addition, the depth at which groundwater was influenced by surface water was determined. The velocity of groundwater in a test well was estimated to be of the order of 10 -6 cm s -1 , based on the ratio of 222 Rn concentration in groundwater before and after it flowed into the well. This method is applicable for monitoring of groundwater flow rate where the velocity in a well is from 10 -5 to 10 -6 cm s -1

Study of environmental isotope distribution in the Aswan High Dam Lake (Egypt) for estimation of evaporation of lake water and its recharge to adjacent groundwater

International Nuclear Information System (INIS)

Aly, A.I.M.; Nada, A.; Awad, M.; Hamza, M.; Salem, W.M.

1993-01-01

Oxygen-18 ( 18 O) and deuterium isotopes were used to estimate the evaporation from the Aswan High Dam Lake and to investigate the inter-relation between the lake water and adjacent groundwater. According to stable isotopic analysis of samples taken in 1988 and 1989, the lake can be divided into two sections. In the first section extending between Abu Simbel and a point between El-Alaki and Krosko, a remarkable vertical gradient of 18 O and deuterium isotopic composition was observed. The second northern sector extending to the High Dam is characterised by a lower vertical isotopic gradient. In this sector in general, higher values of 18 O and deuterium contents were found at the top and lower values at the bottom. Also a strong horizontal increase of the heavy isotope content was observed. Thus, in the northern section evaporation is of dominating influence on the isotopic composition of the lake water. With the help of an evaporation pan experiment it was possible to calibrate the evaporative isotope enrichment in the lake and to facilitate a preliminary estimate of evaporative losses of lake water. The evaporation from the lake was estimated to be about 19% of the input water flow rate. The groundwater around the lake was investigated and samples from production wells and piezometers were subjected to isotopic analysis. The results indicate that recent recharge to the groundwater aquifer is limited to wells near to the lake and up to a maximum distance of about 10 km. The contribution of recent Nile water to the groundwater in these wells was estimated to range between 23 and 70%. Beyond this distance, palaeowater was observed with highly depleted deuterium and 18 O contents, which was also confirmed by 14c dating. The age of palaeo groundwater in this area can reach values of more than 26,000 years. Recommendations are given for efficient water management of the lake water. (Author)

The application of parallel wells to support the use of groundwater for sustainable irrigation

Science.gov (United States)

Suhardi

2018-05-01

The use of groundwater as a source of irrigation is one alternative in meeting water needs of plants. Using groundwater for irrigation requires a high cost because of the discharge that can be taken is limited. In addition, the use of large groundwater can cause environmental damage and social conflict. To minimize costs, maintain quality of the environment and to prevent social conflicts, it is necessary to innovate in the groundwater taking system. The study was conducted with an innovation of using parallel wells. Performance is measured by comparing parallel wells with a single well. The results showed that the use of parallel wells to meet the water needs of rice plants and increase the pump discharge up to 100%. In addition, parallel wells can reduce the influence radius of taking of groundwater compared to single well so as to prevent social conflict. Thus, the use of parallel wells can support the achievement of the use of groundwater for sustainable irrigation.

Workshop on methods for siting groundwater monitoring wells: Proceedings

International Nuclear Information System (INIS)

Jacobson, E.

1992-02-01

The primary purpose of this workshop was to identify methods for the optimum siting of groundwater monitoring wells to minimize the number required that will provide statistically and physically representative samples. In addition, the workshop served to identify information and data gaps, stimulated discussion and provided an opportunity for exchange of ideas between regulators and scientists interested in siting groundwater monitoring wells. These proceedings should serve these objectives and provide a source of relevant information which may be used to evaluate the current state of development of methods for siting groundwater monitoring wells and the additional research needs. The proceedings contain the agenda and list of attendees in the first section. The abstract and viewgraphs for each presentation are given in the second section. For several presentations, abstracts and viewgraphs were not received. After the presentations, four working groups were organized and met for approximately a day. The working group leaders then gave a verbal summary of their sessions. This material was transcribed and is included in the next section of these proceedings. The appendices contain forms describing various methods discussed in the working groups

Characteristic groundwater level regimes in the capture zones of radial collector wells and importance of identification (Case study of Belgrade Groundwater Source

Directory of Open Access Journals (Sweden)

Božović Đorđije

2016-01-01

Full Text Available Assessment of the operating modes of radial collector wells reveals that the pumping levels in the well caissons are very low relative to the depth/elevation of the laterals, which is a common occurrence at Belgrade Groundwater Source. As a result, well discharge capacities vary over a broad range and groundwater levels in the capture zones differ even when the rate of discharge is the same. Five characteristic groundwater level regimes are identified and their origin is analyzed using representative wells as examples. The scope and type of background information needed to identify the groundwater level regime are presented and an interpretation approach is proposed for preliminary assessment of the aquifer potential at the well site for providing the needed amount of groundwater. [Projekat Ministarstva nauke Republike Srbije, br. OI176022, br. TR33039 i br. III43004

Mixed Waste Management Facility (MWMF) groundwater monitoring report

International Nuclear Information System (INIS)

1993-03-01

During fourth quarter 1992, nine constituents exceeded final Primary Drinking Water Standards (PDWS) in one or more groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. As in previous quarters, tritium and trichloroethylene were the most widespread constituents. Fifty-seven (48%) of the 120 monitoring wells, contained elevated tritium activities, and 23 (19%) contained elevated trichloroethylene concentrations. Total alpha-emitting radium, tetrachloroethylene, chloroethene, cadmium, 1,1-dichloroethylene, lead, or nonvolatile beta levels exceeded standards in one or more wells. During 1992, elevated levels of 13 constituents were found in one or more of 80 of the 120 groundwater monitoring wells (67%) at the MWMF and adjacent facilities. Tritium and trichloroethylene exceeded their final PDWS more frequently and more consistently than did other constituents. Tritium activity exceeded its final PDWS m 67 wells and trichloroethylene was. elevated in 28 wells. Lead, tetrachloroethylene, total alpha-emitting radium, gross alpha, cadmium, chloroethene, 1,1-dichloroethylene 1,2-dichloroethane, mercury, or nitrate exceeded standards in one or more wells during the year. Nonvolatile beta exceeded its drinking water screening level in 3 wells during the year

Potential effects of the Hawaii geothermal project on ground-water resources on the Island of Hawaii

Energy Technology Data Exchange (ETDEWEB)

Sorey, M.L.; Colvard, E.M.

1994-07-01

This report provides data and information on the quantity and quality of ground-water resources in and adjacent to proposed geothermal development areas on the Island of Hawaii Geothermal project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. Data presented for about 31 wells and 8 springs describe the chemical, thermal, and hydraulic properties of the ground-water system in and adjacent to the East Rift Zone. On the basis of this information, potential effects of this geothermal development on drawdown of ground-water levels and contamination of ground-water resources are discussed. Significant differences in ground-water levels and in the salinity and temperature of ground water within the study area appear to be related to mixing of waters from different sources and varying degrees of ground-water impoundment by volcanic dikes. Near Pahoa and to the east, the ground-water system within the rift is highly transmissive and receives abundant recharge from precipitation; therefore, the relatively modest requirements for fresh water to support geothermal development in that part of the east rift zone would result in minimal effects on ground-water levels in and adjacent to the rift. To the southwest of Pahoa, dike impoundment reduces the transmissivity of the ground-water system to such an extent that wells might not be capable of supplying fresh water at rates sufficient to support geothermal operations. Water would have to be transported to such developments from supply systems located outside the rift or farther downrift. Contaminant migration resulting from well accidents could be rapid because of relatively high ground-water velocities in parts of the region. Hydrologic monitoring of observation wells needs to be continued throughout development of geothermal resources for the Hawaii Geothermal Project to enable the early detection of leakage and migration of geothermal fluids.

Groundwater quality for 75 domestic wells in Lycoming County, Pennsylvania, 2014

Science.gov (United States)

Gross, Eliza L.; Cravotta, Charles A.

2017-03-06

Groundwater is a major source of drinking water in Lycoming County and adjacent counties in north-central and northeastern Pennsylvania, which are largely forested and rural and are currently undergoing development for hydrocarbon gases. Water-quality data are needed for assessing the natural characteristics of the groundwater resource and the potential effects from energy and mineral extraction, timber harvesting, agriculture, sewage and septic systems, and other human influences.This report, prepared in cooperation with Lycoming County, presents analytical data for groundwater samples from 75 domestic wells sampled throughout Lycoming County in June, July, and August 2014. The samples were collected using existing pumps and plumbing prior to any treatment and analyzed for physical and chemical characteristics, including nutrients, major ions, metals and trace elements, volatile organic compounds, gross-alpha particle and gross beta-particle activity, uranium, and dissolved gases, including methane and radon-222.Results indicate groundwater quality generally met most drinking-water standards, but that some samples exceeded primary or secondary maximum contaminant levels (MCLs) for arsenic, iron, manganese, total dissolved solids (TDS), chloride, pH, bacteria, or radon-222. Arsenic concentrations were higher than the MCL of 10 micrograms per liter (µg/L) in 9 of the 75 (12 percent) well-water samples, with concentrations as high as 23.6 μg/L; arsenic concentrations were higher than the health advisory level (HAL) of 2 μg/L in 23 samples (31 percent). Total iron concentrations exceeded the secondary maximum contaminant level (SMCL) of 300 μg/L in 20 of the 75 samples. Total manganese concentrations exceeded the SMCL of 50 μg/L in 20 samples and the HAL of 300 μg/L in 2 of those samples. Three samples had chloride concentrations that exceeded the SMCL of 250 milligrams per liter (mg/L); two of those samples exceeded the SMCL of 500 mg/L for TDS. The pH ranged

Predicting the risk of groundwater arsenic contamination in drinking water wells

Science.gov (United States)

Cao, Hailong; Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Li, Junxia; Zhan, Hongbin; Liu, Peng

2018-05-01

Arsenic (As)-contaminated groundwater is a global concern with potential detrimental effects on the health of hundreds of millions of people worldwide. However, the extent of this problem may be more severe than anticipated, as many wells have not been tested and may contain unsafe-level of As. An optimized statistical regression model was developed to predict the probability of geogenic high As groundwater (As > 10 μg/L) in this study. Easily obtained hydrogeochemical and geological parameters that are significantly related to As geochemical behaviors were selected as explanatory variables in the model. The results indicate that pH, Cl-, HCO3-, SO42-, and NO3- concentrations, stratigraphic information, and well depth are excellent predictors of As exposure in the Datong Basin, China. Predicted unsafe wells correspond well with the known distribution of high As groundwater in the Datong Basin. The successful application of a data set from Bangladesh also demonstrated the applicability and credibility of this proposed method.

Methane in groundwater from a leaking gas well, Piceance Basin, Colorado, USA

Science.gov (United States)

McMahon, Peter B.; Thomas, Judith C.; Crawford, John T.; Dornblaser, Mark M.; Hunt, Andrew G.

2018-01-01

Site-specific and regional analysis of time-series hydrologic and geochemical data collected from 15 monitoring wells in the Piceance Basin indicated that a leaking gas well contaminated shallow groundwater with thermogenic methane. The gas well was drilled in 1956 and plugged and abandoned in 1990. Chemical and isotopic data showed the thermogenic methane was not from mixing of gas-rich formation water with shallow groundwater or natural migration of a free-gas phase. Water-level and methane-isotopic data, and video logs from a deep monitoring well, indicated that a shale confining layer ~125 m below the zone of contamination was an effective barrier to upward migration of water and gas. The gas well, located 27 m from the contaminated monitoring well, had ~1000 m of uncemented annular space behind production casing that was the likely pathway through which deep gas migrated into the shallow aquifer. Measurements of soil gas near the gas well showed no evidence of methane emissions from the soil to the atmosphere even though methane concentrations in shallow groundwater (16 to 20 mg/L) were above air-saturation levels. Methane degassing from the water table was likely oxidized in the relatively thick unsaturated zone (~18 m), thus rendering the leak undetectable at land surface. Drilling and plugging records for oil and gas wells in Colorado and proxies for depth to groundwater indicated thousands of oil and gas wells were drilled and plugged in the same timeframe as the implicated gas well, and the majority of those wells were in areas with relatively large depths to groundwater. This study represents one of the few detailed subsurface investigations of methane leakage from a plugged and abandoned gas well. As such, it could provide a useful template for prioritizing and assessing potentially leaking wells, particularly in cases where the leakage does not manifest itself at land surface.

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

Directory of Open Access Journals (Sweden)

Milad Mirzaei Aminiyan

2016-07-01

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

Machine Learning for Mapping Groundwater Salinity with Oil Well Log Data

Science.gov (United States)

Chang, W. H.; Shimabukuro, D.; Gillespie, J. M.; Stephens, M.

2016-12-01

An oil field may have thousands of wells with detailed petrophysical logs, and far fewer direct measurements of groundwater salinity. Can the former be used to extrapolate the latter into a detailed map of groundwater salinity? California Senate Bill 4, with its requirement to identify Underground Sources of Drinking Water, makes this a question worth answering. A well-known obstacle is that the basic petrophysical equations describe ideal scenarios ("clean wet sand") and even these equations contain many parameters that may vary with location and depth. Accounting for other common scenarios such as high-conductivity shaly sands or low-permeability diatomite (both characteristic of California's Central Valley) causes parameters to proliferate to the point where the model is underdetermined by the data. When parameters outnumber data points, however, is when machine learning methods are most advantageous. We present a method for modeling a generic oil field, where groundwater salinity and lithology are depth series parameters, and the constants in petrophysical equations are scalar parameters. The data are well log measurements (resistivity, porosity, spontaneous potential, and gamma ray) and a small number of direct groundwater salinity measurements. Embedded in the model are petrophysical equations that account for shaly sand and diatomite formations. As a proof of concept, we feed in well logs and salinity measurements from the Lost Hills Oil Field in Kern County, California, and show that with proper regularization and validation the model makes reasonable predictions of groundwater salinity despite the large number of parameters. The model is implemented using Tensorflow, which is an open-source software released by Google in November, 2015 that has been rapidly and widely adopted by machine learning researchers. The code will be made available on Github, and we encourage scrutiny and modification by machine learning researchers and hydrogeologists alike.

Groundwater storage changes in the Tibetan Plateau and adjacent areas revealed from GRACE satellite gravity data

Science.gov (United States)

Xiang, Longwei; Wang, Hansheng; Steffen, Holger; Wu, Patrick; Jia, Lulu; Jiang, Liming; Shen, Qiang

2016-09-01

Understanding groundwater storage (GWS) changes is vital to the utilization and control of water resources in the Tibetan Plateau. However, well level observations are rare in this big area, and reliable hydrology models including GWS are not available. We use hydro-geodesy to quantitate GWS changes in the Tibetan Plateau and surroundings from 2003 to 2009 using a combined analysis of satellite gravity and satellite altimetry data, hydrology models as well as a model of glacial isostatic adjustment (GIA). Release-5 GRACE gravity data are jointly used in a mascon fitting method to estimate the terrestrial water storage (TWS) changes during the period, from which the hydrology contributions and the GIA effects are effectively deducted to give the estimates of GWS changes for 12 selected regions of interest. The hydrology contributions are carefully calculated from glaciers and lakes by ICESat-1 satellite altimetry data, permafrost degradation by an Active-Layer Depth (ALD) model, soil moisture and snow water equivalent by multiple hydrology models, and the GIA effects are calculated with the new ICE-6G_C (VM5a) model. Taking into account the measurement errors and the variability of the models, the uncertainties are rigorously estimated for the TWS changes, the hydrology contributions (including GWS changes) and the GIA effect. For the first time, we show explicitly separated GWS changes in the Tibetan Plateau and adjacent areas except for those to the south of the Himalayas. We find increasing trend rates for eight basins: + 2.46 ± 2.24 Gt/yr for the Jinsha River basin, + 1.77 ± 2.09 Gt/yr for the Nujiang-Lancangjiang Rivers Source Region, + 1.86 ± 1.69 Gt/yr for the Yangtze River Source Region, + 1.14 ± 1.39 Gt/yr for the Yellow River Source Region, + 1.52 ± 0.95 Gt/yr for the Qaidam basin, + 1.66 ± 1.52 Gt/yr for the central Qiangtang Nature Reserve, + 5.37 ± 2.17 Gt/yr for the Upper Indus basin and + 2.77 ± 0.99 Gt/yr for the Aksu River basin. All these

Functional design criteria for FY 1993-2000 groundwater monitoring wells

International Nuclear Information System (INIS)

Williams, B.A.

1996-01-01

The purpose of this revision is to update the Line Item Project, 93-L-GFW-152 Functional Design Criteria (FDC) to reflect changes approved in change control M-24-91-6, Engineering Change Notices (ECNs), and expand the scope to include subsurface investigations along with the borehole drilling. This revision improves the ability and effectiveness of maintaining RCRA and Operational groundwater compliance by combining borehole and well drilling with subsurface data gathering objectives. The total projected number of wells to be installed under this project has decreased from 200 and the scope has been broadened to include additional subsurface investigation activities that usually occur simultaneously with most traditional borehole drilling and monitoring well installations. This includes borehole hydrogeologic characterization activities, and vadose monitoring. These activities are required under RCRA 40 CFR 264 and 265 and WAC 173-303 for site characterization, groundwater and vadose assessment and well placement

Monitoring effects of river restoration on groundwater with radon

International Nuclear Information System (INIS)

Hoehn, Eduard

2007-01-01

The restoration of the perialpine river Toess in a floodplain of northern Switzerland (Linsental) included the removal of bank reinforcements and tracer studies in the river and in oberservation wells of the adjacent alluvial groundwater. The river water is continuously recharging the aquifer system and the groundwater is used extensively as drinking water. Radon activity concentrations of freshly infiltrated groundwater are interpreted as radon groundwater age between the river and a well. A first flood after the restoration operations resulted in a widening of the river bed and in a reduction of the flow distance to the wells. Sixteen days after a second flood, the results of radon measurements were compared with those from before the restoration. The radon age of the groundwater between the river and the wells decreased, probably as a result of the reduction of the flow distances. Concentrations of autochthonous and coliform bacteria increased after the restoration operation and even more one day after the first flood. Thus the findings on the bacteria corroborate the interpretation of the radon concentrations. The restoration has not yet reduced the quality of the groundwater, which is pumped for drinking water. The study is contributing to the solution of land-use conflicts between river restoration and the supply of drinking water from the alluvial groundwater. (orig.) [de

Studying the impact of climate change on coastal aquifers and adjacent wetlands

Science.gov (United States)

Stigter, Tibor; Ribeiro, Luís.; Oliveira, Rodrigo; Samper, Javier; Fakir, Younes; Fonseca, Luís.; Monteiro, José Paulo; Nunes, João. Pedro; Pisani, Bruno

2010-05-01

program, assessing the impact of climate change on coastal groundwater resources and dependent ecosystems. These resources are often intensively exploited, potentially leading to saltwater intrusion and the degradation of groundwater and dependent wetlands. Climate change may increase this problem in Mediterranean regions, due to the combined effect of rising sea levels and decreasing aquifer recharge. CLIMWAT aims to address this problem by employing a multimethodological approach involving climate scenarios, surface and groundwater flow and transport modeling, as well as hydrochemical indicator and ecological diversity indices. Research is performed in three coastal areas: the Central Algarve in Portugal, the Ebro delta in Spain and the Atlantic Sahel in Morocco. The mean annual temperatures are 17.4 ° C, 17.2 ° C and 17.5 ° C, respectively, whereas mean annual rainfall is lower in the Atlantic Sahel (390 mm) than in the Ebro Delta (520 mm) and the Central Algarve (660 mm). Work package (WP) 1 involves the collection of existing data (in a GIS environment), baseline characterization and the selection of monitoring locations. These include wells and springs of official (water level/quality) monitoring networks, as well as additional observation points selected at strategic locations, including the wetlands receiving groundwater and adjacent aquifer sectors. In WP2 the climate scenarios are selected and integrated in hydrological models (SWAT, GISBALAN), which are developed and calibrated with existing data, prior to scenario modeling. The main focus of this WP is to estimate the evolution of surface runoff and groundwater recharge under climate change. Data on climate change scenarios and model projections are compiled from: (i) the PRUDENCE project; (ii) the ENSEMBLES project; (iii) IPCC scenarios and projections, AR4; (iv) AEMet (Spanish Meteorological Agency) for generation of regional scenarios of climate change in Spain. For Morocco, where runoff is

Groundwater and surface-water resources in the Bureau of Land Management Moab Master Leasing Plan area and adjacent areas, Grand and San Juan Counties, Utah, and Mesa and Montrose Counties, Colorado

Science.gov (United States)

Masbruch, Melissa D.; Shope, Christopher L.

2014-01-01

. The large regional streams (Colorado, Green, and Dolores Rivers) integrate the regional hydrologic partitioning of a very large contributing area and, therefore, the hydrographs for these streams are much more smooth and consistent. Several streams throughout the study area are considered impaired and do not meet the standards set by the Environmental Protection Agency for specific designated-use classifications.Limited data are available to quantitatively estimate the large-scale regional groundwater budget for the study area. Previous studies have estimated groundwater budgets for areas in and adjacent to the current study area, namely Moab-Spanish Valley and parts of the Paradox Basin. Most groundwater recharge to the study area originates as infiltration of precipitation from upland areas and is further enhanced in areas covered with sandy soils or in areas where the bedrock is highly fractured. Additional groundwater recharge occurs as seepage from streams and irrigation water, and as subsurface inflow, both vertically between aquifers and as lateral movement into the study area. Groundwater discharge occurs as seepage to streams, evapotranspiration, to springs and seeps, well withdrawals; and as subsurface outflow, both vertically between aquifers and as lateral movement out of the study area across its defined boundaries. Groundwater use in the study area was determined using data from the Utah Division of Water Rights. Most wells in the study area are categorized as having multiple uses.Mean specific-conductance values for groundwater from wells and springs in the study area range from 101 to 220,000 microsiemens per centimeter at 25° C (μS/cm); most of the wells or springs have mean specific-conductance values of less than or equal to 1,000 μS/cm. Previously reported total dissolved-solids concentrations, specific conductances, and other groundwater-quality data for each of the principal aquifers indicate relative freshwater throughout the study area

Mitigation of non-point source of fluoride on groundwater by dug well recharge

Science.gov (United States)

Ganesan, G.; Lakshmanan, E.

2017-12-01

Groundwater used for drinking purpose is affected in many regions due to the presence of excess fluoride. The excess intake of fluoride through drinking water causes fluorosis to human in many states of India, including Tamil Nadu. The present study was carried out with the objective of assessing hydrogeochemistry of groundwater and the feasibility of dug well recharge to reduce the fluoride concentration in Vaniyar river basin, Tamil Nadu, India. The major source for fluoride in groundwater of this area is the epidote hornblende gneissic and charnockite which are the major rocks occurring in this region. As a pilot study a cost effective induced recharge structure was constructed at Papichettipatty village in the study region. The study shows that the groundwater level around the recharge site raised up to 2 m from 14.5 m (bgl) and fluoride concentration has decreased from 3.8 mg/l to 0.9 mg/l due to dilution. The advantage of this induced recharge structure is of its low cost, the ease of implementation, improved groundwater recharge and dilution of fluoride in groundwater. An area of about 1.5 km2 has benefited due to this dug well recharge system.

A comparison of groundwater investigation using temporary points versus permanent monitoring wells

International Nuclear Information System (INIS)

Thompson, N.T.

1994-01-01

Groundwater investigation within the environmental industry is most often conducted using permanent monitoring wells. A monitoring well, as the term suggests, is permanent to the extent that it is fixed in place to monitor groundwater quality in its immediate vicinity at any given time over the course of an environmental project. Because monitoring wells are relatively time consuming and expensive to construct, a minimum number of wells is normally installed as part of a single investigation event. The initial information obtained from monitoring wells could also be obtained from temporary groundwater sampling points. Temporary points generally are smaller in diameter than monitoring wells, are installed to provide a one time snap shot of the subsurface, and are removed at the completion of the investigation. Since temporary points are usually easier to install and less expensive than monitoring wells, more temporary points can be installed over a single investigation event and can often reduce or eliminate subsequent assessment(s). A brief discussion of temporary point installation and sampling is offered before considering two case studies within the context of the above advantages to temporary point installation. One case study focuses on vertical delineation of dissolved petroleum hydrocarbons, while the second case study discusses lateral delineation of light nonaqueous phase liquid (LNAPL)

Groundwater quality in the Northern Coast Ranges Basins, California

Science.gov (United States)

Mathany, Timothy M.; Belitz, Kenneth

2015-01-01

The Northern Coast Ranges (NOCO) study unit is 633 square miles and consists of 35 groundwater basins and subbasins (California Department of Water Resources, 2003; Mathany and Belitz, 2015). These basins and subbasins were grouped into two study areas based primarily on locality. The groundwater basins and subbasins located inland, not adjacent to the Pacific Ocean, were aggregated into the Interior Basins (NOCO-IN) study area. The groundwater basins and subbasins adjacent to the Pacific Ocean were aggregated into the Coastal Basins (NOCO-CO) study area (Mathany and others, 2011).

An analytical study on groundwater flow in drainage basins with horizontal wells

Science.gov (United States)

Wang, Jun-Zhi; Jiang, Xiao-Wei; Wan, Li; Wang, Xu-Sheng; Li, Hailong

2014-06-01

Analytical studies on release/capture zones are often limited to a uniform background groundwater flow. In fact, for basin-scale problems, the undulating water table would lead to the development of hierarchically nested flow systems, which are more complex than a uniform flow. Under the premise that the water table is a replica of undulating topography and hardly influenced by wells, an analytical solution of hydraulic head is derived for a two-dimensional cross section of a drainage basin with horizontal injection/pumping wells. Based on the analytical solution, distributions of hydraulic head, stagnation points and flow systems (including release/capture zones) are explored. The superposition of injection/pumping wells onto the background flow field leads to the development of new internal stagnation points and new flow systems (including release/capture zones). Generally speaking, the existence of n injection/pumping wells would result in up to n new internal stagnation points and up to 2n new flow systems (including release/capture zones). The analytical study presented, which integrates traditional well hydraulics with the theory of regional groundwater flow, is useful in understanding basin-scale groundwater flow influenced by human activities.

The distribution and hydrogeological controls of fluoride in the groundwater of central Ethiopian rift and adjacent highlands

Science.gov (United States)

Ayenew, Tenalem

2008-05-01

Occurrence of fluoride (F) in groundwater has drawn worldwide attention, since it has considerable impact on human health. In Ethiopia high concentrations of F in groundwaters used for community water supply have resulted in extensive dental and skeletal fluorosis. As a part of a broader study, the distribution of F in groundwater has been investigated, and compared with bedrock geology and pertinent hydrochemical variables. The result indicates extreme spatial variations. High F concentration is often associated with active and sub-active regional thermal fields and acidic volcanics within high temperature rift floor. Variations in F can also be related to changes in calcium concentration resulting from dissolution of calcium minerals and mixing with waters of different chemical composition originated from variable hydrogeological environment across the rift valley. The concentration of F dramatically declines from the rift towards the highlands with the exception of scattered points associated with thermal springs confined in local volcanic centers. There are also interactions of F-rich alkaline lakes and the surrounding groundwater. Meteoric waters recharging volcanic aquifers become enriched with respect to F along the groundwater flow path from highland recharge areas to rift discharge areas. Locally wells drilled along large rift faults acting as conduits of fresh highland waters show relatively lower F. These areas are likely to be possible sources of better quality waters within the rift. The result of this study has important implications on site selection for water well drilling.

Several natural indicators of radial well ageing at the Belgrade groundwater source, part 1.

Science.gov (United States)

Dimkić, M; Pusić, M; Vidovic, D; Petković, A; Boreli-Zdravković, D

2011-01-01

Over time, the radial collector wells of the Belgrade Groundwater Source, located in the alluvial sediments of the Sava River, exhibit a decline in discharge and a reduction in operating efficiency due to well ageing. An increase in hydraulic losses at the lateral screens, due to chemical and biochemical clogging, has been identified as the primary cause. Certain hydrogeological, hydrochemical and microbiological parameters reflect the well-ageing process and can, therefore, be considered as its indicators. An indicator-based determination of scale is an important aspect in the selection of appropriate well locations, structural characteristics, and maintenance approaches. Well ageing was studied over a period of 5 years (2005-2009). The objective was to investigate the causes of well ageing. The correlations established between the groundwater redox potential, the total iron concentration in groundwater, the grain-size distribution of the aquifer, and well discharge, are presented in the paper.

groundwater quality assessment of wells in ifewara, osun state

African Journals Online (AJOL)

influences as a result of factors such as overpopulation and activities (including agriculture, indiscriminate refuse disposal and use of septic tanks, soak away and latrines) which are capable of producing run-offs and leachate which could infiltrate into and pollute groundwater formation. Many households depend on wells ...

Identify the Effective Wells in Determination of Groundwater Depth in Urmia Plain Using Principle Component Analysis

Directory of Open Access Journals (Sweden)

Sahar Babaei Hessar

2017-06-01

observations (n, here it is the number of years. So, for each well there are a 10 * 10 matrix. It should be noted in monitoring adjacent wells to a specific well, its dataset is not used. To quantify the effect of each well according to the number of its participation in the analysis and frequency of its effectiveness, each well is ranked. In the next step, the ineffective wells were recognized and eliminated using both the variation coefficient and Error criteria. Following, the procedure will be discussed. Results Discussion: In this study, at first step using PCA technique wells were identified with a more than 0.9 correlation coefficient. Then each well ranked based on the relative importance and according to the specified thresholds, the variation coefficient and error of monitoring was estimated. The wells remain in threshold 1 led to the lowest variation coefficient, considered as effective wells in the evaluation of aquifer parameters. By eliminating ineffective wells at each threshold, the variation coefficient is reduced because of the elimination of wells with a greater difference in water depth compared to the average of whole wells. To check the certainty of obtained results, the error criteria were calculated for each threshold. According to the results, both variation coefficient and standard error of monitoring in threshold 1 come to be at least. Thus, 12 wells remain in the threshold 1 are considered as the important wells in monitoring the water table of plain Urmia. Monitoring error for these 12 wells is equal to 5.1 % which is negligible and can be introduced as index wells in sampling and estimation of groundwater table in plain Urmia. Using this method, instead measurements of water table in 51 wells it can be performed exclusively in the 12 wells. Conclusion: Due to reduction of precipitation and unauthorized uses of groundwater resources, water table monitoring is very important in the accurate management of these resources. Because of extensive

Heterogeneous redox conditions, arsenic mobility, and groundwater flow in a fractured-rock aquifer near a waste repository site in New Hampshire, USA

Science.gov (United States)

Anthropogenic sources of carbon from landfill or waste leachate can promote reductive dissolution of in situ arsenic (As) and enhance the mobility of As in groundwater. Groundwater from residential-supply wells in a fractured crystalline-rock aquifer adjacent to a Superfund site ...

Evaluation of Pre- and Post- Redevelopment Groundwater Chemical Analyses from LM Monitoring Wells

International Nuclear Information System (INIS)

Kamp, Susan; Dayvault, Jalena

2016-01-01

This report documents the efforts and analyses conducted for the Applied Studies and Technology (AS&T) Ancillary Work Plan (AWP) project titled Evaluation of Pre- and Post- Redevelopment Groundwater Sample Laboratory Analyses from Selected LM Groundwater Monitoring Wells. This effort entailed compiling an inventory of nearly 500 previous well redevelopment events at 16 U.S. Department of Energy Office of Legacy Management (LM) sites, searching the literature for impacts of well redevelopment on groundwater sample quality, and-the focus of this report-evaluating the impacts of well redevelopment on field measurements and sample analytical results. Study Catalyst Monitoring well redevelopment, the surging or high-volume pumping of a well to loosen and remove accumulated sediment and biological build-up from a well, is considered an element of monitoring well maintenance that is implemented periodically during the lifetime of the well to mitigate its gradual deterioration. Well redevelopment has been conducted fairly routinely at a few LM sites in the western United States (e.g., the Grand Junction office site and the Gunnison processing site in Colorado), but at most other sites in this region it is not a routine practice. Also, until recently (2014-2015), there had been no specific criteria for implementing well redevelopment, and documentation of redevelopment events has been inconsistent. A catalyst for this evaluation was the self-identification of these inconsistencies by the Legacy Management Support contractor. As a result, in early 2015 Environmental Monitoring Operations (EMO) staff began collecting and documenting additional field measurements during well redevelopment events. In late 2015, AS&T staff undertook an independent internal evaluation of EMO's well redevelopment records and corresponding pre- and post-well-redevelopment groundwater analytical results. Study Findings Although literature discussions parallel the prevailing industry

Evaluation of Pre- and Post- Redevelopment Groundwater Chemical Analyses from LM Monitoring Wells

Energy Technology Data Exchange (ETDEWEB)

Kamp, Susan [Navarro Reserch and Engineering, Oak Ridge, TN (United States); Dayvault, Jalena [US Department of Energy, Washington, DC (United States). Office of Legacy Management

2016-05-01

This report documents the efforts and analyses conducted for the Applied Studies and Technology (AS&T) Ancillary Work Plan (AWP) project titled Evaluation of Pre- and Post- Redevelopment Groundwater Sample Laboratory Analyses from Selected LM Groundwater Monitoring Wells. This effort entailed compiling an inventory of nearly 500 previous well redevelopment events at 16 U.S. Department of Energy Office of Legacy Management (LM) sites, searching the literature for impacts of well redevelopment on groundwater sample quality, and—the focus of this report—evaluating the impacts of well redevelopment on field measurements and sample analytical results. Study Catalyst Monitoring well redevelopment, the surging or high-volume pumping of a well to loosen and remove accumulated sediment and biological build-up from a well, is considered an element of monitoring well maintenance that is implemented periodically during the lifetime of the well to mitigate its gradual deterioration. Well redevelopment has been conducted fairly routinely at a few LM sites in the western United States (e.g., the Grand Junction office site and the Gunnison processing site in Colorado), but at most other sites in this region it is not a routine practice. Also, until recently (2014–2015), there had been no specific criteria for implementing well redevelopment, and documentation of redevelopment events has been inconsistent. A catalyst for this evaluation was the self-identification of these inconsistencies by the Legacy Management Support contractor. As a result, in early 2015 Environmental Monitoring Operations (EMO) staff began collecting and documenting additional field measurements during well redevelopment events. In late 2015, AS&T staff undertook an independent internal evaluation of EMO's well redevelopment records and corresponding pre- and post-well-redevelopment groundwater analytical results. Study Findings Although literature discussions parallel the prevailing industry

Field Testing of an In-well Point Velocity Probe for the Rapid Characterization of Groundwater Velocity

Science.gov (United States)

Osorno, T.; Devlin, J. F.

2017-12-01

Reliable estimates of groundwater velocity is essential in order to best implement in-situ monitoring and remediation technologies. The In-well Point Velocity Probe (IWPVP) is an inexpensive, reusable tool developed for rapid measurement of groundwater velocity at the centimeter-scale in monitoring wells. IWPVP measurements of groundwater speed are based on a small-scale tracer test conducted as ambient groundwater passes through the well screen and the body of the probe. Horizontal flow direction can be determined from the difference in tracer mass passing detectors placed in four funnel-and-channel pathways through the probe, arranged in a cross pattern. The design viability of the IWPVP was confirmed using a two-dimensional numerical model in Comsol Multiphysics, followed by a series of laboratory tank experiments in which IWPVP measurements were calibrated to quantify seepage velocities in both fine and medium sand. Lab results showed that the IWPVP was capable of measuring the seepage velocity in less than 20 minutes per test, when the seepage velocity was in the range of 0.5 to 4.0 m/d. Further, the IWPVP estimated the groundwater speed with a precision of ± 7%, and an accuracy of ± 14%, on average. The horizontal flow direction was determined with an accuracy of ± 15°, on average. Recently, a pilot field test of the IWPVP was conducted in the Borden aquifer, C.F.B. Borden, Ontario, Canada. A total of approximately 44 IWPVP tests were conducted within two 2-inch groundwater monitoring wells comprising a 5 ft. section of #8 commercial well screen. Again, all tests were completed in under 20 minutes. The velocities estimated from IWPVP data were compared to 21 Point Velocity Probe (PVP) tests, as well as Darcy-based estimates of groundwater velocity. Preliminary data analysis shows strong agreement between the IWPVP and PVP estimates of groundwater velocity. Further, both the IWPVP and PVP estimates of groundwater velocity appear to be reasonable when

The installation of a multiport ground-water sampling system in the 300 Area

International Nuclear Information System (INIS)

Gilmore, T.J.

1989-06-01

In 1988, the Pacific Northwest Laboratory installed a multiport groundwater sampling system in well 399-1-20, drilled north of the 300 Area on the Hanford Site in southwestern Washington State. The purpose of installing the multiport system is to evaluate methods of determining the vertical distribution of contaminants and hydraulic heads in ground water. Well 399-1-20 is adjacent to a cluster of four Resource Conservation and Recovery Act (RCRA) ground-water monitoring wells. This proximity makes it possible to compare sampling intervals and head measurements between the multiport system and the RCRA monitoring wells. Drilling and installation of the multiport system took 42 working days. Six sampling ports were installed in the upper unconfined aquifer at depths of approximately 120, 103, 86, 74, 56, and 44 feet. The locations of the sampling ports were determined by the hydrogeology of the area and the screened intervals of adjacent ground-water monitoring wells. The system was installed by backfilling sand around the sampling ports and isolating the ports with bentonite seals. The method proved adequate. For future installation, however, development and evaluation of an alternative method is recommended. In the alternative method suggested, the multiport system would be placed inside a cased and screened well, using packers to isolate the sampling zones. 4 refs., 8 figs., 1 tab

Explanation of significant differences for the TNX groundwater operable unit

International Nuclear Information System (INIS)

Palmer, E.R.

1997-01-01

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

Using geochemistry to identify the source of groundwater to Montezuma Well, a natural spring in Central Arizona, USA: Part 2

Science.gov (United States)

Johnson, Raymond H.; DeWitt, Ed; Wirt, Laurie; Manning, Andrew H.; Hunt, Andrew G.

2012-01-01

Montezuma Well is a unique natural spring located in a sinkhole surrounded by travertine. Montezuma Well is managed by the National Park Service, and groundwater development in the area is a potential threat to the water source for Montezuma Well. This research was undertaken to better understand the sources of groundwater to Montezuma Well. Strontium isotopes (87Sr/86Sr) indicate that groundwater in the recharge area has flowed through surficial basalts with subsequent contact with the underlying Permian aged sandstones and the deeper, karstic, Mississippian Redwall Limestone. The distinctive geochemistry in Montezuma Well and nearby Soda Springs (higher concentrations of alkalinity, As, B, Cl, and Li) is coincident with added carbon dioxide and mantle-sourced He. The geochemistry and isotopic data from Montezuma Well and Soda Springs allow for the separation of groundwater samples into four categories: (1) upgradient, (2) deep groundwater with carbon dioxide, (3) shallow Verde Formation, and (4) mixing zone. δ18O and δD values, along with noble gas recharge elevation data, indicate that the higher elevation areas to the north and east of Montezuma Well are the groundwater recharge zones for Montezuma Well and most of the groundwater in this portion of the Verde Valley. Adjusted groundwater age dating using likely 14C and δ13C sources indicate an age for Montezuma Well and Soda Springs groundwaters at 5,400–13,300 years, while shallow groundwater in the Verde Formation appears to be older (18,900). Based on water chemistry and isotopic evidence, groundwater flow to Montezuma Well is consistent with a hydrogeologic framework that indicates groundwater flow by (1) recharge in higher elevation basalts to the north and east of Montezuma Well, (2) movement through the upgradient Permian and Mississippian units, especially the Redwall Limestone, and (3) contact with a basalt dike/fracture system that provides a mechanism for groundwater to flow to the surface

Re-thinking the unimpeded tube-well growth under the depleting groundwater resources in the Punjab, Pakistan

Science.gov (United States)

Watto, Muhammad Arif; Mugera, Amin W.; Kingwell, Ross; Saqab, Muhammad Mudasar

2018-04-01

Groundwater resources are crucial in sustaining agro-ecosystems and ensuring food security in many parts of the world, including Pakistan. However, the sustainability of groundwater resources is subject to a number of challenges, including over-extraction, deterioration in quality, and vulnerability to the impacts of climate change and population growth. Given the current state of groundwater resources in Pakistan, policymakers seek to manage groundwater resources by limiting groundwater extraction. To achieve this goal on a national scale, it is important to understand the determinants of the decisions made by local farmers in respect of tube-well adoption. This study investigates smallholder farmers' decisions to adopt tube-well technology in the face of dwindling groundwater resources and falling water tables. Analysis is based on a cross-sectional survey of 200 rural households from the arid to semi-arid predominantly groundwater-irrigated plains of the Punjab province, Pakistan. It is found that farmers will adopt tube-well technology in pursuit of reliable irrigation water supplies to hedge against production risks but not against the risk associated with unfavourable extreme events (downside risk) such as total crop failure. This suggests that the adoption decision is influenced by the expected long-term rather than the short-term benefits. This paper draws attention to the need to regulate groundwater resource exploitation by requiring the use of tube-well technology to be accompanied by irrigation water-efficient techniques and technologies.

An Assessment of Peri-Urban Groundwater Quality from Shallow Dug Wells, Mzuzu, Malawi

Science.gov (United States)

Holm, R.; Felsot, A.

2012-12-01

Throughout Malawi, governmental, non-governmental, religious and civic organizations are targeting the human need for water. Diarrheal diseases, often associated with unsafe drinking water, are a leading cause of mortality in children under five in Malawi with over 6,000 deaths per year (World Health Organization, 2010). From January to March 2012, a field study was undertaken in Malawi to study water quality and develop a public health risk communication strategy. The region studied, Area 1B, represents a comparatively new peri-urban area on the edge of Mzuzu city. Area 1B is serviced by a piped municipal water supply, but many shallow dug wells are also used for household water. Groundwater samples were collected from 30 shallow dug well sites and analyzed for nitrate, total coliform, Escherichia coli, total hardness, total alkalinity and pH. In addition to water quality analyses, a structured household questionnaire was administered to address water use, sanitation, health, consumption patterns, and socioeconomics. Results showed that more than half of the groundwater samples would be considered of unacceptable quality based on World Health Organization (WHO) standards for E. coli contamination. Low levels of nitrate were found in groundwater, but only one well exceeded WHO standards. The structured questionnaire revealed that some residents were still consuming groundwater despite the access to safer municipal water. In general, the widespread E. coli contamination was not statistically correlated with well depth, latrine proximity, or surface features. Similarly, nitrate concentrations were not significantly correlated with proximity to latrines. On the other hand, nitrate was correlated with well depth, which is expected given the high potential for leaching of anionic highly water soluble compounds. E. coli was significantly correlated with nitrate concentration. Projects targeting the need for clean water need to recognize that households with access to a

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

Science.gov (United States)

Bachmann, Matthew P.

2015-10-21

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

Groundwater recharge estimates of the Indian Wells Basin (California) using geochemical analysis of tritium

Science.gov (United States)

Faulkner, K. E.; Hagedorn, K. B.

2017-12-01

Quantifying recharge in groundwater basins located in an arid climate is difficult due to the effects of evapotranspiration and generally low rates of inflow. Constraining recharge for the Indian Wells Valley (IWV) will allow a more refined assessment of groundwater sustainability in the basin. In this study, a well-mixed reservoir model, the decay rate of tritium, groundwater tritium data acquired from USGS, and atmospheric tritium data acquired from IAEA allow for calculation of renewal rate within IWV. The resulting renewal rate throughout the basin show correlation to travel time from the source of recharge to the measurement location in keeping with the well-mixed reservoir model. The renewal rate can be used with porosity and effective aquifer thickness to generate recharge rates ranging from 4.7 cm/yr to 10 cm/yr. Refinement of the porosity and effective aquifer thickness values at each sample location is necessary to constrain recharge rates. Groundwater modeling generated recharge rates (9.32 cm/yr) fall within this range. These results are in keeping with the well-mixed aquifer model and fall within a reasonable range for an arid climate, which shows the applicability of the method.

Review: Moisture loading—the hidden information in groundwater observation well records

Science.gov (United States)

van der Kamp, Garth; Schmidt, Randy

2017-12-01

Changes of total moisture mass above an aquifer such as snow accumulation, soil moisture, and storage at the water table, represent changes of mechanical load acting on the aquifer. The resulting moisture-loading effects occur in all observation well records for confined aquifers. Deep observation wells therefore act as large-scale geological weighing lysimeters, referred to as "geolysimeters". Barometric pressure effects on groundwater levels are a similar response to surface loading and are familiar to every hydrogeologist dealing with the "barometric efficiency" of observation wells. Moisture-loading effects are small and generally not recognized because they are obscured by hydraulic head fluctuations due to other causes, primarily barometric pressure changes. For semiconfined aquifers, long-term moisture-loading effects may be dissipated and obscured by transient flow through overlying aquitards. Removal of barometric and earth tide effects from observation well records allows identification of moisture loading and comparison with hydrological observations, and also comparison with the results of numerical models that can account for transient groundwater flow.

Hydrographs Showing Ground-Water Level Changes for Selected Wells in the Lower Skagit River Basin, Washington

Science.gov (United States)

Fasser, E.T.; Julich, R.J.

2009-01-01

Hydrographs for selected wells in the Lower Skagit River basin, Washington, are presented in an interactive web-based map to illustrate monthly and seasonal changes in ground-water levels in the study area. Ground-water level data and well information were collected by the U.S. Geological Survey using standard techniques and were stored in the USGS National Water Information System (NWIS), Ground-Water Site-Inventory (GWSI) System.

Sustainable in-well vapor stripping: A design, analytical model, and pilot study for groundwater remediation

Science.gov (United States)

Sutton, Patrick T.; Ginn, Timothy R.

2014-12-01

A sustainable in-well vapor stripping system is designed as a cost-effective alternative for remediation of shallow chlorinated solvent groundwater plumes. A solar-powered air compressor is used to inject air bubbles into a monitoring well to strip volatile organic compounds from a liquid to vapor phase while simultaneously inducing groundwater circulation around the well screen. An analytical model of the remediation process is developed to estimate contaminant mass flow and removal rates. The model was calibrated based on a one-day pilot study conducted in an existing monitoring well at a former dry cleaning site. According to the model, induced groundwater circulation at the study site increased the contaminant mass flow rate into the well by approximately two orders of magnitude relative to ambient conditions. Modeled estimates for 5 h of pulsed air injection per day at the pilot study site indicated that the average effluent concentrations of dissolved tetrachloroethylene and trichloroethylene can be reduced by over 90% relative to the ambient concentrations. The results indicate that the system could be used cost-effectively as either a single- or multi-well point technology to substantially reduce the mass of dissolved chlorinated solvents in groundwater.

Strategies for safe exploitation of fresh water through multi-strainer skimming wells in saline groundwater areas

International Nuclear Information System (INIS)

Alam, M.M.; Jaffery, H.M.; Hanif, M.

2005-01-01

Due to growing population of Pakistan, there is a tremendous pressure on our agriculture sector to increase its production to meet the food and fiber requirement. Water is a basic need to increase the agriculture production and to bring more areas under cultivation. The exploitation of groundwater resources is increasing because of limited surface water availability. Statistics indicated that number of public and private tube-wells have increased to more than 5 lacs. Over exploitations of groundwater caused a number of environmental problems including salt water intrusion and increase in the soil and groundwater salinity. A large number of fresh water tube-wells have started pumping saline groundwater in various parts of Pakistan indicating up-coning of saline groundwater in the relatively fresh water aquifers. Use of poor quality groundwater for irrigation is considered as one of the major causes of salinity in the areas of irrigated agriculture. Indiscriminate pumping of the groundwater of marginal quality through skimming fresh water overlain by saline groundwater can not be helpful in the long run. It can add to the root zone salinity and ultimately reduction of crops yield. Mona Reclamation Experimental Project (MREP) is conducting a collaborative research study on 'Root Zone Salinity Management using Fractional Skimming Wells with Pressurized Irrigation' under a research and studies portfolio of the country wide National Drainage Programme (NDP) MREP, IWMI Pakistan and Water Resources Research Institute of PARC are collaborators in this joint research effort. MREP is responsible to specifically address the objective of the study to identify and test a limited number of promising skimming well techniques in the shallow fresh water aquifers which could control the saline water up-coning phenomenon as a consequence of groundwater pumping. Detailed investigations have been done at various locations in the north-central part of Chaj Doab (Sargodha Region) in the

Hydraulic evaluation of the groundwater conditions at Finnsjoen. The effects on dilution in a domestic well

International Nuclear Information System (INIS)

Axelsson, C.L.; Bystroem, J.; Eriksson, Aa.; Holmen, J.; Haitjema, H.M.

1991-09-01

The Swedish Nuclear Fuel and Waste Management Company (SKB) is presently performing a safety analysis study, SKB 91, for a final repository for spent nuclear fuel. The study is carried out for a generic repository located to the Finnsjoen area, which is one of SKBs oldest study-areas. An important part of the safety analysis is the dose calculations. Radionuclides can be transported to the biosphere via the sea, a lake, and via extraction of groundwater from drilled or dug wells. Thus, an important scenario to study is the dilution of radionuclides in a domestic well drilled in the future close to the repository. The present study is discussing; * Localization, drilling and construction of wells. * Specific capacities and chloride content of the rock mass and wells found in the Finnsjoe are. * Risk areas for future drilled wells. * Dilution in future wells drilled in fracture zones or in the hard rock in the vicinity of the repository. The evaluations show that a well pumping 6 m 3 /day, located in a fracture zone or in the rock mass, has no influence on the local groundwater flow system except for the very vicinity of the well. Consequently, a well may be drilled in the hard rock without any risk of pumping groundwater that has passed the repository. Wells may also be located anywhere in fracture zones, except for in the very discharge area, without any risk of getting groundwater affected by the repository. Modelling indicate that a well drilled in the discharge area for contaminated groundwater, may collect all groundwater from the repository. However, this is based on assumptions of homogeneous continuous fracture zones with a high hydraulic conductivity compared to the rock mass, which will give rise to a concentrated discharge area. (44 refs., 31 figs., 6 tabs.) (au)

Environmental implementation plan: Chapter 7, Groundwater protection

International Nuclear Information System (INIS)

Wells, D.

1994-01-01

The Savannah River Site (SRS) uses large quantities of groundwater for drinking, processing, and non-contact cooling. Continued industrial and residential growth along with additional agricultural irrigation in areas adjacent to SRS will increase the demand for groundwater. This increasing demand will require a comprehensive management system to ensure the needed quality and quantity of groundwater is available for all users. The Groundwater Protection Program and the Waste Management Program establish the overall framework for protecting this resource. Ground water under SRS is monitored extensively for radiological, hazardous, and water quality constituents. Groundwater quality is known to have been affected at 33 onsite locations, but none of the contaminant plumes have migrated offsite. Onsite and offsite drinking water supplies are monitored to ensure they are not impacted. The site has more than 1800 monitoring wells from which groundwater samples are analyzed for radiological and non-radiological constituents. SRS is complying with all applicable regulations related to groundwater protection, waste treatment, and waste disposal. The existing waste storage facilities are permitted or are being permitted. Existing hazardous- and mixed-waste storage facilities are being included in the site Resource Conservation and Recovery Act (RCRA) Part B Permit. Part B permitting has been initiated for many of the planned hazardous- and mixed-waste treatment and disposal facilities

A case study of optimization in the decision process: Siting groundwater monitoring wells

International Nuclear Information System (INIS)

Cardwell, H.; Huff, D.; Douthitt, J.; Sale, M.

1993-12-01

Optimization is one of the tools available to assist decision makers in balancing multiple objectives and concerns. In a case study of the siting decision for groundwater monitoring wells, we look at the influence of the optimization models on the decisions made by the responsible groundwater specialist. This paper presents a multi-objective integer programming model for determining the location of monitoring wells associated with a groundwater pump-and-treat remediation. After presenting the initial optimization results, we analyze the actual decision and revise the model to incorporate elements of the problem that were later identified as important in the decision-making process. The results of a revised model are compared to the actual siting plans, the recommendations from the initial optimization runs, and the initial monitoring network proposed by the decision maker

Installation of Groundwater Monitoring Wells TAV-MW15 and TAV-MW16.

Energy Technology Data Exchange (ETDEWEB)

Lum, Clinton C. L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

This report documents the installation of two groundwater monitoring wells at the Technical Area V Groundwater (TAVG) Area of Concern at Sandia National Laboratories, New Mexico (SNL/NM). SNL/NM is managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA- 0003525. Well installation activities were conducted in accordance with the New Mexico Environment Department (NMED) Hazardous Waste Bureau (HWB)-approved work plan Revised Treatability Study Work Plan for In-Situ Bioremediation at the Technical Area-V Groundwater Area of Concern (Work Plan) (SNL/NM March 2016). The Work Plan was approved by NMED HWB prior to the start of field work (NMED May 2016). Project activities were performed from November 2016 through January 2017 by SNL/NM Environmental Restoration (ER) Operations personnel, and the SNL/NM drilling contractor Cascade Drilling LP. Drilling activities began with borehole drilling and sampling on November 30, 2016. Well construction and development fieldwork was completed on January 31, 2017. Land surveys to establish the location coordinates and elevations of the two wells were completed on March 23, 2017, and transmitted to SNL/NM personnel on April 17, 2017.

The Savannah River Site's Groundwater Monitoring Program 1991 well installation report

International Nuclear Information System (INIS)

1992-06-01

This report is a summary of the well and environmental soil boring information compiled for the groundwater monitoring program of the Environmental Protection Department/Environmental Monitoring Section (EPD/EMS) at the Savannah River Site (SRS) during 1991. It includes discussion of environmental soil borings, surveying, well installations, abandonments, maintenance, and stabilization

Properties of Sealing Materials in Groundwater Wells

DEFF Research Database (Denmark)

Köser, Claus

pellets as sealing material in groundwater wells. The way and the pattern, in which bentonite pellets are deposited, have been shown to have an effect on the swelling pressure of the bentonite seal. During the transport phase of pellets from the terrain to a given sedimentation depth, a sorting process......) into densities for clay/water systems has been developed. This method has successfully been used to evaluate e.g., macroporosity, homogenization of the bentonite seal during the hydration of water, hydraulic conductivity and the creation of channels in the bentonite seals. Based on the results obtained...

Nitrate variability in groundwater of North Carolina using monitoring and private well data models.

Science.gov (United States)

Messier, Kyle P; Kane, Evan; Bolich, Rick; Serre, Marc L

2014-09-16

Nitrate (NO3-) is a widespread contaminant of groundwater and surface water across the United States that has deleterious effects to human and ecological health. This study develops a model for predicting point-level groundwater NO3- at a state scale for monitoring wells and private wells of North Carolina. A land use regression (LUR) model selection procedure is developed for determining nonlinear model explanatory variables when they are known to be correlated. Bayesian Maximum Entropy (BME) is used to integrate the LUR model to create a LUR-BME model of spatial/temporal varying groundwater NO3- concentrations. LUR-BME results in a leave-one-out cross-validation r2 of 0.74 and 0.33 for monitoring and private wells, effectively predicting within spatial covariance ranges. Results show significant differences in the spatial distribution of groundwater NO3- contamination in monitoring versus private wells; high NO3- concentrations in the southeastern plains of North Carolina; and wastewater treatment residuals and swine confined animal feeding operations as local sources of NO3- in monitoring wells. Results are of interest to agencies that regulate drinking water sources or monitor health outcomes from ingestion of drinking water. Lastly, LUR-BME model estimates can be integrated into surface water models for more accurate management of nonpoint sources of nitrogen.

Mixed Waste Management Facility (MWMF) groundwater monitoring report. Fourth quarter 1992 and 1992 summary

Energy Technology Data Exchange (ETDEWEB)

1993-03-01

During fourth quarter 1992, nine constituents exceeded final Primary Drinking Water Standards (PDWS) in one or more groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. As in previous quarters, tritium and trichloroethylene were the most widespread constituents. Fifty-seven (48%) of the 120 monitoring wells, contained elevated tritium activities, and 23 (19%) contained elevated trichloroethylene concentrations. Total alpha-emitting radium, tetrachloroethylene, chloroethene, cadmium, 1,1-dichloroethylene, lead, or nonvolatile beta levels exceeded standards in one or more wells. During 1992, elevated levels of 13 constituents were found in one or more of 80 of the 120 groundwater monitoring wells (67%) at the MWMF and adjacent facilities. Tritium and trichloroethylene exceeded their final PDWS more frequently and more consistently than did other constituents. Tritium activity exceeded its final PDWS m 67 wells and trichloroethylene was. elevated in 28 wells. Lead, tetrachloroethylene, total alpha-emitting radium, gross alpha, cadmium, chloroethene, 1,1-dichloroethylene 1,2-dichloroethane, mercury, or nitrate exceeded standards in one or more wells during the year. Nonvolatile beta exceeded its drinking water screening level in 3 wells during the year.

Well-Construction, Water-Level, and Water-Quality Data for Ground-Water Monitoring Wells for the J4 Hydrogeologic Study, Arnold Air Force Base, Tennessee

National Research Council Canada - National Science Library

Haugh, Connor J

1996-01-01

...) in Coffee County, Tennessee. The wells ranged from 28 to 289 feet deep and were installed to provide information on subsurface lithology, aquifer characteristics, ground-water levels, and ground-water quality...

Development and application of groundwater flow meter in fractured rocks: Measurement of velocity and direction of groundwater flow in single well

International Nuclear Information System (INIS)

Kawanishi, M.; Miyakawa, K.; Hirata, Y.

2001-01-01

For the confirmation of safety for the geological disposal of radioactive wastes, it is very important to demonstrate the groundwater flow by in-situ investigation in the deep underground. We have developed a groundwater flow meter to measure simultaneously the velocity and direction of groundwater flow by means of detecting the electric potential difference between the groundwater to evaluate and the distilled water as a tracer in a single well. In this paper, we describe the outline of the groundwater flow meter system developed by CRIEPI and Taisei-Kiso-Sekkei Co. Ltd. and the evaluation methodology for observed data by using it in fractured rocks. Furthermore, applied results to in-situ tests at the Tounou mine of Japan Nuclear Fuel Cycle Development Institute (JNC) and the Aespoe Hard Rock Laboratory (HRL) of Swedish Nuclear Fuel and Waste Management Co. (SK) are described. Both sites are different type of fractured rock formations of granite. From these results, it was made clear that this flow meter system can be practically used to measure the groundwater flow direction and velocity as low as order of 1x10 -3 ∼10 -7 cm/sec. (author)

Ground-water contribution to dose from past Hanford Operations

International Nuclear Information System (INIS)

Freshley, M.D.; Thorne, P.D.

1992-08-01

The Hanford Environmental Dose Reconstruction (HEDR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides migrating in ground water on the Hanford Site could have reached the public have been identified: (1) through contaminated ground water migrating to the Columbia River; (2) through wells on or adjacent to the Hanford Site; (3) through wells next to the Columbia River downstream of Hanford that draw some or all of their water from the river (riparian wells); and (4) through atmospheric deposition resulting in contamination of a small watershed that, in turn, results in contamination of a shallow well or spring by transport in the ground water. These four pathways make up the ''ground-water pathway,'' which is the subject of this study. Assessment of the ground-water pathway was performed by (1) reviewing the existing extensive literature on ground water and ground-water monitoring at Hanford and (2) performing calculations to estimate radionuclide concentrations where no monitoring data were collected. Radiation doses that would result from exposure to these radionuclides were calculated

Ground-water altitudes and well data, Nye County, Nevada, and Inyo County, California

International Nuclear Information System (INIS)

Ciesnik, M.S.

1995-01-01

This report contains ground-water altitudes and well data for wells located in Nye County, Nevada, and Inyo County, California, south of Yucca Mountain, Nevada, the potential site for a high-level nuclear waste repository. Data are from wells whose coordinates are within the Beatty and Death Valley Junction, California-Nevada maps from the US Geological Survey, scale 1:100,000 (30-minute x 60-minute quadrangle). Compilation of these data was made to provide a reference for numerical models of ground-water flow at Yucca Mountain and its vicinity. Water-level measurements were obtained from the US Geological Survey National Water Information System (NWIS) data base, and span the period of October 1951 to May 1991; most measurements were made from 1980 to 1990

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

Science.gov (United States)

Barlow, Paul M.; Leake, Stanley A.

2012-11-02

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

Ground-water monitoring at the Hanford Site, January-December 1984

Energy Technology Data Exchange (ETDEWEB)

Cline, C.S.; Rieger, J.T.; Raymond, J.R.

1985-09-01

This program is designed to evaluate existing and potential pathways of exposure to radioactivity and hazardous chemicals from site operations. This document contains an evaluation of data collected during CY 1984. During 1984, 339 monitoring wells were sampled at various times for radioactive and nonradioactive constituents. Two of these constituents, specifically, tritium and nitrate, have been selected for detailed discussion in this report. Tritium and nitrate in the primary plumes originating from the 200 Areas continue to move generally eastward toward the Columbia River in the direction of ground-water flow. The movement within these plumes is indicated by changes in trends within the analytical data from the monitoring wells. No discernible impact on ground water has yet been observed from the start-up of the PUREX plant in December 1983. The shape of the present tritium plume is similar to those described in previous ground-water monitoring reports, although slight changes on the outer edges have been noted. Radiological impacts from two potential pathways for radionuclide transport in ground water to the environment are discussed in this report. The pathways are: (1) human consumption of ground water from onsite wells, and (2) seepage of ground water into the Columbia River. Concentrations of tritium in spring samples that were collected and analyzed in 1983, and in wells sampled adjacent to the Columbia River in 1984 confirmed that constituents in the ground water are entering the river via springs and subsurface flow. The primary areas where radionuclides enter the Columbia River via ground-water flow are the 100-N and 300 Areas and the shoreline adjacent to the Hanford Townsite. 44 refs., 25 figs., 11 tabs.

Using hydrogeology to identify the source of groundwater to Montezuma Well, a natural spring in central Arizona: part 1

Science.gov (United States)

Johnson, Raymond H.; DeWitt, Ed H.; Arnold, L. Rick

2012-01-01

Montezuma Well is a natural spring located within a “sinkhole” in the desert environment of the Verde Valley in Central Arizona. It is managed by the National Park Service as part of Montezuma Castle National Monument. Because of increasing development of groundwater in the area, this research was undertaken to better understand the sources of groundwater to Montezuma Well. The use of well logs and geophysics provides details on the geology in the area around Montezuma Well. This includes characterizing the extent and position of a basalt dike that intruded a deep fracture zone. This low permeability barrier forces groundwater to the surface at the Montezuma Well “pool” with sufficient velocity to entrain sand-sized particles from underlying bedrock. Permeable fractures along and above the basalt dike provide conduits that carry deep sourced carbon dioxide to the surface, which can dissolve carbonate minerals along the transport path in response to the added carbon dioxide. At the ground surface, CO2 degasses, depositing travertine. Geologic cross sections, rock geochemistry, and semi-quantitative groundwater flow modeling provide a hydrogeologic framework that indicates groundwater flow through a karstic limestone at depth (Redwall Limestone) as the most significant source of groundwater to Montezuma Well. Additional groundwater flow from the overlying formations (Verde Formation and Permian Sandstones) is a possibility, but significant flow from these units is not indicated.

Temperature logging of groundwater in bedrock wells for geothermal gradient characterization in New Hampshire, 2012

Science.gov (United States)

Degnan, James; Barker, Gregory; Olson, Neil; Wilder, Leland

2012-01-01

The U.S. Geological Survey, in cooperation with the New Hampshire Geological Survey, measured the fluid temperature of groundwater in deep bedrock wells in the State of New Hampshire in order to characterize geothermal gradients in bedrock. All wells selected for the study had low water yields, which correspond to low groundwater flow from fractures. This reduced the potential for flow-induced temperature changes that would mask the natural geothermal gradient in the bedrock. All the wells included in this study were privately owned, and permission to use the wells was obtained from homeowners before logging.

Electromagnetic analysis of groundwater on the Arizona-Utah border

Science.gov (United States)

Vander Vis, T.; Porter, R. C.; Macy, J. P.

2016-12-01

Understanding subsurface structure and groundwater flow is an essential part of managing groundwater resources, especially in southwestern United States where supply is limited and demand is increasing. This study describes the preliminary results of a transient electromagnetic survey conducted on the Arizona-Utah border to better understand the groundwater system which supplies water to many wells and springs in the region. Electromagnetic surveys are ideal for groundwater investigations because they can locate and characterize areas of high conductivity, which often are indicative of groundwater. The study area is on the southwestern margin of the Colorado Plateau and consists of uplifted, flat-lying sedimentary units. Regionally, groundwater is located within the Navajo Sandstone and underlying Kayenta Formation as an unconfined aquifer that extends from Pipe Springs National Monument north to the East Fork of the Virgin River. This area is characterized by step-like structural blocks that accommodate small amounts of extension and are bounded by long north-south-trending normal faults. The Sevier Fault runs through the sedimentary units near the study area and has been shown to influence groundwater movement by offsetting permeable units west of the fault adjacent to impermeable units east of the fault. Electromagnetic measurements were recorded with a Zonge GDP-32 receiver at 30 receiver locations at 16 and 32 Hz with a 100mx100m transmitter loop. These data were used to create a subsurface conductivity model. Water levels from local wells and local geologic data were utilized to relate the geophysical data to the groundwater system. Preliminary results define the depth to water table and the location of the groundwater divide between the groundwater that flows north towards the springs that feed the East Fork of the Virgin River and the groundwater that flows south towards Pipe Springs National Monument.

The value of iodide as a parameter in the chemical characterisation of groundwaters

Science.gov (United States)

Lloyd, J. W.; Howard, K. W. F.; Pacey, N. R.; Tellam, J. H.

1982-06-01

Brackish and saline groundwaters can severely constrain the use of fresh groundwaters. Their chemical characterisation is important in understanding the hydraulic conditions controlling their presence in an aquifer. Major ions are frequently of limited value but minor ions can be used. Iodide in groundwater is particularly significant in many environments due to the presence of soluble iodine in aquifer matrix materials. Iodide is found in groundwaters in parts of the English Chalk aquifer in concentrations higher than are present in modern seawater. Its presence is considered as a indication of groundwater residence and is of use in the characterisation of fresh as well as saline waters. Under certain circumstances modern seawater intrusion into aquifers along English estuaries produces groundwaters which are easily identified due to iodide enrichment from estuarine muds. In other environments iodide concentrations are of value in distinguishing between groundwaters in limestones and shaly gypsiferous rocks as shown by a study in Qatar, while in an alluvial aquifer study in Peru iodide has been used to identify groundwaters entering the aquifer from adjacent granodiorites.

Groundwater Discharge to Upper Barataria Basin Driven by Mississippi River Stage

Science.gov (United States)

Cable, J. E.; Kim, J.; Johannesson, K. H.; Kolker, A.; Telfeyan, K.; Breaux, A.

2017-12-01

Groundwater flow into deltaic wetlands occurs despite the heterogeneous and anisotropic depositional environment of deltas. Along the Mississippi River this groundwater flow is augmented by the vast alluvial aquifer and the levees which confine the river to a zone much more narrow than the historical floodplain. The effect of the levees has been to force the river stage to as much as 10 m above the adjacent back-levee wetlands. Consequently, the head difference created by higher river stages can drive groundwater flow into these wetlands, especially during flood seasons. We measured Rn-222 in the surface waters of a bayou draining a bottomland hardwood swamp in the lower Mississippi River valley over a 14-month period. With a half-life of 3.83 days and its conservative geochemical behavior, Rn-222 is a well-known tracer for groundwater inputs in both fresh and marine environments. Transects from the mouth to the headwaters of the bayou were monitored for Rn-222 in real-time using Rad-7s on a semi-monthly basis. We found that Rn-222 decreased exponentially from the swamp at the headwaters to the mouth of the bayou. Using a mass balance approach, we calculated groundwater inputs to the bayou headwaters and compared these discharge estimates to variations in Mississippi River stage. Groundwater inputs to the Barataria Basin, Louisiana, represent a significant fraction of the freshwater budget of the basin. The flow appears to occur through the sandy Point Bar Aquifer that lies adjacent to the river and underlies many of the freshwater swamps of the Basin. Tracer measurements throughout the Basin in these swamp areas appear to confirm our hypothesis about the outlet for groundwater in this deltaic environment.

Design of Infiltration Well in Wetlands Area that Suitable for Giving Maximum Groundwater Recharge

Directory of Open Access Journals (Sweden)

Irfan Prasetia

2016-02-01

Full Text Available Growth in residential, industrial, and office  area,are significantly occurred in all city in Indonesia. Unfortunately, this is also caused more land that being covered by pavement and concrete in the cities. Realized or not it will disturb the availability of the groundwater and also lead to flooding in the rainy season. One of the effective solutions to solve this problem is by making sufficient numbers of infiltration well in the city, especially in the residential area. This research was conducted to analyze the ideal design of the infiltration well in the residential area. The design was made according to the equation by Sunjoto, which also refers to Indonesia standard (SNI No: 03- 2453-2002. The results show that the ideal dimension for the infiltration well is to use the radius of the well (R of 1.25 m. With the R of 1.25 will give a significant recharge to the groundwater as much as ≈ 2.400 liter. It is expected that this research encourage a development in the urban drainage systems which will consider the environment and the groundwater reservation for the balance of our ecosystem.

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

Science.gov (United States)

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

2011-01-01

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

Hydrologic conditions in urban Miami-Dade County, Florida, and the effect of groundwater pumpage and increased sea level on canal leakage and regional groundwater flow

Science.gov (United States)

Hughes, Joseph D.; White, Jeremy T.

2014-01-01

The extensive and highly managed surface-water system in southeastern Florida constructed during the 20th Century has allowed for the westward expansion of urban and agricultural activities in Miami-Dade County. In urban areas of the county, the surface-water system is used to (1) control urban flooding, (2) supply recharge to production well fields, and (3) control seawater intrusion. Previous studies in Miami-Dade County have determined that on a local scale, leakage from canals adjacent to well fields can supply a large percentage (46 to 78 percent) of the total groundwater pumpage from production well fields. Canals in the urban areas also receive seepage from the Biscayne aquifer that is derived from a combination of local rainfall and groundwater flow from Water Conservation Area 3 and Everglades National Park, which are west of urban areas of Miami-Dade County.

Well-construction, water-level, geophysical, and water-quality data for ground-water monitoring wells for Arnold Air Force Base, Tennessee

Science.gov (United States)

Hough, C.J.; Mahoney, E.N.; Robinson, J.A.

1992-01-01

Sixty-five wells were installed at 39 sites in the Arnold Air Force Base area in Coffee and Franklin Counties, Tennessee. The wells were installed to provide information on subsurface lithology, aquifer characteristics, ground-water levels, and ground-water quality. Well depths ranged from 11 to 384 feet. Water-quality samples were collected from 60 wells and analyzed for common inorganic ions, trace metals, and volatile organic compounds. The median dissolved-solids concentrations were 60 milligrams per liter in the shallow aquifer, 48 million gallons per liter in the Manchester aquifer, 1,235 milligrams per liter in the Fort Payne aquifer, and 1,712 milligrams per liter in the upper Central Basin aquifer. Caliper, temperature, natural gamma, electric, neutron porosity, gamma-gamma density, and acoustic velocity borehole-geophysical logs were obtained for the six deep wells completed below the Chattanooga Shale. Petrographic and modal analysis were performed on rock samples from each deep well. These six deep wells provide the first information in the study area on hydraulic head and water quality from below the Chattanooga Shale.

Evaluation of groundwater levels in the South Platte River alluvial aquifer, Colorado, 1953-2012, and design of initial well networks for monitoring groundwater levels

Science.gov (United States)

Wellman, Tristan

2015-01-01

The South Platte River and underlying alluvial aquifer form an important hydrologic resource in northeastern Colorado that provides water to population centers along the Front Range and to agricultural communities across the rural plains. Water is regulated based on seniority of water rights and delivered using a network of administration structures that includes ditches, reservoirs, wells, impacted river sections, and engineered recharge areas. A recent addendum to Colorado water law enacted during 2002-2003 curtailed pumping from thousands of wells that lacked authorized augmentation plans. The restrictions in pumping were hypothesized to increase water storage in the aquifer, causing groundwater to rise near the land surface at some locations. The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board and the Colorado Water Institute, completed an assessment of 60 years (yr) of historical groundwater-level records collected from 1953 to 2012 from 1,669 wells. Relations of "high" groundwater levels, defined as depth to water from 0 to 10 feet (ft) below land surface, were compared to precipitation, river discharge, and 36 geographic and administrative attributes to identify natural and human controls in areas with shallow groundwater.

Desalination of brackish groundwater and concentrate disposal by deep well injection

NARCIS (Netherlands)

Wolthek, N.; Raat, K.; Ruijter, J.A.; Kemperman, Antonius J.B.; Oosterhof, A.

2013-01-01

In the province of Friesland (in the Northern part of The Netherlands), problems have arisen with the abstraction of fresh groundwater due to salinization of wells by upcoming of brackish water. A solution to this problem is to intercept (abstract) the upcoming brackish water, desalinate it with a

Incorporation of groundwater losses and well level data in rainfall-runoff models illustrated using the PDM

Directory of Open Access Journals (Sweden)

R. J. Moore

2002-01-01

Full Text Available Intermittent streamflow is a common occurrence in permeable catchments, especially where there are pumped abstractions to water supply. Many rainfall-runoff models are not formulated so as to represent ephemeral streamflow behaviour or to allow for the possibility of negative recharge arising from groundwater pumping. A groundwater model component is formulated here for use in extending existing rainfall-runoff models to accommodate such ephemeral behaviour. Solutions to the Horton-Izzard equation resulting from the conceptual model of groundwater storage are adapted and the form of nonlinear storage extended to accommodate negative inputs, water storage below which outflow ceases, and losses to external springs and underflows below the gauged catchment outlet. The groundwater model component is demonstrated through using it as an extension of the PDM rainfall-runoff model. It is applied to the River Lavant, a catchment in Southern England on the English Chalk, where it successfully simulates the ephemeral streamflow behaviour and flood response together with well level variations. Keywords: groundwater, rainfall-runoff model, ephemeral stream, well level, spring, abstraction

Potential effects of the Hawaii Geothermal Project on ground-water resources on the island of Hawaii

Science.gov (United States)

Sorey, M.L.; Colvard, E.M.

1994-01-01

In 1990, the State of Hawaii proposed the Hawaii Geothermal Project for the development of as much as 500 MW of electric power from the geothermal system in the East Rift Zone of Kilauea Volcano. This report uses data from 31 wells and 8 springs to describe the properties of the ground-water system in and adjacent to the East Rift Zone. Potential effects of this project on ground-water resources are also discussed. Data show differences in ground-water chemistry and heads within the study area that appear to be related to mixing of waters of different origins and ground-water impoundment by volcanic dikes. East of Pahoa, the ground-water system within the rift is highly transmissive and receives abundant recharge from precipitation; therefore, the pumping of freshwater to support geothermal development in that part of the rift zone would have a minimal effect on ground-water levels. To the southwest of Pahoa, dike impoundment reduces the transmissivity of the ground-water system to such an extent that wells might not be capable of supplying sufficient fresh water to support geothermal operations. Contamination of ground-water resources by accidental release of geothermal fluids into shallow aquifers is possible because of corrosive conditions in the geothermal wells, potential well blowouts, and high ground-water velocities in parts of the region. Hydrologic monitoring of water level, temperature, and chemistry in observation wells should continue throughout development of geothermal resources for the Hawaii Geothermal Project for early detection of leakage and migration of geothermal fluids within the groundwater system.

Hydrographs Showing Groundwater Level Changes for Selected Wells in the Chambers-Clover Creek Watershed and Vicinity, Pierce County, Washington

Science.gov (United States)

Justin, G.B.; Julich, R.; Payne, K.L.

2009-01-01

Selected groundwater level hydrographs for the Chambers-Clover Creek watershed (CCCW) and vicinity, Washington, are presented in an interactive web-based map to illustrate changes in groundwater levels in and near the CCCW on a monthly and seasonal basis. Hydrographs are linked to points corresponding to the well location on an interactive map of the study area. Groundwater level data and well information from Federal, State, and local agencies were obtained from the U.S. Geological Survey National Water Information System (NWIS), Groundwater Site Inventory (GWSI) System.

Sampling art for ground-water monitoring wells in nuclide migration

International Nuclear Information System (INIS)

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

2010-01-01

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

Groundwater flow analysis and dose rate estimates from releases to wells at a coastal site

Energy Technology Data Exchange (ETDEWEB)

Kattilakoski, E.; Suolanen, V. [VTT Energy, Espoo (Finland)

2000-09-01

In the groundwater flow modelling part of this work the effective dilution volume in the well scenario was estimated by means of transient simulations of groundwater flow and transport, which are coupled due to the varying salinity. Both deep, drilled wells and shallow surface wells in the vicinity of the repository were considered. The simulations covered the time period from the present to 1000 years after the present. Conceptually the fractured bedrock consists of planar fracture zones (with a high fracture density and a greater ability to conduct water) and the intact rock (in which the fracture density and the hydraulic conductivity are low). For them the equivalent-continuum model was applied separately. Thus, the fractured bedrock was considered as piecewise homogeneous (except for the depth dependence) and isotropic continuum with representative average characteristics. A generic simulation model for groundwater flow and solute transport was developed on the basis of geological, hydrogeological and hydrogeochemical data at a coastal area. The simulation model contains all the data necessary for the numerical simulations, i.e. the groundwater table and topography, salinity, the postglacial land uplift and sea level rise, the conceptual geometry of fracture zones, the hydraulic properties of the bedrock as well as the description of the modelling volume. The model comprises an area of about 26 km{sup 2}. It covers an island and the surrounding sea. The finite element code FEFTRA (formerly known as FEFLOW) was used in this work for the numerical solution. The channelling along the flow routes was found to be critical for the resulting in a well. A deep well may extend near the area of the deep flow routes, but in order to get flow routes into a shallow well, it has to be placed in the immediate vicinity of the discharge areas. According to the groundwater flow analyses the effective dilution volume of the well seems to vary from 30 000 m{sup 3}/a to 460 000 m

Design, placement, and sampling of groundwater monitoring wells for the management of hazardous waste disposal facilities

International Nuclear Information System (INIS)

Tsai, S.Y.

1988-01-01

Groundwater monitoring is an important technical requirement in managing hazardous waste disposal facilities. The purpose of monitoring is to assess whether and how a disposal facility is affecting the underlying groundwater system. This paper focuses on the regulatory and technical aspects of the design, placement, and sampling of groundwater monitoring wells for hazardous waste disposal facilities. Such facilities include surface impoundments, landfills, waste piles, and land treatment facilities. 8 refs., 4 figs

In-situ bioremediation via horizontal wells

International Nuclear Information System (INIS)

Hazen, T.C.; Looney, B.B.; Enzien, M.; Franck, M.M.; Fliermans, C.B.; Eddy, C.A.

1993-01-01

This project is designed to demonstrate in situ bioremediation of groundwater and sediment contaminated with chlorinated solvents. Indigenous microorganisms were stimulated to degrade TCE, PCE and their daughter products in situ by addition of nutrients to the contaminated zone. In situ biodegradation is a highly attractive technology for remediation because contaminants are destroyed, not simply moved to another location or immobilized, thus decreasing costs, risks, and time, while increasing efficiency and public and regulatory acceptability. Bioremediation has been found to be among the least costly technologies in applications where it will work (Radian 1989). Subsurface soils and water adjacent to an abandoned process sewer line at the SRS have been found to have elevated levels of TCE (Marine and Bledsoe 1984). This area of subsurface and groundwater contamination is the focus of a current integrated demonstration of new remediation technologies utilizing horizontal wells. Bioremediation has the potential to enhance the performance of in situ air stripping as well as offering stand-alone remediation of this and other contaminated sites (Looney et al. 1991). Horizontal wells could also be used to enhance the recovery of groundwater contaminants for bioreactor conversions from deep or inaccessible areas (e.g., under buildings) and to enhance the distribution of nutrient or microbe additions in an in situ bioremediation

Veterinary Antibiotics in Young Dutch Groundwater under Intensive Livestock Farming

Science.gov (United States)

Vliet, M. V.; Kivits, T.; Broers, H. P.; Beeltje, H.; Griffioen, J.

2016-12-01

Dutch groundwater is heavily affected by nutrient loads from agricultural origin. The use of antibiotics is also widespread in Dutch farming practice, 200.000 kg active substance over 1.839.000 ha of agricultural land. National measures were established to reduce the applications. Spreading of manure over farmlands is assumed to be the main pathway for the leaching of antibiotics to groundwater, but actual numbers are lacking. We studied the occurrence of veterinary antibiotics in groundwater in two areas with intensive livestock farming, sampling existing multi-level wells that were previously age dated using tritium-helium. Wells were selected based on the following criteria: the uppermost screen is situated just below the average groundwater level, which is not deeper than 3 meters, the well is in an agricultural field where rainwater infiltrates avoiding areas adjacent to ditches or streams, the groundwater quality is known for several years and the age of the extracted water is known to be young (antibiotics used in in intensive livestock farming were analyzed belonging to the following groups: tetracyclines, sulfonamides, diaminopyrimidines, β-lactams, macrolides, lincosamides, quinolones and in addition nitrofurans and chloramphenicol. The samples were analyzed for antibiotics by liquid chromatography/mass spectrometry preceded by solid phase extraction (Oasis HLB cartridge). Five out of 22 antibiotics were detected: sulfamethazine, sulfadiazine, sulfamethoxazole, lincomycin, chloramphenicol in concentration ranges of 0.2 to 18 ng/l. Sulfamethazine was most frequently found, and shows a continuous concentration-depth profile in 3 out of 4 multi-level wells. Sulfonamides were found in groundwater up to 20 m. depth and in water aged between 1 and 25 years old. The study shows that sulfonamides are omnipresent in groundwater up to 25 years old, which corresponds with the known history of the use of antibiotics in veterinary practice.

Can groundwater sampling techniques used in monitoring wells influence methane concentrations and isotopes?

Science.gov (United States)

Rivard, Christine; Bordeleau, Geneviève; Lavoie, Denis; Lefebvre, René; Malet, Xavier

2018-03-06

Methane concentrations and isotopic composition in groundwater are the focus of a growing number of studies. However, concerns are often expressed regarding the integrity of samples, as methane is very volatile and may partially exsolve during sample lifting in the well and transfer to sampling containers. While issues concerning bottle-filling techniques have already been documented, this paper documents a comparison of methane concentration and isotopic composition obtained with three devices commonly used to retrieve water samples from dedicated observation wells. This work lies within the framework of a larger project carried out in the Saint-Édouard area (southern Québec, Canada), whose objective was to assess the risk to shallow groundwater quality related to potential shale gas exploitation. The selected sampling devices, which were tested on ten wells during three sampling campaigns, consist of an impeller pump, a bladder pump, and disposable sampling bags (HydraSleeve). The sampling bags were used both before and after pumping, to verify the appropriateness of a no-purge approach, compared to the low-flow approach involving pumping until stabilization of field physicochemical parameters. Results show that methane concentrations obtained with the selected sampling techniques are usually similar and that there is no systematic bias related to a specific technique. Nonetheless, concentrations can sometimes vary quite significantly (up to 3.5 times) for a given well and sampling event. Methane isotopic composition obtained with all sampling techniques is very similar, except in some cases where sampling bags were used before pumping (no-purge approach), in wells where multiple groundwater sources enter the borehole.

Report on the radiochemical and environmental isotope character for monitoring well UE-1-q: Groundwater Characterization Program

International Nuclear Information System (INIS)

Davisson, M.L.; Hudson, G.B.; Kenneally, J.; Nimz, G.J.; Rego, J.H.

1993-06-01

Well UE-1-q is located in the northeastern portion of area 1 of the Nevada Test Site in southwestern Nevada, 1244.1 meters above sea level. The well was originally an exploratory hole drilled to a depth of 743 meters below the surface (mbs) by LANL in November of 1980. In May 1992, the Groundwater Characterization Program (GCP) extended the total depth to approximately 792.5 mbs. UE-1-q is cased to a total depth of 749.5 mbs, with the remaining uncased depth exposed exclusively to Paleozoicaged carbonate rock, the principle zone of groundwater sampling. Geologic logging indicates approximately 390 meters of tuffaceous and calcareous alluvium overlies 320 meters of Tertiary-aged volcanic ash-flow and bedded tuffs. Paleozoic carbonate lithology extends from 716 mbs to the total well depth and is separated from the overlying Tertiary volcanic deposits by 6 meters of paleocolluvium. This report outlines the results and interpretations of radiochemical and environmental isotopic analyses of groundwater sampled from UE-1-q on July 10, 1992 during the well pump test following well development. In addition, results of the field tritium monitoring performed during the well drilling are reported in Appendix 1. Sampling, analytical techniques, and analytical uncertainties for the groundwater analyses are presented in Appendix 2

Prediction of groundwater flowing well zone at An-Najif Province, central Iraq using evidential belief functions model and GIS.

Science.gov (United States)

Al-Abadi, Alaa M; Pradhan, Biswajeet; Shahid, Shamsuddin

2015-10-01

The objective of this study is to delineate groundwater flowing well zone potential in An-Najif Province of Iraq in a data-driven evidential belief function model developed in a geographical information system (GIS) environment. An inventory map of 68 groundwater flowing wells was prepared through field survey. Seventy percent or 43 wells were used for training the evidential belief functions model and the reset 30 % or 19 wells were used for validation of the model. Seven groundwater conditioning factors mostly derived from RS were used, namely elevation, slope angle, curvature, topographic wetness index, stream power index, lithological units, and distance to the Euphrates River in this study. The relationship between training flowing well locations and the conditioning factors were investigated using evidential belief functions technique in a GIS environment. The integrated belief values were classified into five categories using natural break classification scheme to predict spatial zoning of groundwater flowing well, namely very low (0.17-0.34), low (0.34-0.46), moderate (0.46-0.58), high (0.58-0.80), and very high (0.80-0.99). The results show that very low and low zones cover 72 % (19,282 km(2)) of the study area mostly clustered in the central part, the moderate zone concentrated in the west part covers 13 % (3481 km(2)), and the high and very high zones extended over the northern part cover 15 % (3977 km(2)) of the study area. The vast spatial extension of very low and low zones indicates that groundwater flowing wells potential in the study area is low. The performance of the evidential belief functions spatial model was validated using the receiver operating characteristic curve. A success rate of 0.95 and a prediction rate of 0.94 were estimated from the area under relative operating characteristics curves, which indicate that the developed model has excellent capability to predict groundwater flowing well zones. The produced map of groundwater

A 82Br tracer study of coastal groundwater movement at Hat Head, NSW

International Nuclear Information System (INIS)

Hughes, C.; Stone, D.

2003-01-01

At Hat Head, NSW, on the eastern Australian coast, a radioisotope tracer study of groundwater flow in response to tidal forcing was conducted adjacent to a tidal creek. Using radiotracer, 82 Br, groundwater movement was tracked in-situ over 5 days on two occasions encompassing both neap and spring tide conditions. The tracer was injected into one borehole and gamma counts monitored from an adjacent borehole using NaI(Th) detectors. This technique maps the path of the slow moving tracer without sampling and allows the net groundwater movement to be distinguished from short term tidally driven fluxes. During the neap tide period net groundwater movement of 0.1 m/d was observed with horizontal tidal fluctuations in the order of 0.04 m. This contrasts with the tidally dominated spring tide period where net groundwater movement was negligible but tidally driven fluctuations of up to 0.13 m were observed

40 CFR 265 interim status indicator-evaluation ground-water monitoring plan for the 216-B-63 trench

International Nuclear Information System (INIS)

Bjornstad, B.N.; Dudziak, S.

1989-03-01

This document outlines a ground-water monitoring plan for the 216-B-63 trench located in the northeast corner of the 200-East Area on the Hanford Site in southeastern Washington State. It has been determined that hazardous materials (corrosives) were disposed of to the trench during past operations. Installation of an interim-status ground-water monitoring system is required to determine whether hazardous chemicals are leaching to the ground water from beneath the trench. This document summarizes the existing data that are available from near the 216-B-63 trench and presents a plan to determine the extent of ground-water contamination, if any, derived from the trench. The plan calls for the installation of four new monitoring wells located near the west end of the trench. These wells will be used to monitor ground-water levels and water quality immediately adjacent to the trench. Two existing RCRA monitoring wells, which are located near the trench and hydraulically upgradient of it, will be used as background wells. 46 refs., 15 figs., 12 tabs

Numerical Simulation of Borehole Flow in Deep Monitor Wells, Pearl Harbor Aquifer, Oahu, Hawaii

Science.gov (United States)

Rotzoll, K.; Oki, D. S.; El-Kadi, A. I.

2010-12-01

Salinity profiles collected from uncased deep monitor wells are commonly used to monitor freshwater-lens thickness in coastal aquifers. However, vertical flow in these wells can cause the measured salinity to differ from salinity in the adjacent aquifer. Substantial borehole flow has been observed in uncased wells in the Pearl Harbor aquifer, Oahu, Hawaii. A numerical modeling approach, incorporating aquifer hydraulic characteristics and recharge rates representative of the Pearl Harbor aquifer, was used to evaluate the effects of borehole flow on measured salinity profiles from deep monitor wells. Borehole flow caused by vertical hydraulic gradients associated with the natural regional groundwater-flow system and local groundwater withdrawals was simulated. Model results were used to estimate differences between vertical salinity profiles in deep monitor wells and the adjacent aquifer in areas of downward, horizontal, and upward flow within the regional flow system—for cases with and without nearby pumped wells. Aquifer heterogeneity, represented in the model as layers of contrasting permeability, was incorporated in model scenarios. Results from this study provide insight into the magnitude of the differences between vertical salinity profiles from deep monitor wells and the salinity distributions in the aquifers. These insights are relevant and are critically needed for management and predictive modeling purposes.

Mechanism and rate of denitrification in an agricultural watershed: Electron and mass balance along groundwater flow paths

Science.gov (United States)

Tesoriero, Anthony J.; Liebscher, Hugh; Cox, Stephen E.

2000-01-01

The rate and mechanism of nitrate removal along and between groundwater flow paths were investigated using a series of well nests screened in an unconfined sand and gravel aquifer. Intensive agricultural activity in this area has resulted in nitrate concentrations in groundwater often exceeding drinking water standards. Both the extent and rate of denitrification varied depending on the groundwater flow path. While little or no denitrification occurred in much of the upland portions of the aquifer, a gradual redox gradient is observed as aerobic upland groundwater moves deeper in the aquifer. In contrast, a sharp shallow redox gradient is observed adjacent to a third‐order stream as aerobic groundwater enters reduced sediments. An essentially complete loss of nitrate concurrent with increases in excess N2 provide evidence that denitrification occurs as groundwater enters this zone. Electron and mass balance calculations suggest that iron sulfide (e.g., pyrite) oxidation is the primary source of electrons for denitrification. Denitrification rate estimates were based on mass balance calculations using nitrate and excess N2 coupled with groundwater travel times. Travel times were determined using a groundwater flow model and were constrained by chlorofluorocarbon‐based age dates. Denitrification rates were found to vary considerably between the two areas where denitrification occurs. Denitrification rates in the deep, upland portions of the aquifer were found to range from from 1.0 to 2.7 mM of N per year. Potential denitrification rates in groundwater adjacent to the stream may be much faster, with rates up to 140 mM per year based on an in situ experiment conducted in this zone.

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-07-01

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

Response of selenium concentrations in groundwater to seasonal canal leakage, lower Gunnison River Basin, Colorado, 2013

Science.gov (United States)

Linard, J.I.; McMahon, P.B.; Arnold, L.R.; Thomas, J.C.

2016-05-23

Selenium is a water-quality concern in the lower Gunnison River Basin because irrigation water interacting with seleniferous soils derived from the Mancos Shale Formation has mobilized selenium and increased its concentrations in surface water. Understanding the occurrence of elevated selenium concentrations in groundwater is necessary because groundwater discharge is an important source of selenium in surface water in the basin. In 2013, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation and the Colorado Water Conservation Board, began a study to understand how changes in groundwater levels attributed to canal leakage affected the concentrations and speciation of dissolved selenium in groundwater. The purpose of this report is to characterize the groundwater adjacent to an unlined leaky canal. Two locations, near the East Canal (W-N1 and W-N2) and farther from the East Canal (W-M1 and W-M2), were selected for nested monitoring well installations. The pressure exerted by changes in canal stage was more readily transferred to the deep groundwater measured in the W-N1 near the canal than the shallow groundwater at the W-N2 well. No definitive relation could be made between canal water-level elevation and water-level elevations in monitoring wells farther from the canal (W-M1 and W-M2). 

Evaluation Of The Hydraulic Connection Between The Surface Water And The Groundwater Along El-Salam Canal, North Eastern Coast, Egypt

International Nuclear Information System (INIS)

Ismail, Y.L.; Ismail, N.A.; Abdel Mogheeth, S.M.; Salem, W.M.

2012-01-01

In the present study, the interconnection between the surface water of El-Salam Canal and the shallow groundwater in the adjacent aquifer has been discussed using both the environmental isotopes and the chemical analyses of the different water bodies along the canal trajectory from Faraskour in the west to Balousa in the east. The isotopic techniques were applied to investigate this relationship and to estimate the possible contribution from various sources such as groundwater, sea water and/or irrigation water, and finally to determine the extent of mixing between El-Salam Canal and the adjacent aquifers. Since the groundwater in the area is saline (more than 10000 ppm) while the mixed canal water is mainly fresh (less than 1000 ppm), the interconnection between the canal water and surrounding shallow groundwater leads to one of the following two hydrologic processes; seepage from the canal water to the shallow groundwater which means fresh water losses or leakage from the groundwater into the surface water which means water quality deterioration The present study aims to detect the hydraulic interconnection between the two water bodies by using environmental isotope techniques as well as detailed chemical analysis. For this purpose, 31 water samples from both surface water and groundwater were collected and analyzed for 18 O and 2 H contents as well as 44 representative water samples were collected and analyzed for the chemical components (anions and cations) as a major ions and minor constituents. The distribution of the analyzed samples on the 18 O vs. D diagram indicated that the samples could be classified into three genetic groups representing different sources of water. The first group reflects a contribution from evaporated rain water prior to infiltration to the groundwater, the second group represents a mixing trend between both of El-Farma drain water and El-Manzala lake water with the groundwater which have enriched isotopic values as well as high

Evidence for Legacy Contamination of Nitrate in Groundwater of North Carolina Using Monitoring and Private Well Data Models

Science.gov (United States)

Messier, K. P.; Kane, E.; Bolich, R.; Serre, M. L.

2014-12-01

Nitrate (NO3-) is a widespread contaminant of groundwater and surface water across the United States that has deleterious effects to human and ecological health. Legacy contamination, or past releases of NO3-, is thought to be impacting current groundwater and surface water of North Carolina. This study develops a model for predicting point-level groundwater NO3- at a state scale for monitoring wells and private wells of North Carolina. A land use regression (LUR) model selection procedure known as constrained forward nonlinear regression and hyperparameter optimization (CFN-RHO) is developed for determining nonlinear model explanatory variables when they are known to be correlated. Bayesian Maximum Entropy (BME) is then used to integrate the LUR model to create a LUR-BME model of spatial/temporal varying groundwater NO3- concentrations. LUR-BME results in a leave-one-out cross-validation r2 of 0.74 and 0.33 for monitoring and private wells, effectively predicting within spatial covariance ranges. The major finding regarding legacy sources NO3- in this study is that the LUR-BME models show the geographical extent of low-level contamination of deeper drinking-water aquifers is beyond that of the shallower monitoring well. Groundwater NO3- in monitoring wells is highly variable with many areas predicted above the current Environmental Protection Agency standard of 10 mg/L. Contrarily, the private well results depict widespread, low-level NO3-concentrations. This evidence supports that in addition to downward transport, there is also a significant outward transport of groundwater NO3- in the drinking water aquifer to areas outside the range of sources. Results indicate that the deeper aquifers are potentially acting as a reservoir that is not only deeper, but also covers a larger geographical area, than the reservoir formed by the shallow aquifers. Results are of interest to agencies that regulate surface water and drinking water sources impacted by the effects of

Investigation of the Effect of Water Removal from Wells Surrounding Parishan Lake on Groundwater and Surface Water Levels

International Nuclear Information System (INIS)

Shafiei, M.; Raini Sarjaz, M.; Fazloli, R.; Gholami Sefidkouhi, M. A.

2017-01-01

In recent decades the human impacts on global warming and, its consequences, climate change, stirred up earth ecosystems balance and has created many problems all over the world. Unauthorized underground water removal, especially in arid and semi-arid regions of Iran, along with recent decade drought occurrences significantly lowered underground and surface water levels. To investigate the impacts of water removal from surrounding wells in Parishan Lake water level, during 1996 to 2009 interval, 8 buffer layers surrounding the lake were mapped in ArcGIS 9.3 environment. Each buffer layer wells and their total annual discharges were determined. Using SPSS 16 software, the regression equations between wells water levels and water discharges were computed. By employing Thiessen function and creating Thiessen network (TIN) around observation wells, decline of groundwater levels was evaluated. Finally regression equations between wells discharges and groundwater level declines were created. The findings showed that there are highly significant correlations (p ≤ 0.01), in all buffer layers, between water levels and wells discharges. Investigation of the observation wells surrounding lake showed that severe groundwater level declines has been started since the beginning of the first decade of the 21st century. Using satellite images in ArcGIS 9.3 environment it was confirmed that lake’s area has been reduced significantly. In conclusion, it is obvious that human interferences on lake’s natural ecosystem by digging unauthorized wells and removing underground water more than annual recharges significantly impacted surface and groundwater levels.

Tritium activity concentrations and residence times of groundwater collected in Rokkasho, Japan

International Nuclear Information System (INIS)

Hasegawa, Hidenao; Ueda, Shinji; Kakiuchi, Hideki; Hisamatsu, Shun'ichi; Akata, Naofumi

2015-01-01

Tritium ( 3 H) concentrations were measured in groundwater samples from four surface wells (4-10 m deep), four shallow wells (24-26.5 m deep) and a 150-m-deep well in the Futamata River catchment area, which is adjacent to the large-scale commercial spent nuclear fuel reprocessing plant in Rokkasho, Japan. The 3 H concentrations in most of the surface- and shallow-well samples (<0.03-0.57 Bq l -1 ) were similar to those in precipitation (annual mean: 0.31-0.79 Bq l -1 ), suggesting that the residence time of the water in those wells was 0-15 y. The 3 H concentrations in the samples from a 26-m-deep well and the 150-m-deep well were lower than those in the other wells, indicating that groundwater with a long residence time exists in deep aquifers and the estuary area of the catchment. It is not clear whether 3 H released during test operation of the plant with actual spent nuclear fuel affected the 3 H concentrations observed in this study. (authors)

U-234/U-238 ratio: Qualitative estimate of groundwater flow in Rocky Flats monitoring wells

International Nuclear Information System (INIS)

Laul, J.C.

1994-01-01

Groundwater movement through various pathways is the primary mechanism for the transport of radionuclides and trace elements in a water/rock interaction. About three dozen wells, installed in the Rocky Flats Plant (RFP) Solar Evaporation Ponds (SEP) area, are monitored quarterly to evaluate the extent of any lateral and downgradient migration of contaminants from the Solar Evaporation Ponds: 207-A; 207-B North, 207-B Center, and 207-B South; and 207-C. The Solar Ponds are the main source for the various contaminants: radionuclides (U-238, U-234, Pu-239, 240 and Am-241); anions; and trace metals to groundwaters. The U-238 concentrations in Rocky Flats groundwaters vary from 2 (CO 3 ) 2 2- , because of the predominant bicarbonate medium

Pumping and recovery test analysis of groundwater Well in Martajasah, Bangkalan, Madura

International Nuclear Information System (INIS)

Adi Gunawan Muhammad

2010-01-01

Martajasah is one of the villages in Bangkalan Region, Madura, which have difficulty of fresh water. This area has a lot of potential that can be developed, particularly the potential of religious tourism. To increase the utilization potential of the region and support the public healthy, in 2007 PPGN - BATAN cooperated with the Government of Bangkalan has made one (I) exploration/production groundwater - wells with the expectation it can meet a demand of fresh water in the Martajasah Village area. To determine the capacity of the wells, the maximum discharge pumping and the optimum discharge pumping from the wells pumping test it is necessary should be conducted, which includes step draw down pumping test, constant rate pumping test and recovery test. The purpose of this activity is to determine amount of well loss, loss of aquifer, well hydraulics equations and the value of the efficiency of wells to determine the optimum and maximum discharge wells and calculate the value of transmissivity / transmissivity (T) from the aquifer. The scope of these activities include the preparation of working equipment, testing of all equipment, measurement of static groundwater table, pumping test, and analysis of pumping test. Based on the result from step draw down test, well hydraulics equations obtained Sw = 0.0079 Q + 0.000003 Q 2 , so that according to the well hydraulics equations are than obtained a maximum pumping discharge (Q max ) = 3.9 liters / second (336.7 m 3 ) / days) with the well efficiency (E) = 89%, so the optimum pumping discharge (Q opt )=3.455 liters / second = 298.52 m 3 /day. Based on the result from constant rate pumping test and recovery test showed adequate transmissivity of wells, i e T = 136.5 m 2 / day = 5.6875 m 2 / hour = 0.094 m 2 /minute. (author)

Ground-Water Flow, 2004-07, and Water Quality, 1992-2007, in McBaine Bottoms, Columbia, Missouri

Science.gov (United States)

Smith, Brenda Joyce; Richards, Joseph M.

2008-01-01

The U.S. Geological Survey, in cooperation with the city of Columbia, Missouri, and the Missouri Department of Conservation, collected ground-water quality data, surface-water quality data, and water-level data in McBaine Bottoms, southwest of Columbia. McBaine Bottoms, adjacent to the Missouri River, is the location of the municipal-supply well field for the city of Columbia, the city of Columbia wastewater-treatment wetlands, and the Missouri Department of Conservation Eagle Bluffs Conservation Area. This report describes the ground-water flow and water quality of McBaine Bottoms and provides information to better understand the interaction between treated effluent from the wetlands used on the Eagle Bluffs Conservation Area and the water in the alluvial aquifer that is pumped from the city of Columbia municipal-supply well field. Changes in major chemical constituent concentrations have been detected at several sampling sites between pre- and post-effluent application data. Analysis of post-effluent data indicates substantial changes in calcium, potassium, sodium, chloride, and sulfate concentrations in ground water. These changes became apparent shortly after the beginning of the operation of the wastewater-treatment wetland in 1994 and the formation of the Eagle Bluffs Conservation Area, which uses the treated effluent as a water source for the management of migratory water fowl. The changes have continued throughout the 15 years of sample collection. The concentrations of these major chemical constituents are on the mixing continuum between pre-effluent ground water as one end member and the treated wastewater effluent as the other end member. For monitoring wells that had changes in major chemical constituent concentrations, the relative percentage of treated effluent in the ground water, assuming chloride is conservative, ranged from 6 to 88 percent. Twenty-two monitoring wells throughout McBaine Bottoms have been affected by effluent based on chloride

Geogenic As and Mo groundwater contamination caused by an abundance of domestic supply wells

International Nuclear Information System (INIS)

Pichler, Thomas; Renshaw, Carl E.; Sültenfuß, Jürgen

2017-01-01

Lacking a connection to a municipal water supply, each household in the municipality of Lithia, approximately 30 km southeast of Tampa, Florida (USA), is responsible for its own supply of drinking water, causing a high-density of private domestic supply wells (DSW) in this area. There, a multilayered aquifer system exists, which can be subdivided into three distinct hydro stratigraphic units, which are, from the top down: the Surficial Aquifer System (SAS), the Intermediate Aquifer System (IAS), and the Upper Floridan Aquifer System (UFA). Despite the relatively small area, the geochemical and hydrogeological setting in Lithia is complex, consisting of: i) extensive cyclical pumping in a municipal well field to the west, ii) large seasonal changes in hydraulic head, ii) multiple aquifers with different hydraulic heads, and iv) a large density of domestic supply wells (DSW). Within the zone of highest As concentrations, there are approximately 100 wells in an area of 2.5 km × 1.5 km. Most of these wells have large open screened intervals, often open to all three aquifers, allowing the downward flow of oxygenated and upward flow of anoxic groundwater. A survey of groundwater quality found that As and Mo concentrations in the DSW were up to 371 μg/L and 4740 μg/L, respectively. To obtain information about the individual aquifers, 5 well clusters with 4 monitoring intervals (approximately 50 m, 65 m, 80 m and 95 m below surface) and 8 push core wells (approximately 9 m below surface) were installed and sampled. In those wells, As and Mo were only elevated in a permeable layer within the IAS at a depth of 50 m. Values were up to 195 μg/L for As and up to 5050 μg/L for Mo. Using the tritium-helium ("3H–"3He) method, the ages of those samples high in As and Mo were determined to be 40, 30 and 30 years, respectively, while all other samples had ages older than 50 years. This indicated that mixing between young and old groundwater could be responsible

Pumping Drainage Well Layout and Optimum Capacity Design to Lower Groundwater Table in Urban Areas

Directory of Open Access Journals (Sweden)

Mojtaba Shourian

2017-11-01

Full Text Available High groundwater levels in urban areas pose major problems in construction and mining projects. A typical and effective solution in these situations is to dig drainage wells to lower the water table to the desired level through an appropriate pumping strategy. Although the method is efficient, the operating costs are relatively high and it is, therefore, of great importance to optimize the groundwater pumping system to save costs. In this paper, a simulation-based optimization approach is exploited to minimize the total costs through optimizing the layout and capacity of pumping wells. For this purpose, MODFLOW, the groundwater simulation software, is used to investigate aquifer behavior under pumping wells and the well-known Firefly Optimization Algorithm is exploited to find the optimal well layout and capacity. The proposed FOA-MODFLOW model is tested on the small urban ancient Grand Mosque region in Kerman City, southeast of Iran, to minimize the cost of the draining project. Experimental results indicate that the proposed cost-effective design noticeably outperforms the one proposed by the consulting engineers in terms of both the number of drilled wells and the associated pumping costs. The optimal strategy observes the constraints and demands by constructing only two wells with a total pumping rate of 5503 m3/day and a water table drawdown of more than 1.5 m provided the ground subsidence is within the allowable limit of less than 80 mm. Additionally, examination of the values obtained for the various design parameters shows that the proposed strategy is the best and its sensitivity to maximum permissible water level and pumping rates is highest as compared with other similar designs.

Groundwater Monitoring Plan for the Nonradioactive Dangerous Waste Landfill

International Nuclear Information System (INIS)

Lindberg, J.S.; Hartman, M.J.

1999-01-01

The Nonradioactive Dangerous Waste Landfill (NRDWL), which received nonradioactive hazardous waste between 1975 and 1985, is located in the central Hanford Site (Figure 1.1) in southeastern Washington State. The Solid Waste Landfill, which is regulated and monitored separately, is adjacent to the NRDWL. The NRDWL is regulated under the Resource Conservation and Recovery Act of 1976 (RCRA) and monitored by Pacific Northwest National Laboratory. Monitoring is done under interim-status, indicator-evaluation requirements (WAC 173-303 and by reference, 40 CFR 265.92). The well network includes three upgradient wells (one shared with the Solid Waste Landfill) and six downgradient wells. The wells are sampled semiannually for contaminant indicator parameters and site-specific parameters and annually for groundwater quality parameters

The study of planning and realization of deep groundwater well construction at Tangkil, Kemalang, Klaten

International Nuclear Information System (INIS)

Sartapa

2009-01-01

The deep groundwater well at Tangkil is one of the cooperation outcomes between the Government of Klaten and P2BGGN - BATAN in a framework of using Klaten water sources. The method of work involves literature study, data analysis, evaluation and interpretation, respectively. The Well has 205.79 m in depth by diameter of 12.25 inch and 15.654 m3 in volume. Construction design of PVC ducks is 8 inch through 200 m depth, the volume of pipe construction is 7.825 m3 and annulus volume is 7.825 m3. The annulus filled with 7.4558 m3 of gravel wrapped, 0.0846 m3 of partition and 0.0846 m3 sanitation cement. The volume of developed pipe construction is 6.936 m3 by depth of 182 m, 8.718 m3 of annulus volume filled with 7.260 m3 or 83,28% of gravel wrapped, therefore the existence of space between its grains which is not filled with 1.013 m3 or 16,72% of gravel wrapped may become an entrance path of sands into the well and may interfere the performance of its pump. The screen pipes has been developed until 174 m depth and 136.60 m of groundwater static surface, hence the round up of groundwater by 73 m of screen pipes is suitable enough for pump installation and water well discharge. The efficiency of annulus relatively poor, therefore periodically need of checking and cleaning the entering of sands into the well has to be conducted. (author)

Baseline groundwater quality from 34 wells in Wayne County, Pennsylvania, 2011 and 2013

Science.gov (United States)

Sloto, Ronald A.

2014-01-01

Wayne County, Pennsylvania, is underlain by the Marcellus Shale, which currently (2014) is being developed elsewhere in Pennsylvania for natural gas. All residents of largely rural Wayne County rely on groundwater for water supply, primarily from bedrock aquifers (shales and sandstones). This study, conducted by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey (Pennsylvania Geological Survey), provides a groundwater-quality baseline for Wayne County prior to development of the natural gas resource in the Marcellus Shale. Selected wells completed in the Devonian-age Catskill Formation, undifferentiated; the Poplar Gap and Packerton Members of the Catskill Formation, undivided; and the Long Run and Walcksville Members of the Catskill Formation, undivided, were sampled.

Groundwater-Surface water interaction in agricultural watershed that encompasses dense network of High Capacity wells

Science.gov (United States)

Talib, A.; Desai, A. R.

2017-12-01

The Central Sands region of Wisconsin is characterized by productive trout streams, lakes, farmland and forest. However, stream channelization, past wetland drainage, and ground water withdrawals have disrupted the hydrology of this Central Sands region. Climatically driven conditions in last decade (2000-2008) alone are unable to account for the severely depressed water levels. Increased interception and evapotranspiration from afforested areas in central sand Wisconsin may also be culprit for reduced water recharge. Hence, there is need to study the cumulative effects of changing precipitation patterns, groundwater withdrawals, and forest evapotranspiration to improve projections of the future of lake levels and water availability in this region. Here, the SWAT-MODFLOW coupled model approach was applied at large spatio-temporal scale. The coupled model fully integrates a watershed model (SWAT) with a groundwater flow model (MODFLOW). Surface water and ground water flows were simulated integratively at daily time step to estimate the groundwater discharge to the stream network in Central Sands that encompasses high capacity wells. The model was calibrated (2010-2013) and validated (2014-2017) based on streamflow, groundwater extraction, and water table elevation. As the long-term trends in some of the primary drivers is presently ambiguous in Central Sands under future climate, as is the case for total precipitation or timing of precipitation, we relied on a sensitivity student to quantitatively access how primary and secondary drivers may influence future net groundwater recharge. We demonstrate how such an approach could then be coupled with decision-making models to evaluate the effectiveness of groundwater withdrawal policies under a changing climate.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Monitoring well utility in a heterogeneous DNAPL source zone area: Insights from proximal multilevel sampler wells and sampling capture-zone modelling.

Science.gov (United States)

McMillan, Lindsay A; Rivett, Michael O; Wealthall, Gary P; Zeeb, Peter; Dumble, Peter

2018-03-01

Groundwater-quality assessment at contaminated sites often involves the use of short-screen (1.5 to 3 m) monitoring wells. However, even over these intervals considerable variation may occur in contaminant concentrations in groundwater adjacent to the well screen. This is especially true in heterogeneous dense non-aqueous phase liquid (DNAPL) source zones, where cm-scale contamination variability may call into question the effectiveness of monitoring wells to deliver representative data. The utility of monitoring wells in such settings is evaluated by reference to high-resolution multilevel sampler (MLS) wells located proximally to short-screen wells, together with sampling capture-zone modelling to explore controls upon well sample provenance and sensitivity to monitoring protocols. Field data are analysed from the highly instrumented SABRE research site that contained an old trichloroethene source zone within a shallow alluvial aquifer at a UK industrial facility. With increased purging, monitoring-well samples tend to a flow-weighted average concentration but may exhibit sensitivity to the implemented protocol and degree of purging. Formation heterogeneity adjacent to the well-screen particularly, alongside pump-intake position and water level, influence this sensitivity. Purging of low volumes is vulnerable to poor reproducibility arising from concentration variability predicted over the initial 1 to 2 screen volumes purged. Marked heterogeneity may also result in limited long-term sample concentration stabilization. Development of bespoke monitoring protocols, that consider screen volumes purged, alongside water-quality indicator parameter stabilization, is recommended to validate and reduce uncertainty when interpreting monitoring-well data within source zone areas. Generalised recommendations on monitoring well based protocols are also developed. A key monitoring well utility is their proportionately greater sample draw from permeable horizons constituting

Monitoring well utility in a heterogeneous DNAPL source zone area: Insights from proximal multilevel sampler wells and sampling capture-zone modelling

Science.gov (United States)

McMillan, Lindsay A.; Rivett, Michael O.; Wealthall, Gary P.; Zeeb, Peter; Dumble, Peter

2018-03-01

Groundwater-quality assessment at contaminated sites often involves the use of short-screen (1.5 to 3 m) monitoring wells. However, even over these intervals considerable variation may occur in contaminant concentrations in groundwater adjacent to the well screen. This is especially true in heterogeneous dense non-aqueous phase liquid (DNAPL) source zones, where cm-scale contamination variability may call into question the effectiveness of monitoring wells to deliver representative data. The utility of monitoring wells in such settings is evaluated by reference to high-resolution multilevel sampler (MLS) wells located proximally to short-screen wells, together with sampling capture-zone modelling to explore controls upon well sample provenance and sensitivity to monitoring protocols. Field data are analysed from the highly instrumented SABRE research site that contained an old trichloroethene source zone within a shallow alluvial aquifer at a UK industrial facility. With increased purging, monitoring-well samples tend to a flow-weighted average concentration but may exhibit sensitivity to the implemented protocol and degree of purging. Formation heterogeneity adjacent to the well-screen particularly, alongside pump-intake position and water level, influence this sensitivity. Purging of low volumes is vulnerable to poor reproducibility arising from concentration variability predicted over the initial 1 to 2 screen volumes purged. Marked heterogeneity may also result in limited long-term sample concentration stabilization. Development of bespoke monitoring protocols, that consider screen volumes purged, alongside water-quality indicator parameter stabilization, is recommended to validate and reduce uncertainty when interpreting monitoring-well data within source zone areas. Generalised recommendations on monitoring well based protocols are also developed. A key monitoring well utility is their proportionately greater sample draw from permeable horizons constituting a

Estimated rates of groundwater recharge to the Chicot, Evangeline and Jasper aquifers by using environmental tracers in Montgomery and adjacent counties, Texas, 2008 and 2011

Science.gov (United States)

Oden, Timothy D.; Truini, Margot

2013-01-01

Montgomery County is in the northern part of the Houston, Texas, metropolitan area, the fourth most populous metropolitan area in the United States. As populations have increased since the 1980s, groundwater has become an important resource for public-water supply and industry in the rapidly growing area of Montgomery County. Groundwater availability from the Gulf Coast aquifer system is a primary concern for water managers and community planners in Montgomery County and requires a better understanding of the rate of recharge to the system. The Gulf Coast aquifer system in Montgomery County consists of the Chicot, Evangeline, and Jasper aquifers, the Burkeville confining unit, and underlying Catahoula confining system. The individual sand and clay sequences of the aquifers composing the Gulf Coast aquifer system are not laterally or vertically continuous on a regional scale; however, on a local scale, individual sand and clay lenses can extend over several miles. The U.S. Geological Survey, in cooperation with the Lone Star Groundwater Conservation District, collected groundwater-quality samples from selected wells within or near Montgomery County in 2008 and analyzed these samples for concentrations of chlorofluorocarbons (CFCs), sulfur hexafluoride (SF6), tritium (3H), helium-3/tritium (3He/3H), helium-4 (4He), and dissolved gases (DG) that include argon, carbon dioxide, methane, nitrogen and oxygen. Groundwater ages, or apparent age, representing residence times since time of recharge, were determined by using the assumption of a piston-flow transport model. Most of the environmental tracer data indicated the groundwater was recharged prior to the 1950s, limiting the usefulness of CFCs, SF6, and 3H concentrations as tracers. In many cases, no tracer was usable at a well for the purpose of estimating an apparent age. Wells not usable for estimating an apparent age were resampled in 2011 and analyzed for concentrations of major ions and carbon-14 (14C). At six of

Tritium activity concentrations and residence times of groundwater collected in Rokkasho, Japan.

Science.gov (United States)

Hasegawa, Hidenao; Ueda, Shinji; Akata, Naofumi; Kakiuchi, Hideki; Hisamatsu, Shun'ichi

2015-11-01

Tritium ((3)H) concentrations were measured in groundwater samples from four surface wells (4-10 m deep), four shallow wells (24-26.5 m deep) and a 150-m-deep well in the Futamata River catchment area, which is adjacent to the large-scale commercial spent nuclear fuel reprocessing plant in Rokkasho, Japan. The (3)H concentrations in most of the surface- and shallow-well samples (<0.03-0.57 Bq l(-1)) were similar to those in precipitation (annual mean: 0.31-0.79 Bq l(-1)), suggesting that the residence time of the water in those wells was 0-15 y. The (3)H concentrations in the samples from a 26-m-deep well and the 150-m-deep well were lower than those in the other wells, indicating that groundwater with a long residence time exists in deep aquifers and the estuary area of the catchment. It is not clear whether (3)H released during test operation of the plant with actual spent nuclear fuel affected the (3)H concentrations observed in this study. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

High-throughput DNA microarray detection of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley, Nepal.

Science.gov (United States)

Inoue, Daisuke; Hinoura, Takuji; Suzuki, Noriko; Pang, Junqin; Malla, Rabin; Shrestha, Sadhana; Chapagain, Saroj Kumar; Matsuzawa, Hiroaki; Nakamura, Takashi; Tanaka, Yasuhiro; Ike, Michihiko; Nishida, Kei; Sei, Kazunari

2015-01-01

Because of heavy dependence on groundwater for drinking water and other domestic use, microbial contamination of groundwater is a serious problem in the Kathmandu Valley, Nepal. This study investigated comprehensively the occurrence of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley by applying DNA microarray analysis targeting 941 pathogenic bacterial species/groups. Water quality measurements found significant coliform (fecal) contamination in 10 of the 11 investigated groundwater samples and significant nitrogen contamination in some samples. The results of DNA microarray analysis revealed the presence of 1-37 pathogen species/groups, including 1-27 biosafety level 2 ones, in 9 of the 11 groundwater samples. While the detected pathogens included several feces- and animal-related ones, those belonging to Legionella and Arthrobacter, which were considered not to be directly associated with feces, were detected prevalently. This study could provide a rough picture of overall pathogenic bacterial contamination in the Kathmandu Valley, and demonstrated the usefulness of DNA microarray analysis as a comprehensive screening tool of a wide variety of pathogenic bacteria.

Hydrologic analysis of data from the Lower Lost Lake Aquifer at recovery well RWM-12

International Nuclear Information System (INIS)

Hiergesell, R.A.

1994-04-01

This report presents an analysis of water level responses that were monitored in wells near recovery well RWM-12 when it was brought online on March 23, 1992 as part of the system of wells used to pump and treat a groundwater contaminant plume of trichloroethylene (TCE) beneath the A/M Areas of the Savannah River Site. The series of wells, all similar to RWM-12, pump groundwater and deliver it to air strippers that effectively separate and remove the TCE. Water level responses to pumping at RWM-12 were monitored using both pressure transducers/data loggers, and electric tapes. The purpose of obtaining measurements of water level responses was to obtain the data that is needed to make a quantitative estimate of hydraulic conductivity in the pumped horizon, and to assess the hydraulic connection between adjacent layers

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

Science.gov (United States)

Belcher, Wayne R.; Sweetkind, Donald S.

2010-01-01

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

Generating false negatives and false positives for As and Mo concentrations in groundwater due to well installation.

Science.gov (United States)

Wallis, Ilka; Pichler, Thomas

2018-08-01

Groundwater monitoring relies on the acquisition of 'representative' groundwater samples, which should reflect the ambient water quality at a given location. However, drilling of a monitoring well for sample acquisition has the potential to perturb groundwater conditions to a point that may prove to be detrimental to the monitoring objective. Following installation of 20 monitoring wells in close geographic proximity in central Florida, opposing concentration trends for As and Mo were observed. In the first year after well installation As and Mo concentrations increased in some wells by a factor of 2, while in others As and Mo concentrations decreased by a factor of up to 100. Given this relatively short period of time, a natural change in groundwater composition of such magnitude is not expected, leaving well installation itself as the likely cause for the observed concentration changes. Hence, initial concentrations were identified as 'false negatives' if concentrations increased with time or as 'false positives' if concentrations decreased. False negatives were observed if concentrations were already high, i.e., the As or Mo were present at the time of drilling. False positives were observed if concentrations were relatively lower, i.e., As or Mo were present at low concentrations of approximately 1 to 2μg/L before drilling, but then released from the aquifer matrix as a result of drilling. Generally, As and Mo were present in the aquifer matrix in either pyrite or organic matter, both of which are susceptible to dissolution if redox conditions change due to the addition of oxygen. Thus, introduction of an oxidant into an anoxic aquifer through use of an oxygen saturated drilling fluid served as the conceptual model for the trends where concentrations decreased with time. Mixing between drilling fluid and groundwater (i.e., dilution) was used as the conceptual model for scenarios where increasing trends were observed. Conceptual models were successfully tested

Y-12 Groundwater Protection Program Monitoring Optimization Plan for Groundwater Monitoring Wells at the U.S. Department of Energy Y-12 National Security Complex

International Nuclear Information System (INIS)

2006-01-01

This document is the monitoring optimization plan for groundwater monitoring wells associated with the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee (Figure A.1). The plan describes the technical approach that will be implemented under the Y-12 Groundwater Protection Program (GWPP) to focus available resources on the monitoring wells at Y-12 that provide the most useful hydrologic and water-quality monitoring data. The technical approach is based on the GWPP status designation for each well (Section 2.0). Under this approach, wells granted ''active'' status are used by the GWPP for hydrologic monitoring and/or groundwater quality sampling (Section 3.0), whereas wells granted ''inactive'' status are not used for either purpose. The status designation also defines the frequency at which the GWPP will inspect applicable wells, the scope of these well inspections, and extent of any maintenance actions initiated by the GWPP (Section 3.0). Details regarding the ancillary activities associated with implementation of this plan (e.g., well inspection) are deferred to the referenced GWPP plans and procedures (Section 4.0). This plan applies to groundwater wells associated with Y-12 and related waste management areas and facilities located within three hydrogeologic regimes (Figure A.1): the Bear Creek Hydrogeologic Regime (Bear Creek Regime), the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime), and the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek Regime encompasses a section of Bear Creek Valley (BCV) immediately west of Y-12. The East Fork Regime encompasses most of the Y-12 process, operations, and support facilities in BCV and, for the purposes of this plan, includes a section of Union Valley east of the DOE Oak Ridge Reservation (ORR) boundary along Scarboro Road. The Chestnut Ridge Regime encompasses a section of Chestnut Ridge directly south of Y-12 that is bound on the

Hydrology and snowmelt simulation of Snyderville Basin, Park City, and adjacent areas, Summit County, Utah

Science.gov (United States)

Brooks, Lynette E.; Mason, James L.; Susong, David D.

1998-01-01

Increasing residential and commercial development is placing increased demands on the ground- and surface-water resources of Snyderville Basin, Park City, and adjacent areas in the southwestern corner of Summit County, Utah. Data collected during 1993-95 were used to assess the quantity and quality of the water resources in the study area.Ground water within the study area is present in consolidated rocks and unconsolidated valley fill. The complex geology makes it difficult to determine the degree of hydraulic connection between different blocks of consolidated rocks. Increased ground-water withdrawal during 1983- 95 generally has not affected ground-water levels. Ground-water withdrawal in some areas, however, caused seasonal fluctuations and a decline in ground-water levels from 1994 to 1995, despite greater-than-normal recharge in the spring of 1995.Ground water generally has a dissolved-solids concentration that ranges from 200 to 600 mg/L. Higher sulfate concentrations in water from wells and springs near Park City and in McLeod Creek and East Canyon Creek than in other parts of the study area are the result of mixing with water that discharges from the Spiro Tunnel. The presence of chloride in water from wells and springs near Park City and in streams and wells near Interstate Highway 80 is probably caused by the dissolution of applied road salt. Chlorofluorocarbon analyses indicate that even though water levels rise within a few weeks of snowmelt, the water took 15 to 40 years to move from areas of recharge to areas of discharge.Water budgets for the entire study area and for six subbasins were developed to better understand the hydrologic system. Ground-water recharge from precipitation made up about 80 percent of the ground-water recharge in the study area. Ground-water discharge to streams made up about 40 percent of the surface water in the study area and ground-water discharge to springs and mine tunnels made up about 25 percent. Increasing use of

Hydrochemical trends for public supply well fields in The Netherlands (1898–2008), natural backgrounds and upscaling to groundwater bodies

NARCIS (Netherlands)

Mendizabal, I.; Stuijfzand, P.J.; Baggelaar, P.K.

2012-01-01

Statistical trend analysis is applied to a 110. years long groundwater quality time series from the national network of public supply well fields (PSWFs) in The Netherlands. Such a groundwater quality monitoring network should be available in many countries, so that approaches and experiences

Installation of a groundwater monitoring-well network on the east side of the Uncompahgre River in the Lower Gunnison River Basin, Colorado, 2014

Science.gov (United States)

Thomas, Judith C.

2015-10-07

The east side of the Uncompahgre River Basin has been a known contributor of dissolved selenium to recipient streams. Discharge of groundwater containing dissolved selenium contributes to surface-water selenium concentrations and loads; however, the groundwater system on the east side of the Uncompahgre River Basin is not well characterized. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board and the Bureau of Reclamation, has established a groundwater-monitoring network on the east side of the Uncompahgre River Basin. Thirty wells total were installed for this project: 10 in 2012 (DS 923, http://dx.doi.org/10.3133/ds923), and 20 monitoring wells were installed during April and June 2014 which are presented in this report. This report presents location data, lithologic logs, well-construction diagrams, and well-development information. Understanding the groundwater system can provide managers with an additional metric for evaluating the effectiveness of salinity and selenium control projects.

Hydrology and numerical simulation of groundwater flow and streamflow depletion by well withdrawals in the Malad-Lower Bear River Area, Box Elder County, Utah

Science.gov (United States)

Stolp, Bernard J.; Brooks, Lynette E.; Solder, John

2017-03-28

The Malad-Lower Bear River study area in Box Elder County, Utah, consists of a valley bounded by mountain ranges and is mostly agricultural or undeveloped. The Bear and Malad Rivers enter the study area with a combined average flow of about 1,100,000 acre-feet per year (acre-ft/yr), and this surface water dominates the hydrology. Groundwater occurs in consolidated rock and basin fill. Groundwater recharge occurs from precipitation in the mountains and moves through consolidated rock to the basin fill. Recharge occurs in the valley from irrigation. Groundwater discharge occurs to rivers, springs and diffuse seepage areas, evapotranspiration, field drains, and wells. Groundwater, including springs, is a source for municipal and domestic water supply. Although withdrawal from wells is a small component of the groundwater budget, there is concern that additional groundwater development will reduce the amount of flow in the Malad River. Historical records of surface-water diversions, land use, and groundwater levels indicate relatively stable hydrologic conditions from the 1960s to the 2010s, and that current groundwater development has had little effect on the groundwater system. Average annual recharge to and discharge from the groundwater flow system are estimated to be 164,000 and 228,000 acre-ft/yr, respectively. The imbalance between recharge and discharge represents uncertainties resulting from system complexities, and the possibility of groundwater inflow from surrounding basins.This study reassesses the hydrologic system, refines the groundwater budget, and creates a numerical groundwater flow model that is used to analyze the effects of groundwater withdrawals on surface water. The model uses the detailed catalog of locations and amounts of groundwater recharge and discharge defined during this study. Calibrating the model to adequately simulate recharge, discharge, and groundwater levels results in simulated aquifer properties that can be used to understand

Heavy metal contamination and human health risk assessment in drinking water from shallow groundwater wells in an agricultural area in Ubon Ratchathani province, Thailand.

Science.gov (United States)

Wongsasuluk, Pokkate; Chotpantarat, Srilert; Siriwong, Wattasit; Robson, Mark

2014-02-01

Most local people in the agricultural areas of Hua-ruea sub-district, Ubon Ratchathani province (Thailand), generally consume shallow groundwater from farm wells. This study aimed to assess the health risk related to heavy metal contamination in that groundwater. Samples were randomly collected from 12 wells twice in each of the rainy and the dry seasons and were analyzed by inductive coupled plasma spectrometry-mass spectrometry (ICP-MS). The concentration of detected metals in each well and the overall mean were below the acceptable groundwater standard limits for As, Cd, Cr, Cu, Hg, Ni and Zn, but Pb levels were higher in four wells with an overall average Pb concentration of 16.66 ± 18.52 μg/l. Exposure questionnaires, completed by face-to-face interviews with 100 local people who drink groundwater from farm wells, were used to evaluate the hazard quotients (HQs) and hazard indices (HIs). The HQs for non-carcinogenic risk for As, Cu, Zn and Pb, with a range of 0.004-2.901, 0.053-54.818, 0.003-6.399 and 0.007-26.80, respectively, and the HI values (range from 0.10 to 88.21) exceeded acceptable limits in 58 % of the wells. The HI results were higher than one for groundwater wells located in intensively cultivated chili fields. The highest cancer risk found was 2.6 × 10(-6) for As in well no. 11. This study suggested that people living in warmer climates are more susceptible to and at greater risk of groundwater contamination because of their increased daily drinking water intake. This may lead to an increased number of cases of non-carcinogenic and carcinogenic health defects among local people exposed to heavy metals by drinking the groundwater.

Proglacial Groundwater Flux and Storage in the Cordillera Blanca, Peru

Science.gov (United States)

Chavez, D.; McKenzie, J. M.; Baraer, M.; Mark, B. G.

2012-12-01

As tropical glaciers continue to rapidly retreat in the Cordillera Blanca, Peru, dry-season water resources are becoming more dependent on groundwater baseflow. Therefore, understanding the flux and storage of proglacial groundwater is necessary to forecast how groundwater storage can offset decreasing water resources. Recent studies of the Rio Santa Watershed, which drains the western slopes of the Cordillera Blanca, have identified that groundwater is the largest contributor to outflow from many watersheds during the dry season and that the flux of groundwater is temporarily available (clay to silt sized glaciolacustrine material at each drill site. This layer was typically less than 5 m in thickness and had a low hydraulic conductivity (clay layer were water bearing units of course material (either well-sorted sand/gravel or talus deposits) with an average hydraulic conductivity of 10-5 m/s. Additionally numerous discontinuous sand lenses and localized glaciofluvial gravel deposits were observed within the clay layer. The glaciolacustrine deposits behave as confining units that were capable of generating localized artesian conditions in the coarse grain units. The occurrence of the clay units adjacent to the main stream channels suggests that the flatness of the valley floors is not the result of river meander. The coarse grained units have the potential to act as important aquifers with significant groundwater storage and flow. Our preliminary findings indicate that the course grained units are important hydrogeological conduits with the ability to buffer low flow conditions in proglacial streams during the dry season. We present a new schematic model of how groundwater moves through these important proglacial environments, providing temporal storage of glacial meltwater and precipitation.

Groundwater quality monitoring well installation for waste area grouping 7 and solid waste storage area 1, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Mortimore, J.A.; Ebers, M.L.

1994-09-01

The purpose of this report is to document the drilling and installation of the groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 7 and at Solid Waste Storage Area (SWSA) 1, which is a part of WAG 1. Installation of GQM wells was required at Oak Ridge National Laboratory (ORNL) for regulatory compliance. Data obtained from these wells will be used to characterize and assess groundwater quality at the perimeter of each WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The wells in WAG 7 and SWSA 1 were drilled and developed during the period from June 1989 to March 1990

Groundwater quality monitoring well installation for Waste Area Grouping 5 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Mortimore, J.A.; Ebers, M.L.

1994-09-01

This report documents the drilling and installation of 22 groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 5. WAG 5 is located south of the Oak Ridge National Laboratory main plant area in Melton Valley and includes 33 solid waste management units. The wells at WAG 5 were drilled and developed between July 1987 and March 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAG 5. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

Field evaluation of a horizontal well recirculation system for groundwater treatment: Pilot test at the Clean Test Site Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

International Nuclear Information System (INIS)

Muck, M.T.; Kearl, P.M.; Siegrist, R.L.

1998-01-01

This report presents the results of field testing a horizontal well recirculation system at the Portsmouth Gaseous Diffusion Plant (PORTS). The recirculation system uses a pair of horizontal wells, one for groundwater extraction and treatment and the other for reinjection of treated groundwater, to set up a recirculation flow field. The induced flow field from the injection well to the extraction well establishes a sweeping action for the removal and treatment of groundwater contaminants. The overall purpose of this project is to study treatment of mixed groundwater contaminants that occur in a thin water-bearing zone not easily targeted by traditional vertical wells. The project involves several research elements, including treatment-process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and pilot testing at a contaminated site. The results of the pilot test at an uncontaminated site, the Clean Test Site (CTS), are presented in this report

Groundwater Pumping and Streamflow in the Yuba Basin, Sacramento Valley, California

Science.gov (United States)

Moss, D. R.; Fogg, G. E.; Wallender, W. W.

2011-12-01

Water transfers during drought in California's Sacramento Valley can lead to increased groundwater pumping, and as yet unknown effects on stream baseflow. Two existing groundwater models of the greater Sacramento Valley together with localized, monitoring of groundwater level fluctuations adjacent to the Bear, Feather, and Yuba Rivers, indicate cause and effect relations between the pumping and streamflow. The models are the Central Valley Hydrologic Model (CVHM) developed by the U.S. Geological Survey and C2VSIM developed by Department of Water Resources. Using two models which have similar complexity and data but differing approaches to the agricultural water boundary condition illuminates both the water budget and its uncertainty. Water budget and flux data for localized areas can be obtained from the models allowing for parameters such as precipitation, irrigation recharge, and streamflow to be compared to pumping on different temporal scales. Continuous groundwater level measurements at nested, near-stream piezometers show seasonal variations in streamflow and groundwater levels as well as the timing and magnitude of recharge and pumping. Preliminary results indicate that during years with relatively wet conditions 65 - 70% of the surface recharge for the groundwater system comes from irrigation and precipitation and 30 - 35% comes from streamflow losses. The models further indicate that during years with relatively dry conditions, 55 - 60% of the surface recharge for the groundwater system comes from irrigation and precipitation while 40 - 45% comes from streamflow losses. The models irrigation water demand, surface-water and groundwater supply, and deep percolation are integrated producing values for irrigation pumping. Groundwater extractions during the growing season, approximately between April and October, increase by almost 200%. The effects of increased pumping seasonally are not readily evident in stream stage measurements. However, during dry time

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

Energy Technology Data Exchange (ETDEWEB)

None

2003-09-30

This document is the monitoring optimization plan for groundwater monitoring wells associated with the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee (Figure 1). The plan describes the technical approach that will be implemented under the Y-12 Groundwater Protection Program (GWPP) to focus available resources on the monitoring wells at Y-12 which provide the most useful hydrologic and water-quality monitoring data. The technical approach is based on the GWPP status designation for each well (Section 2.0). Under this approach, wells granted ''active'' status are used by the GWPP for hydrologic monitoring and/or groundwater sampling (Section 3.0), whereas well granted ''inactive'' status are not used for either purpose. The status designation also determines the frequency at which the GWPP will inspect applicable wells, the scope of these well inspections, and extent of any maintenance actions initiated by the GWPP (Section 4.0). Details regarding the ancillary activities associated with implementation of this plan (e.g., well inspection) are deferred to the referenced GWPP plans and procedures (Section 5.0). This plan applies to groundwater monitoring wells associated with Y-12 and related waste management facilities located within three hydrogeologic regimes (Figure 1): the Bear Creek Hydrogeologic Regime (Bear Creek Regime), the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime), and the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime). The Bear Creek Regime encompasses a section of Bear Creek Valley (BCV) immediately west of Y-12. The East Fork Regime encompasses most of the Y-12 process, operations, and support facilities in BCV and, for the purposes of this plan, includes a section of Union Valley east of the DOE Oak Ridge Reservation (ORR) boundary along Scarboro Road. The Chestnut Ridge Regime is directly south of Y-12 and encompasses a section of Chestnut Ridge that is bound to the

Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

Science.gov (United States)

Back, W.; Lesser, J.M.

1981-01-01

Two critical objectives of water management in the Yucatan are: (1) to develop regional groundwater supplies for an expanding population and tourism based on the Mayan archeological sites and excellent beaches; and (2) to control groundwater pollution in a chemically sensitive system made vulnerable by geologic conditions. The Yucatan peninsula is a coastal plain underlain by permeable limestone and has an annual rainfall of more than 1000 mm. Such a setting should provide abundant supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that decrease the amount of available fresh water. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed by extensive use of groundwater. The religion was water-oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supplies by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution resulting from the use of a sewage disposal well adjacent to each supply well. The modern phase of water management began in 1959 when the Secretari??a de Recursos Hidra??ulicos (S.R.H.) was charged with the responsibility for both scientific investigations and development programmes for water-supply and sewage-disposal systems for cities, villages and islands. ?? 1981.

An optimized groundwater extraction system for the toxic burning pits area of J-Field, Aberdeen Proving Ground, Maryland

Energy Technology Data Exchange (ETDEWEB)

Quinn, J.J.; Johnson, R.L.; Patton, T.L.; Martino, L.E.

1996-06-01

Testing and disposal of chemical warfare agents, munitions, and industrial chemicals at the J-Field area of the Aberdeen Proving Ground (APG) have resulted in contamination of soil and groundwater. The discharge of contaminated groundwater to on-site marshes and adjacent estuaries poses a potential risk to ecological receptors. The Toxic Burning Pits (TBP) area is of special concern because of its disposal history. This report describes a groundwater modeling study conducted at J-Field that focused on the TBP area. The goal of this modeling effort was optimization of the groundwater extraction system at the TBP area by applying linear programming techniques. Initially, the flow field in the J-Field vicinity was characterized with a three-dimensional model that uses existing data and several numerical techniques. A user-specified border was set near the marsh and used as a constraint boundary in two modeled remediation scenarios: containment of the groundwater and containment of groundwater with an impermeable cap installed over the TBP area. In both cases, the objective was to extract the minimum amount of water necessary while satisfying the constraints. The smallest number of wells necessary was then determined for each case. This optimization approach provided two benefits: cost savings, in that the water to be treated and the well installation costs were minimized, and minimization of remediation impacts on the ecology of the marsh.

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

Science.gov (United States)

Belcher, Wayne R.

2004-01-01

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

Simulation of ground-water flow in coastal Georgia and adjacent parts of South Carolina and Florida-predevelopment, 1980, and 2000

Science.gov (United States)

Payne, Dorothy F.; Rumman, Malek Abu; Clarke, John S.

2005-01-01

A digital model was developed to simulate steady-state ground-water flow in a 42,155-square-mile area of coastal Georgia and adjacent parts of South Carolina and Florida. The model was developed to (1) understand and refine the conceptual model of regional ground-water flow, (2) serve as a framework for the development of digital subregional ground-water flow and solute-transport models, and (3) serve as a tool for future evaluations of hypothetical pumping scenarios used to facilitate water management in the coastal area. Single-density ground-water flow was simulated using the U.S. Geological Survey finite-difference code MODFLOW-2000 for mean-annual conditions during predevelopment (pre?1900) and the years 1980 and 2000. The model comprises seven layers: the surficial aquifer system, the Brunswick aquifer system, the Upper Floridan aquifer, the Lower Floridan aquifer, and the intervening confining units. A combination of boundary conditions was applied, including a general-head boundary condition on the top active cells of the model and a time-variable fixed-head boundary condition along part of the southern lateral boundary. Simulated heads for 1980 and 2000 conditions indicate a good match to observed values, based on a plus-or-minus 10-foot (ft) calibration target and calibration statistics. The root-mean square of residual water levels for the Upper Floridan aquifer was 13.0 ft for the 1980 calibration and 9.94 ft for the 2000 calibration. Some spatial patterns of residuals were indicated for the 1980 and 2000 simulations, and are likely a result of model-grid cell size and insufficiently detailed hydraulic-property and pumpage data in some areas. Simulated potentiometric surfaces for predevelopment, 1980, and 2000 conditions all show major flow system features that are indicated by estimated peotentiometric maps. During 1980?2000, simulated water levels at the centers of pumping at Savannah and Brunswick rose more than 20 ft and 8 ft, respectively, in

Thermal use of groundwater: International legislation and ecological considerations

Science.gov (United States)

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

2009-04-01

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

A two-dimensional analytical well model with applications to groundwater flow and convective transport modelling in the geosphere

International Nuclear Information System (INIS)

Chan, T.; Nakka, B.W.

1994-12-01

A two-dimensional analytical well model has been developed to describe steady groundwater flow in an idealized, confined aquifer intersected by a withdrawal well. The aquifer comprises a low-dipping fracture zone. The model is useful for making simple quantitative estimates of the transport of contaminants along groundwater pathways in the fracture zone to the well from an underground source that intercepts the fracture zone. This report documents the mathematical development of the analytical well model. It outlines the assumptions and method used to derive an exact analytical solution, which is verified by two other methods. It presents expressions for calculating quantities such as streamlines (groundwater flow paths), fractional volumetric flow rates, contaminant concentration in well water and minimum convective travel time to the well. In addition, this report presents the results of applying the analytical model to a site-specific conceptual model of the Whiteshell Research Area in southeastern Manitoba, Canada. This hydrogeological model includes the presence of a 20-m-thick, low-dipping (18 deg) fracture zone (LD1) that intercepts the horizon of a hypothetical disposal vault located at a depth of 500 m. A withdrawal well intercepts LD1 between the vault level and the ground surface. Predictions based on parameters and boundary conditions specific to LD1 are presented graphically. The analytical model has specific applications in the SYVAC geosphere model (GEONET) to calculate the fraction of a plume of contaminants moving up the fracture zone that is captured by the well, and to describe the drawdown in the hydraulic head in the fracture zone caused by the withdrawal well. (author). 16 refs., 6 tabs., 35 figs

Estimating Natural Recharge in a Desert Environment Facing Increasing Ground-Water Demands

Science.gov (United States)

Nishikawa, T.; Izbicki, J. A.; Hevesi, J. A.; Martin, P.

2004-12-01

Ground water historically has been the sole source of water supply for the community of Joshua Tree in the Joshua Tree ground-water subbasin of the Morongo ground-water basin in the southern Mojave Desert. Joshua Basin Water District (JBWD) supplies water to the community from the underlying Joshua Tree ground-water subbasin, and ground-water withdrawals averaging about 960 acre-ft/yr have resulted in as much as 35 ft of drawdown. As growth continues in the desert, ground-water resources may need to be supplemented using imported water. To help meet future demands, JBWD plans to construct production wells in the adjacent Copper Mountain ground-water subbasin. To manage the ground-water resources and to identify future mitigating measures, a thorough understanding of the ground-water system is needed. To this end, field and numerical techniques were applied to determine the distribution and quantity of natural recharge. Field techniques included the installation of instrumented boreholes in selected washes and at a nearby control site. Numerical techniques included the use of a distributed-parameter watershed model and a ground-water flow model. The results from the field techniques indicated that as much as 70 acre-ft/yr of water infiltrated downward through the two principal washes during the study period (2001-3). The results from the watershed model indicated that the average annual recharge in the ground-water subbasins is about 160 acre-ft/yr. The results from the calibrated ground-water flow model indicated that the average annual recharge for the same area is about 125 acre-ft/yr. Although the field and numerical techniques were applied to different scales (local vs. large), all indicate that natural recharge in the Joshua Tree area is very limited; therefore, careful management of the limited ground-water resources is needed. Moreover, the calibrated model can now be used to estimate the effects of different water-management strategies on the ground-water

Groundwater connectivity of upland-embedded wetlands in the Prairie Pothole Region

Science.gov (United States)

Neff, Brian; Rosenberry, Donald O.

2018-01-01

Groundwater connections from upland-embedded wetlands to downstream waterbodies remain poorly understood. In principle, water from upland-embedded wetlands situated high in a landscape should flow via groundwater to waterbodies situated lower in the landscape. However, the degree of groundwater connectivity varies across systems due to factors such as geologic setting, hydrologic conditions, and topography. We use numerical models to evaluate the conditions suitable for groundwater connectivity between upland-embedded wetlands and downstream waterbodies in the prairie pothole region of North Dakota (USA). Results show groundwater connectivity between upland-embedded wetlands and other waterbodies is restricted when these wetlands are surrounded by a mounding water table. However, connectivity exists among adjacent upland-embedded wetlands where water–table mounds do not form. In addition, the presence of sand layers greatly facilitates groundwater connectivity of upland-embedded wetlands. Anisotropy can facilitate connectivity via groundwater flow, but only if it becomes unrealistically large. These findings help consolidate previously divergent views on the significance of local and regional groundwater flow in the prairie pothole region.

"Know Your Well" A Groundwater Quality Project to Inform Students and Well-Owners

Science.gov (United States)

Olson, C.; Snow, D.; Samal, A.; Ray, C.; Kreifels, M.

2017-12-01

Over 15 million U.S. households rely on private, household wells for drinking water, and these sources are not protected under the Safe Drinking Water Act. Data on private well water quality is slowly being collected and evaluated from a number of different agencies, sources and projects. A new project is designed both for training high school students and to help assess the quality of water from rural domestic wells in Nebraska. This "crowd sourced" program engaging high school agricultural education programs, FFA chapters, and science classes with students sampling and testing water sampling from rural domestic wells from 12 districts across the state. Students and teachers from selected school were trained through multiple school visits, both in the classroom and in the field. Classroom visits were used to introduce topics such as water quality and groundwater, and testing methods for specific analytes. During the field visit, students were exposed to field techniques, the importance of accuracy in data collection, and what factors might influence the water in sampled wells. High school students learn to sample and test water independently. Leadership and initiative is developed through the program, and many experience the enlightenment that comes with citizen science. A customized mobile app was developed for ease of data entry and visualization, and data uploaded to a secure website where information was stored and compared to laboratory tests of the same measurements. General water quality parameters, including pH, electrical conductivity, major anions are tested in the field and laboratory, as well as environmental contaminants such as arsenic, uranium, pesticides, bacteria. Test kits provided to each class were used by the students to measure selected parameters, and then duplicate water samples were analyzed at a university laboratory. Five high schools are involved in the project during its first year. Nitrate, bacteria and pesticides represent major

The groundwater regime of the Harwell region

International Nuclear Information System (INIS)

Alexander, J.

1983-12-01

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

Modeling of groundwater using the isotopic technique in the sedimentary aquifer of the Mahafaly basin, southwestern Madagascar

International Nuclear Information System (INIS)

Fareze, L.H.

2016-01-01

The Mahafaly sedimentary basin, southwest of Madagascar belongs to the region where the water resources management problem, such as high groundwater mineralization and dry wells lingers. In this research work, hydrochemistry and isotopes techniques are used to assess the groundwater characteristics, to determine the groundwater origin and to understand their geochemical evolution. The development of an hydrological model using Modflow software contribute to control the groundwater flow and predict the dissolved particles evolution and travel time according to their flow direction. Dissolution of halite, calcite and gypsum and cation exchange are the main sources of the groundwater mineralization in the study area. The groundwater isotopic composition indicates that the groundwaters are directly recharged by local precipitation, having a mean time of 25 years. A mixture of groundwater and Onilahy river water occurs in adjacent aquifers, of which residence time is about 60 years. A mixture of recent and old groundwaters by the upwelling of the deep waters is observed in the southern aquifer of Isalo, confirmed by the tritium concentration value, which is lower than 0,5UT. The model established indicates a high groundwater flow rate from the recharge area, located in Betioky hill. This is due to a steep slope with a hydraulic conductivity of about 10 -5 m.s -1 , although other flow directions have been identified. The model predicts a decrease of the hydraulic head during the last decades. [fr

Accumulation of steroid hormones in soil and its adjacent aquatic environment from a typical intensive vegetable cultivation of North China.

Science.gov (United States)

Zhang, Feng-Song; Xie, Yun-Feng; Li, Xue-Wen; Wang, Dai-Yi; Yang, Lin-Sheng; Nie, Zhi-Qiang

2015-12-15

Steroid hormones released from manure agricultural application are a matter of global concern. The residual levels of steroid hormones were studied in a typical intensive vegetable cultivation area in northeast China, with a long history of heavy manure application. Seven steroids (estrone, 17α-estradiol, 17β-estradiol, estriol, testosterone, androstendione and progesterone) were analyzed from soil sampled from vegetable greenhouses, from sediments and water from the adjacent drainage ditch and from the groundwater. The results showed that target steroids were detected in the soil samples, with detection frequencies varying from 3.13 to 100%. The steroid concentrations varied substantially in soils, ranging from below the detection limit to 109.7μg·kg(-1). Three steroids-progesterone, androstendione and estrone-were found to have relatively high residue concentrations in soil, with maximum concentrations of 109.7, 9.83 and 13.30μg·kg(-1), respectively. In adjacent groundwater, all the steroids, with the exception of estrone, were detected in one or more of the 13 groundwater samples. The concentrations of steroids in groundwater ranged from below the method detection limit to 2.38ng·L(-1). Six of the seven (excluding androstendione) were detected in drainage ditch water samples, with concentrations ranging from below the detection limit to 14ng·L(-1). Progesterone, androstendione and estrone accumulated relatively easily in soils; their concentrations in groundwater were lower than those of other steroids. The concentrations of testosterone and estriol were relatively low in soil, while in groundwater were higher than those of other steroids. The residual levels of steroids in soil and groundwater showed a clear spatial variation in the study area. The residual levels of steroid hormones in soil varied substantially between differently planted greenhouses. Copyright © 2015. Published by Elsevier B.V.

Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, Southern Coast Ranges, California

Science.gov (United States)

Burton, Carmen

2018-05-30

The Monterey-Salinas Shallow Aquifer study unit covers approximately 7,820 square kilometers (km2) in Santa Cruz, Monterey, and San Luis Obispo Counties in the Central Coast Hydrologic Region of California. The study unit was divided into four study areas—Santa Cruz, Pajaro Valley, Salinas Valley, and Highlands. More than 75 percent of the water used for drinking-water supply in the Central Coast Hydrologic Region of California is groundwater, and there are more than 8,000 well driller’s logs for domestic wells (California Department of Water Resources, 2013).

Groundwater levels and water quality during a 96-hour aquifer test in Pickaway County, Ohio, 2012

Science.gov (United States)

Haefner, Ralph J.; Runkle, Donna L.; Mailot, Brian E.

2014-01-01

During October–November 2012, a 96-hour aquifer test was performed at a proposed well field in northern Pickaway County, Ohio, to investigate groundwater with elevated nitrate concentrations. Earlier sampling done by the City of Columbus revealed that some wells had concentrations of nitrate that approached 10 milligrams per liter (mg/L), whereas other wells and the nearby Scioto River had concentrations from 2 to 6 mg/L. The purpose of the current test was to examine potential changes in water quality that may be expected if the site was developed into a public water-supply source; therefore, water-transmitting properties determined during a previous test were not determined a second time. Before and during the test, water-level data and water-quality samples were obtained from observation wells while a test production well was pumped at 1,300 gallons per minute. Before the test, local groundwater levels indicated that groundwater was being discharged to the nearby Scioto River, but during the test, the stream was losing streamflow owing to infiltration. Water levels declined in the pumping well, in adjacent observation wells, and in a nearby streambed piezometer as pumping commenced. The maximum drawdown in the pumping well was 29.75 feet, measured about 95 hours after pumping began. Water-quality data, including analyses for field parameters, major and trace elements, nutrients, and stable isotopes of oxygen and nitrogen in nitrate, demonstrated only small variations before and during the test. Concentrations of nitrate in five samples from the pumping well ranged from about 5.10 to 5.42 mg/L before and during the test, whereas concentrations of nitrate in five samples on or about the same sampling dates and times at a monitoring site on the Scioto River adjacent to the pumping well ranged from 3.46 to 4.97 mg/L. Water from two nearby observation wells had nitrate concentrations approaching 10 mg/L, which is the U.S. Environmental Protection Agency’s Maximum

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

National Research Council Canada - National Science Library

Ferland, Derek

2000-01-01

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

Mapping and quantifying groundwater inflows to Deep Creek (Maribyrnong catchment, SE Australia) using 222Rn, implications for protecting groundwater-dependant ecosystems

International Nuclear Information System (INIS)

Cartwright, Ian; Gilfedder, Benjamin

2015-01-01

Highlights: • Groundwater inflows in a chain-of-ponds river quantified. • Groundwater inflow vs. discharge relationship determined using Rn. • First long-term continuous Rn monitoring in a river indicates temporal changes to groundwater inflows. • Application to protection of groundwater-dependant ecosystems. - Abstract: Understanding groundwater inflows to rivers is important in managing connected groundwater and surface water systems and for protecting groundwater-dependant ecosystems. This study defines the distribution of gaining reaches and estimates groundwater inflows to a 62 km long section of Deep Creek (Maribyrnong catchment, Australia) using 222 Rn. During summer months, Deep Creek ceases to flow and comprises a chain of ponds that δ 18 O and δ 2 H values, major ion concentrations, and 222 Rn activities imply are groundwater fed. During the period where the river flows, the relative contribution of groundwater inflows to total river discharge ranges from ∼14% at high flow conditions to ∼100% at low flows. That the predicted groundwater inflows account for all of the increase in discharge at low flow conditions lends confidence to the mass balance calculations. Near-continuous 27 week 222 Rn monitoring at one location in the middle of the catchment confirms the inverse correlation between river discharge and relative groundwater inflows, and also implies that there are limited bank return flows. Variations in groundwater inflows are related to geology and topography. High groundwater inflows occur where the river is at the edge of its floodplain, adjacent to hills composed of basement rocks, or flowing through steep incised valleys. Understanding the distribution of groundwater inflows and quantifying the contribution of groundwater to Deep Creek is important for managing and protecting the surface water resources, which support the endangered Yarra pygmy perch

Predicted impacts of future water level decline on monitoring wells using a ground-water model of the Hanford Site

International Nuclear Information System (INIS)

Wurstner, S.K.; Freshley, M.D.

1994-12-01

A ground-water flow model was used to predict water level decline in selected wells in the operating areas (100, 200, 300, and 400 Areas) and the 600 Area. To predict future water levels, the unconfined aquifer system was stimulated with the two-dimensional version of a ground-water model of the Hanford Site, which is based on the Coupled Fluid, Energy, and Solute Transport (CFEST) Code in conjunction with the Geographic Information Systems (GIS) software package. The model was developed using the assumption that artificial recharge to the unconfined aquifer system from Site operations was much greater than any natural recharge from precipitation or from the basalt aquifers below. However, artificial recharge is presently decreasing and projected to decrease even more in the future. Wells currently used for monitoring at the Hanford Site are beginning to go dry or are difficult to sample, and as the water table declines over the next 5 to 10 years, a larger number of wells is expected to be impacted. The water levels predicted by the ground-water model were compared with monitoring well completion intervals to determine which wells will become dry in the future. Predictions of wells that will go dry within the next 5 years have less uncertainty than predictions for wells that will become dry within 5 to 10 years. Each prediction is an estimate based on assumed future Hanford Site operating conditions and model assumptions

Interaction of surface water and groundwater in the Nile River basin: isotopic and piezometric evidence

Science.gov (United States)

Kebede, Seifu; Abdalla, Osman; Sefelnasr, Ahmed; Tindimugaya, Callist; Mustafa, Osman

2017-05-01

Past discussions around water-resources management and development in the River Nile basin disregard groundwater resources from the equation. There is an increasing interest around factoring the groundwater resources as an integral part of the Nile Basin water resources. This is hampered by knowledge gap regarding the groundwater resources dynamics (recharge, storage, flow, quality, surface-water/groundwater interaction) at basin scale. This report provides a comprehensive analysis of the state of surface-water/groundwater interaction from the headwater to the Nile Delta region. Piezometric and isotopic (δ18O, δ2H) evidence reveal that the Nile changes from a gaining stream in the headwater regions to mostly a loosing stream in the arid lowlands of Sudan and Egypt. Specific zones of Nile water leakage to the adjacent aquifers is mapped using the two sources of evidence. Up to 50% of the surface-water flow in the equatorial region of the Nile comes from groundwater as base flow. The evidence also shows that the natural direction and rate of surface-water/groundwater interaction is largely perturbed by human activities (diversion, dam construction) particularly downstream of the Aswan High Dam in Egypt. The decrease in discharge of the Nile River along its course is attributed to leakage to the aquifers as well as to evaporative water loss from the river channel. The surface-water/groundwater interaction occurring along the Nile River and its sensitivity to infrastructure development calls for management strategies that account groundwater as an integral part of the Nile Basin resources.

Cyclic metal migration in a groundwater stream

International Nuclear Information System (INIS)

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

1988-04-01

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

A comparative assessment of GIS-based data mining models and a novel ensemble model in groundwater well potential mapping

Science.gov (United States)

Naghibi, Seyed Amir; Moghaddam, Davood Davoodi; Kalantar, Bahareh; Pradhan, Biswajeet; Kisi, Ozgur

2017-05-01

In recent years, application of ensemble models has been increased tremendously in various types of natural hazard assessment such as landslides and floods. However, application of this kind of robust models in groundwater potential mapping is relatively new. This study applied four data mining algorithms including AdaBoost, Bagging, generalized additive model (GAM), and Naive Bayes (NB) models to map groundwater potential. Then, a novel frequency ratio data mining ensemble model (FREM) was introduced and evaluated. For this purpose, eleven groundwater conditioning factors (GCFs), including altitude, slope aspect, slope angle, plan curvature, stream power index (SPI), river density, distance from rivers, topographic wetness index (TWI), land use, normalized difference vegetation index (NDVI), and lithology were mapped. About 281 well locations with high potential were selected. Wells were randomly partitioned into two classes for training the models (70% or 197) and validating them (30% or 84). AdaBoost, Bagging, GAM, and NB algorithms were employed to get groundwater potential maps (GPMs). The GPMs were categorized into potential classes using natural break method of classification scheme. In the next stage, frequency ratio (FR) value was calculated for the output of the four aforementioned models and were summed, and finally a GPM was produced using FREM. For validating the models, area under receiver operating characteristics (ROC) curve was calculated. The ROC curve for prediction dataset was 94.8, 93.5, 92.6, 92.0, and 84.4% for FREM, Bagging, AdaBoost, GAM, and NB models, respectively. The results indicated that FREM had the best performance among all the models. The better performance of the FREM model could be related to reduction of over fitting and possible errors. Other models such as AdaBoost, Bagging, GAM, and NB also produced acceptable performance in groundwater modelling. The GPMs produced in the current study may facilitate groundwater exploitation

Investigating riparian groundwater flow close to a losing river using diurnal temperature oscillations at high vertical resolution

Directory of Open Access Journals (Sweden)

T. Vogt

2012-02-01

Full Text Available River-water infiltration is of high relevance for hyporheic and riparian groundwater ecology as well as for drinking water supply by river-bank filtration. Heat has become a popular natural tracer to estimate exchange rates between rivers and groundwater. However, quantifying flow patterns and velocities is impeded by spatial and temporal variations of exchange fluxes, insufficient sensors spacing during field investigations, or simplifying assumptions for analysis or modeling such as uniform flow. The objective of this study is to investigate lateral shallow groundwater flow upon river-water infiltration at the shoreline of the riverbed and in the adjacent riparian zone of the River Thur in northeast Switzerland. Here we have applied distributed temperature sensing (DTS along optical fibers wrapped around tubes to measure high-resolution vertical temperature profiles of the unsaturated zone and shallow riparian groundwater. Diurnal temperature oscillations were tracked in the subsurface and analyzed by means of dynamic harmonic regression to extract amplitudes and phase angles. Subsequent calculations of amplitude attenuation and time shift relative to the river signal show in detail vertical and temporal variations of heat transport in shallow riparian groundwater. In addition, we apply a numerical two-dimensional heat transport model for the unsaturated zone and shallow groundwater to obtain a better understanding of the observed heat transport processes in shallow riparian groundwater and to estimate the groundwater flow velocity. Our results show that the observed riparian groundwater temperature distribution cannot be described by uniform flow, but rather by horizontal groundwater flow velocities varying over depth. In addition, heat transfer of diurnal temperature oscillations from the losing river through shallow groundwater is influenced by thermal exchange with the unsaturated zone. Neglecting the influence of the unsaturated zone

Regional groundwater-flow model of the Redwall-Muav, Coconino, and alluvial basin aquifer systems of northern and central Arizona

Science.gov (United States)

Pool, D.R.; Blasch, Kyle W.; Callegary, James B.; Leake, Stanley A.; Graser, Leslie F.

2011-01-01

A numerical flow model (MODFLOW) of the groundwater flow system in the primary aquifers in northern Arizona was developed to simulate interactions between the aquifers, perennial streams, and springs for predevelopment and transient conditions during 1910 through 2005. Simulated aquifers include the Redwall-Muav, Coconino, and basin-fill aquifers. Perennial stream reaches and springs that derive base flow from the aquifers were simulated, including the Colorado River, Little Colorado River, Salt River, Verde River, and perennial reaches of tributary streams. Simulated major springs include Blue Spring, Del Rio Springs, Havasu Springs, Verde River headwater springs, several springs that discharge adjacent to major Verde River tributaries, and many springs that discharge to the Colorado River. Estimates of aquifer hydraulic properties and groundwater budgets were developed from published reports and groundwater-flow models. Spatial extents of aquifers and confining units were developed from geologic data, geophysical models, a groundwater-flow model for the Prescott Active Management Area, drill logs, geologic logs, and geophysical logs. Spatial and temporal distributions of natural recharge were developed by using a water-balance model that estimates recharge from direct infiltration. Additional natural recharge from ephemeral channel infiltration was simulated in alluvial basins. Recharge at wastewater treatment facilities and incidental recharge at agricultural fields and golf courses were also simulated. Estimates of predevelopment rates of groundwater discharge to streams, springs, and evapotranspiration by phreatophytes were derived from previous reports and on the basis of streamflow records at gages. Annual estimates of groundwater withdrawals for agriculture, municipal, industrial, and domestic uses were developed from several sources, including reported withdrawals for nonexempt wells, estimated crop requirements for agricultural wells, and estimated per

Impacts of swine manure pits on groundwater quality

International Nuclear Information System (INIS)

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

2002-01-01

New information is presented on impacts on groundwater by manure storage in deep ground pits. - 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 δ 15 N and δ 18 O 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

Impacts of swine manure pits on groundwater quality

Energy Technology Data Exchange (ETDEWEB)

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

2002-12-01

New information is presented on impacts on groundwater by manure storage in deep ground pits. - 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 {delta}{sup 15}N and {delta}{sup 18}O 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

Fate and groundwater impacts of produced water releases at OSPER "B" site, Osage County, Oklahoma

Science.gov (United States)

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.

Consequences of Groundwater Development on Water Resources of Hawai`i

Science.gov (United States)

Rotzoll, K.; Izuka, S. K.; El-Kadi, A. I.

2017-12-01

The availability of fresh groundwater for human use is limited by whether the impacts of withdrawals are deemed acceptable by community stakeholders and water-resource managers. Quantifying the island-wide hydrologic impacts of withdrawal—saltwater intrusion, water-table decline, and reduction of groundwater discharge to streams, nearshore environments and downgradient groundwater bodies—is thus a key step for assessing fresh groundwater availability in Hawai`i. Groundwater-flow models of the individual islands of Kaua`i, O`ahu, and Maui were constructed using MODFLOW 2005 with the Seawater-Intrusion Package (SWI2). Consistent model construction among the islands, calibration, and analysis were streamlined using Python scripts. Results of simulating historical withdrawals from Hawai`i's volcanic aquifers show that the types and magnitudes of impacts that can limit fresh groundwater availability vary among each islands' unique hydrogeologic settings. In high-permeability freshwater-lens aquifers, saltwater intrusion and reductions in coastal groundwater discharge are the principal consequences of withdrawals that can limit groundwater availability. In dike-impounded groundwater and thickly saturated low-permeability aquifers, reduced groundwater discharge to streams, water-table decline, or reduced flows to adjacent freshwater-lens aquifers can limit fresh groundwater availability. The numerical models are used to quantify and delineate the spatial distribution of these impacts for the three islands. The models were also used to examine how anticipated changes in groundwater recharge and withdrawals will affect fresh groundwater availability in the future.

Development of a single well dilution probe for groundwater velocity measurements

International Nuclear Information System (INIS)

Jain, S.K.; Santra, A.B.; Kulkarni, U.P.; Rao, S.M.

1982-01-01

The paper describes the development and design of a single well dilution probe for the measurement of groundwater velocities at different sections of the borehole. In this probe, the radioactive tracer is introduced in the measuring volume by dissolving a gelatine capsule containing the tracer. The continuous mixing of the tracer solution is achieved by a specially designed magnetic stirrer. To prevent vertical flows, the measuring volume is sealed off in the bore-hole at the top and bottom by inflator rubber tubes which are inflated by compressed air from the ground surface. The concentration of the gamma tracer solution is measured 'insitu' by a NaI crystal scintillation detector incorporated in the probe. (author)

Uranium Elemental and Isotopic Constraints on Groundwater Flow Beneath the Nopal I Uranium Deposit, Pena Blanca, Mexico

International Nuclear Information System (INIS)

S.J. Goldstein; M.T. Murrell; A.M. Simmons

2005-01-01

The Nopal I uranium deposit in Chihuahua, Mexico, is an excellent analogue for evaluating the fate of spent fuel, associated actinides, and fission products over long time scales for the proposed Yucca Mountain high-level nuclear waste repository. In 2003, three groundwater wells were drilled directly adjacent to (PB-1) and 50 m on either side of the uranium deposit (PB-2 and PB-3) in order to evaluate uranium-series transport in three dimensions. After drilling, uranium concentrations were elevated in all of the three wells (0.1-18 ppm) due to drilling activities and subsequently decreased to ∼5-20% of initial values over the next several months. The 234 U/ 238 U activity ratios were similar for PB-1 and PB-2 (1.005 to 1.079) but distinct for PB-3 (1.36 to 1.83) over this time period, suggesting limited mixing between groundwater from these wells over these short time and length scales. Regional groundwater wells located up to several km from the deposit also have distinct uranium isotopic characteristics and constrain mixing over larger length and time scales. We model the decreasing uranium concentrations in the newly drilled wells with a simple one-dimensional advection-dispersion model, assuming uranium is introduced as a slug to each of the wells and transported as a conservative tracer. Using this model for our data, the relative uranium concentrations are dependent on both the longitudinal dispersion as well as the mean groundwater flow velocity. These parameters have been found to be correlated in both laboratory and field studies of groundwater velocity and dispersion (Klotz et al., 1980). Using typical relationships between velocity and dispersion for field and laboratory studies along with the relationship observed from our uranium data, both velocity (1-10 n/yr) and dispersion coefficient (1E-5 to 1E-2 cm 2 /s) can be derived from the modeling. As discussed above, these relatively small flow velocities and dispersivities agree with mixing

Assessment of well vulnerability for groundwater source protection based on a solute transport model: a case study from Jilin City, northeast China

Science.gov (United States)

Huan, Huan; Wang, Jinsheng; Lai, Desheng; Teng, Yanguo; Zhai, Yuanzheng

2015-05-01

Well vulnerability assessment is essential for groundwater source protection. A quantitative approach to assess well vulnerability in a well capture zone is presented, based on forward solute transport modeling. This method was applied to three groundwater source areas (Jiuzhan, Hadawan and Songyuanhada) in Jilin City, northeast China. The ratio of the maximum contaminant concentration at the well to the released concentration at the contamination source ( c max/ c 0) was determined as the well vulnerability indicator. The results indicated that well vulnerability was higher close to the pumping well. The well vulnerability in each groundwater source area was low. Compared with the other two source areas, the cone of depression at Jiuzhan resulted in higher spatial variability of c max/ c 0 and lower minimum c max/ c 0 by three orders of magnitude. Furthermore, a sensitivity analysis indicated that the denitrification rate in the aquifer was the most sensitive with respect to well vulnerability. A process to derive a NO3-N concentration at the pumping well is presented, based on determining the maximum nitrate loading limit to satisfy China's drinking-water quality standards. Finally, the advantages, disadvantages and prospects for improving the precision of this well vulnerability assessment approach are discussed.

Concentrations of hormones, pharmaceuticals and other micropollutants in groundwater affected by septic systems in New England and New York

Science.gov (United States)

Phillips, Patrick J.; Schubert, Christopher E.; Argue, Denise M.; Fisher, Irene J.; Furlong, Edward T.; Foreman, William T.; Gray, James L.; Chalmers, Ann T.

2015-01-01

Septic-system discharges can be an important source of micropollutants (including pharmaceuticals and endocrine active compounds) to adjacent groundwater and surface water systems. Groundwater samples were collected from well networks tapping glacial till in New England (NE) and sandy surficial aquifer New York (NY) during one sampling round in 2011. The NE network assesses the effect of a single large septic system that receives discharge from an extended health care facility for the elderly. The NY network assesses the effect of many small septic systems used seasonally on a densely populated portion of Fire Island. The data collected from these two networks indicate that hydrogeologic and demographic factors affect micropollutant concentrations in these systems.

Groundwater management under uncertainty using a stochastic multi-cell model

Science.gov (United States)

Joodavi, Ata; Zare, Mohammad; Ziaei, Ali Naghi; Ferré, Ty P. A.

2017-08-01

The optimization of spatially complex groundwater management models over long time horizons requires the use of computationally efficient groundwater flow models. This paper presents a new stochastic multi-cell lumped-parameter aquifer model that explicitly considers uncertainty in groundwater recharge. To achieve this, the multi-cell model is combined with the constrained-state formulation method. In this method, the lower and upper bounds of groundwater heads are incorporated into the mass balance equation using indicator functions. This provides expressions for the means, variances and covariances of the groundwater heads, which can be included in the constraint set in an optimization model. This method was used to formulate two separate stochastic models: (i) groundwater flow in a two-cell aquifer model with normal and non-normal distributions of groundwater recharge; and (ii) groundwater management in a multiple cell aquifer in which the differences between groundwater abstractions and water demands are minimized. The comparison between the results obtained from the proposed modeling technique with those from Monte Carlo simulation demonstrates the capability of the proposed models to approximate the means, variances and covariances. Significantly, considering covariances between the heads of adjacent cells allows a more accurate estimate of the variances of the groundwater heads. Moreover, this modeling technique requires no discretization of state variables, thus offering an efficient alternative to computationally demanding methods.

Characterization of microbial communities distributed in the groundwater pumped from deep tube wells in the Kathmandu Valley of Nepal.

Science.gov (United States)

Tanaka, Yasuhiro; Nishida, Kei; Nakamura, Takashi; Chapagain, Saroj Kumar; Inoue, Daisuke; Sei, Kazunari; Mori, Kazuhiro; Sakamoto, Yasushi; Kazama, Futaba

2012-03-01

Although groundwater is a major water supply source in the Kathmandu Valley of Nepal, it is known that the groundwater has significant microbial contamination exceeding the drinking water quality standard recommended by the World Health Organization (WHO), and that this has been implicated in causing a variety of diseases among people living in the valley. However, little is known about the distribution of pathogenic microbes in the groundwater. Here, we analysed the microbial communities of the six water samples from deep tube wells by using the 16S rRNA gene sequences based culture-independent method. The analysis showed that the groundwater has been contaminated with various types of opportunistic microbes in addition to fecal microbes. Particularly, the clonal sequences related to the opportunistic microbes within the genus Acinetobacter were detected in all samples. As many strains of Acinetobacter are known as multi-drug resistant microbes that are currently spreading in the world, we conducted a molecular-based survey for detection of the gene encoding carbapenem-hydrolysing β-lactamase (bla(oxa-23-like) gene), which is a key enzyme responsible for multi-drug resistance, in the groundwater samples. Nested polymerase chain reaction (PCR) using two specific primer sets for amplifying bla(oxa-23-like) gene indicated that two of six groundwater samples contain multi-drug resistant Acinetobacter.

Ensemble control of the Hardhof well field under constraints

Science.gov (United States)

Marti, Beatrice; McLaughlin, Dennis; Kinzelbach, Wolfgang; Kaiser, Hans-Peter

2013-04-01

Practical control of flow in aquifers has been based on deterministic models, not including stochastic information in the optimization (Bauser et al., 2010 or Marti et al., 2012). Only recently robust ensemble control of aquatic systems has been analyzed in linear and synthetic problems (Lin, B., 2012). We propose a control under constraints, which takes into account the stochastic information contained in an ensemble of realizations of a groundwater flow model with uncertain parameters, boundary and initial conditions. This control is applied to a real life problem setting (the Hardhof well field in Zurich) and analyzed with regard to efficiency of the control compared to a similar control based on a deterministic model. The Hardhof well field, which lies in the city of Zurich, Switzerland, provides roughly 15% of the town's drinking water demand from the Limmat valley aquifer. Groundwater and river filtrate are withdrawn in four large horizontal wells, each with a capacity of up to 48'000 m3 per day. The well field is threatened by potential pollution from leachate of a nearby land fill, possible accidents on the adjacent rail and road lines, and by diffuse pollution from former industrial sites and sewers located upstream of the well field. A line of recharge wells and basins forms a hydraulic barrier against the potentially contaminated water and increases the capacity of the well field. The amount and distribution of the artificial recharge to 3 infiltration basins and 12 infiltration wells has to be controlled on a daily basis to guarantee the effectiveness of the hydraulic barrier in the highly dynamic flow field. The Hardhof well field is simulated with a 2D-real-time groundwater flow model. The model is coupled to a controller, minimizing the inflow of potentially contaminated groundwater to the drinking water wells under various constraints (i.e. keeping the groundwater level between given thresholds, guaranteeing production of the drinking water demand

An integrated approach to risk-based remediation of a former bulk fuel storage facility adjacent a marine environment

Energy Technology Data Exchange (ETDEWEB)

Kemp, L.; Hers, I. [Golder Associates Ltd., Vancouver, BC (Canada)

2006-07-01

An integrated approach to risk-based remediation of a former bulk fuel storage facility adjacent to a marine environment was discussed. The presentation provided an introduction and illustration to the site location and history, located close to Skagway, Alaska and northwestern British Columbia. The site investigation and conceptual model were also presented. The remedial approach was also described with reference to a risk-based action approach, remedial objectives, soil vapour extraction (SVE)-bioventing, and air sparging-biosparging. The objectives were to minimize potential exposure to aquatic receptors by minimizing non-aqueous phase liquids (NAPL) mobility and dissolved transport of petroleum hydrocarbons. Groundwater modeling to assess the attenuation rate and to determine remedial targets was also discussed. Model validation and results of groundwater modeling as well as remediation system details and performance were then provided. It was determined that significant attenuation is occurring and that effective mass removal and concentrations have been decreasing over time. It was demonstrated that risk-based remedial goals and hydrogeology can change with land use/development. tabs., figs.

Hydrogeology, groundwater flow, and groundwater quality of an abandoned underground coal-mine aquifer, Elkhorn Area, West Virginia

Science.gov (United States)

Kozar, Mark D.; McCoy, Kurt J.; Britton, James Q.; Blake, B.M.

2017-01-01

The Pocahontas No. 3 coal seam in southern West Virginia has been extensively mined by underground methods since the 1880’s. An extensive network of abandoned mine entries in the Pocahontas No. 3 has since filled with good-quality water, which is pumped from wells or springs discharging from mine portals (adits), and used as a source of water for public supplies. This report presents results of a three-year investigation of the geology, hydrology, geochemistry, and groundwater flow processes within abandoned underground coal mines used as a source of water for public supply in the Elkhorn area, McDowell County, West Virginia. This study focused on large (> 500 gallon per minute) discharges from the abandoned mines used as public supplies near Elkhorn, West Virginia. Median recharge calculated from base-flow recession of streamflow at Johns Knob Branch and 12 other streamflow gaging stations in McDowell County was 9.1 inches per year. Using drainage area versus mean streamflow relationships from mined and unmined watersheds in McDowell County, the subsurface area along dip of the Pocahontas No. 3 coal-mine aquifer contributing flow to the Turkey Gap mine discharge was determined to be 7.62 square miles (mi2), almost 10 times larger than the 0.81 mi2 surface watershed. Results of this investigation indicate that groundwater flows down dip beneath surface drainage divides from areas up to six miles east in the adjacent Bluestone River watershed. A conceptual model was developed that consisted of a stacked sequence of perched aquifers, controlled by stress-relief and subsidence fractures, overlying a highly permeable abandoned underground coal-mine aquifer, capable of substantial interbasin transfer of water. Groundwater-flow directions are controlled by the dip of the Pocahontas No. 3 coal seam, the geometry of abandoned mine workings, and location of unmined barriers within that seam, rather than surface topography. Seven boreholes were drilled to intersect

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

Science.gov (United States)

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.

2016-01-01

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.

Neural Network approach to assess the thermal affected zone around the injection well in a groundwater heat pump system

Science.gov (United States)

Lo Russo, Stefano; Taddia, Glenda; Verda, Vittorio

2014-05-01

The common use of well doublets for groundwater-sourced heating or cooling results in a thermal plume of colder or warmer re-injected groundwater known as the Thermal Affected Zone(TAZ). The plumes may be regarded either as a potential anthropogenic geothermal resource or as pollution, depending on downstream aquifer usage. A fundamental aspect in groundwater heat pump (GWHP) plant design is the correct evaluation of the thermally affected zone that develops around the injection well. Temperature anomalies are detected through numerical methods. Crucial elements in the process of thermal impact assessment are the sizes of installations, their position, the heating/cooling load of the building, and the temperature drop/increase imposed on the re-injected water flow. For multiple-well schemes, heterogeneous aquifers, or variable heating and cooling loads, numerical models that simulate groundwater and heat transport are needed. These tools should consider numerous scenarios obtained considering different heating/cooling loads, positions, and operating modes. Computational fluid dynamic (CFD) models are widely used in this field because they offer the opportunity to calculate the time evolution of the thermal plume produced by a heat pump, depending on the characteristics of the subsurface and the heat pump. Nevertheless, these models require large computational efforts, and therefore their use may be limited to a reasonable number of scenarios. Neural networks could represent an alternative to CFD for assessing the TAZ under different scenarios referring to a specific site. The use of neural networks is proposed to determine the time evolution of the groundwater temperature downstream of an installation as a function of the possible utilization profiles of the heat pump. The main advantage of neural network modeling is the possibility of evaluating a large number of scenarios in a very short time, which is very useful for the preliminary analysis of future multiple

Isotope Hydrology Investigation of Zonguldak And Province Groundwater

International Nuclear Information System (INIS)

Erduran, B.; Toerk, K.; Oektue, G.

2002-01-01

The most important coal area of Turkey is situated in Zonguldak and province. The coal series occurred during Westfalien (Carboniferous) are lower-bounded by Visean aged karstic limestones and upper-bounded by Aptian-Barremian aged karstic limestones. The isotope hydrology, which consists one of the studies dealed with karst hydrogeology, was held to determine the groundwater relations between the karstic limestones adjacent to the coal layers located in the Zonguldak coal mine areas. Environmental isotope samples were collected in the basin during 1994 - 1995 period, from the surface and groundwater. Deuterium ( 2 H), Oxygen 18 ( 18 O) and Tritium ( 3 H) analysis were carried out on the samples. Recharge elevation, water origin and transit time of the groundwater system were determined with the evaluation of the analysis results. Waters encountered in the area are of marine origined rainfall, recharging at an elevation of 400-500 meters and consisting of shallow and deep circulation systems. Groundwater that intruding the coal mine galleries, have a short flow period and are recharged from recent precipitations

The efficacy of the well of the well (WOW) culture system on development of bovine embryos in a small group and the effect of number of adjacent embryos on their development.

Science.gov (United States)

Kang, Sung-Sik; Ofuji, Sosuke; Imai, Kei; Huang, Weiping; Koyama, Keisuke; Yanagawa, Yojiro; Takahashi, Yoshiyuki; Nagano, Masashi

2015-06-01

The aim of the present study was to clarify the efficacy of the well of the well (WOW) culture system for a small number of embryos and the effect of number of adjacent embryos in a WOW dish on blastocyst development. In conventional droplet culture, embryos in the small-number group (5-6 embryos/droplet) showed low blastocyst development compared with a control group (25-26 embryos/droplet). However, small and large numbers of embryos (5-6 and 25 embryos, respectively) in a WOW dish showed no significant differences in cleavage, blastocyst rates, and mean cell number in blastocysts compared with the control group (25-30 embryos/droplet). In addition, the number of adjacent embryos in a WOW dish did not affect the development to blastocysts and cell number in blastocysts. In conclusion, a WOW dish can provide high and stable blastocyst development in small group culture wherever embryos are placed in microwells of the WOW dish.

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

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

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.

Ground-Water Quality Data in the Owens and Indian Wells Valleys Study Unit, 2006: Results from the California GAMA Program

Science.gov (United States)

Densmore, Jill N.; Fram, Miranda S.; Belitz, Kenneth

2009-01-01

Ground-water quality in the approximately 1,630 square-mile Owens and Indian Wells Valleys study unit (OWENS) was investigated in September-December 2006 as part of the Priority Basin Project of Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board (SWRCB). The Owens and Indian Wells Valleys study was designed to provide a spatially unbiased assessment of raw ground-water quality within OWENS study unit, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 74 wells in Inyo, Kern, Mono, and San Bernardino Counties. Fifty-three of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (grid wells), and 21 wells were selected to evaluate changes in water chemistry in areas of interest (understanding wells). The ground-water samples were analyzed for a large number of synthetic organic constituents [volatile organic compounds (VOCs), pesticides and pesticide degradates, pharmaceutical compounds, and potential wastewater- indicator compounds], constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), and 1,2,3- trichloropropane (1,2,3-TCP)], naturally occurring inorganic constituents [nutrients, major and minor ions, and trace elements], radioactive constituents, and microbial indicators. Naturally occurring isotopes [tritium, and carbon-14, and stable isotopes of hydrogen and oxygen in water], and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. This study evaluated the quality of raw ground water in the aquifer in the OWENS study unit and did not attempt to evaluate the quality of treated water

Groundwater sustainability strategies

Science.gov (United States)

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

2010-01-01

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

Influence of groundwater on distribution of dwarf wedgemussels (Alasmidonta heterodon) in the upper reaches of the Delaware River, northeastern USA

Science.gov (United States)

Rosenberry, Donald O.; Briggs, Martin A.; Voytek, Emily B.; Lane, John W.

2016-01-01

The remaining populations of the endangered dwarf wedgemussel (DWM) (Alasmidonta heterodon) in the upper Delaware River, northeastern USA, were hypothesized to be located in areas of greater-than-normal groundwater discharge to the river. We combined physical (seepage meters, monitoring wells and piezometers), thermal (fiber-optic distributed temperature sensing, infrared, vertical bed-temperature profiling), and geophysical (electromagnetic-induction) methods at several spatial scales to characterize known DWM habitat and explore this hypothesis. Numerous springs were observed using visible and infrared imaging along the river banks at all three known DWM-populated areas, but not in adjacent areas where DWM were absent. Vertical and lateral groundwater gradients were toward the river along all three DWM-populated reaches, with median upward gradients 3 to 9 times larger than in adjacent reaches. Point-scale seepage-meter measurements indicated that upward seepage across the riverbed was faster and more consistently upward at DWM-populated areas. Discrete and areally distributed riverbed-temperature measurements indicated numerous cold areas of groundwater discharge during warm summer months; all were within areas populated by DWM. Electromagnetic-induction measurements, which may indicate riverbed geology, showed patterning but little correlation between bulk streambed electromagnetic conductivity and areal distribution of DWM. In spite of complexity introduced by hyporheic exchange, multiple lines of research provide strong evidence that DWM are located within or directly downstream of areas of substantial focused groundwater discharge to the river. Broad scale thermal-reconnaissance methods (e.g., infrared) may be useful in locating and protecting other currently unknown mussel populations.

Influence of groundwater on distribution of dwarf wedgemussels (Alasmidonta heterodon in the upper reaches of the Delaware River, northeastern USA

Directory of Open Access Journals (Sweden)

D. O. Rosenberry

2016-10-01

Full Text Available The remaining populations of the endangered dwarf wedgemussel (DWM (Alasmidonta heterodon in the upper Delaware River, northeastern USA, were hypothesized to be located in areas of greater-than-normal groundwater discharge to the river. We combined physical (seepage meters, monitoring wells and piezometers, thermal (fiber-optic distributed temperature sensing, infrared, vertical bed-temperature profiling, and geophysical (electromagnetic-induction methods at several spatial scales to characterize known DWM habitat and explore this hypothesis. Numerous springs were observed using visible and infrared imaging along the river banks at all three known DWM-populated areas, but not in adjacent areas where DWM were absent. Vertical and lateral groundwater gradients were toward the river along all three DWM-populated reaches, with median upward gradients 3 to 9 times larger than in adjacent reaches. Point-scale seepage-meter measurements indicated that upward seepage across the riverbed was faster and more consistently upward at DWM-populated areas. Discrete and areally distributed riverbed-temperature measurements indicated numerous cold areas of groundwater discharge during warm summer months; all were within areas populated by DWM. Electromagnetic-induction measurements, which may indicate riverbed geology, showed patterning but little correlation between bulk streambed electromagnetic conductivity and areal distribution of DWM. In spite of complexity introduced by hyporheic exchange, multiple lines of research provide strong evidence that DWM are located within or directly downstream of areas of substantial focused groundwater discharge to the river. Broad scale thermal-reconnaissance methods (e.g., infrared may be useful in locating and protecting other currently unknown mussel populations.

Groundwater quality in wells in central rural Finland: a microbiological and radiochemical survey

International Nuclear Information System (INIS)

Korhonen, L.; Niskanen, M.; Heinonen-Tanski, H.; Martikainen, P.J.; Salonen, L.; Taipalinen, I.

1996-01-01

The microbiological, physicochemical, and radiochemical water quality from samples of 150 rural wells in Finland was analyzed. Organic matter exceeded 12 mg KMnO4 L(-1) in 63% and nitrate 25 mg NO3 L(-1) in 29% of the wells. NO3--concentrations were higher in wells with cattle. Fecal coliforms and fecal streptococci were found in 10-40%. There was no direct positive correlation between heterotrophic and indicator bacteria. Salmonella or Campylobacter were not detected. Human pathogen Listeria monocytogenes was isolated from two and Yersinia enterocolitica serotypes O5 or O6 from four waters not containing fecal coliforms. Thus, the predictive value of fecal coliforms to indicate these pathogens is poor. Coliphages were found in seven wells. Mean concentrations of radon and long-lived alpha-active radionuclides were lower and those of beta-emitting radionuclides higher than the mean concentrations measured from groundwater in Finland. Radionuclides from the Chernobyl fallout were not detected

Groundwater quality monitoring well installation for Waste Area Grouping 17 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Mortimore, J.A.; Ebers, M.L.

1994-09-01

This report documents the drilling and installation of groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 17. WAG 17 is composed of approximately 23 acres and is located in Bethel Valley about 3,100 ft east of the Oak Ridge National Laboratory (ORNL) main plant area. The facilities in WAG 17 constitute the ORNL Services Area and include the shipping and receiving departments, machine shops, carpenter shops, paint shops, lead burning facilities, tritium facility, and the materials storage area. The wells at WAG 17 were drilled and developed between November 1989 and April 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAG 17. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG 17 characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

Hydrochemical trends for public supply well fields in The Netherlands (1898-2008), natural backgrounds and upscaling to groundwater bodies

Science.gov (United States)

Mendizabal, Igor; Baggelaar, Paul K.; Stuyfzand, Pieter J.

2012-07-01

SummaryStatistical trend analysis is applied to a 110 years long groundwater quality time series from the national network of public supply well fields (PSWFs) in The Netherlands. Such a groundwater quality monitoring network should be available in many countries, so that approaches and experiences presented here could be of interest world wide. Trendless concentration data series measured in the early years, which should bear the least anthropogenic influences, are selected to quantify the regional natural background concentration levels (NBLs) of groundwater resources at the depth of abstraction. Trends in the period 1960-2005, which contained a more homogeneous data set, are normalized to drinking water standards, mapped in planar view and cross sections, and used to identify the responsible hydrochemical processes. Seven representative trend bundles are defined by aggregation of trends for individual chemical parameters. Trend reversals due to either environmental sanitation measures or well field adaptation measures are identified by comparing significant trends obtained for two different periods within the time series. Natural background levels (NBLs) for individual PSWFs are upscaled to the national groundwater body level (as reported to EU), by aggregating them according to a PSWF typology based on a Hydrochemical System Analysis. This aggregation method groups together PSWFs that deliver waters of the same origin and similar hydrogeochemical environment. PSWFs delivering old groundwaters with a very stable quality are clearly differentiated from PSWFs pumping highly vulnerable aquifers characterized by strongly deteriorating water quality trends. Results are presented on national maps of The Netherlands with NBLs and water quality trends for selected major constituents. A normalized concentration change index (NCC) is defined and mapped to relate the quality difference between a recent survey (in 2008) and calculated NBLs, to the EU drinking water

Simulations of groundwater flow, transport, and age in Albuquerque, New Mexico, for a study of transport of anthropogenic and natural contaminants (TANC) to public-supply wells

Science.gov (United States)

Heywood, Charles E.

2013-01-01

Vulnerability to contamination from manmade and natural sources can be characterized by the groundwater-age distribution measured in a supply well and the associated implications for the source depths of the withdrawn water. Coupled groundwater flow and transport models were developed to simulate the transport of the geochemical age-tracers carbon-14, tritium, and three chlorofluorocarbon species to public-supply wells in Albuquerque, New Mexico. A separate, regional-scale simulation of transport of carbon-14 that used the flow-field computed by a previously documented regional groundwater flow model was calibrated and used to specify the initial concentrations of carbon-14 in the local-scale transport model. Observations of the concentrations of each of the five chemical species, in addition to water-level observations and measurements of intra-borehole flow within a public-supply well, were used to calibrate parameters of the local-scale groundwater flow and transport models. The calibrated groundwater flow model simulates the mixing of “young” groundwater, which entered the groundwater flow system after 1950 as recharge at the water table, with older resident groundwater that is more likely associated with natural contaminants. Complexity of the aquifer system in the zone of transport between the water table and public-supply well screens was simulated with a geostatistically generated stratigraphic realization based upon observed lithologic transitions at borehole control locations. Because effective porosity was simulated as spatially uniform, the simulated age tracers are more efficiently transported through the portions of the simulated aquifer with relatively higher simulated hydraulic conductivity. Non-pumping groundwater wells with long screens that connect aquifer intervals having different hydraulic heads can provide alternate pathways for contaminant transport that are faster than the advective transport through the aquifer material. Simulation of

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-02-24

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

Pesticides and nitrate in groundwater underlying citrus croplands, Lake Wales Ridge, central Florida, 1999-2005.

Science.gov (United States)

Choquette, Anne F.

2014-01-01

This report summarizes pesticide and nitrate (as nitrogen) results from quarterly sampling of 31 surficial-aquifer wells in the Lake Wales Ridge Monitoring Network during April 1999 through January 2005. The wells, located adjacent to citrus orchards and used for monitoring only, were generally screened (sampled) within 5 to 40 feet of the water table. Of the 44 citrus pesticides and pesticide degradates analyzed, 17 were detected in groundwater samples. Parent pesticides and degradates detected in quarterly groundwater samples, ordered by frequency of detection, included norflurazon, demethyl norflurazon, simazine, diuron, bromacil, aldicarb sulfone, aldicarb sulfoxide, deisopropylatrazine (DIA), imidacloprid, metalaxyl, thiazopyr monoacid, oxamyl, and aldicarb. Reconnaissance sampling of five Network wells yielded detection of four additional pesticide degradates (hydroxysimazine, didealkylatrazine, deisopropylhydroxyatrazine, and hydroxyatrazine). The highest median concentration values per well, based on samples collected during the 1999–2005 period (n=14 to 24 samples per well), included 3.05 µg/L (micrograms per liter) (simazine), 3.90 µg/L (diuron), 6.30 µg/L (aldicarb sulfone), 6.85 µg/L (aldicarb sulfoxide), 22.0 µg/L (demethyl norflurazon), 25.0 µg/ (norflurazon), 89 µg/ (bromacil), and 25.5 mg/L (milligrams per liter) (nitrate). Nitrate concentrations exceeded the 10 mg/L (as nitrogen) drinking water standard in one or more groundwater samples from 28 of the wells, and the median nitrate concentration among these wells was 14 mg/L. Sampled groundwater pesticide concentrations exceeded Florida’s health-guidance benchmarks for aldicarb sulfoxide and aldicarb sulfone (4 wells), the sum of aldicarb and its degradates (6 wells), simazine (2 wells), the sum of simazine and DIA (3 wells), diuron (2 wells), bromacil (1 well), and the sum of norflurazon and demethyl norflurazon (1 well). The magnitude of fluctuations in groundwater pesticide

Groundwater quality monitoring well installation for Waste Area Grouping 3 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Mortimore, J.A.; Ebers, M.L.

1994-09-01

This report documents the drilling and installation of 15 groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 3. WAG 3 is located in Melton Valley, approximately 3,000 ft west of the west gate of Oak Ridge National Laboratory, and consists of an estimated 22 acres. The subject site contains three solid waste management units: the Contractors' Landfill, the Closed Scrap Metal Area, and Solid Waste Storage Area 3. The wells at WAG 3 were drilled and developed between September 1987 and August 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The wells at WAG 3 were drilled with auger or air rotary rigs. Depending upon the hydrogeologic conditions present at each proposed well location, one of four basic installation methods was utilized. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAG 3. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

Using 14C and 3H to understand groundwater flow and recharge in an aquifer window

Science.gov (United States)

Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendón, D. I.; Unland, N. P.; Hofmann, H.

2014-12-01

Knowledge of groundwater residence times and recharge locations is vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge from rainfall and recharge from the Gellibrand River. To determine recharge patterns and groundwater flow paths, environmental isotopes (3H, 14C, δ13C, δ18O, δ2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. The water table fluctuates by 0.9 to 3.7 m annually, implying recharge rates of 90 and 372 mm yr-1. However, residence times of shallow (11 to 29 m) groundwater determined by 14C are between 100 and 10 000 years, 3H activities are negligible in most of the groundwater, and groundwater electrical conductivity remains constant over the period of study. Deeper groundwater with older 14C ages has lower δ18O values than younger, shallower groundwater, which is consistent with it being derived from greater altitudes. The combined geochemistry data indicate that local recharge from precipitation within the valley occurs through the aquifer window, however much of the groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High. The Gellibrand Valley is a regional discharge zone with upward head gradients that limits local recharge to the upper 10 m of the aquifer. Additionally, the groundwater head gradients adjacent to the Gellibrand River are generally upwards, implying that it does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10

Determination of protection zones for Dutch groundwater wells against virus contamination--uncertainty and sensitivity analysis.

Science.gov (United States)

Schijven, J F; Mülschlegel, J H C; Hassanizadeh, S M; Teunis, P F M; de Roda Husman, A M

2006-09-01

Protection zones of shallow unconfined aquifers in The Netherlands were calculated that allow protection against virus contamination to the level that the infection risk of 10(-4) per person per year is not exceeded with a 95% certainty. An uncertainty and a sensitivity analysis of the calculated protection zones were included. It was concluded that protection zones of 1 to 2 years travel time (206-418 m) are needed (6 to 12 times the currently applied travel time of 60 days). This will lead to enlargement of protection zones, encompassing 110 unconfined groundwater well systems that produce 3 x 10(8) m3 y(-1) of drinking water (38% of total Dutch production from groundwater). A smaller protection zone is possible if it can be shown that an aquifer has properties that lead to greater reduction of virus contamination, like more attachment. Deeper aquifers beneath aquitards of at least 2 years of vertical travel time are adequately protected because vertical flow in the aquitards is only 0.7 m per year. The most sensitive parameters are virus attachment and inactivation. The next most sensitive parameters are grain size of the sand, abstraction rate of groundwater, virus concentrations in raw sewage and consumption of unboiled drinking water. Research is recommended on additional protection by attachment and under unsaturated conditions.

Uranium Elemental and Isotopic Constraints on Groundwater Flow Beneath the Nopal I Uranium Deposit, Pena Blanca, Mexico

Energy Technology Data Exchange (ETDEWEB)

S.J. Goldstein; M.T. Murrell; A.M. Simmons

2005-07-11

The Nopal I uranium deposit in Chihuahua, Mexico, is an excellent analogue for evaluating the fate of spent fuel, associated actinides, and fission products over long time scales for the proposed Yucca Mountain high-level nuclear waste repository. In 2003, three groundwater wells were drilled directly adjacent to (PB-1) and 50 m on either side of the uranium deposit (PB-2 and PB-3) in order to evaluate uranium-series transport in three dimensions. After drilling, uranium concentrations were elevated in all of the three wells (0.1-18 ppm) due to drilling activities and subsequently decreased to {approx}5-20% of initial values over the next several months. The {sup 234}U/{sup 238}U activity ratios were similar for PB-1 and PB-2 (1.005 to 1.079) but distinct for PB-3 (1.36 to 1.83) over this time period, suggesting limited mixing between groundwater from these wells over these short time and length scales. Regional groundwater wells located up to several km from the deposit also have distinct uranium isotopic characteristics and constrain mixing over larger length and time scales. We model the decreasing uranium concentrations in the newly drilled wells with a simple one-dimensional advection-dispersion model, assuming uranium is introduced as a slug to each of the wells and transported as a conservative tracer. Using this model for our data, the relative uranium concentrations are dependent on both the longitudinal dispersion as well as the mean groundwater flow velocity. These parameters have been found to be correlated in both laboratory and field studies of groundwater velocity and dispersion (Klotz et al., 1980). Using typical relationships between velocity and dispersion for field and laboratory studies along with the relationship observed from our uranium data, both velocity (1-10 n/yr) and dispersion coefficient (1E-5 to 1E-2 cm{sup 2}/s) can be derived from the modeling. As discussed above, these relatively small flow velocities and dispersivities agree with

Forecasting of Groundwater Level using Artificial Neural Network by incorporating river recharge and river bank infiltration

Directory of Open Access Journals (Sweden)

Nizar Shamsuddin Mohd Khairul

2017-01-01

Full Text Available Groundwater tables forecasting during implemented river bank infiltration (RBI method is important to identify adequate storage of groundwater aquifer for water supply purposes. This study illustrates the development and application of artificial neural networks (ANNs to predict groundwater tables in two vertical wells located in confined aquifer adjacent to the Langat River. ANN model was used in this study is based on the long period forecasting of daily groundwater tables. ANN models were carried out to predict groundwater tables for 1 day ahead at two different geological materials. The input to the ANN models consider of daily rainfall, river stage, water level, stream flow rate, temperature and groundwater level. Two different type of ANNs structure were used to predict the fluctuation of groundwater tables and compared the best forecasting values. The performance of different models structure of the ANN is used to identify the fluctuation of the groundwater table and provide acceptable predictions. Dynamics prediction and time series of the system can be implemented in two possible ways of modelling. The coefficient correlation (R, Mean Square Error (MSE, Root Mean Square Error (RMSE and coefficient determination (R2 were chosen as the selection criteria of the best model. The statistical values for DW1 are 0.8649, 0.0356, 0.01, and 0.748 respectively. While for DW2 the statistical values are 0.7392, 0.0781, 0.0139, and 0.546 respectively. Based on these results, it clearly shows that accurate predictions can be achieved with time series 1-day ahead of forecasting groundwater table and the interaction between river and aquifer can be examine. The findings of the study can be used to assist policy marker to manage groundwater resources by using RBI method.

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

Directory of Open Access Journals (Sweden)

Heryadi Tirtomihardjo

2014-06-01

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

Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells

Science.gov (United States)

Clark, Brian R.; Landon, Matthew K.; Kauffman, Leon J.; Hornberger, George Z.

2008-01-01

Contamination of public-supply wells has resulted in public-health threats and negative economic effects for communities that must treat contaminated water or find alternative water supplies. To investigate factors controlling vulnerability of public-supply wells to anthropogenic and natural contaminants using consistent and systematic data collected in a variety of principal aquifer settings in the United States, a study of Transport of Anthropogenic and Natural Contaminants to public-supply wells was begun in 2001 as part of the U.S. Geological Survey National Water-Quality Assessment Program. The area simulated by the ground-water flow model described in this report was selected for a study of processes influencing contaminant distribution and transport along the direction of ground-water flow towards a public-supply well in southeastern York, Nebraska. Ground-water flow is simulated for a 60-year period from September 1, 1944, to August 31, 2004. Steady-state conditions are simulated prior to September 1, 1944, and represent conditions prior to use of ground water for irrigation. Irrigation, municipal, and industrial wells were simulated using the Multi-Node Well package of the modular three-dimensional ground-water flow model code, MODFLOW-2000, which allows simulation of flow and solutes through wells that are simulated in multiple nodes or layers. Ground-water flow, age, and transport of selected tracers were simulated using the Ground-Water Transport process of MODFLOW-2000. Simulated ground-water age was compared to interpreted ground-water age in six monitoring wells in the unconfined aquifer. The tracer chlorofluorocarbon-11 was simulated directly using Ground-Water Transport for comparison with concentrations measured in six monitoring wells and one public supply well screened in the upper confined aquifer. Three alternative model simulations indicate that simulation results are highly sensitive to the distribution of multilayer well bores where leakage

Using Oil and Gas Well Log Records to Understand Possible Connections Between Wastewater Injection Zones and Usable Groundwater Aquifers in California

Science.gov (United States)

Shimabukuro, D.; Haugen, E. A.; Battistella, C.; Treguboff, E. W.; Kale, J. M.

2015-12-01

Although the disposal of produced water in wastewater injection wells has been occurring in California for decades, it is not clear whether injected fluids may be migrating into usable groundwater aquifers. One problem is the poor characterization of federally-protected (oil and gas well records collected by the California Division of Oil, Gas, and Geothermal Resources (DOGGR). These scanned records contain two useful sources of information. First, geophysical well logs, such those measuring resistivity and porosity, can be used to determine aquifer salinity. This allows a three-dimensional understanding of the distribution of protected groundwater. Second, driller's logs contain lithological descriptions at depth. These lithologies can be used to construct a three-dimensional texture model, which can then be used in a groundwater flow model. A large number of undergraduate researchers at CSU Sacramento and CSU Long Beach have been collecting information on well records in the Ventura Basin and the Southern San Joaquin Valley. Each well record is examined with basic metadata entered into an online database in an effort to identify appropriate geophysical well logs and driller's logs. High-quality driller's logs are coded and used to create three-dimensional framework models for each well field. The geophysical logs are digitized and will be used to determine aquifer salinity. In addition, we are using information from the DOGGR well records to investigate wellbore integrity, waste disposal and waterflood injection volumes, and the possibility of induced seismicity. This project is part of the broader effort of the California State Water Resources Control Board to implement Senate Bill 4.

Groundwater mixing and mineralization processes in a mountain-oasis-desert basin, northwest China: hydrogeochemistry and environmental tracer indicators

Science.gov (United States)

Ma, Bin; Jin, Menggui; Liang, Xing; Li, Jing

2018-02-01

Hydrogeochemistry and environmental tracers (2H, 18O, 87Sr/86Sr) in precipitation, river and reservoir water, and groundwater have been used to determine groundwater recharge sources, and to identify mixing characteristics and mineralization processes in the Manas River Basin (MRB), which is a typical mountain-oasis-desert ecosystem in arid northwest China. The oasis component is artificial (irrigation). Groundwater with enriched stable isotope content originates from local precipitation and surface-water leakage in the piedmont alluvial-oasis plain. Groundwater with more depleted isotopes in the north oasis plain and desert is recharged by lateral flow from the adjacent mountains, for which recharge is associated with high altitude and/or paleo-water infiltrating during a period of much colder climate. Little evaporation and isotope exchange between groundwater and rock and soil minerals occurred in the mountain, piedmont and oasis plain. Groundwater δ2H and δ18O values show more homogeneous values along the groundwater flow direction and with well depths, indicating inter-aquifer mixing processes. A regional contrast of groundwater allows the 87Sr/86Sr ratios and δ18O values to be useful in a combination with Cl, Na, Mg, Ca and Sr concentrations to distinguish the groundwater mixing characteristics. Two main processes are identified: groundwater lateral-flow mixing and river leakage in the piedmont alluvial-oasis plain, and vertical mixing in the north oasis plain and the desert. The 87Sr/86Sr ratios and selected ion ratios reveal that carbonate dissolution and mixing with silicate from the southern mountain area are primarily controlling the strontium isotope hydrogeochemistry.

Impact of Submarine Groundwater Discharge on Marine Water Quality and Reef Biota of Maui.

Directory of Open Access Journals (Sweden)

Daniel W Amato

Full Text Available Generally unseen and infrequently measured, submarine groundwater discharge (SGD can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potential, land-based nutrient sources on Maui. Three common reef algae, Acanthophora spicifera, Hypnea musciformis, and Ulva spp. were collected and/or deployed at six locations with SGD. Algal tissue nitrogen (N parameters (δ15N, N %, and C:N were compared with nutrient and δ15N-nitrate values of coastal groundwater and nearshore surface water at all locations. Benthic community composition was estimated for ten 10-m transects per location. Reefs adjacent to sugarcane farms had the greatest abundance of macroalgae, low species diversity, and the highest concentrations of N in algal tissues, coastal groundwater, and marine surface waters compared to locations with low anthropogenic impact. Based on δ15N values of algal tissues, we estimate ca. 0.31 km2 of Kahului Bay is impacted by effluent injected underground at the Kahului Wastewater Reclamation Facility (WRF; this region is barren of corals and almost entirely dominated by colonial zoanthids. Significant correlations among parameters of algal tissue N with adjacent surface and coastal groundwater N indicate that these bioassays provided a useful measure of nutrient source and loading. A conceptual model that uses Ulva spp. tissue δ15N and N % to identify potential N source(s and relative N loading is proposed for Hawai'i. These results indicate that SGD can be a significant transport pathway for land-based nutrients with important biogeochemical and ecological implications in tropical, oceanic islands.

Impact of Submarine Groundwater Discharge on Marine Water Quality and Reef Biota of Maui.

Science.gov (United States)

Amato, Daniel W; Bishop, James M; Glenn, Craig R; Dulai, Henrietta; Smith, Celia M

2016-01-01

Generally unseen and infrequently measured, submarine groundwater discharge (SGD) can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potential, land-based nutrient sources on Maui. Three common reef algae, Acanthophora spicifera, Hypnea musciformis, and Ulva spp. were collected and/or deployed at six locations with SGD. Algal tissue nitrogen (N) parameters (δ15N, N %, and C:N) were compared with nutrient and δ15N-nitrate values of coastal groundwater and nearshore surface water at all locations. Benthic community composition was estimated for ten 10-m transects per location. Reefs adjacent to sugarcane farms had the greatest abundance of macroalgae, low species diversity, and the highest concentrations of N in algal tissues, coastal groundwater, and marine surface waters compared to locations with low anthropogenic impact. Based on δ15N values of algal tissues, we estimate ca. 0.31 km2 of Kahului Bay is impacted by effluent injected underground at the Kahului Wastewater Reclamation Facility (WRF); this region is barren of corals and almost entirely dominated by colonial zoanthids. Significant correlations among parameters of algal tissue N with adjacent surface and coastal groundwater N indicate that these bioassays provided a useful measure of nutrient source and loading. A conceptual model that uses Ulva spp. tissue δ15N and N % to identify potential N source(s) and relative N loading is proposed for Hawai'i. These results indicate that SGD can be a significant transport pathway for land-based nutrients with important biogeochemical and ecological implications in tropical, oceanic islands.

Groundwater-Quality Data in the Madera-Chowchilla Study Unit, 2008: Results from the California GAMA Program

Science.gov (United States)

Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

2009-01-01

Groundwater quality in the approximately 860-square-mile Madera-Chowchilla study unit (MADCHOW) was investigated in April and May 2008 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The study was designed to provide a spatially unbiased assessment of the quality of raw groundwater used for public water supplies within MADCHOW, and to facilitate statistically consistent comparisons of groundwater quality throughout California. Samples were collected from 35 wells in Madera, Merced, and Fresno Counties. Thirty of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (grid wells), and five more were selected to provide additional sampling density to aid in understanding processes affecting groundwater quality (flow-path wells). Detection summaries in the text and tables are given for grid wells only, to avoid over-representation of the water quality in areas adjacent to flow-path wells. Groundwater samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOCs], low-level 1,2-dibromo-3-chloropropane [DBCP] and 1,2-dibromoethane [EDB], pesticides and pesticide degradates, polar pesticides and metabolites, and pharmaceutical compounds), constituents of special interest (N-nitrosodimethylamine [NDMA], perchlorate, and low-level 1,2,3-trichloropropane [1,2,3-TCP]), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), and radioactive constituents (uranium isotopes, and gross alpha and gross beta particle activities). Naturally occurring isotopes and geochemical tracers (stable isotopes of hydrogen

Groundwater quality monitoring well installation for Waste Area Grouping 4 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Mortimore, J.A.

1994-09-01

This report documents the drilling and installation of 15 groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 4. WAG 4 is comprised of about 27 acres located in Melton Valley approximately 2700 ft southwest of the Oak Ridge National Laboratory main plant. It contains three inactive solid waste management units: (1) the abandoned intermediate level liquid waste transfer line located along the WAG's northwestern boundary, (2) the experimental pilot pit area, and (3) SWSA 4, the largest unit in the WAG. The wells at WAG 4 were drilled and developed between September 1987 and October 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy (DOE), state, and Environmental Protection Agency regulatory requirements. The wells at WAG 4 were drilled with auger or air rotary rigs. Depending on the hydrogeologic conditions present at each proposed well location, one of four basic installation methods was utilized. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAG 4. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

Nonradiological groundwater quality at low-level radioactive waste disposal sites

International Nuclear Information System (INIS)

Goode, D.J.

1986-04-01

The NRC is investigating appropriate regulatory options for disposal of low-level radioactive waste containing nonradiological hazardous constituents, as defined by EPA regulations. Standard EPA/RCRA procedures to determine hazardous organics, metals, indicator parameters, and general water quality are applied to samples from groundwater monitoring wells at two commercial low-level radioactive waste disposal sites. At the Sheffield, IL site (nonoperating), several typical organic solvents are identified in elevated concentrations in onsite wells and in an offsite area exhibiting elevated tritium concentrations. At the Barnwell, SC site (operating), only very low concentrations of three organics are found in wells adjacent to disposal units. Hydrocarbons associated with petroleum products are detected at both sites. Hazardous constituents associated with previosuly identified major LLW mixed waste streams, toluene, xylene, chromium, and lead, are at or below detection limits or at background levels in all samples. Review of previously collected data also supports the conclusion that organic solvents are the primary nonradiological contaminants associated with LLW disposal

Geohydrology of the Aucilla-Suwannee-Ochlockonee River Basin, south-central Georgia and adjacent parts of Florida

Science.gov (United States)

Torak, Lynn J.; Painter, Jaime A.; Peck, Michael F.

2010-01-01

Brooks and Lowndes Counties, Ga., create karst features that enhance water-transmitting and storage properties of the Upper Floridan aquifer, promoting groundwater recharge and water exchange between the aquifer, land surface, and surface water. Structural control of groundwater flow and hydraulic properties combine with climatic effects and increased hydrologic stress from agricultural pumpage to yield unprecedented groundwater-level decline in the northwestern and central parts of the ASO River Basin. Hydrographs from continuous-record observation wells in these regions document declining groundwater levels, indicating diminished water-resource potential of the Upper Floridan aquifer through time. More than 24 ft of groundwater-level decline occurred along the basin's northwestern boundary with the lower Apalachicola-Chattahoochee-Flint River Basin, lowering hydraulic gradients that provide the potential for groundwater flow into the ASO River Basin and southeastward across the Gulf Trough-Apalachicola Embayment region. Slow-moving groundwater across the trough-embayment region coupled with downward-vertical flow from upper to lower limestone units composing the Upper Floridan aquifer resulted in 40-50 ft of groundwater-level decline since 1969 in southeastern Colquitt County. Multi-year episodes of dry climatic conditions during the 1980s through the early 2000s contributed to seasonal and long-term groundwater-level decline by reducing recharge to the Upper Floridan aquifer and increasing hydrologic stress by agricultural pumpage. Unprecedented and continued groundwater-level decline since 1969 caused 40-50 ft of aquifer dewatering in southeastern Colquitt County that reduced aquifer transmissivity and the ability to supply groundwater to wells, resulting in depletion of the groundwater resource.

In search of thermogenic methane in groundwater in the Netherlands, with emphasis on the location of a historic gas well blowout

Science.gov (United States)

Schout, G.; Griffioen, J.; Hassanizadeh, S. M.; Hartog, N.

2017-12-01

Similar to the US, the Netherlands has a long history of oil & gas production, with around 2500 onshore hydrocarbon wells drilled since the late 1930s. While conventional reserves are diminishing, a governmental moratorium was put in place on shale gas exploration and production until 2023, in part due to concerns about its effects on groundwater quality. To investigate the industry's historic and potential future impact on groundwater quality in the country, a study was carried out to assess i) baseline methane concentrations and origin ii) the natural connectivity of deeper gas-bearing layers with the shallower groundwater systems. Through datamining, a dataset consisting of 12,200 groundwater analyses with methane concentrations was assembled. Furthermore, 25 additional samples were collected at targeted locations and analysed for dissolved gas molecular and isotopic composition. Methane concentrations are positively skewed with median, mean and maximum concentrations of 0.28, 2.17 and 120 mg/L, respectively. No correlation between methane concentrations and distance to hydrocarbon wells or faults is observed. In general, concentrations cannot be readily explained by factors such as the depth, geographic location, host formation and depositional environment. Thermogenic methane was first encountered at several hundred meters depth, below thick successions of marine Paleogene and Neogene clays that are present throughout the country and impede vertical flow. All methane encountered above these formations was found to be biogenic in origin, with one notable exception - a sample taken at the site of a catastrophic gas well blowout that occurred in 1965 near the village of Sleen. Combined, these findings suggest that thermogenic methane does not naturally occur in Dutch shallow groundwater and its presence can be used as an indicator of anthropogenic gas leakage. The unique Sleen blowout site was selected for a detailed investigation of the long-term effects of

Saline groundwater in crystalline bedrock

International Nuclear Information System (INIS)

Lampen, P.

1992-11-01

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

Deep groundwater flow systems and their characterization in single-well settings by ''push-pull'' tracer tests

International Nuclear Information System (INIS)

Hebig-Schubert, Klaus

2014-01-01

This thesis demonstrates the growing importance of deep groundwater research and the increasing demand for the development of suitable single-well test methods. At the forefront of the research on groundwater in the deep underground, radioactive waste disposal in deep geological repositories, CO 2 storage, geothermal energy supply, and aquifer storage and recovery systems (ASR) are on the agenda. The developments of suitable methods for investigating these resources are a main target. Currently available methods show considerable limitations. Accordingly, comprehensive methods for the hydraulic and hydrochemical characterization of deeper aquifers with single-well access are needed. Therefore, the goal of this PhD thesis was to identify, test, and enhance potentially suitable single-well methods for characterization of groundwater flow and solute transport in such settings. For this, several Single-Well Injection-Withdrawal (''push-pull'') tracer tests were applied at the Hamasato field site (Horonobe, Japan) in a ∝100 m deep groundwater monitoring well. Aim was to characterize the impact of a dynamic saltwater-freshwater interface on a coastal aquifer. Based on the experiences of the first methodological test, a second field campaign was conducted. This campaign focused on a systematic evaluation of the push-pull tracer test method for the first time at all. The experiments focused on the investigation of the so-called ''chaser'' and its impact on the test results. The chaser is a specific part of many push-pull tracer tests setups. From these experiments, a specific test design for the investigation of the saltwater-freshwater interface in a single-well setting was developed. The application of this design on questions regarding different fluids within the same system, e.g. different mineralized fluids (saltwater-freshwater-interface, ASR) or temperatures (geothermal research), are promising future approaches for this

Deep groundwater flow systems and their characterization in single-well settings by ''push-pull'' tracer tests

Energy Technology Data Exchange (ETDEWEB)

Hebig-Schubert, Klaus

2014-11-21

This thesis demonstrates the growing importance of deep groundwater research and the increasing demand for the development of suitable single-well test methods. At the forefront of the research on groundwater in the deep underground, radioactive waste disposal in deep geological repositories, CO{sub 2} storage, geothermal energy supply, and aquifer storage and recovery systems (ASR) are on the agenda. The developments of suitable methods for investigating these resources are a main target. Currently available methods show considerable limitations. Accordingly, comprehensive methods for the hydraulic and hydrochemical characterization of deeper aquifers with single-well access are needed. Therefore, the goal of this PhD thesis was to identify, test, and enhance potentially suitable single-well methods for characterization of groundwater flow and solute transport in such settings. For this, several Single-Well Injection-Withdrawal (''push-pull'') tracer tests were applied at the Hamasato field site (Horonobe, Japan) in a ∝100 m deep groundwater monitoring well. Aim was to characterize the impact of a dynamic saltwater-freshwater interface on a coastal aquifer. Based on the experiences of the first methodological test, a second field campaign was conducted. This campaign focused on a systematic evaluation of the push-pull tracer test method for the first time at all. The experiments focused on the investigation of the so-called ''chaser'' and its impact on the test results. The chaser is a specific part of many push-pull tracer tests setups. From these experiments, a specific test design for the investigation of the saltwater-freshwater interface in a single-well setting was developed. The application of this design on questions regarding different fluids within the same system, e.g. different mineralized fluids (saltwater-freshwater-interface, ASR) or temperatures (geothermal research), are promising future approaches for

Environmental Baseline Survey for Installation of Five New Hydrogeologic Groundwater Monitoring Wells

Energy Technology Data Exchange (ETDEWEB)

Catechis, Christopher S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-07-01

This Phase I Environmental Baseline Survey (EBS) provides the findings of a survey and assessment for termination of an existing easement granted to the Department of Energy (DOE) for the installation of 5 new hydrogeologic groundwater monitoring wells located on KAFB, New Mexico. The purpose of this EBS is to: Document the nature, magnitude, and extent of any environmental contamination of the property. Identify potential environmental contamination liabilities associated with the property. Develop sufficient information to assess the health and safety risks. Ensure adequate protection for human health and the environment related to a specific property. Determine possible effects of contamination on property valuation, and serve as the basis for notice of environmental condition for applicable federal or local real property disclosure requirements.

Submarine groundwater discharge to a small estuary estimated from radon and salinity measurements and a box model

Directory of Open Access Journals (Sweden)

J. Crusius

2005-01-01

Full Text Available Submarine groundwater discharge was quantified by a variety of methods for a 4-day period during the early summer of 2004, in Salt Pond, adjacent to Nauset Marsh, on Cape Cod, USA. Discharge estimates based on radon and salinity took advantage of the presence of the narrow channel connecting Salt Pond to Nauset Marsh, which allowed constructing whole-pond mass balances as water flowed in and out due to tidal fluctuations. The data suggest that less than one quarter of the discharge in the vicinity of Salt Pond happened within the pond itself, while three quarters or more of the discharge occurred immediately seaward of the pond, either in the channel or in adjacent regions of Nauset Marsh. Much of this discharge, which maintains high radon activities and low salinity, is carried into the pond during each incoming tide. A box model was used as an aid to understand both the rates and the locations of discharge in the vicinity of Salt Pond. The model achieves a reasonable fit to both the salinity and radon data assuming submarine groundwater discharge is fresh and that most of it occurs either in the channel or in adjacent regions of Nauset Marsh. Salinity and radon data, together with seepage meter results, do not rule out discharge of saline groundwater, but suggest either that the saline discharge is at most comparable in volume to the fresh discharge or that it is depleted in radon. The estimated rate of fresh groundwater discharge in the vicinity of Salt Pond is 3000-7000 m3 d-1. This groundwater flux estimated from the radon and salinity data is comparable to a value of 3200-4500 m3 d-1 predicted by a recent hydrologic model (Masterson, 2004; Colman and Masterson, 2004, although the model predicts this rate of discharge to the pond whereas our data suggest most of the groundwater bypasses the pond prior to discharge. Additional work is needed to determine if the measured rate of discharge is representative of the long-term average, and to

Groundwater conditions and studies in Georgia, 2008-2009

Science.gov (United States)

Peck, Michael F.; Leeth, David C.; Painter, Jaime A.

2011-01-01

The U.S. Geological Survey collects groundwater data and conducts studies to monitor hydrologic conditions, better define groundwater resources, and address problems related to water supply, water use, and water quality. In Georgia, water levels were monitored continuously at 179 wells during 2008 and 181 wells during 2009. Because of missing data or short periods of record (less than 3 years) for several of these wells, a total of 161 wells are discussed in this report. These wells include 17 in the surficial aquifer system, 19 in the Brunswick aquifer and equivalent sediments, 66 in the Upper Floridan aquifer, 16 in the Lower Floridan aquifer and underlying units, 10 in the Claiborne aquifer, 1 in the Gordon aquifer, 11 in the Clayton aquifer, 12 in the Cretaceous aquifer system, 2 in Paleozoic-rock aquifers, and 7 in crystalline-rock aquifers. Data from the well network indicate that water levels generally rose during the 2008-2009 period, with water levels rising in 135 wells and declining in 26. In contrast, water levels declined over the period of record at 100 wells, increased at 56 wells, and remained relatively constant at 5 wells. In addition to continuous water-level data, periodic water-level measurements were collected and used to construct potentiometric-surface maps for the Upper Floridan aquifer in Camden, Charlton, and Ware Counties, Georgia, and adjacent counties in Florida during September 2008 and May 2009; in the Brunswick, Georgia area during July 2008 and July-August 2009; and in the City of Albany-Dougherty County, Georgia area during November 2008 and November 2009. In general, water levels in these areas were higher during 2009 than during 2008; however, the configuration of the potentiometric surfaces in each of the areas showed little change. Groundwater quality in the Floridan aquifer system is monitored in the Albany, Savannah, Brunswick, and Camden County areas of Georgia. In the Albany area, nitrate as nitrogen concentrations in the

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

Science.gov (United States)

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

2015-11-01

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

Effect of the decommissioned Roger open dump, João Pessoa, Brazil, on local groundwater quality

Directory of Open Access Journals (Sweden)

Giulliano de Souza Fagundes

2009-04-01

Full Text Available Throughout 45 years (1958-2003 the solid wastes from João Pessoa were disposed off in the former Roger’s open dump, which is situated adjacent to the mangrove at the sides of Sanhauá river, intensifying environmental problems and threatening the health of people living nearby. Between 1999 and 2003 the decommissioned open dump received wastes from the cities of Cabedelo and Bayeux. Several environmental impacts result from this inadequate disposal of solid wastes, including the pollution of groundwater nearby the former Roger´s open dump, which is the major point of investigation of this paper. The water quality of 6 wells situated in the region of influence of the open dump were monitored. Results have shown that the groundwater near the open dump cannot be drunk by the population without previous treatment, since it has some parameters of water quality in discordance with Brazilian legislation concerned with drinking water. Results have also shown that the level of pollution is higher in the wells closer to the open dump.

Groundwater-quality data in seven GAMA study units: results from initial sampling, 2004-2005, and resampling, 2007-2008, of wells: California GAMA Program Priority Basin Project

Science.gov (United States)

Kent, Robert; Belitz, Kenneth; Fram, Miranda S.

2014-01-01

The Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The GAMA-PBP began sampling, primarily public supply wells in May 2004. By the end of February 2006, seven (of what would eventually be 35) study units had been sampled over a wide area of the State. Selected wells in these first seven study units were resampled for water quality from August 2007 to November 2008 as part of an assessment of temporal trends in water quality by the GAMA-PBP. The initial sampling was designed to provide a spatially unbiased assessment of the quality of raw groundwater used for public water supplies within the seven study units. In the 7 study units, 462 wells were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study area. Wells selected this way are referred to as grid wells or status wells. Approximately 3 years after the initial sampling, 55 of these previously sampled status wells (approximately 10 percent in each study unit) were randomly selected for resampling. The seven resampled study units, the total number of status wells sampled for each study unit, and the number of these wells resampled for trends are as follows, in chronological order of sampling: San Diego Drainages (53 status wells, 7 trend wells), North San Francisco Bay (84, 10), Northern San Joaquin Basin (51, 5), Southern Sacramento Valley (67, 7), San Fernando–San Gabriel (35, 6), Monterey Bay and Salinas Valley Basins (91, 11), and Southeast San Joaquin Valley (83, 9). The groundwater samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOCs], pesticides, and pesticide degradates), constituents of special interest (perchlorate, N

Simulations of Groundwater Flow and Particle Tracking Analysis in the Area Contributing Recharge to a Public-Supply Well near Tampa, Florida, 2002-05

Science.gov (United States)

Crandall, Christy A.; Kauffman, Leon J.; Katz, Brian G.; Metz, Patricia A.; McBride, W. Scott; Berndt, Marian P.

2009-01-01

Shallow ground water in the north-central Tampa Bay region, Florida, is affected by elevated nitrate concentrations, the presence of volatile organic compounds, and pesticides as a result of groundwater development and intensive urban land use. The region relies primarily on groundwater for drinking-water supplies. Sustainability of groundwater quality for public supply requires monitoring and understanding of the mechanisms controlling the vulnerability of public-supply wells to contamination. A single public-supply well was selected for intensive study based on the need to evaluate the dominant processes affecting the vulnerability of public-supply wells in the Upper Floridan aquifer in the City of Temple Terrace near Tampa, Florida, and the presence of a variety of chemical constituents in water from the well. A network of 29 monitoring wells was installed, and water and sediment samples were collected within the area contributing recharge to the selected public-supply well to support a detailed analysis of physical and chemical conditions and processes affecting the water chemistry in the well. A three-dimensional, steady-state groundwater flow model was developed to evaluate the age of groundwater reaching the well and to test hypotheses on the vulnerability of the well to nonpoint source input of nitrate. Particle tracking data were used to calculate environmental tracer concentrations of tritium and sulfur hexafluoride and to calibrate traveltimes and compute flow paths and advective travel times in the model area. The traveltime of particles reaching the selected public-supply well ranged from less than 1 day to 127.0 years, with a median of 13.1 years; nearly 45 percent of the simulated particle ages were less than about 10 years. Nitrate concentrations, derived primarily from residential/commercial fertilizer use and atmospheric deposition, were highest (2.4 and 6.11 milligrams per liter as nitrogen, median and maximum, respectively) in shallow

Assessment of Groundwater Resources in Kirana Hills Region, Rabwah, District Chiniot, Pakistan

Directory of Open Access Journals (Sweden)

Mirza Naseer Ahmad

2016-12-01

Full Text Available This study was planned to assess the groundwater quality of the area adjacent to Precambrian Kirana Hills, Pakistan. The majority of the people in the area use groundwater from private wells for drinking and domestic use. Therefore, it is important to provide an overview of the groundwater quality. This information would be beneficial to local people and the administration for selecting suitable water treatment methods. Samples were collected from different wells of Rabwah town, close to the Kirana Hills. Parameters like EC, pH, alkalinity and total dissolved solids (TDS were determined for 142 samples. While 40 samples were analyzed for hardness, Ca, Mg, Cl, SO4, NO3, and F. standards set by the World Health Organization (WHO were considered to evaluate the quality of groundwater. Geographic Information System (GIS was used to interpolate analyzed physicochemical parameters. The results showed that EC, TDS, hardness, Cl, SO4, and Ca were very high in the water samples of the area. Fifty-two percent of samples had pH values lower than the permissible limits. Results suggest that the water quality is extremely adverse close to the hills. The poor water quality in the area near the hills may be due to the limited recharge of aquifers because of the hills and shallow basement, which may act as a barrier to subsurface water movement. Some physical and chemical parameters indicated that the quality of water at deeper levels (i.e. >150 ft is relatively better. This may be due to limited exploitation of water from deeper aquifers as compared to shallow aquifers. Hence, proper aquifer management is required to prevent water quality deterioration due to over exploiataion. NO3 was found within the acceptable limits and all water samples were found free of any significant contamination by human activities.

Hydrogeology and groundwater quality at monitoring wells installed for the Tunnel and Reservoir Plan System and nearby water-supply wells, Cook County, Illinois, 1995–2013

Science.gov (United States)

Kay, Robert T.

2016-04-04

Groundwater-quality data collected from 1995 through 2013 from 106 monitoring wells open to the base of the Silurian aquifer surrounding the Tunnel and Reservoir Plan (TARP) System in Cook County, Illinois, were analyzed by the U.S. Geological Survey, in cooperation with the Metropolitan Water Reclamation District of Greater Chicago, to assess the efficacy of the monitoring network and the effects of water movement from the tunnel system to the surrounding aquifer. Groundwater from the Silurian aquifer typically drains to the tunnel system so that analyte concentrations in most of the samples from most of the monitoring wells primarily reflect the concentration of the analyte in the nearby Silurian aquifer. Water quality in the Silurian aquifer is spatially variable because of a variety of natural and non-TARP anthropogenic processes. Therefore, the trends in analyte values at a given well from 1995 through 2013 are primarily a reflection of the spatial variation in the value of the analyte in groundwater within that part of the Silurian aquifer draining to the tunnels. Intermittent drainage of combined sewer flow from the tunnel system to the Silurian aquifer when flow in the tunnel systemis greater than 80 million gallons per day may affect water quality in some nearby monitoring wells. Intermittent drainage of combined sewer flow from the tunnel system to the Silurian aquifer appears to affect the values of electrical conductivity, hardness, sulfate, chloride, dissolved organic carbon, ammonia, and fecal coliform in samples from many wells but typically during less than 5 percent of the sampling events. Drainage of combined sewer flow into the aquifer is most prevalent in the downstream parts of the tunnel systems because of the hydraulic pressures elevated above background values and long residence time of combined sewer flow in those areas. Elevated values of the analytes emplaced during intermittent migration of combined sewer flow into the Silurian aquifer

Horizontal wells in subsurface remediation

International Nuclear Information System (INIS)

Losonsky, G.; Beljin, M.S.

1992-01-01

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

Bayesian Nitrate Source Apportionment to Individual Groundwater Wells in the Central Valley by use of Nitrogen, Oxygen, and Boron Isotopic Tracers

Science.gov (United States)

Lockhart, K.; Harter, T.; Grote, M.; Young, M. B.; Eppich, G.; Deinhart, A.; Wimpenny, J.; Yin, Q. Z.

2014-12-01

Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide, an example of which is the San Joaquin Valley, California. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. Dairy manure and synthetic fertilizers are the major sources of nitrate in groundwater in the San Joaquin Valley, however, septic waste can be a major source in some areas. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤150 m deep), of which many have been affected by nitrate. Consumption of water containing nitrate above the drinking water limit has been linked to major health effects including low blood oxygen in infants and certain cancers. Knowledge of the proportion of each of the three main nitrate sources (manure, synthetic fertilizer, and septic waste) contributing to individual well nitrate can aid future regulatory decisions. Nitrogen, oxygen, and boron isotopes can be used as tracers to differentiate between the three main nitrate sources. Mixing models quantify the proportional contributions of sources to a mixture by using the concentration of conservative tracers within each source as a source signature. Deterministic mixing models are common, but do not allow for variability in the tracer source concentration or overlap of tracer concentrations between sources. Bayesian statistics used in conjunction with mixing models can incorporate variability in the source signature. We developed a Bayesian mixing model on a pilot network of 32 private domestic wells in the San Joaquin Valley for which nitrate as well as nitrogen, oxygen, and boron isotopes were measured. Probability distributions for nitrogen, oxygen, and boron isotope source signatures for manure, fertilizer, and septic waste were compiled from the literature and from a previous groundwater monitoring project on several

Groundwater-level analysis of selected wells in the Hoosic River Valley near Hoosick Falls, New York, for aquifer framework and properties

Science.gov (United States)

Williams, John H.; Heisig, Paul M.

2018-03-05

The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, analyzed groundwater levels, drilling record logs, and field water-quality data from selected wells, and the surficial geology in the Hoosic River valley south of the village of Hoosick Falls, New York, to provide information about the framework and properties of a confined aquifer. The aquifer, which consists of ice-contact sand and gravel overlain by lacustrine clay and silt, was evaluated by the New York State Department of Environmental Conservation as part of their investigation of alternate water supplies for the village whose wellfield has been affected by perfluorooctanoic acid. Wells inventoried in the study area were classified as confined, water table, or transitional between the two aquifer conditions. Groundwater levels in three confined-aquifer wells and a transitional-aquifer well responded to pumping of a test production well finished in the confined aquifer. Groundwater levels in a water-table well showed no detectable water-level change in response to test-well pumping. Analysis of drawdown and recovery data from the three confined-aquifer wells and a transitional-aquifer well through the application of the Theis type-curve method provided estimates of aquifer properties. Representation of a constant-head boundary in the analysis where an unnamed pond and fluvial-terrace deposits abut the valley wall resulted in satisfactory matches of the Theis type curves with the observed water-level responses. Aquifer transmissivity estimates ranged from 1,160 to 1,370 feet squared per day. Aquifer storativity estimates ranged from 5.2×10–5 to 1.1×10–3 and were consistent with the inferred degree of confinement and distance from the represented recharge boundary.

Groundwater discharge mapping by thermal infra-red imagery

International Nuclear Information System (INIS)

Brereton, N.R.

1984-02-01

An area around Altnabreac in northern Scotland has been studied as part of the UK programme of research into the feasibility of disposal of radioactive waste into geological formations. An essential prerequisite to being able to predict the behaviour, migratory pathways and travel times of radionuclides emanating from a waste repository is an understanding of the regional and near surface groundwater flow systems and groundwater geochemical evolution. The groundwater system at depth has been studied by means of boreholes but an understanding of the shallow groundwater flow, and its interaction with groundwater upwelling from depth, can be gained from studies of the spatial distribution and geochemistry of surface springs and discharges. A survey was carried out using the thermal infra-red linescan technique with the objective of locating all significant spring discharges over the study area. The terrain around Altnabreac is largely covered by superficial deposits which overlie weathered granite. The survey was carried out from a height of 275m at a spatial resolution of about 0.5m. About 280 line Km were covered but allowing for overlap between adjacent flight lines and some repeat coverage, the actual area surveyed was 68 sq Km. The most striking aspect of the results is the wide distribution of groundwater discharges in the Altnabreac area. An analysis of the data identified three general categories of spring and many of these springs were subsequently visited for verification and to allow samples to be collected for chemical analysis. The results from this survey indicates that the groundwater table is strongly influenced by local topography and that the majority of the spring discharges represent near surface recent groundwaters circulating within the superficial deposits and weathered granite

Groundwater use in Pakistan: opportunities and limitations

International Nuclear Information System (INIS)

Bhutta, M.N.

2005-01-01

Groundwater potential in the Indus Basin is mainly due to recharge from irrigation system, rivers and rainfall. Its quality and quantity varies spatially and temporally. However, the potential is linked with the surface water supplies. Irrigated agriculture is the major user of groundwater. Annual recharge to groundwater in the basin is estimated as 68 MAF. But 50 percent of the area has marginal to hazardous groundwater quality. Existing annual groundwater pumpage is estimated as 45 MAF (55 BCM). More than 13 MAF mainly of groundwater is lost as non-beneficial ET losses. Groundwater contributes 35 percent of total agricultural water requirements in the country. Annual cropping intensities have increased from 70% to 150% due to groundwater use. Increase in crop yield due to groundwater use has been observed 150-200. percent. Total investment on private tube wells has been made more than Rs.25.0 billion. In the areas where farmers are depending more on groundwater. mining of groundwater has been observed. Population pressure, inadequate supply of canal water and development of cheap local tub well technology have encouraged farmers to invest in the groundwater development. Deterioration of groundwater has also been observed due to excessive exploitation. The available information about the private tube wells is insufficient for different areas. Although during the past decade the growth of tube wells was tremendous but was not reflected accordingly in the statistics. Monitoring of groundwater quality is not done systematically and adequately. It is very difficult to manage a resource for which adequate information is not available. The present scenario of groundwater use is not sustainable and therefore certain measures are needed to be taken. It is recommended to. have a systematic monitoring of groundwater. For the sustainable use of groundwater, it is recommended to manage the demand of water i.e. grow more crops with less water. To achieve high productivity of

Groundwater quality in Geauga County, Ohio: status, including detection frequency of methane in water wells, 2009, and changes during 1978-2009

Science.gov (United States)

Jagucki, Martha L.; Kula, Stephanie P.; Mailot, Brian E.

2015-01-01

Domestic wells that are not safeguarded by regular water-quality testing provide drinking water for 79 percent of the residents of Geauga County, in northeastern Ohio. Since 1978, the U.S. Geological Survey (USGS) has worked cooperatively with the Board of Commissioners and Geauga County Planning Commission to monitor the quality of groundwater in four commonly used aquifers in county—the glacial deposits, the Pottsville Formation, the Cuyahoga Group, and the Berea Sandstone. A 33-percent growth in population from 1980 to 2009 increased the potential for humans to influence groundwater resources by withdrawing more groundwater, disposing of more human waste near the land surface, treating an expanded network of township roads with deicing salt, and likely using more solvents, pesticides, and other chemicals on the land surface than were used in preceding decades.

Groundwater quality monitoring well installation for Upper Waste Areas Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Mortimore, J.A.; Lee, T.A.

1994-09-01

This report documents the drilling and installation of seven groundwater quality monitoring (GQM) wells on the perimeter of Upper Waste Area Grouping (WAG) 2. Upper WAG 2 is composed of portions of White Oak Creek (WOC), Melton Branch, two of Melton Branch's tributaries, and the floodplains surrounding these water bodies. The WOC section of the subject site begins at the confluence of WOC and Melton Branch and extends 0.62 mile upstream to the 7,500 bridge. The Melton Branch portion of the site also begins at the confluence of WOC and Melton Branch and extends eastward 0.88 mile upstream. The wells at Upper WAG 2 were drilled and developed between December 1989 and October 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The purpose of the well installation program was to install GQM wells for groundwater characterization at Upper WAG-2. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

Groundwater level status report for 2009, Los Alamos National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Koch, Richard J.; Schmeer, Sarah

2010-03-01

The status of groundwater level monitoring at Los Alamos National Laboratory in 2009 is provided in this report. This report summarizes groundwater level data for 179 monitoring wells, including 55 regional aquifer wells (including 11 regional/intermediate wells), 26 intermediate wells, 98 alluvial wells, and 12 water supply wells. Pressure transducers were installed in 161 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well. The report also summarizes the groundwater temperatures recorded in intermediate and regional aquifer monitoring wells.

Groundwater recharge in suburban areas of Hanoi, Vietnam: effect of decreasing surface-water bodies and land-use change

Science.gov (United States)

Kuroda, Keisuke; Hayashi, Takeshi; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Funabiki, Ayako; Takizawa, Satoshi

2017-05-01

Over-exploited groundwater is expected to remain the predominant source of domestic water in suburban areas of Hanoi, Vietnam. In order to evaluate the effect on groundwater recharge, of decreasing surface-water bodies and land-use change caused by urbanization, the relevant groundwater systems and recharge pathways must be characterized in detail. To this end, water levels and water quality were monitored for 3 years regarding groundwater and adjacent surface-water bodies, at two typical suburban sites in Hanoi. Stable isotope (δ18O, δD of water) analysis and hydrochemical analysis showed that the water from both aquifers and aquitards, including the groundwater obtained from both the monitoring wells and the neighboring household tubewells, was largely derived from evaporation-affected surface-water bodies (e.g., ponds, irrigated farmlands) rather than from rivers. The water-level monitoring results suggested distinct local-scale flow systems for both a Holocene unconfined aquifer (HUA) and Pleistocene confined aquifer (PCA). That is, in the case of the HUA, lateral recharge through the aquifer from neighboring ponds and/or irrigated farmlands appeared to be dominant, rather than recharge by vertical rainwater infiltration. In the case of the PCA, recharge by the above-lying HUA, through areas where the aquitard separating the two aquifers was relatively thin or nonexistent, was suggested. As the decrease in the local surface-water bodies will likely reduce the groundwater recharge, maintaining and enhancing this recharge (through preservation of the surface-water bodies) is considered as essential for the sustainable use of groundwater in the area.

Hydrogeology and simulation of ground-water flow near the Lantana Landfill, Palm Beach County, Florida

Science.gov (United States)

Russell, G.M.; Wexler, E.J.

1993-01-01

The Lantana landfill in Palm Beach County has a surface that is 40 to 50 feet above original ground level and consists of about 250 acres of compacted garbage and trash. Parts of the landfill are below the water table. Surface-resistivity measurements and water-quality analyses indicate that leachate-enriched ground water along the eastern perimeter of the landfill has moved about 500 feet eastward toward an adjacent lake. Concentrations of chloride and nutrients within the leachate-enriched ground water were greater than background concentrations. The surficial aquifer system in the area of the landfill consists primarily of sand of moderate permeability, from land surface to a depth of about 68 feet deep, and consists of sand interbedded with sandstone and limestone of high permeability from a depth of about 68 feet to a depth of 200 feet. The potentiometric surface in the landfill is higher than that in adjacent areas to the east, indicating ground-water movement from the landfill toward a lake to the east. Steady-state simulation of ground-water flow was made using a telescoping-grid technique where a model covering a large area is used to determine boundaries and fluxes for a finer scale model. A regional flow model encompassing a 500-square mile area in southeastern Palm Beach County was used to calculate ground-water fluxes in a 126.5-square mile subregional area. Boundary fluxes calculated by the subregional model were then used to calculate boundary fluxes for a local model of the 3.75-square mile area representing the Lantana landfill site and vicinity. Input data required for simulating ground-water flow in the study area were obtained from the regional flow models, thus, effectively coupling the models. Additional simulations were made using the local flow model to predict effects of possible remedial actions on the movement of solutes in the ground-water system. Possible remedial actions simulated included capping the landfill with an impermeable layer

Methane occurrence in groundwater of south-central New York State, 2012: summary of findings

Science.gov (United States)

Heisig, Paul M.; Scott, Tia-Marie

2013-01-01

A survey of methane in groundwater was undertaken to document methane occurrence on the basis of hydrogeologic setting within a glaciated 1,810-square-mile area of south-central New York that has not seen shale-gas resource development. The adjacent region in northeastern Pennsylvania has undergone shale-gas resource development from the Marcellus Shale. Well construction and subsurface data were required for each well sampled so that the local hydrogeologic setting could be classified. All wells were also at least 1 mile from any known gas well (active, exploratory, or abandoned). Sixty-six domestic wells and similar purposed supply wells were sampled during summer 2012. Field water-quality characteristics (pH, specific conductance, dissolved oxygen, and temperature) were measured at each well, and samples were collected and analyzed for dissolved gases, including methane and short-chain hydrocarbons. Carbon and hydrogen isotopic ratios of methane were measured in 21 samples that had at least 0.3 milligram per liter (mg/L) methane.

Groundwater age, mixing and flow rates in the vicinity of large open pit mines, Pilbara region, northwestern Australia

Science.gov (United States)

Cook, Peter; Dogramaci, Shawan; McCallum, James; Hedley, Joanne

2017-01-01

Determining groundwater ages from environmental tracer concentrations measured on samples obtained from open bores or long-screened intervals is fraught with difficulty because the sampled water represents a variety of ages. A multi-tracer technique (Cl, 14C, 3H, CFC-11, CFC-12, CFC-113 and SF6) was used to decipher the groundwater ages sampled from long-screened production bores in a regional aquifer around an open pit mine in the Pilbara region of northwest Australia. The changes in tracer concentrations due to continuous dewatering over 7 years (2008-2014) were examined, and the tracer methods were compared. Tracer concentrations suggest that groundwater samples are a mixture of young and old water; the former is inferred to represent localised recharge from an adjacent creek, and the latter to be diffuse recharge. An increase in 14C activity with time in wells closest to the creek suggests that dewatering of the open pit to achieve dry mining conditions has resulted in change in flow direction, so that localised recharge from the creek now forms a larger proportion of the pumped groundwater. The recharge rate prior to development, calculated from a steady-state Cl mass balance, is 6 mm/y, and is consistent with calculations based on the 14C activity. Changes in CFC-12 concentrations with time may be related to the change in water-table position relative to the depth of the well screen.

Current Status of Groundwater Monitoring Networks in Korea

Directory of Open Access Journals (Sweden)

Jin-Yong Lee

2016-04-01

Full Text Available Korea has been operating groundwater monitoring systems since 1996 as the Groundwater Act enacted in 1994 enforces nationwide monitoring. Currently, there are six main groundwater monitoring networks operated by different government ministries with different purposes: National Groundwater Monitoring Network (NGMN, Groundwater Quality Monitoring Network (GQMN, Seawater Intrusion Monitoring Network (SIMN, Rural Groundwater Monitoring Network (RGMN, Subsidiary Groundwater Monitoring Network (SGMN, and Drinking Water Monitoring Network (DWMN. The Networks have a total of over 3500 monitoring wells and the majority of them are now equipped with automatic data loggers and remote terminal units. Most of the monitoring data are available to the public through internet websites. These Networks have provided scientific data for designing groundwater management plans and contributed to securing the groundwater resource particularly for recent prolonged drought seasons. Each Network, however, utilizes its own well-specifications, probes, and telecommunication protocols with minimal communication with other Networks, and thus duplicate installations of monitoring wells are not uncommon among different Networks. This mini-review introduces the current regulations and the Groundwater Monitoring Networks operated in Korea and provides some suggestions to improve the sustainability of the current groundwater monitoring system in Korea.

Groundwater level status report for 2010, Los Alamos National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Koch, Richard J.; Schmeer, Sarah

2011-03-01

The status of groundwater level monitoring at Los Alamos National Laboratory in 2010 is provided in this report. This report summarizes groundwater level data for 194 monitoring wells, including 63 regional aquifer wells (including 10 regional/intermediate wells), 34 intermediate wells, 97 alluvial wells, and 12 water supply wells. Pressure transducers were installed in 162 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well. The report also summarizes the groundwater temperatures recorded in intermediate and regional aquifer monitoring wells and seasonal responses to snowmelt runoff observed in intermediate wells.

Hydrodynamic analysis of potential groundwater extraction capacity increase: case study of 'Nelt' groundwater source at Dobanovci

Directory of Open Access Journals (Sweden)

Bajić Dragoljub I.

2017-01-01

Full Text Available A comprehensive hydrodynamic analysis of the groundwater regime undertaken to assess the potential for expanding the 'Nelt' groundwater source at Dobanovci, or developing a new groundwater source for a future baby food factory, including the quantification of the impact on the production wells of the nearby 'Pepsi' groundwater source, is presented in the paper. The existing Nelt source is comprised of three active production wells that tap a subartesian aquifer formed in sands and gravelly sands; however, the analysis considers only the two nearest wells. A long-term group pumping test was con-ducted of production wells N-1 and N2 (Nelt source and production wells B-1 and B-2 (Pepsi source, while the piezometric head in the vicinity of these wells was monitored at observation well P-1, which is located in the area considered for Nelt source expansion. Data were collected at maximum pumping capacity of all the production wells. A hydrodynamic model of groundwater flow in the extended area of the Nelt source was generated for the purposes of the comprehensive hydrodynamic analysis. Hydrodynamic prognostic calculations addressed two solution alternatives for the capacity increase over a period of ten years. Licensed Visual MODFLOW Pro software, deemed to be at the very top in this field, was used for the calculations.

Groundwater quality and simulation of sources of water to wells in the Marsh Creek valley at the U.S. Geological Survey Northern Appalachian Research Laboratory, Tioga County, Pennsylvania

Science.gov (United States)

Risser, Dennis W.; Breen, Kevin J.

2012-01-01

This report provides a November 2010 snapshot of groundwater quality and an analysis of the sources of water to wells at the U.S. Geological Survey (USGS) Northern Appalachian Research Laboratory (NARL) near Wellsboro, Pennsylvania. The laboratory, which conducts fisheries research, currently (2011) withdraws 1,000 gallons per minute of high-quality groundwater from three wells completed in the glacial sand and gravel aquifer beneath the Marsh Creek valley; a fourth well that taps the same aquifer provides the potable supply for the facility. The study was conducted to document the source areas and quality of the water supply for this Department of Interior facility, which is surrounded by the ongoing development of natural gas from the Marcellus Shale. Groundwater samples were collected from the four wells used by the NARL and from two nearby domestic-supply wells. The domestic-supply wells withdraw groundwater from bedrock of the Catskill Formation. Samples were analyzed for major ions, nutrients, trace metals, radiochemicals, dissolved gases, and stable isotopes of oxygen and hydrogen in water and carbon in dissolved carbonate to document groundwater quality. Organic constituents (other than hydrocarbon gases) associated with hydraulic fracturing and other human activities were not analyzed as part of this assessment. Results show low concentrations of all constituents. Only radon, which ranged from 980 to 1,310 picocuries per liter, was somewhat elevated. These findings are consistent with the pristine nature of the aquifer in the Marsh Creek valley, which is the reason the laboratory was sited at this location. The sources of water and areas contributing recharge to wells were identified by the use of a previously documented MODFLOW groundwater-flow model for the following conditions: (1) withdrawals of 1,000 to 3,000 gallons per minute from the NARL wells, (2) average or dry hydrologic conditions, and (3) withdrawals of 1,000 gallons per minute from a new

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

2017-09-01

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

Groundwater-surface water interaction

International Nuclear Information System (INIS)

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

2001-01-01

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

Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

Science.gov (United States)

Stamos, Christina L.; Christensen, Allen H.; Langenheim, Victoria

2017-07-19

The increasing demands on groundwater for water supply in desert areas in California and the western United States have resulted in the need to better understand groundwater sources, availability, and sustainability. This is true for a 650-square-mile area that encompasses the Antelope Valley, El Mirage Valley, and Upper Mojave River Valley groundwater basins, about 50 miles northeast of Los Angeles, California, in the western part of the Mojave Desert. These basins have been adjudicated to ensure that groundwater rights are allocated according to legal judgments. In an effort to assess if the boundary between the Antelope Valley and El Mirage Valley groundwater basins could be better defined, the U.S. Geological Survey began a cooperative study in 2014 with the Mojave Water Agency to better understand the hydrogeology in the area and investigate potential controls on groundwater flow and availability, including basement topography.Recharge is sporadic and primarily from small ephemeral washes and streams that originate in the San Gabriel Mountains to the south; estimates range from about 400 to 1,940 acre-feet per year. Lateral underflow from adjacent basins has been considered minor in previous studies; underflow from the Antelope Valley to the El Mirage Valley groundwater basin has been estimated to be between 100 and 1,900 acre-feet per year. Groundwater discharge is primarily from pumping, mostly by municipal supply wells. Between October 2013 and September 2014, the municipal pumpage in the Antelope Valley and El Mirage Valley groundwater basins was reported to be about 800 and 2,080 acre-feet, respectively.This study was motivated by the results from a previously completed regional gravity study, which suggested a northeast-trending subsurface basement ridge and saddle approximately 3.5 miles west of the boundary between the Antelope Valley and El Mirage Valley groundwater basins that might influence groundwater flow. To better define potential basement

Arsenic transport in groundwater, surface water, and the hyporheic zone of a mine-influenced stream-aquifer system

OpenAIRE

Brown, Brendan

2005-01-01

We investigated the transport of dissolved arsenic in groundwater, surface water and the hyporheic zone in a stream-aquifer system influenced by an abandoned arsenopyrite mine. Mine tailing piles consisting of a host of arsenic-bearing minerals including arsenopyrite and scorodite remain adjacent to the stream and represent a continuous source of arsenic. Arsenic loads from the stream, springs, and groundwater were quantified at the study reach on nine dates from January to August 2005 and ...

Changes between early development (1930–60) and recent (2005–15) groundwater-level altitudes and dissolved-solids and nitrate concentrations In and near Gaines, Terry, and Yoakum Counties, Texas

Science.gov (United States)

Thomas, Jonathan V.; Teeple, Andrew; Payne, Jason; Ikard, Scott

2016-06-21

Llano Estacado Underground Water Conservation District, Sandy Land Underground Water Conservation District, and South Plains Underground Water Conservation District manage groundwater resources in a part of west Texas near the Texas-New Mexico State line. Declining groundwater levels have raised concerns about the amount of available groundwater in the study area and the potential for water-quality changes resulting from dewatering and increased vertical groundwater movement between adjacent water-bearing units.

Hydrogeologic correlations for selected wells on Long Island, New York; a data base with retrieval program

Science.gov (United States)

Buxton, H.T.; Shernoff, P.K.; Smolensky, D.A.

1989-01-01

Accurate delineation of the internal hydrogeologic structure of Long Island, NY is integral to the understanding and management of the groundwater system. This report presents a computerized data base of hydrogeologic correlations for 3,146 wells on Long Island and adjacent parts of New York City. The data base includes the well identification number, the latitude-longitude of the well location, the altitude of land surface at the well and of the bottom of the drilled hole, and the altitude of the top of the major hydrogeologic units penetrated by the well. A computer program is included that allows retrieval of selected types of data for all of, or any local area of, Long Island. These data retrievals are a valuable aid to the construction of hydrogeologic surface maps. (USGS)

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

Directory of Open Access Journals (Sweden)

Polomčić Dušan M.

2014-01-01

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

High-resolution monitoring across the soil-groundwater interface - Revealing small-scale hydrochemical patterns with a novel multi-level well

Science.gov (United States)

Gassen, Niklas; Griebler, Christian; Stumpp, Christine

2016-04-01

Biogeochemical turnover processes in the subsurface are highly variable both in time and space. In order to capture this variability, high resolution monitoring systems are required. Particular in riparian zones the understanding of small-scale biogeochemical processes is of interest, as they are regarded as important buffer zones for nutrients and contaminants with high turnover rates. To date, riparian research has focused on influences of groundwater-surface water interactions on element cycling, but little is known about processes occurring at the interface between the saturated and the unsaturated zone during dynamic flow conditions. Therefore, we developed a new type of high resolution multi-level well (HR-MLW) that has been installed in the riparian zone of the Selke river. This HR-MLW for the first time enables to derive water samples both from the unsaturated and the saturated zone across one vertical profile with a spatial vertical resolution of 0.05 to 0.5 m to a depth of 4 m b.l.s. Water samples from the unsaturated zone are extracted via suction cup sampling. Samples from the saturated zone are withdrawn through glass filters and steel capillaries. Both, ceramic cups and glass filters, are installed along a 1" HDPE piezometer tube. First high resolution hydrochemical profiles revealed a distinct depth-zonation in the riparian alluvial aquifer. A shallow zone beneath the water table carried a signature isotopically and hydrochemically similar to the nearby river, while layers below 1.5 m were influenced by regional groundwater. This zonation showed temporal dynamics related to groundwater table fluctuations and microbial turnover processes. The HR-MLW delivered new insight into mixing and turnover processes between riverwater and groundwater in riparian zones, both in a temporal and spatial dimension. With these new insights, we are able to improve our understanding of dynamic turnover processes at the soil - groundwater interface and of surface

Design, revision, and application of ground-water flow models for simulation of selected water-management scenarios in the coastal area of Georgia and adjacent parts of South Carolina and Florida

Science.gov (United States)

Clarke, John S.; Krause, Richard E.

2000-01-01

Ground-water flow models of the Floridan aquifer system in the coastal area of Georgia and adjacent parts of South Carolina and Florida, were revised and updated to ensure consistency among the various models used, and to facilitate evaluation of the effects of pumping on the ground-water level near areas of saltwater contamination. The revised models, developed as part of regional and areal assessments of ground-water resources in coastal Georgia, are--the Regional Aquifer-System Analysis (RASA) model, the Glynn County area (Glynn) model, and the Savannah area (Savannah) model. Changes were made to hydraulic-property arrays of the RASA and Glynn models to ensure consistency among all of the models; results of theses changes are evidenced in revised water budgets and calibration statistics. Following revision, the three models were used to simulate 32 scenarios of hypothetical changes in pumpage that ranged from about 82 million gallons per day (Mgal/d) lower to about 438 Mgal/d higher, than the May 1985 pumping rate of 308 Mgal/d. The scenarios were developed by the Georgia Department of Natural Resources, Environmental Protection Division and the Chatham County-Savannah Metropolitan Planning Commission to evaluate water-management alternatives in coastal Georgia. Maps showing simulated ground-water-level decline and diagrams presenting changes in simulated flow rates are presented for each scenario. Scenarios were grouped on the basis of pumping location--entire 24-county area, central subarea, Glynn-Wayne-Camden County subarea, and Savannah-Hilton Head Island subarea. For those scenarios that simulated decreased pumpage, the water level at both Brunswick and Hilton Head Island rose, decreasing the hydraulic gradient and reducing the potential for saltwater contamination. Conversely, in response to scenarios of increased pumpage, the water level at both locations declined, increasing the hydraulic gradient and increasing the potential for saltwater contamination

Groundwater Level Monitoring using Levelogger and the Importance of Long-Term Groundwater Level Data

International Nuclear Information System (INIS)

Nazran Harun; Ahmad Hasnulhadi Che Kamaruddin

2016-01-01

This review paper is focused on groundwater level monitoring using levelogger and the importance of long-term groundwater level data. The levelogger provides an inexpensive and convenient method to measure level, temperature and conductivity all in one probe. It can provide real time view as data is being recorded by the connected data logger. Water-level measurements from observation wells are the principal source of information about the hydrologic stresses acting on aquifers and how these stresses affect ground-water recharge, storage, and discharge. Long-term and systematic measurements of water levels provide essential data needed to evaluate changes in the resource over time to develop ground-water models, forecast trends and monitor the effectiveness of groundwater management. A significant advantage of this method of data collection and reporting are the groundwater level data can be updated real time. The accessibility of water level data is greatly enhanced by the Geographic Information System (GIS) to visually illustrate the locations of observation wells relative to relevant topographic, geologic, or hydrologic features. GIS and internet greatly enhance the capability for retrieval and transmittal of water-level data to potential users. (author)

Nitrate in groundwater of the United States, 1991-2003

Science.gov (United States)

Burow, Karen R.; Nolan, Bernard T.; Rupert, Michael G.; Dubrovsky, Neil M.

2010-01-01

An assessment of nitrate concentrations in groundwater in the United States indicates that concentrations are highest in shallow, oxic groundwater beneath areas with high N inputs. During 1991-2003, 5101 wells were sampled in 51 study areas throughout the U.S. as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) program. The well networks reflect the existing used resource represented by domestic wells in major aquifers (major aquifer studies), and recently recharged groundwater beneath dominant land-surface activities (land-use studies). Nitrate concentrations were highest in shallow groundwater beneath agricultural land use in areas with well-drained soils and oxic geochemical conditions. Nitrate concentrations were lowest in deep groundwater where groundwater is reduced, or where groundwater is older and hence concentrations reflect historically low N application rates. Classification and regression tree analysis was used to identify the relative importance of N inputs, biogeochemical processes, and physical aquifer properties in explaining nitrate concentrations in groundwater. Factors ranked by reduction in sum of squares indicate that dissolved iron concentrations explained most of the variation in groundwater nitrate concentration, followed by manganese, calcium, farm N fertilizer inputs, percent well-drained soils, and dissolved oxygen. Overall, nitrate concentrations in groundwater are most significantly affected by redox conditions, followed by nonpoint-source N inputs. Other water-quality indicators and physical variables had a secondary influence on nitrate concentrations.

Integrating a Linear Signal Model with Groundwater and Rainfall time-series on the Characteristic Identification of Groundwater Systems

Science.gov (United States)

Chen, Yu-Wen; Wang, Yetmen; Chang, Liang-Cheng

2017-04-01

Groundwater resources play a vital role on regional supply. To avoid irreversible environmental impact such as land subsidence, the characteristic identification of groundwater system is crucial before sustainable management of groundwater resource. This study proposes a signal process approach to identify the character of groundwater systems based on long-time hydrologic observations include groundwater level and rainfall. The study process contains two steps. First, a linear signal model (LSM) is constructed and calibrated to simulate the variation of underground hydrology based on the time series of groundwater levels and rainfall. The mass balance equation of the proposed LSM contains three major terms contain net rate of horizontal exchange, rate of rainfall recharge and rate of pumpage and four parameters are required to calibrate. Because reliable records of pumpage is rare, the time-variant groundwater amplitudes of daily frequency (P ) calculated by STFT are assumed as linear indicators of puamage instead of pumpage records. Time series obtained from 39 observation wells and 50 rainfall stations in and around the study area, Pintung Plain, are paired for model construction. Second, the well-calibrated parameters of the linear signal model can be used to interpret the characteristic of groundwater system. For example, the rainfall recharge coefficient (γ) means the transform ratio between rainfall intention and groundwater level raise. The area around the observation well with higher γ means that the saturated zone here is easily affected by rainfall events and the material of unsaturated zone might be gravel or coarse sand with high infiltration ratio. Considering the spatial distribution of γ, the values of γ decrease from the upstream to the downstream of major rivers and also are correlated to the spatial distribution of grain size of surface soil. Via the time-series of groundwater levels and rainfall, the well-calibrated parameters of LSM have

TECHNICAL EVALUATION OF TEMPORAL GROUNDWATER MONITORING VARIABILITY IN MW66 AND NEARBY WELLS, PADUCAH GASEOUS DIFFUSION PLANT

Energy Technology Data Exchange (ETDEWEB)

Looney, B.; Eddy-Dilek, C.

2012-08-28

Evaluation of disposal records, soil data, and spatial/temporal groundwater data from the Paducah Gaseous Diffusion Plant (PGDP) Solid Waste Management Unit (SWMU) 7 indicate that the peak contaminant concentrations measured in monitoring well (MW) 66 result from the influence of the regional PGDP NW Plume, and does not support the presence of significant vertical transport from local contaminant sources in SWMU 7. This updated evaluation supports the 2006 conceptualization which suggested the high and low concentrations in MW66 represent different flow conditions (i.e., local versus regional influences). Incorporation of the additional lines of evidence from data collected since 2006 provide the basis to link high contaminant concentrations in MW66 (peaks) to the regional 'Northwest Plume' and to the upgradient source, specifically, the C400 Building Area. The conceptual model was further refined to demonstrate that groundwater and the various contaminant plumes respond to complex site conditions in predictable ways. This type of conceptualization bounds the expected system behavior and supports development of environmental cleanup strategies, providing a basis to support decisions even if it is not feasible to completely characterize all of the 'complexities' present in the system. We recommend that the site carefully consider the potential impacts to groundwater and contaminant plume migration as they plan and implement onsite production operations, remediation efforts, and reconfiguration activities. For example, this conceptual model suggests that rerouting drainage water, constructing ponds or basin, reconfiguring cooling water systems, capping sites, decommissioning buildings, fixing (or not fixing) water leaks, and other similar actions will potentially have a 'direct' impact on the groundwater contaminant plumes. Our conclusion that the peak concentrations in MW66 are linked to the regional PGDP NW Plume does not imply that

Shallow bedrock limits groundwater seepage-based headwater climate refugia

Science.gov (United States)

Briggs, Martin A.; Lane, John W.; Snyder, Craig D.; White, Eric A.; Johnson, Zachary; Nelms, David L.; Hitt, Nathaniel P.

2018-01-01

Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive to seasonal and long-term air temperature dynamics. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We employ rapid, cost-effective passive seismic measurements to evaluate the variable thickness of the shallow colluvial and alluvial aquifer sediments along a headwater stream supporting cold water-dependent brook trout (Salvelinus fontinalis) in Shenandoah National Park, VA, USA. Using a mean depth to bedrock of 2.6 m, numerical models predicted strong sensitivity of shallow aquifer temperature to the downward propagation of surface heat. The annual temperature dynamics (annual signal amplitude attenuation and phase shift) of potential seepage sourced from the shallow modeled aquifer were compared to several years of paired observed stream and air temperature records. Annual stream water temperature patterns were found to lag local air temperature by ∼8–19 d along the stream corridor, indicating that thermal exchange between the stream and shallow groundwater is spatially variable. Locations with greater annual signal phase lag were also associated with locally increased amplitude attenuation, further suggestion of year-round buffering of channel water temperature by groundwater seepage. Numerical models of shallow groundwater temperature that incorporate regional expected climate warming trends indicate that the summer cooling capacity of this groundwater seepage will be reduced over time, and lower-elevation stream sections may no longer serve as larger

Evaluation of fall chinook salmon spawning adjacent to the In-Situ Redox Manipulation treatability test site, Hanford Site, Washington

International Nuclear Information System (INIS)

Mueller, R.P.; Geist, D.R.

1998-10-01

The In Situ Redox Manipulation (ISRM) experiment is being evaluated as a potential method to remove contaminants from groundwater adjacent to the Columbia River near the 100-D Area. The ISRM experiment involves using sodium dithionate (Na 2 O 6 S 2 ) to precipitate chromate from the groundwater. The treatment will likely create anoxic conditions in the groundwater down-gradient of the ISRM treatability test site; however, the spatial extent of this anoxic plume is not exactly known. Surveys were conducted in November 1997, following the peak spawning of fall chinook salmon. Aerial surveys documented 210 redds (spawning nests) near the downstream island in locations consistent with previous surveys. Neither aerial nor underwater surveys documented fall chinook spawning in the vicinity of the ISRM treatability test site. Based on measurements of depth, velocity, and substrate, less than 1% of the study area contained suitable fall chinook salmon spawning habitat, indicating low potential for fall chinook salmon to spawn in the vicinity of the ISRM experiment

Hydrogeologic Settings and Ground-Water Flow Simulations for Regional Studies of the Transport of Anthropogenic and Natural Contaminants to Public-Supply Wells - Studies Begun in 2001

Science.gov (United States)

Paschke, Suzanne S.

2007-01-01

This study of the Transport of Anthropogenic and Natural Contaminants to public-supply wells (TANC study) is being conducted as part of the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program and was designed to increase understanding of the most important factors to consider in ground-water vulnerability assessments. The seven TANC studies that began in 2001 used retrospective data and ground-water flow models to evaluate hydrogeologic variables that affect aquifer susceptibility and vulnerability at a regional scale. Ground-water flow characteristics, regional water budgets, pumping-well information, and water-quality data were compiled from existing data and used to develop conceptual models of ground-water conditions for each study area. Steady-state regional ground-water flow models were used to represent the conceptual models, and advective particle-tracking simulations were used to compute areas contributing recharge and traveltimes from recharge to selected public-supply wells. Retrospective data and modeling results were tabulated into a relational database for future analysis. Seven study areas were selected to evaluate a range of hydrogeologic settings and management practices across the Nation: the Salt Lake Valley, Utah; the Eagle Valley and Spanish Springs Valley, Nevada; the San Joaquin Valley, California; the Northern Tampa Bay region, Florida; the Pomperaug River Basin, Connecticut; the Great Miami River Basin, Ohio; and the Eastern High Plains, Nebraska. This Professional Paper Chapter presents the hydrogeologic settings and documents the ground-water flow models for each of the NAWQA TANC regional study areas that began work in 2001. Methods used to compile retrospective data, determine contributing areas of public-supply wells, and characterize oxidation-reduction (redox) conditions also are presented. This Professional Paper Chapter provides the foundation for future susceptibility and vulnerability analyses in the TANC

Numerical and machine learning simulation of parametric distributions of groundwater residence time in streams and wells

Science.gov (United States)

Starn, J. J.; Belitz, K.; Carlson, C.

2017-12-01

Groundwater residence-time distributions (RTDs) are critical for assessing susceptibility of water resources to contamination. This novel approach for estimating regional RTDs was to first simulate groundwater flow using existing regional digital data sets in 13 intermediate size watersheds (each an average of 7,000 square kilometers) that are representative of a wide range of glacial systems. RTDs were simulated with particle tracking. We refer to these models as "general models" because they are based on regional, as opposed to site-specific, digital data. Parametric RTDs were created from particle RTDs by fitting 1- and 2-component Weibull, gamma, and inverse Gaussian distributions, thus reducing a large number of particle travel times to 3 to 7 parameters (shape, location, and scale for each component plus a mixing fraction) for each modeled area. The scale parameter of these distributions is related to the mean exponential age; the shape parameter controls departure from the ideal exponential distribution and is partly a function of interaction with bedrock and with drainage density. Given the flexible shape and mathematical similarity of these distributions, any of them are potentially a good fit to particle RTDs. The 1-component gamma distribution provided a good fit to basin-wide particle RTDs. RTDs at monitoring wells and streams often have more complicated shapes than basin-wide RTDs, caused in part by heterogeneity in the model, and generally require 2-component distributions. A machine learning model was trained on the RTD parameters using features derived from regionally available watershed characteristics such as recharge rate, material thickness, and stream density. RTDs appeared to vary systematically across the landscape in relation to watershed features. This relation was used to produce maps of useful metrics with respect to risk-based thresholds, such as the time to first exceedance, time to maximum concentration, time above the threshold

Radon as an indicator of submarine groundwater discharge in coastal regions

International Nuclear Information System (INIS)

Jacob, Noble; Shivanna, K.; Suresh Babu, D.S.

2009-01-01

This article reviews the various available methodologies to estimate submarine groundwater discharge (SGD) and demonstrates the utility of radon with a case study. An attempt has been made to identify the existence of submarine groundwater discharge (SGD) and semi-quantitatively estimate its rate in the coastal area of Vizhinjam, Thiruvananthapuram, Kerala. Natural 222 Rn (half-life = 3.8 days) was used as a tracer of SGD because of its conservative nature, short half-life, easiness in measurement and high abundance in groundwater. As in situ radon ( 222 Rn) monitoring study conducted in this region indicated comparatively higher 222 Rn activities (average 14.1±1.7 Bq/m 3 ) in the coastal waters revealing significant submarine groundwater discharge. The SGD may be a combination of fresh groundwater and recirculated seawater that is controlled by the hydraulic gradient in the adjacent aquifer and varying tidal conditions in the coastal waters. Using a transient 222 Rn mass balance model for the coastal waters, SGD rates were computed and the average value was found to be 10.9±6.1 cm/day. These estimates are comparable with those reported in the literature. In general, identification and estimation of submarine groundwater discharge is important in the Indian context because of the possibility of large amounts of groundwater loss through its long coastline, that can be judiciously exploited to cater to the present water requirements for drinking and irrigation purposes. (author)

Investigation of the geochemical evolution of groundwater under agricultural land: A case study in northeastern Mexico

Science.gov (United States)

Ledesma-Ruiz, Rogelio; Pastén-Zapata, Ernesto; Parra, Roberto; Harter, Thomas; Mahlknecht, Jürgen

2015-02-01

Zona Citrícola is an important area for Mexico due to its citriculture activity. Situated in a sub-humid to humid climate adjacent to the Sierra Madre Oriental, this valley hosts an aquifer system that represents sequences of shales, marls, conglomerates, and alluvial deposits. Groundwater flows from mountainous recharge areas to the basin-fill deposits and provides base flows to supply drinking water to the adjacent metropolitan area of Monterrey. Recent studies examining the groundwater quality of the study area urge the mitigation of groundwater pollution. The objective of this study was to characterize the physical and chemical properties of the groundwater and to assess the processes controlling the groundwater's chemistry. Correlation was used to identify associations among various geochemical constituents. Factor analysis was applied to identify the water's chemical characteristics that were responsible for generating most of the variability within the dataset. Hierarchical cluster analysis was employed in combination with a post-hoc analysis of variance to partition the water samples into hydrochemical water groups: recharge waters (Ca-HCO3), transition zone waters (Ca-HCO3-SO4 to Ca-SO4-HCO3) and discharge waters (Ca-SO4). Inverse geochemical models of these groups were developed and constrained using PHREEQC to elucidate the chemical reactions controlling the water's chemistry between an initial (recharge) and final water. The primary reactions contributing to salinity were the following: (1) water-rock interactions, including the weathering of evaporitic rocks and dedolomitization; (2) dissolution of soil gas carbon dioxide; and (3) input from animal/human wastewater and manure in combination with by denitrification processes. Contributions from silicate weathering to salinity ranged from less important to insignificant. The findings suggest that it may not be cost-effective to regulate manure application to mitigate groundwater pollution.

Application of the Drilling Impact Study (DIS) to Forsmark groundwaters

International Nuclear Information System (INIS)

Gascoyne, Mel; Gurban, Ioana

2008-01-01

Characterisation of a geological formation as a repository for nuclear fuel waste requires deep drilling into the bedrock to gain an understanding of the geological structure, rock types, groundwater flow and the chemical composition of groundwater and the adjacent rock. The methods of characterisation from a hydrogeochemical point of view, might be affected by the various drilling activities and techniques for determining groundwater composition have been employed so that the composition can be corrected for these activities. SKB has developed and supported the Drilling Impact Study (DIS) project in which a tracer is used as an indicator of contamination to attempt to correct the groundwater composition for dilution or contamination by surface waters. The project began about five years ago with the intention of developing a routine method for determining the extent of contamination of borehole groundwater by drilling water. The main objectives of this work were: 1. Determine the extent of drilling water contamination in permeable zones in a test borehole on the Forsmark site. 2. Correct measured chemical compositions of the groundwaters based on contamination results. 3. Provide a workable methodology for routine correction of groundwater composition. 4. Apply the modified DIS model to suitable borehole zones at the Forsmark site in a systematic fashion 5. Determine uncertainties in DIS modelling. A memorandum was prepared by describing the characteristics of borehole KFM06 and its drilling history. Estimates were made of the amount of drilling water in permeable zones in the borehole and the various approaches to applying results of DIS were described and recommendations made, with an example calculation

Continuous Groundwater Monitoring Collocated at USGS Streamgages

Science.gov (United States)

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

2012-12-01

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

Hanford well remediation and decommissioning plan

International Nuclear Information System (INIS)

Ledgerwood, R.K.

1993-01-01

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

Tracking groundwater discharge to a large river using tracers and geophysics.

Science.gov (United States)

Harrington, Glenn A; Gardner, W Payton; Munday, Tim J

2014-01-01

Few studies have investigated large reaches of rivers in which multiple sources of groundwater are responsible for maintaining baseflow. This paper builds upon previous work undertaken along the Fitzroy River, one of the largest perennial river systems in north-western Australia. Synoptic regional-scale sampling of both river water and groundwater for a suite of environmental tracers ((4) He, (87) Sr/(86) Sr, (222) Rn and major ions), and subsequent modeling of tracer behavior in the river, has enabled definition and quantification of groundwater input from at least three different sources. We show unambiguous evidence of both shallow "local" groundwater, possibly recharged to alluvial aquifers beneath the adjacent floodplain during recent high-flow events, and old "regional" groundwater introduced via artesian flow from deep confined aquifers. We also invoke hyporheic exchange and either bank return flow or parafluvial flow to account for background (222) Rn activities and anomalous chloride trends along river reaches where there is no evidence of the local or regional groundwater inputs. Vertical conductivity sections acquired through an airborne electromagnetic (AEM) survey provide insights to the architecture of the aquifers associated with these sources and general groundwater quality characteristics. These data indicate fresh groundwater from about 300 m below ground preferentially discharging to the river, at locations consistent with those inferred from tracer data. The results demonstrate how sampling rivers for multiple environmental tracers of different types-including stable and radioactive isotopes, dissolved gases and major ions-can significantly improve conceptualization of groundwater-surface water interaction processes, particularly when coupled with geophysical techniques in complex hydrogeological settings. © 2013, National Ground Water Association.

Implementation of a permeable reactive barrier for treatment of groundwater impacted by strontium-90

International Nuclear Information System (INIS)

Przepiora, A.; Bodine, D.; Dollar, P.; Smith, P.

2014-01-01

A funnel and gate permeable reactive barrier (PRB) system was constructed to treat strontium-90 (Sr- 90) in groundwater migrating from a legacy waste disposal area into an adjacent wetland. The PRB system was designed to contain and direct the Sr-90 impacted groundwater into treatment 'gates' containing zeolite using a low permeability 'funnel' sections constructed with soil-bentonite slurry. The constructed PRB met all dimension and permeability specifications. Initial performance monitoring results indicate that the PRB captured the Sr-90 impacted groundwater plume and the beta radiation values in groundwater emerging from the treatment gates ranged from 35 to 86 Becquerel's per litre (Bq/L), equivalent to a reduction by 88% to 99% from the influent values. Those initial performance results were influenced by residual impacts present in the aquifer material prior to PRB installation. It is anticipated that the clean-up target of 5 Bq/L will be achieved with time as treated groundwater emerging from the PRB flushes through the downgradient aquifer zone. (author)

Coupling of bio-PRB and enclosed in-well aeration system for remediation of nitrobenzene and aniline in groundwater.

Science.gov (United States)

Liu, Na; Ding, Feng; Wang, Liu; Liu, Peng; Yu, Xiaolong; Ye, Kang

2016-05-01

A laboratory-scale bio-permeable reactive barrier (bio-PRB) was constructed and combined with enclosed in-well aeration system to treat nitrobenzene (NB) and aniline (AN) in groundwater. Batch-style experiments were first conducted to evaluate the effectiveness of NB and AN degradation, using suspension (free cells) of degrading consortium and immobilized consortium by a mixture of perlite and peat. The NB and AN were completely degraded in 4 mg L(-1) when the aeration system was applied into the bio-PRB system. The NB and AN were effectively removed when the aeration system was functional in the bio-PRB. The removal efficiency decreased when the aeration system malfunctioned for 20 days, thus indicating that DO was an important factor for the degradation of NB and AN. The regain of NB and AN removal after the malfunction indicates the robustness of degradation consortium. No original organics and new formed by-products were observed in the effluent. The results indicate that NB and AN in groundwater can be completely mineralized in a bio-PRB equipped with enclosed in-well aeration system and filled with perlite and peat attached with degrading consortium.

Uranium concentrations in groundwater, northeastern Washington

Science.gov (United States)

Kahle, Sue C.; Welch, Wendy B.; Tecca, Alison E.; Eliason, Devin M.

2018-04-18

A study of uranium in groundwater in northeastern Washington was conducted to make a preliminary assessment of naturally occurring uranium in groundwater relying on existing information and limited reconnaissance sampling. Naturally occurring uranium is associated with granitic and metasedimentary rocks, as well as younger sedimentary deposits, that occur in this region. The occurrence and distribution of uranium in groundwater is poorly understood. U.S. Environmental Protection Agency (EPA) regulates uranium in Group A community water systems at a maximum contaminant level (MCL) of 30 μg/L in order to reduce uranium exposure, protect from toxic kidney effects of uranium, and reduce the risk of cancer. However, most existing private wells in the study area, generally for single family use, have not been sampled for uranium. This document presents available uranium concentration data from throughout a multi-county region, identifies data gaps, and suggests further study aimed at understanding the occurrence of uranium in groundwater.The study encompasses about 13,000 square miles (mi2) in the northeastern part of Washington with a 2010 population of about 563,000. Other than the City of Spokane, most of the study area is rural with small towns interspersed throughout the region. The study area also includes three Indian Reservations with small towns and scattered population. The area has a history of uranium exploration and mining, with two inactive uranium mines on the Spokane Indian Reservation and one smaller inactive mine on the outskirts of Spokane. Historical (1977–2016) uranium in groundwater concentration data were used to describe and illustrate the general occurrence and distribution of uranium in groundwater, as well as to identify data deficiencies. Uranium concentrations were detected at greater than 1 microgram per liter (μg/L) in 60 percent of the 2,382 historical samples (from wells and springs). Uranium concentrations ranged from less than 1 to

Assessing the recharge process and importance of montane water to adjacent tectonic valley-plain groundwater using a ternary end-member mixing analysis based on isotopic and chemical tracers

Science.gov (United States)

Peng, Tsung-Ren; Zhan, Wen-Jun; Tong, Lun-Tao; Chen, Chi-Tsun; Liu, Tsang-Sen; Lu, Wan-Chung

2018-03-01

A study in eastern Taiwan evaluated the importance of montane water contribution (MC) to adjacent valley-plain groundwater (VPG) in a tectonic suture zone. The evaluation used a ternary natural-tracer-based end-member mixing analysis (EMMA). With this purpose, VPG and three end-member water samples of plain precipitation (PP), mountain-front recharge (MFR), and mountain-block recharge (MBR) were collected and analyzed for stable isotopic compositions (δ 2H and δ 18O) and chemical concentrations (electrical conductivity (EC) and Cl-). After evaluation, Cl- is deemed unsuitable for EMMA in this study, and the contribution fractions of respective end members derived by the δ 18O-EC pair are similar to those derived by the δ 2H-EC pair. EMMA results indicate that the MC, including MFR and MBR, contributes at least 70% (679 × 106 m3 water volume) of the VPG, significantly greater than the approximately 30% of PP contribution, and greater than the 20-50% in equivalent humid regions worldwide. The large MC is attributable to highly fractured strata and the steep topography of studied catchments caused by active tectonism. Furthermore, the contribution fractions derived by EMMA reflect the unique hydrogeological conditions in the respective study sub-regions. A region with a large MBR fraction is indicative of active lateral groundwater flow as a result of highly fractured strata in montane catchments. On the other hand, a region characterized by a large MFR fraction may possess high-permeability stream beds or high stream gradients. Those hydrogeological implications are helpful for water resource management and protection authorities of the studied regions.

Factors affecting ground-water exchange and catchment size for Florida lakes in mantled karst terrain

Science.gov (United States)

Lee, Terrie Mackin

2002-01-01

In the mantled karst terrain of Florida, the size of the catchment delivering ground-water inflow to lakes is often considerably smaller than the topographically defined drainage basin. The size is determined by a balance of factors that act individually to enhance or diminish the hydraulic connection between the lake and the adjacent surficial aquifer, as well as the hydraulic connection between the surficial aquifer and the deeper limestone aquifer. Factors affecting ground-water exchange and the size of the ground-water catchment for lakes in mantled karst terrain were examined by: (1) reviewing the physical and hydrogeological characteristics of 14 Florida lake basins with available ground-water inflow estimates, and (2) simulating ground-water flow in hypothetical lake basins. Variably-saturated flow modeling was used to simulate a range of physical and hydrogeologic factors observed at the 14 lake basins. These factors included: recharge rate to the surficial aquifer, thickness of the unsaturated zone, size of the topographically defined basin, depth of the lake, thickness of the surficial aquifer, hydraulic conductivity of the geologic units, the location and size of karst subsidence features beneath and onshore of the lake, and the head in the Upper Floridan aquifer. Catchment size and the magnitude of ground-water inflow increased with increases in recharge rate to the surficial aquifer, the size of the topographically defined basin, hydraulic conductivity in the surficial aquifer, the degree of confinement of the deeper Upper Floridan aquifer, and the head in the Upper Floridan aquifer. The catchment size and magnitude of ground-water inflow increased with decreases in the number and size of karst subsidence features in the basin, and the thickness of the unsaturated zone near the lake. Model results, although qualitative, provided insights into: (1) the types of lake basins in mantled karst terrain that have the potential to generate small and large

Local assessment of the risk on groundwater resources related to unconventional hydrocarbon development

Science.gov (United States)

Raynauld, Melanie; Peel, Morgan; Lefebvre, Rene; Crow, Heather; Gloaguen, Erwan; Molson, John; Ahad, Jason; Aquilina, Luc

2014-05-01

. Hydrogeochemical conditions were defined on the basis of a multivariate analysis of 16 chemical parameters. Quite wide variations in geochemistry were encountered, with evolved groundwater types affected by cation exchange or mixing with sea water. Groundwater residence time can thus be quite long, which may be due to the relatively high porosity (5-10%) of the rock. Methane is of mixed origin and preferentially associated with evolved water types. SALTFLOW, a variable-density flow and mass transport simulator, was used to represent the peninsula as well as the adjacent highlands in a 2D vertical section model. The interaction of the highland and peninsula recharge leads to nested flow systems with converging-diverging flow conditions under the peninsula, with a relatively shallow active flow zone. The observed and simulated conditions support a conceptual model that can be used to infer the level of risk for groundwater quality related to oil and gas industry activities.

Groundwater quality monitoring well installation for Waste Area Grouping at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

International Nuclear Information System (INIS)

Mortimore, J.A.; Lee, T.A.

1994-09-01

This report documents the drilling and installation of 18 groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 11. WAG 11 (White Wing Scrap Yard) is located on the west end of East Fork Ridge between White Wing Road and the Oak Ridge Turnpike. The scrap yard is approximately 25 acres in size. The wells at WAG 11 were drilled and developed between January 1990 and October 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The wells at WAG 11 were drilled with auger or air rotary rigs. Depending on the hydrogeologic conditions present at each proposed well location, one of four basic installation methods was utilized. Detailed procedures for well construction were specified by the Engineering Division to ensure that the wells would provide water samples representative of the aquifer. To ensure conformance with the specifications, Energy Systems Construction Engineering and ERCE provided continuous oversight of field activities. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAG 11. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

Validation Analysis of the Shoal Groundwater Flow and Transport Model

Energy Technology Data Exchange (ETDEWEB)

A. Hassan; J. Chapman

2008-11-01

Environmental restoration at the Shoal underground nuclear test is following a process prescribed by a Federal Facility Agreement and Consent Order (FFACO) between the U.S. Department of Energy, the U.S. Department of Defense, and the State of Nevada. Characterization of the site included two stages of well drilling and testing in 1996 and 1999, and development and revision of numerical models of groundwater flow and radionuclide transport. Agreement on a contaminant boundary for the site and a corrective action plan was reached in 2006. Later that same year, three wells were installed for the purposes of model validation and site monitoring. The FFACO prescribes a five-year proof-of-concept period for demonstrating that the site groundwater model is capable of producing meaningful results with an acceptable level of uncertainty. The corrective action plan specifies a rigorous seven step validation process. The accepted groundwater model is evaluated using that process in light of the newly acquired data. The conceptual model of ground water flow for the Project Shoal Area considers groundwater flow through the fractured granite aquifer comprising the Sand Springs Range. Water enters the system by the infiltration of precipitation directly on the surface of the mountain range. Groundwater leaves the granite aquifer by flowing into alluvial deposits in the adjacent basins of Fourmile Flat and Fairview Valley. A groundwater divide is interpreted as coinciding with the western portion of the Sand Springs Range, west of the underground nuclear test, preventing flow from the test into Fourmile Flat. A very low conductivity shear zone east of the nuclear test roughly parallels the divide. The presence of these lateral boundaries, coupled with a regional discharge area to the northeast, is interpreted in the model as causing groundwater from the site to flow in a northeastward direction into Fairview Valley. Steady-state flow conditions are assumed given the absence of

Radon as a groundwater tracer in Forsmark and Laxemar

International Nuclear Information System (INIS)

Grolander, Sara

2009-10-01

Radon concentrations were measured in different water types in Forsmark and Laxemar during the site investigation and within this study. From these measurements it can be concluded that large differences between surface water, near surface groundwater and deep groundwater can be found in both Laxemar and Forsmark. The differences in radon concentrations between different water types are used in this study to detect interactions between surface water, near surface water and deep groundwater. From the radon measurements it can also be concluded that radon concentration in deep groundwater varies largely with depth. These variations with depth are probably caused by groundwater flow in conductive fracture zones in the bedrock. The focus of this study has been the radon concentration of near surface groundwater and the interaction between near surface groundwater and deep groundwater. Radon measurements have been done using the RAD-7 radon detector within this study. It could be concluded that RAD-7 is a good technique for radon measurements and also easy to use in field. The radon concentrations measured in near surface groundwater in Laxemar within this study were low and homogenous. The variation in radon concentration has been analyses and compared to other parameters. Since the hypothesis of this study has been that there are differences in radon concentrations between recharging and discharging groundwater, the most important parameter to consider is the recharge/discharge field classification of the wells. No correlation between the recharge/discharge classifications of wells and the radon concentrations were found. The lack of correlation between groundwater flow patterns and radon concentration means that it is not possible to detect flow patterns in near surface groundwater using radon as a tracer in the Laxemar area. The lack of correlation can be caused by the fact that there are just a few wells located in areas classified as recharge area. It can also be

Geohydrology and ground-water quality beneath the 300 Area, Hanford Site, Washington

International Nuclear Information System (INIS)

Lindberg, J.W.; Bond, F.W.

1979-06-01

Ground water enters the 300 Area from the northwest, west, and southwest. However, throughout most of the 300 Area, the flow is to the east and southeast. Ground water flows to the northeast only in the southern portion of the 300 Area. Variations in level of the Columbia River affected the ground-water system by altering the level and shape of the 300 Area watertable. Large quantities of process waste water, when warmed during summer months by solar radiation or cooled during winter months by ambient air temperature, influenced the temperature of the ground water. Leaking pipes and the intentional discharge of waste water (or withdrawal of ground water) affected the ground-water system in the 300 Area. Water quality tests of Hanford ground water in and adjacent to the 300 Area showed that in the area of the Process Water Trenches and Sanitary Leaching Trenches, calcium, magnesium, sodium, bicarbonate, and sulfate ions are more dilute, and nitrate and chloride ions are more concentrated than in surrounding areas. Fluoride, uranium, and beta emitters are more concentrated in ground water along the bank of the Columbia River in the central and southern portions of the 300 Area and near the 340 Building. Test wells and routine ground-water sampling are adequate to point out contamination. The variable Thickness Transient (VTT) Model of ground-water flow in the unconfined aquifer underlying the 300 Area has been set up, calibrated, and verified. The Multicomponent Mass Transfer (MMT) Model of distribution of contaminants in the saturated regime under the 300 Area has been set up, calibrated, and tested

Application of hydrogeology and groundwater-age estimates to assess the travel time of groundwater at the site of a landfill to the Mahomet Aquifer, near Clinton, Illinois

Science.gov (United States)

Kay, Robert T.; Buszka, Paul M.

2016-03-02

The U.S. Geological Survey used interpretations of hydrogeologic conditions and tritium-based groundwater age estimates to assess the travel time of groundwater at a landfill site near Clinton, Illinois (the “Clinton site”) where a chemical waste unit (CWU) was proposed to be within the Clinton landfill unit #3 (CLU#3). Glacial deposits beneath the CWU consist predominantly of low-permeability silt- and clay-rich till interspersed with thin (typically less than 2 feet in thickness) layers of more permeable deposits, including the Upper and Lower Radnor Till Sands and the Organic Soil unit. These glacial deposits are about 170 feet thick and overlie the Mahomet Sand Member of the Banner Formation. The Mahomet aquifer is composed of the Mahomet Sand Member and is used for water supply in much of east-central Illinois.Eight tritium analyses of water from seven wells were used to evaluate the overall age of recharge to aquifers beneath the Clinton site. Groundwater samples were collected from six monitoring wells on or adjacent to the CLU#3 that were open to glacial deposits above the Mahomet aquifer (the upper and lower parts of the Radnor Till Member and the Organic Soil unit) and one proximal production well (approximately 0.5 miles from the CLU#3) that is screened in the Mahomet aquifer. The tritium-based age estimates were computed with a simplifying, piston-flow assumption: that groundwater moves in discrete packets to the sampled interval by advection, without hydrodynamic dispersion or mixing.Tritium concentrations indicate a recharge age of at least 59 years (pre-1953 recharge) for water sampled from deposits below the upper part of the Radnor Till Member at the CLU#3, with older water expected at progressively greater depth in the tills. The largest tritium concentration from a well sampled by this study (well G53S; 0.32 ± 0.10 tritium units) was in groundwater from a sand deposit in the upper part of the Radnor Till Member; the shallowest permeable unit

Water use and groundwater contamination

International Nuclear Information System (INIS)

Elton, J.J.; Livingstone, B.

1998-01-01

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

Characterization Well R-7 Geochemistry Report

International Nuclear Information System (INIS)

Longmire, P.; Goff, F.

2002-01-01

This report provides analytical results for four groundwater-sampling rounds conducted at characterization well R-7. The goal of the characterization efforts was to assess the hydrochemistry and to determine if contaminants from Technical Area (TA)-2 and TA-21 of the Los Alamos National Laboratory (LANL or the Laboratory) are present in the regional aquifer in the vicinity of the well. Figure 1.0-1 shows the well's location in the narrow upper part of Los Alamos Canyon, between the inactive Omega West reactor and the mouth of DP Canyon. Well R-7 is in an excellent location to characterize the hydrology and groundwater chemistry in both perched groundwater and the regional aquifer near sites of known Laboratory effluent release, including radionuclides and inorganic chemicals (Stone et al. 2002, 72717). The Risk Reduction and Environmental Stewardship-Remediation (RRES-R) Program (formerly the Environmental Restoration [ER] Project) installed well R-7 as part of groundwater investigations to satisfy requirements of the ''Hydrogeologic Workplan'' (LANL 1998, 59599) and to support the Laboratory's ''Groundwater Protection Management Program Plan'' (LANL 1996, 70215). Well R-7 was designed primarily to provide geochemical or water quality and hydrogeologic data for the regional aquifer within the Puye Formation. This report also presents a geochemical evaluation of the analytical results for well R-7 and provides hydrogeochemical interpretations using analytical results for groundwater samples collected at the well. Discussion of other hydrogeochemical data collected within the east-central portion of the Laboratory, however, is deferred until they can be evaluated in the context of sitewide information collected from other RRES and Hydrogeologic Workplan characterization wells (R-8A, R-9, and R-9i). Once all deep groundwater investigations in the east-central portion of the Laboratory are completed, geochemical and hydrogeologic conceptual models for the Los Alamos

Impact of Spatial Pumping Patterns on Groundwater Management

Science.gov (United States)

Yin, J.; Tsai, F. T. C.

2017-12-01

Challenges exist to manage groundwater resources while maintaining a balance between groundwater quantity and quality because of anthropogenic pumping activities as well as complex subsurface environment. In this study, to address the impact of spatial pumping pattern on groundwater management, a mixed integer nonlinear multi-objective model is formulated by integrating three objectives within a management framework to: (i) maximize total groundwater withdrawal from potential wells; (ii) minimize total electricity cost for well pumps; and (iii) attain groundwater level at selected monitoring locations as close as possible to the target level. Binary variables are used in the groundwater management model to control the operative status of pumping wells. The NSGA-II is linked with MODFLOW to solve the multi-objective problem. The proposed method is applied to a groundwater management problem in the complex Baton Rouge aquifer system, southeastern Louisiana. Results show that (a) non-dominated trade-off solutions under various spatial distributions of active pumping wells can be achieved. Each solution is optimal with regard to its corresponding objectives; (b) operative status, locations and pumping rates of pumping wells are significant to influence the distribution of hydraulic head, which in turn influence the optimization results; (c) A wide range of optimal solutions is obtained such that decision makers can select the most appropriate solution through negotiation with different stakeholders. This technique is beneficial to finding out the optimal extent to which three objectives including water supply concern, energy concern and subsidence concern can be balanced.

A partial exponential lumped parameter model to evaluate groundwater age distributions and nitrate trends in long-screened wells

Science.gov (United States)

Jurgens, Bryant; Böhlke, John Karl; Kauffman, Leon J.; Belitz, Kenneth; Esser, Bradley K.

2016-01-01

A partial exponential lumped parameter model (PEM) was derived to determine age distributions and nitrate trends in long-screened production wells. The PEM can simulate age distributions for wells screened over any finite interval of an aquifer that has an exponential distribution of age with depth. The PEM has 3 parameters – the ratio of saturated thickness to the top and bottom of the screen and mean age, but these can be reduced to 1 parameter (mean age) by using well construction information and estimates of the saturated thickness. The PEM was tested with data from 30 production wells in a heterogeneous alluvial fan aquifer in California, USA. Well construction data were used to guide parameterization of a PEM for each well and mean age was calibrated to measured environmental tracer data (3H, 3He, CFC-113, and 14C). Results were compared to age distributions generated for individual wells using advective particle tracking models (PTMs). Age distributions from PTMs were more complex than PEM distributions, but PEMs provided better fits to tracer data, partly because the PTMs did not simulate 14C accurately in wells that captured varying amounts of old groundwater recharged at lower rates prior to groundwater development and irrigation. Nitrate trends were simulated independently of the calibration process and the PEM provided good fits for at least 11 of 24 wells. This work shows that the PEM, and lumped parameter models (LPMs) in general, can often identify critical features of the age distributions in wells that are needed to explain observed tracer data and nonpoint source contaminant trends, even in systems where aquifer heterogeneity and water-use complicate distributions of age. While accurate PTMs are preferable for understanding and predicting aquifer-scale responses to water use and contaminant transport, LPMs can be sensitive to local conditions near individual wells that may be inaccurately represented or missing in an aquifer-scale flow model.

STakeholder-Objective Risk Model (STORM): Determiningthe aggregated risk of multiple contaminant hazards in groundwater well catchments

DEFF Research Database (Denmark)

Enzenhoefer, R.; Binning, Philip John; Nowak, W.

2015-01-01

Risk is often defined as the product of probability, vulnerability and value. Drinking water supply from groundwater abstraction is often at risk due to multiple hazardous land use activities in the well catchment. Each hazard might or might not introduce contaminants into the subsurface at any......-pathway-receptor concept, mass-discharge-based aggregation of stochastically occuring spill events, accounts for uncertainties in the involved flow and transport models through Monte Carlo simulation, and can address different stakeholder objectives. We illustrate the application of STORM in a numerical test case inspired...

New Module to Simulate Groundwater-Surface Water Interactions in Small-Scale Alluvial Aquifer System.

Science.gov (United States)

Flores, L.

2017-12-01

Streamflow depletion can occur when groundwater pumping wells lower water table elevations adjacent to a nearby stream. Being able to accurately model the severity of this process is of critical importance in semi-arid regions where groundwater-surface water interactions affect water rights and the sustainability of water resource practices. The finite-difference flow model MODFLOW is currently the standard for estimating groundwater-surface water interactions in many regions in the western United States. However, certain limitations of the model persist when highly-resolved spatial scales are used to represent the stream-aquifer system, e.g. when the size of computational grid cells is much less than the river width. In this study, an external module is developed and linked with MODFLOW that (1) allows for multiple computational grid cells over the width of the river; (2) computes streamflow and stream stage along the length of the river using the one-dimensional (1D) steady (over a stress period) shallow water equations, which allows for more accurate stream stages when normal flow cannot be assumed or a rating curve is not available; and (3) incorporates a process for computing streamflow loss when an unsaturated zone develops under the streambed. Use of the module not only provides highly-resolved estimates of streamflow depletion, but also of streambed hydraulic conductivity. The new module is applied to the stream-aquifer alluvial system along the South Platte River south of Denver, Colorado, with results tested against field-measured groundwater levels, streamflow, and streamflow depletion.

Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

Science.gov (United States)

Johnson, Timothy C.; Slater, Lee D.; Ntarlagiannis, Dimitris; Day-Lewis, Frederick D.; Elwaseif, Mehrez

2012-01-01

Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides superior spatial coverage in two or three dimensions, potentially high-resolution information in time, and information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever-increasing size and complexity of long-term, three-dimensional (3-D) time series conductivity data sets. Here we use 3-D surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater-surface water interactions along a stretch of the Columbia River adjacent to the Hanford 300 near Richland, Washington, USA. We reduce the resulting 3-D conductivity time series using both time-series and time-frequency analyses to isolate a paleochannel causing enhanced groundwater-surface water interactions. Correlation analysis on the time-lapse imaging results concisely represents enhanced groundwater-surface water interactions within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) transform provides additional information by identifying the stage periodicities driving groundwater-surface water interactions due to upstream dam operations, and identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 Area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.

Bayesian nitrate source apportionment to individual groundwater wells in the Central Valley by use of elemental and isotopic tracers

Science.gov (United States)

Ransom, Katherine M; Grote, Mark N.; Deinhart, Amanda; Eppich, Gary; Kendall, Carol; Sanborn, Matthew E.; Sounders, A. Kate; Wimpenny, Joshua; Yin, Qing-zhu; Young, Megan B.; Harter, Thomas

2016-01-01

Groundwater quality is a concern in alluvial aquifers that underlie agricultural areas, such as in the San Joaquin Valley of California. Shallow domestic wells (less than 150 m deep) in agricultural areas are often contaminated by nitrate. Agricultural and rural nitrate sources include dairy manure, synthetic fertilizers, and septic waste. Knowledge of the relative proportion that each of these sources contributes to nitrate concentration in individual wells can aid future regulatory and land management decisions. We show that nitrogen and oxygen isotopes of nitrate, boron isotopes, and iodine concentrations are a useful, novel combination of groundwater tracers to differentiate between manure, fertilizers, septic waste, and natural sources of nitrate. Furthermore, in this work, we develop a new Bayesian mixing model in which these isotopic and elemental tracers were used to estimate the probability distribution of the fractional contributions of manure, fertilizers, septic waste, and natural sources to the nitrate concentration found in an individual well. The approach was applied to 56 nitrate-impacted private domestic wells located in the San Joaquin Valley. Model analysis found that some domestic wells were clearly dominated by the manure source and suggests evidence for majority contributions from either the septic or fertilizer source for other wells. But, predictions of fractional contributions for septic and fertilizer sources were often of similar magnitude, perhaps because modeled uncertainty about the fraction of each was large. For validation of the Bayesian model, fractional estimates were compared to surrounding land use and estimated source contributions were broadly consistent with nearby land use types.

Arsenic speciation and uranium concentrations in drinking water supply wells in Northern Greece: Correlations with redox indicative parameters and implications for groundwater treatment

International Nuclear Information System (INIS)

Katsoyiannis, Ioannis A.; Hug, Stephan J.; Ammann, Adrian; Zikoudi, Antonia; Hatziliontos, Christodoulos

2007-01-01

The cities in the Aksios and Kalikratia areas in Northern Greece rely on arsenic contaminated groundwater for their municipal water supply. As remedial action strongly depends on arsenic speciation, the presence of other possible contaminants, and on the general water composition, a detailed study with samples from 21 representative locations was undertaken. Arsenic concentrations were typically 10-70 μg/L. In the groundwaters of the Aksios area with lower Eh values (87-172 mV), pH 7.5-8.2 and 4-6 mM HCO 3 alkalinity, As(III) predominated. Manganese concentrations were mostly above the EC standard of 0.05 mg/L (0.1-0.7 mg/L). In groundwaters of the Kalikratia area with higher Eh values (272-352 mV), pH 6.7-7.5 and 6-12 mM HCO 3 alkalinity, As(V) was the main species. Uranium in the groundwaters was also investigated and correlations with total arsenic concentrations and speciation were examined to understand more of the redox chemistry of the examined groundwaters. Uranium concentrations were in the range 0.01-10 μg/L, with the higher concentrations to occur in the oxidizing groundwaters of the Kalikratia area. Uranium and total arsenic concentrations showed no correlation, whereas uranium concentrations correlated strongly with As(III)/As(tot) ratios, depicting their use as a possible indicator of groundwater redox conditions. Finally, boron was found to exceed the EC drinking water standard of 1 mg/L in some wells in the Kalikratia area and its removal should also be considered in the design of a remedial action

Water Follies: Groundwater Pumping and the Fate of America's Fresh Waters

Science.gov (United States)

Glennon, R.

2002-12-01

The next time you open a bottle of spring water, consider that it may have come from a well that is drying up a blue-ribbon trout stream. The next time you super-size a meal at McDonald's, note that the fries are all the same length. That's because the potato farmers irrigate their fields with groundwater from wells, some adjacent to nearby rivers. The next time you purchase gold jewelry, consider that it may have come from a mine that has pumped so much groundwater to de-water the gold-bearing rock that 60 to100 years will pass before the water table recovers. The next time you water your suburban lawn, pause to reflect on what that's doing to the nearby wetland. And the next time you visit Las Vegas and flip on the light in your hotel room, consider that the electricity may have been generated by a coal-fired power plant supplied by a slurry pipeline that uses groundwater critical to springs sacred to the Hopi people. These and countless other seemingly innocuous activities reflect our individual and societal dependence on groundwater that is hydrologically connected to surface water. Hydrologists understand that ground and surface water are interconnected, but frequently the legal rules governing water distinguish between ground and surface water. This has led to groundwater pumping that has dried up many rivers, particularly in the arid West. In Arizona, many once verdant streams have become desiccated sandboxes as city, mines, and farms pumped groundwater to such an extent that surface flows were totally depleted. The problem of the impact of groundwater pumping on the environment, however, is not confined to the arid West. It is an enormous national, indeed international problem. This presentation will focus on the United States and illustrate with examples from around the country the array of environmental problems caused by excessive groundwater pumping. The locations of these case studies range from Maine to California, from Minnesota to Florida, and from

Radon as a groundwater tracer in Forsmark and Laxemar

Energy Technology Data Exchange (ETDEWEB)

Grolander, Sara

2009-10-15

Radon concentrations were measured in different water types in Forsmark and Laxemar during the site investigation and within this study. From these measurements it can be concluded that large differences between surface water, near surface groundwater and deep groundwater can be found in both Laxemar and Forsmark. The differences in radon concentrations between different water types are used in this study to detect interactions between surface water, near surface water and deep groundwater. From the radon measurements it can also be concluded that radon concentration in deep groundwater varies largely with depth. These variations with depth are probably caused by groundwater flow in conductive fracture zones in the bedrock. The focus of this study has been the radon concentration of near surface groundwater and the interaction between near surface groundwater and deep groundwater. Radon measurements have been done using the RAD-7 radon detector within this study. It could be concluded that RAD-7 is a good technique for radon measurements and also easy to use in field. The radon concentrations measured in near surface groundwater in Laxemar within this study were low and homogenous. The variation in radon concentration has been analyses and compared to other parameters. Since the hypothesis of this study has been that there are differences in radon concentrations between recharging and discharging groundwater, the most important parameter to consider is the recharge/discharge field classification of the wells. No correlation between the recharge/discharge classifications of wells and the radon concentrations were found. The lack of correlation between groundwater flow patterns and radon concentration means that it is not possible to detect flow patterns in near surface groundwater using radon as a tracer in the Laxemar area. The lack of correlation can be caused by the fact that there are just a few wells located in areas classified as recharge area. It can also be

Groundwater conditions in Utah, spring of 2013

Science.gov (United States)

Burden, Carole B.; Birken, Adam S.; Derrick, V. Noah; Fisher, Martel J.; Holt, Christopher M.; Downhour, Paul; Smith, Lincoln; Eacret, Robert J.; Gibson, Travis L.; Slaugh, Bradley A.; Whittier, Nickolas R.; Howells, James H.; Christiansen, Howard K.

2013-01-01

This is the fiftieth in a series of annual reports that describe groundwater conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing groundwater conditions. This report, like the others in the series, contains information on well construction, groundwater withdrawals from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of groundwater. Supplementary data are included in reports of this series only for those years or areas that are important to a discussion of changing groundwater conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of groundwater development in the State for calendar year 2012. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is also available online at http://www.waterrights.utah.gov/techinfo/ and http://ut.water. usgs.gov/publications/GW2013.pdf. Groundwater conditions in Utah for calendar year 2011 are reported in Burden and others (2012) and available online at http://ut.water.usgs.gov/ publications/GW2012.pdf

Groundwater Energy Designer (GED). Computerized design tool for use of groundwater as heating and cooling source - Final report; Groundwater Energy Designer (GED). Computergestuetztes Auslegungstool zur Waerme- und Kaeltenutzung von Grundwasser - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Poppei, J.; Mayer, G.; Schwarz, R.

2006-11-15

We have developed the graphic-based tool Groundwater Energy Designer (GED) for the dimensioning of groundwater withdrawal and reinjection facilities for the purpose of thermal energy exploitation. The tool is designed to support persons planning and constructing small and medium sized installations as well as licensing authorities. GED takes into account the site-specific energy demand and hydrogeological situation. Starting from the analysis of heating or cooling demand, the possibilities of a direct utilization of the groundwater are tested interactively. The well bores for groundwater withdrawal are dimensioned based on a simplified hydrogeological characterisation. The options for the reinjection of used water are investigated considering the local situation (available area and natural groundwater flow). The situation is assessed with consideration of: (i) the technical feasibility at the site (drawdown in the well, distance between production and reinjection wells); (ii) the potential thermal impact on the groundwater (delineation of the heat propagation front for an evaluation of licensing feasibility). GED combines interactive user interfaces for the input of data and characterisation of the local situation, a database with technical and hydrogeological parameters and a flow and heat transfer simulator based on a finite volume code with an automatic mesh generator. The program is available for purchase from the developer. (authors)

A model for evaluating the three-dimensional groundwater dividing pathline between a contaminant source and a partially penetrating water-supply well

Science.gov (United States)

Harmsen, Eric W.; Converse, James C.; Anderson, Mary P.; Hoopes, John A.

1991-09-01

Effluent from septic tank-drainfields can degrade groundwater quality and contaminate nearby water-supply wells. Such groundwater contamination is a problem in the unsewered subdivisions of the sand plain of central Wisconsin, for example. To help planners minimize the risk of direct contamination of a water-supply well by a septic system, a model was developed to estimate the location of the critical dividing pathline between a rectangular contaminant source (the septic tank drainfield) and a partially penetrating pumping well. The model is capable of handling three-dimensional, transient flow in an unconfined, homogeneous, anisotropic aquifer of infinite areal extent, under a regional horizontal hydraulic gradient. Model results are in very good agreement with several other numerical and analytical models. Examples are given for which the safe, horizontal and vertical separation distances to avoid well water contamination are determined for typical central Wisconsin sand plain conditions. A companion paper (Harmsen et al., 1991) describes the application of this model, using a Monte-Carlo analysis, to study the variation of these separation distances in the Wisconsin sand plain. The model can also be applied to larger scale problems and, therefore, could be useful in implementing the U.S. Environmental Protection Agency's new well head protection program.

Simulation of groundwater flow and pumping scenarios for 1900–2050 near Mount Pleasant, South Carolina

Science.gov (United States)

Fine, Jason M.; Petkewich, Matthew D.; Campbell, Bruce G.

2017-10-31

Groundwater withdrawals from the Upper Cretaceous-age Middendorf aquifer in South Carolina have created a large, regional cone of depression in the potentiometric surface of the Middendorf aquifer in Charleston and Berkeley Counties, South Carolina. Groundwater-level declines of as much as 249 feet have been observed in wells over the past 125 years and are a result of groundwater use for public water supply, irrigation, and private industry. To address the concerns of users of the Middendorf aquifer, the U.S. Geological Survey, in cooperation with Mount Pleasant Waterworks (MPW), recalibrated an existing groundwater-flow model to incorporate additional groundwater-use and water-level data since 2008. This recalibration process consisted of a technique of parameter estimation that uses regularized inversion and employs “pilot points” for spatial hydraulic property characterization. The groundwater-flow system of the Coastal Plain physiographic province of South Carolina and parts of Georgia and North Carolina was simulated using the U.S. Geological Survey finite-difference computer code MODFLOW-2000.After the model recalibration, the following six predictive water-management scenarios were created to simulate potential changes in groundwater flow and groundwater-level conditions in the Mount Pleasant, South Carolina, area: Scenario 1—maximize MPW reverse-osmosis plant capacity by increasing groundwater withdrawals from the Middendorf aquifer from 3.9 million gallons per day (Mgal/d), which was the amount withdrawn in 2015, to 8.58 Mgal/d; Scenario 2—same as Scenario 1, but with the addition of a 0.5 Mgal/d supply well in the Middendorf aquifer near Moncks Corner, South Carolina; Scenario 3—same as Scenario 1, but with the addition of a 1.5 Mgal/d supply well in the Middendorf aquifer near Moncks Corner, South Carolina; Scenario 4—maximize MPW well capacity by increasing withdrawals from the Middendorf aquifer from 3.9 Mgal/d (in 2015) to 10.16 Mgal

Groundwater quality monitoring well installation for Waste Area Groupings 8 and 9 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Mortimore, J.A.; Ebers, M.L.

1994-09-01

This report documents the drilling and installation of nine groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 8 and two GQM wells on the perimeter of WAG 9. WAG 8 encompasses approximately 34 acres, most of which are located in Melton Valley. Irregular in shape, the site has two sinuous extensions from its northern end that contain the low-level radioactive waste (LLW) transfer lines. WAG 8 contains 22 solid waste management units (SWMUs) that can be divided into 4 groups. These groups include the High Flux Isotope Reactor/Transuranium Processing Facility waste collection basins, the LLW line leak sites, and the active LLW tanks. WAG 9 encompasses about 3 acres and is located west of the main portion of WAG 8 and south of Melton Valley Drive. WAG 9 contains four SWMUs. The wells in WAGs 8 and 9 were drilled and developed from June 1989 to March 1990. Monitoring wells were installed to characterize and assess the WAGs in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAGs 8 and 9. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-05-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-05-01

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

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

International Nuclear Information System (INIS)

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

1993-05-01

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

Monitoring effects of river restoration on groundwater with radon; Ueberwachung der Auswirkungen von Flussaufweitungen auf das Grundwasser mittels Radon

Energy Technology Data Exchange (ETDEWEB)

Hoehn, Eduard [Eawag, Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesserschutz, Duebendorf (Switzerland)

2007-03-15

The restoration of the perialpine river Toess in a floodplain of northern Switzerland (Linsental) included the removal of bank reinforcements and tracer studies in the river and in oberservation wells of the adjacent alluvial groundwater. The river water is continuously recharging the aquifer system and the groundwater is used extensively as drinking water. Radon activity concentrations of freshly infiltrated groundwater are interpreted as radon groundwater age between the river and a well. A first flood after the restoration operations resulted in a widening of the river bed and in a reduction of the flow distance to the wells. Sixteen days after a second flood, the results of radon measurements were compared with those from before the restoration. The radon age of the groundwater between the river and the wells decreased, probably as a result of the reduction of the flow distances. Concentrations of autochthonous and coliform bacteria increased after the restoration operation and even more one day after the first flood. Thus the findings on the bacteria corroborate the interpretation of the radon concentrations. The restoration has not yet reduced the quality of the groundwater, which is pumped for drinking water. The study is contributing to the solution of land-use conflicts between river restoration and the supply of drinking water from the alluvial groundwater. (orig.) [German] Die Renaturierung des voralpinen Flusses Toess in der Schotterebene des Linsentals (suedlich Winterthur, Nordschweiz) mit einer Befreiung von seinen Uferverbauungen gab Anlass zu Traceruntersuchungen im Fluss und im Grundwasser des kiessandigen Schotters. In diesem Gebiet infiltriert der Fluss ueberall und immer natuerlicherweise ins Grundwasser, welches stark als Trinkwasser genutzt wird. Radon-Aktivitaetskonzentrationen von frisch infiltriertem Grundwasser wurden interpretiert als Radon-Grundwasseralter fuer Strecken zwischen dem Fluss und Grundwasserbeobachtungsrohren. Nach einem

Full-scale testing and early production results from horizontal air sparging and soil vapor extraction wells remediating jet fuel in soil and groundwater at JFK International Airport, New York

International Nuclear Information System (INIS)

Roth, R.J.; Bianco, P.; Pressly, N.C.

1996-01-01

Jet fuel contaminated soil and groundwater contaminated at the International Arrivals Building (IAB) of the JFK International Airport in Jamaica, New York, are being remediated using soil vapor extraction (SVE) and air sparging (AS). The areal extent of the contaminated soil is estimated to be 70 acres and the volume of contaminated groundwater is estimated to be 2.3 million gallons. The remediation uses approximately 13,000 feet of horizontal SVE (HSVE) wells and 7,000 feet of horizontal AS (HAS) wells. The design of the HSVE and HAS wells was based on a pilot study followed by a full-scale test. In addition to the horizontal wells, 28 vertical AS wells and 15 vertical SVE wells are used. Three areas are being remediated, thus, three separate treatment systems have been installed. The SVE and AS wells are operated continuously while groundwater will be intermittently extracted at each HAS well, treated by liquid phase activated carbon and discharged into stormwater collection sewerage. Vapors extracted by the SVE wells are treated by vapor phase activated carbon and discharged into ambient air. The duration of the remediation is anticipated to be between two and three years before soil and groundwater are remediated to New York State cleanup criteria for the site. Based on the monitoring data for the first two months of operation, approximately 14,600 lbs. of vapor phase VOCs have been extracted. Analyses show that the majority of the VOCs are branched alkanes, branched alkenes, cyclohexane and methylated cyclohexanes

Groundwater Contamination in Agbowo Community, Ibadan Nigeria: Impact of Septic Tanks Distances to Wells

Directory of Open Access Journals (Sweden)

Odetokun, I. A.

2011-01-01

Full Text Available In Nigeria, inadequate supply of pipe borne water is a major concern; hence many homes have wells as a source of water for household uses. The groundwater of forty wells in Agbowo community was assessed for Total Aerobic Bacteria Counts (TABC and Total Coliform Counts (TCC. The location and distances of wells from septic tanks were determined using the Global Positioning System (GPS device and a tape rule respectively. All the wells sampled had high TABC (4.76 ± 1.41 log CFU/mL and TCC (2.2 9± 0.67 log CFU/mL counts which exceeded the international standard of 0 per 100 mL of potable water. There were no significant differences in the bacterial counts between covered and uncovered wells (p>0.05. The mean distance (8.93±3.61m of wells from the septic tanks was below the limit (15.24 m or 50 ft set by United State Environmental Protection Agency (USEPA. TABC increased with a decrease in distance between the wells and septic tanks though not significant (p<0.05. A very weak positive correlation (r2 =0.021 ensued between the distance from septic tank and CC, while a weak negative correlation (r2 = ‒0.261 was obtained between the TCC and TABC. This study accentuates the need to set standards for the siting of wells from septic tanks while considering all possible sources of well contamination as well as treatment of ground water before use.

Final report on the waste area grouping perimeter groundwater quality monitoring well installation program at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Greene, J.A.

1991-06-01

A groundwater quality monitoring well installation program was conducted at Oak Ridge National Laboratory (ORNL) to meet the requirements of environmental regulations, including the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). A total of 173 wells were installed and developed at 11 different waste area groupings (WAGs) between June 1986 and November 1990. A location map of the wells is included

Estimation of Net Groundwater Recharge Using Natural Drawdown Events in Subtropical Isolated Wetland Ecosystems

Science.gov (United States)

Perkins, D. B.; Min, J.; Jawitz, J. W.

2008-12-01

Restoration of ditched and drained wetlands in the Lake Okeechobee basin, Florida, USA is currently under study for possible amelioration of anthropogenic phosphorus enrichment of the lake. To date most research in this area has focused on the biogeochemical role of these wetlands. Here we focus on the dynamic hydrology of these systems and the resulting control on biogeochemical cycling. Four depressional wetlands in the basin were monitored for approximately three years to understand the interaction between wetland surface water and adjacent upland groundwater system. A coupled hydrologic-biogeochemical model was created to evaluate restoration scenarios. Determining wetland-scale hydraulic conductivity was an important aspect of the hydrologic model. Based on natural drawdown events observed at wetland-upland well pairs, hydraulic conductivities of top sandy soil layers surrounding the isolated wetlands were calculated using the Dupuit equation under a constrained water budget framework. The drawdown-based hydraulic conductivity estimates of 1.1 to 18.7 m/d (geometric mean of 4.8 m/d) were about three times greater than slug test- based values (1.5 ± 1.1 m/d), which is consistent with scale-dependent expectations. Model-based net groundwater recharge rate at each depressional wetland was predicted based on the estimated hydraulic conductivities, which corresponded to 50 to 72% of rainfall in the same period. These variances appeared to be due to the relative difference of ditch bottom elevation controlling the surface runoff as well as the spatial heterogeneity of the sandy aquifer. Results from this study have implications for nutrient loads to Lake Okeechobee via groundwater as well as water quality monitoring and management strategies aimed to reduce solute export (especially P) from the upstream catchment area to Lake Okeechobee.

Hydrologic conditions, groundwater quality, and analysis of sink hole formation in the Albany area of Dougherty County, Georgia, 2009

Science.gov (United States)

Gordon, Debbie W.; Painter, Jaime A.; McCranie, John M.

2012-01-01

The U.S. Geological Survey, in cooperation with the Albany Water, Gas, and Light Commission has conducted water resources investigations and monitored groundwater conditions and availability in the Albany, Georgia, area since 1977. This report presents an overview of hydrologic conditions, water quality, and groundwater studies in the Albany area of Dougherty County, Georgia, during 2009. Historical data also are presented for comparison with 2009 data. During 2009, groundwater-level data were collected in 29 wells in the Albany area to monitor water-level trends in the surficial, Upper Floridan, Claiborne, Clayton, and Providence aquifers. Groundwater-level data from 21 of the 29 wells indicated an increasing trend during 2008–09. Five wells show no trend due to lack of data and three wells have decreasing trends. Period-of-record water levels (period of record ranged between 1957–2009 and 2003–2009) declined slightly in 10 wells and increased slightly in 4 wells tapping the Upper Floridan aquifer; declined in 1 well and increased in 2 wells tapping the Claiborne aquifer; declined in 4 wells and increased in 2 wells tapping the Clayton aquifer; and increased in 1 well tapping the Providence aquifer. Analyses of groundwater samples collected during 2009 from 12 wells in the Upper Floridan aquifer in the vicinity of a well field located southwest of Albany indicate that overall concentrations of nitrate plus nitrite as nitrogen increased slightly from 2008 in 8 wells. A maximum concentration of 12.9 milligrams per liter was found in a groundwater sample from a well located upgradient from the well field. The distinct difference in chemical constituents of water samples collected from the Flint River and samples collected from wells located in the well-field area southwest of Albany indicates that little water exchange occurs between the Upper Floridan aquifer and Flint River where the river flows adjacent to, but downgradient of, the well field. Water

Catchment tracers reveal discharge, recharge and sources of groundwater-borne pollutants in a novel lake modelling approach

Science.gov (United States)

Kristensen, Emil; Madsen-Østerbye, Mikkel; Massicotte, Philippe; Pedersen, Ole; Markager, Stiig; Kragh, Theis

2018-02-01

Groundwater-borne contaminants such as nutrients, dissolved organic carbon (DOC), coloured dissolved organic matter (CDOM) and pesticides can have an impact the biological quality of lakes. The sources of pollutants can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from the lake and temporary groundwater wells, installed every 50 m within a distance of 5-45 m to the shore, were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN, groundwater only), total nitrogen (TN, lake only), total dissolved phosphorus (TDP, groundwater only), total phosphorus (TP, lake only), δ18O / δ16O isotope ratios and fluorescent dissolved organic matter (FDOM) components derived from parallel factor analysis (PARAFAC). The isolation of groundwater recharge areas was based on δ18O measurements and areas with a high groundwater recharge rate were identified using a microbially influenced FDOM component. Groundwater discharge sites and the fractions of water delivered from the individual sites were isolated with the Community Assembly via Trait Selection model (CATS). The CATS model utilized tracer measurements of TDP, TDN, DOC and CDOM from the groundwater samples and related these to the tracer measurements of TN, TP, DOC and CDOM in the lake. A direct comparison between the lake and the inflowing groundwater was possible as degradation rates of the tracers in the lake were taken into account and related to a range of water retention times (WRTs) of the lake (0.25-3.5 years in 0.25-year increments). These estimations showed that WRTs above 2 years required a higher tracer concentration of inflowing water than found in any of the groundwater wells around the lake. From the estimations of inflowing tracer concentration, the CATS model isolated

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

International Nuclear Information System (INIS)

Gleeson, Tom; Wada, Yoshihide

2013-01-01

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

A Multi-Methodology for improving Adelaide's Groundwater Management

Science.gov (United States)

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

2015-04-01

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

Groundwater conditions in Utah, spring of 2014

Science.gov (United States)

Burden, Carole B.; Birken, Adam S.; Gerner, Steven J.; Carricaburu, John P.; Derrick, V. Noah; Downhour, Paul; Smith, Lincoln; Eacret, Robert J.; Gibson, Travis L.; Slaugh, Bradley A.; Whittier, Nickolas R.; Howells, James H.; Christiansen, Howard K.; Fisher, Martel J.

2014-01-01

This is the fifty-first in a series of annual reports that describe groundwater conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing groundwater conditions.This report, like the others in the series, contains information on well construction, groundwater withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of groundwater. Supplementary data are included in reports of this series only for those years or areas that are important to a discussion of changing groundwater conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of groundwater development in the State for calendar year 2013. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is also available online at http://www.waterrights.utah.gov/techinfo/ and http://ut.water. usgs.gov/publications/GW2014.pdf. Groundwater conditions in Utah for calendar year 2012 are reported in Burden and others (2013) and are available online at http://ut.water.usgs. gov/publications/GW2013.pdf

Groundwater conditions in Utah, spring of 2012

Science.gov (United States)

Burden, Carole B.; Allen, David V.; Holt, Christopher M.; Fisher, Martel J.; Downhour, Paul; Smith, Lincoln; Eacret, Robert J.; Gibson, Travis L.; Slaugh, Bradley A.; Whittier, Nickolas R.; Howells, James H.; Christiansen, Howard K.

2012-01-01

This is the forty-ninth in a series of annual reports that describe groundwater conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing groundwater conditions. This report, like the others in the series, contains information on well construction, groundwater withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of groundwater. Supplementary data are included in reports of this series only for those years or areas that are important to a discussion of changing groundwater conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of groundwater development in the State for calendar year 2011. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is also available online at http:// www.waterrights.utah.gov/techinfo/ and http://ut.water.usgs. gov/publications/GW2012.pdf. Groundwater conditions in Utah for calendar year 2010 are reported in Burden and others (2011) and available online at http://ut.water.usgs.gov/ publications/GW2011.pdf.

Groundwater sampling in uranium reconnaissance

International Nuclear Information System (INIS)

Butz, T.R.

1977-03-01

The groundwater sampling program is based on the premise that ground water geochemistry reflects the chemical composition of, and geochemical processes active in the strata from which the sample is obtained. Pilot surveys have shown that wells are the best source of groundwater, although springs are sampled on occasion. The procedures followed in selecting a sampling site, the sampling itself, and the field measurements, as well as the site records made, are described

Groundwater-level trends and forecasts, and salinity trends, in the Azraq, Dead Sea, Hammad, Jordan Side Valleys, Yarmouk, and Zarqa groundwater basins, Jordan

Science.gov (United States)

Goode, Daniel J.; Senior, Lisa A.; Subah, Ali; Jaber, Ayman

2013-01-01

Changes in groundwater levels and salinity in six groundwater basins in Jordan were characterized by using linear trends fit to well-monitoring data collected from 1960 to early 2011. On the basis of data for 117 wells, groundwater levels in the six basins were declining, on average about -1 meter per year (m/yr), in 2010. The highest average rate of decline, -1.9 m/yr, occurred in the Jordan Side Valleys basin, and on average no decline occurred in the Hammad basin. The highest rate of decline for an individual well was -9 m/yr. Aquifer saturated thickness, a measure of water storage, was forecast for year 2030 by using linear extrapolation of the groundwater-level trend in 2010. From 30 to 40 percent of the saturated thickness, on average, was forecast to be depleted by 2030. Five percent of the wells evaluated were forecast to have zero saturated thickness by 2030. Electrical conductivity was used as a surrogate for salinity (total dissolved solids). Salinity trends in groundwater were much more variable and less linear than groundwater-level trends. The long-term linear salinity trend at most of the 205 wells evaluated was not increasing, although salinity trends are increasing in some areas. The salinity in about 58 percent of the wells in the Amman-Zarqa basin was substantially increasing, and the salinity in Hammad basin showed a long-term increasing trend. Salinity increases were not always observed in areas with groundwater-level declines. The highest rates of salinity increase were observed in regional discharge areas near groundwater pumping centers.

Spatially variable stage-driven groundwater-surface water interaction inferred from time-frequency analysis of distributed temperature sensing data

Science.gov (United States)

Mwakanyamale, Kisa; Slater, Lee; Day-Lewis, Frederick D.; Elwaseif, Mehrez; Johnson, Carole D.

2012-01-01

Characterization of groundwater-surface water exchange is essential for improving understanding of contaminant transport between aquifers and rivers. Fiber-optic distributed temperature sensing (FODTS) provides rich spatiotemporal datasets for quantitative and qualitative analysis of groundwater-surface water exchange. We demonstrate how time-frequency analysis of FODTS and synchronous river stage time series from the Columbia River adjacent to the Hanford 300-Area, Richland, Washington, provides spatial information on the strength of stage-driven exchange of uranium contaminated groundwater in response to subsurface heterogeneity. Although used in previous studies, the stage-temperature correlation coefficient proved an unreliable indicator of the stage-driven forcing on groundwater discharge in the presence of other factors influencing river water temperature. In contrast, S-transform analysis of the stage and FODTS data definitively identifies the spatial distribution of discharge zones and provided information on the dominant forcing periods (≥2 d) of the complex dam operations driving stage fluctuations and hence groundwater-surface water exchange at the 300-Area.

Ecology and living conditions of groundwater fauna

Energy Technology Data Exchange (ETDEWEB)

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

2008-09-15

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

Ecology and living conditions of groundwater fauna

International Nuclear Information System (INIS)

Thulin, Barbara; Hahn, Hans Juergen

2008-09-01

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

Comparison of CO₂ Detection Methods Tested in Shallow Groundwater Monitoring Wells at a Geological Sequestration Site

Energy Technology Data Exchange (ETDEWEB)

Edenborn, Harry M.; Jain, Jinesh N.

2016-05-17

The geological storage of anthropogenic carbon dioxide (CO₂) is one method of reducing the amount of CO₂ released into the atmosphere. Monitoring programs typically determine baseline conditions in surface and near-surface environments before, during, and after CO₂ injection to evaluate if impacts related to injection have occurred. Because CO₂ concentrations in groundwater fluctuate naturally due to complex geochemical and geomicrobiologicalinteractions, a clear understanding of the baseline behavior of CO₂ in groundwater near injection sites is important. Numerous ways of measuring aqueous CO₂ in the field and lab are currently used, but most methods have significant shortcomings (e.g., are tedious, lengthy, have interferences, or have significant lag time before a result is determined). In this study, we examined the effectiveness of two novel CO₂ detection methods and their ability to rapidly detect CO2in shallow groundwater monitoring wells associated with the Illinois Basin –Decatur Project geological sequestration site. The CarboQC beverage carbonation meter was used to measure the concentration of CO₂ in water by monitoring temperature and pressure changes and calculating the PCO₂ from the ideal gas law. Additionally, a non-dispersive infrared (NDIR) CO< sub>2sensor enclosed in a gas-permeable, water-impermeable membrane measured CO2by determining an equilibrium concentration. Results showed that the CarboQC method provided rapid (< 3 min) and repeatable results under field conditions within a measured concentration range of 15 –125 mg/L CO₂. The NDIR sensor results correlated well (r²= 0.93) with the CarboQC data, but CO₂ equilibration required at least 15 minutes, making the method somewhat less desirable under field conditions. In contrast, NDIR-based sensors have a greater potential for long-term deployment. Both

Groundwater quality monitoring well installation for Lower Waste Area Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

International Nuclear Information System (INIS)

Mortimore, J.A.; Lee, T.A.

1994-09-01

This report documents the drilling and installation of 11 groundwater quality monitoring (GQM) wells on the perimeter of Lower Waste Area Grouping (WAG) 2. Lower WAG 2 consists of White Oak Lake and the embayment below White Oak Dam above the Clinch River. The wells in Lower WAG 2 were drilled and developed between December 1989 and September 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The wells at Lower WAG 2 were drilled with auger or air rotary rigs. Depending on the hydrogeologic conditions present at each proposed well location, one of three basic installation methods was utilized. Detailed procedures for well construction were specified by the Engineering Division to ensure that the wells would provide water samples representative of the aquifer. To ensure conformance with the specifications, Energy Systems Construction Engineering and ERCE provided continuous oversight of field activities. The purpose of the well installation program was to install GQM wells for groundwater characterization at Lower WAG 2. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

Estimating nitrate concentrations in groundwater at selected wells and springs in the surficial aquifer system and Upper Floridan aquifer, Dougherty Plain and Marianna Lowlands, Georgia, Florida, and Alabama, 2002-50

Science.gov (United States)

Crandall, Christy A.; Katz, Brian G.; Berndt, Marian P.

2013-01-01

Groundwater from the surficial aquifer system and Upper Floridan aquifer in the Dougherty Plain and Marianna Lowlands in southwestern Georgia, northwestern Florida, and southeastern Alabama is affected by elevated nitrate concentrations as a result of the vulnerability of the aquifer, irrigation water-supply development, and intensive agricultural land use. The region relies primarily on groundwater from the Upper Floridan aquifer for drinking-water and irrigation supply. Elevated nitrate concentrations in drinking water are a concern because infants under 6 months of age who drink water containing nitrate concentrations above the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter as nitrogen can become seriously ill with blue baby syndrome. In response to concerns about water quality in domestic wells and in springs in the lower Apalachicola–Chattahoochee–Flint River Basin, the Florida Department of Environmental Protection funded a study in cooperation with the U.S. Geological Survey to examine water quality in groundwater and springs that provide base flow to the Chipola River. A three-dimensional, steady-state, regional-scale groundwater-flow model and two local-scale models were used in conjunction with particle tracking to identify travel times and areas contributing recharge to six groundwater sites—three long-term monitor wells (CP-18A, CP-21A, and RF-41) and three springs (Jackson Blue Spring, Baltzell Springs Group, and Sandbag Spring) in the lower Apalachicola–Chattahoochee–Flint River Basin. Estimated nitrate input to groundwater at land surface, based on previous studies of nitrogen fertilizer sales and atmospheric nitrate deposition data, were used in the advective transport models for the period 2002 to 2050. Nitrate concentrations in groundwater samples collected from the six sites during 1993 to 2007 and groundwater age tracer data were used to calibrate the transport aspect of the simulations

Brackish groundwater in the United States

Science.gov (United States)

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

2017-04-05

in the United States. Previously published digital data relating to brackish groundwater resources were limited to a small number of State- and regional-level studies. Data sources for this assessment ranged from single publications to large datasets and from local studies to national assessments. Geochemical data included concentrations of dissolved solids, major ions, trace elements, nutrients, and radionuclides as well as physical properties of the water (pH, temperature, and specific conductance). Additionally, the database provides selected well information (location, yield, depth, and contributing aquifer) necessary for evaluating the water resource.The assessment was divided into national-, regional-, and aquifer-scale analyses. National-scale analyses included evaluation of the three-dimensional distribution of observed dissolved-solids concentrations in groundwater, the three-dimensional probability of brackish groundwater occurrence, and the geochemical characteristics of saline (greater than or equal to 1,000 mg/L of dissolved solids) groundwater resources. Regional-scale analyses included a summary of the percentage of observed grid cell volume in the region that was occupied by brackish groundwater within the mixture of air, water, and rock for multiple depth intervals. Aquifer-scale analyses focused primarily on four regions that contained the largest amounts of observed brackish groundwater and included a generalized description of hydrogeologic characteristics from previously published work; the distribution of dissolved-solids concentrations; considerations for developing brackish groundwater resources, including a summary of other chemical characteristics that may limit the use of brackish groundwater and the ability of sampled wells producing brackish groundwater to yield useful amounts of water; and the amount of saline groundwater being used in 2010.

Skew-adjacency matrices of graphs

NARCIS (Netherlands)

Cavers, M.; Cioaba, S.M.; Fallat, S.; Gregory, D.A.; Haemers, W.H.; Kirkland, S.J.; McDonald, J.J.; Tsatsomeros, M.

2012-01-01

The spectra of the skew-adjacency matrices of a graph are considered as a possible way to distinguish adjacency cospectral graphs. This leads to the following topics: graphs whose skew-adjacency matrices are all cospectral; relations between the matchings polynomial of a graph and the characteristic

Radioactivity in the groundwater of a high background radiation area.

Science.gov (United States)

Shabana, E I; Kinsara, A A

2014-11-01

Natural radioactivity was measured in groundwater samples collected from 37 wells scattered in an inhabited area of high natural background radiation, in a purpose of radiation protection. The study area is adjacent to Aja heights of granitic composition in Hail province, Saudi Arabia. Initial screening for gross α and gross β activities showed levels exceeded the national regulation limits set out for gross α and gross β activities in drinking water. The gross α activity ranged from 0.17 to 5.41 Bq L(-)(1) with an average value of 2.15 Bq L(-)(1), whereas gross β activity ranged from 0.48 to 5.16 Bq L(-)(1), with an average value of 2.60 Bq L(-)(1). The detail analyses indicated that the groundwater of this province is contaminated with uranium and radium ((226)Ra and (228)Ra). The average activity concentrations of (238)U, (234)U, (226)Ra and (228)Ra were 0.40, 0.77, 0.29 and 0.46 Bq L(-)(1), respectively. The higher uranium content was found in the samples of granitic aquifers, whereas the higher radium content was found in the samples of sandstone aquifers. Based on the obtained results, mechanism of leaching of the predominant radionuclides has been discussed in detail. Copyright © 2014 Elsevier Ltd. All rights reserved.

Solute transport in a well under slow-purge and no-purge conditions

Science.gov (United States)

Plummer, M. A.; Britt, S. L.; Martin-Hayden, J. M.

2010-12-01

Non-purge sampling techniques, such as diffusion bags and in-situ sealed samplers, offer reliable and cost-effective groundwater monitoring methods that are a step closer to the goal of real-time monitoring without pumping or sample collection. Non-purge methods are, however, not yet completely accepted because questions remain about how solute concentrations in an unpurged well relate to concentrations in the adjacent formation. To answer questions about how undisturbed well water samples compare to formation concentrations, and to provide the information necessary to interpret results from non-purge monitoring systems, we have conducted a variety of physical experiments and numerical simulations of flow and transport in and through monitoring wells under low-flow and ambient flow conditions. Previous studies of flow and transport in wells used a Darcy’s law - based continuity equation for flow, which is often justified under the strong, forced-convection flow caused by pumping or large vertical hydraulic potential gradients. In our study, we focus on systems with weakly forced convection, where density-driven free convection may be of similar strength. We therefore solved Darcy’s law for porous media domains and the Navier Stokes equations for flow in the well, and coupled solution of the flow equations to that of solute transport. To illustrate expected in-well transport behavior under low-flow conditions, we present results of three particular studies: (1) time-dependent effluent concentrations from a well purged at low-flow pumping rates, (2) solute-driven density effects in a well under ambient horizontal flow and (3) temperature-driven mixing in a shallow well subject to seasonal temperature variations. Results of the first study illustrate that assumptions about the nature of in-well flow have a significant impact on effluent concentration curves even during pumping, with Poiseuille-type flow producing more rapid removal of concentration differences

Developing a methodology for identifying action zones to protect and manage groundwater well fields

Science.gov (United States)

Bellier, Sandra; Viennot, Pascal; Ledoux, Emmanuel; Schott, Celine

2013-04-01

Implementation of a long term action plan to manage and protect well fields is a complex and very expensive process. In this context, the relevance and efficiency of such action plans on water quality should be evaluated. The objective of this study is to set up a methodology to identify relevant actions zones in which environmental changes may significantly impact the quantity or quality of pumped water. In the Seine-et-Marne department (France), under French environmental laws three sectors integrating numerous well-field pumping in Champigny's limestone aquifer are considered as priority. This aquifer, located at south-east of Paris, supplies more than one million people with drinking water. Catchments areas of these abstractions are very large (2000 km2) and their intrinsic vulnerability was established by a simple parametric approach that does not permit to consider the complexity of hydrosystem. Consequently, a methodology based on a distributed modeling of the process of the aquifer was developed. The basin is modeled using the hydrogeological model MODCOU, developed in MINES ParisTech since the 1980s. It simulates surface and groundwater flow in aquifer systems and allows to represent the local characteristics of the hydrosystem (aquifers communicating by leakage, rivers infiltration, supply from sinkholes and locally perched or dewatering aquifers). The model was calibrated by matching simulated river discharge hydrographs and piezometric heads with observed ones since the 1970s. Thanks to this modelling tool, a methodology based on the transfer of a theoretical tracer through the hydrosystem from the ground surface to the outlets was implemented to evaluate the spatial distribution of the contribution areas at contrasted, wet or dry recharge periods. The results show that the surface of areas contributing to supply most catchments is lower than 300 km2 and the major contributory zones are located along rivers. This finding illustrates the importance of

Composition of Groundwater Bacterial Communities before and after Air Surging in a Groundwater Heat Pump System According to a Pyrosequencing Assay

Directory of Open Access Journals (Sweden)

Heejung Kim

2017-11-01

Full Text Available The geothermal energy of groundwater has aroused increasing interest as a solution to climate change. The groundwater heat pumps (GWHP system using groundwater is the most environmentally friendly system to date and has been examined in several studies. However, biological clogging by microorganisms negatively affects the thermal efficiency of the GWHP system. In this study, we employed air surging, the most popular among well management methods, and pyrosequencing to analyze the genetic diversity in bacteria before and after air surging in a geothermal well. Furthermore, the diversity of dominant bacterial genera and those related to clogging were evaluated. The bacterial diversity of the groundwater well increased after air surging. Nevertheless, the proportion of bacterial genera thought to be related to microbiological clogging decreased. In cooling and heating systems based on the geothermal energy of groundwater, the wells should be maintained regularly by air surging to reduce efficiency problems caused by microbiological clogging and to prevent secondary damage to human health, e.g., pneumonia due to human pathogenic bacteria including Pseudomonas aeruginosa and Acinetobacter.

Numerical modelling of groundwater flow to understand the impacts of pumping on arsenic migration in the aquifer of North Bengal Plain

Science.gov (United States)

Sikdar, P. K.; Chakraborty, Surajit

2017-03-01

In this paper, numerical simulations of regional-scale groundwater flow of North Bengal Plain have been carried out with special emphasis on the arsenic (As)-rich alluvium filled gap between the Rajmahal hills on the west and the Garo hills on the east. The proposed concern of this modelling arose from development that has led to large water table declines in the urban area of English Bazar block, Malda district, West Bengal and possible transport of As in the near future from the adjacent As-polluted aquifer. Groundwater occurs under unconfined condition in a thick zone of saturation within the Quaternary alluvial sediments. Modelling indicates that current pumping has significantly changed the groundwater flowpaths from pre-development condition. At the present pumping rate, the pumping wells of the urban area may remain uncontaminated till the next 25 yrs, considering only pure advection of water but some water from the As-polluted zone may enter wells by 50 yrs. But geochemical and other processes such as adsorption, precipitation, redox reaction and microbial activity may significantly retard the predicted rate by advective transport. In the rural areas, majority of the water pumped from the aquifer is for irrigation, which is continuously re-applied on the surface. The near-vertical nature of the flowpaths indicates that, where As is present or released at shallow depths, it will continue to occur in pumping wells. Modelling also indicates that placing all the pumping wells at depths below 100 m may not provide As-free water permanently.

Isotopic Survey of Lake Davis and the Local Groundwater

Energy Technology Data Exchange (ETDEWEB)

Ridley, M N; Moran, J E; Singleton, M J

2007-08-21

In September 2007, California Fish and Game (CAFG) plans to eradicate the northern pike from Lake Davis. As a result of the eradication treatment, local residents have concerns that the treatment might impact the local groundwater quality. To address the concerns of the residents, Lawrence Livermore National Laboratory (LLNL) recommended measuring the naturally occurring stable oxygen isotopes in local groundwater wells, Lake Davis, and the Lake Davis tributaries. The purpose of these measurements is to determine if the source of the local groundwater is either rain/snowmelt, Lake Davis/Big Grizzly Creek water or a mixture of Lake Davis/Big Grizzly Creek and rain/snowmelt. As a result of natural evaporation, Lake Davis and the water flowing into Big Grizzly Creek are naturally enriched in {sup 18}oxygen ({sup 18}O), and if a source of a well's water is Lake Davis or Big Grizzly Creek, the well water will contain a much higher concentration of {sup 18}O. This survey will allow for the identification of groundwater wells whose water source is Lake Davis or Big Grizzly Creek. The results of this survey will be useful in the development of a water-quality monitoring program for the upcoming Lake Davis treatment. LLNL analyzed 167 groundwater wells (Table 1), 12 monthly samples from Lake Davis (Table 2), 3 samples from Lake Davis tributaries (Table 2), and 8 Big Grizzly Creek samples (Table 2). Of the 167 groundwater wells sampled and analyzed, only 2 wells contained a significant component of evaporated water, with an isotope composition similar to Lake Davis water. The other 163 groundwater wells have isotope compositions which indicate that their water source is rain/snowmelt.

1997 Comprehensive TNX Area Annual Groundwater and Effectiveness Monitoring Report

International Nuclear Information System (INIS)

Chase, J.

1998-04-01

Shallow groundwater beneath the TNX Area at the Savannah River Site (SRS) has been contaminated with chlorinated volatile organic compounds (CVOCs) such as trichloroethylene (TCE) and carbon tetrachloride. In November 1994, an Interim Record of Decision (IROD) was agreed to and signed by the U. S. Department of Energy (DOE), the Environmental Protection Agency (EPA), and the South Carolina Department of Health ampersand Environmental Control (SCDHEC). The Interim Record of Decision requires the installation of a hybrid groundwater corrective action (HGCA) to stabilize the plume of groundwater contamination and remove CVOCs dissolved in the groundwater. The hybrid groundwater corrective action included a recovery well network, purge water management facility, air stripper, and an airlift recirculation well. The recirculation well was dropped pursuant to a test that indicated it to be ineffective at the TNX Area. Consequently, the groundwater corrective action was changed from a hybrid to a single action, pump-and-treat approach. The Interim Action (IA) T-1 air stripper system began operation on September 16, 1996. a comprehensive groundwater monitoring program was initiated to measure the effectiveness of the system. As of December 31, 1997, the system has treated 32 million gallons of contaminated groundwater removed 32 pounds of TCE. The recovery well network created a 'capture zone' that stabilized the plume of contaminated groundwater

1997 Comprehensive TNX Area Annual Groundwater and Effectiveness Monitoring Report

Energy Technology Data Exchange (ETDEWEB)

Chase, J.

1998-04-01

Shallow groundwater beneath the TNX Area at the Savannah River Site (SRS) has been contaminated with chlorinated volatile organic compounds (CVOCs) such as trichloroethylene (TCE) and carbon tetrachloride. In November 1994, an Interim Record of Decision (IROD) was agreed to and signed by the U. S. Department of Energy (DOE), the Environmental Protection Agency (EPA), and the South Carolina Department of Health {ampersand} Environmental Control (SCDHEC). The Interim Record of Decision requires the installation of a hybrid groundwater corrective action (HGCA) to stabilize the plume of groundwater contamination and remove CVOCs dissolved in the groundwater. The hybrid groundwater corrective action included a recovery well network, purge water management facility, air stripper, and an airlift recirculation well. The recirculation well was dropped pursuant to a test that indicated it to be ineffective at the TNX Area. Consequently, the groundwater corrective action was changed from a hybrid to a single action, pump-and-treat approach. The Interim Action (IA) T-1 air stripper system began operation on September 16, 1996. a comprehensive groundwater monitoring program was initiated to measure the effectiveness of the system. As of December 31, 1997, the system has treated 32 million gallons of contaminated groundwater removed 32 pounds of TCE. The recovery well network created a `capture zone` that stabilized the plume of contaminated groundwater.

Effects of changes in pumping on regional groundwater-flow paths, 2005 and 2010, and areas contributing recharge to discharging wells, 1990–2010, in the vicinity of North Penn Area 7 Superfund site, Montgomery County, Pennsylvania

Science.gov (United States)

Senior, Lisa A.; Goode, Daniel J.

2017-06-06

A previously developed regional groundwater flow model was used to simulate the effects of changes in pumping rates on groundwater-flow paths and extent of recharge discharging to wells for a contaminated fractured bedrock aquifer in southeastern Pennsylvania. Groundwater in the vicinity of the North Penn Area 7 Superfund site, Montgomery County, Pennsylvania, was found to be contaminated with organic compounds, such as trichloroethylene (TCE), in 1979. At the time contamination was discovered, groundwater from the underlying fractured bedrock (shale) aquifer was the main source of supply for public drinking water and industrial use. As part of technical support to the U.S. Environmental Protection Agency (EPA) during the Remedial Investigation of the North Penn Area 7 Superfund site from 2000 to 2005, the U.S. Geological Survey (USGS) developed a model of regional groundwater flow to describe changes in groundwater flow and contaminant directions as a result of changes in pumping. Subsequently, large decreases in TCE concentrations (as much as 400 micrograms per liter) were measured in groundwater samples collected by the EPA from selected wells in 2010 compared to 2005‒06 concentrations.To provide insight on the fate of potentially contaminated groundwater during the period of generally decreasing pumping rates from 1990 to 2010, steady-state simulations were run using the previously developed groundwater-flow model for two conditions prior to extensive remediation, 1990 and 2000, two conditions subsequent to some remediation 2005 and 2010, and a No Pumping case, representing pre-development or cessation of pumping conditions. The model was used to (1) quantify the amount of recharge, including potentially contaminated recharge from sources near the land surface, that discharged to wells or streams and (2) delineate the areas contributing recharge that discharged to wells or streams for the five conditions.In all simulations, groundwater divides differed from

Groundwater monitoring procedures and evaluation at Nabarlek, N.T

International Nuclear Information System (INIS)

Grounds, J.A.

1983-01-01

Queensland Mines Limited operates a uranium extraction plant at Nabarlek in the Northern Territory. All water used for the ore processing, sewage waters, or waters generated from runoff in the restricted release zone are contained within water storage structures. Water can only be removed from these structures by evaporation and seepage. The monitoring of the groundwater flow systems adjacent to the plant water management structures is carried out on a regular basis to determine what effects seepage will have both within the operational life of the mine and after mining and rehabilitation have ceased

Concentration and size distribution of particles in abstracted groundwater.

Science.gov (United States)

van Beek, C G E M; de Zwart, A H; Balemans, M; Kooiman, J W; van Rosmalen, C; Timmer, H; Vandersluys, J; Stuyfzand, P J

2010-02-01

Particle number concentrations have been counted and particle size distributions calculated in groundwater derived by abstraction wells. Both concentration and size distribution are governed by the discharge rate: the higher this rate the higher the concentration and the higher the proportion of larger particles. However, the particle concentration in groundwater derived from abstraction wells, with high groundwater flow velocities, is much lower than in groundwater from monitor wells, with minimal flow velocities. This inconsistency points to exhaustion of the particle supply in the aquifer around wells due to groundwater abstraction for many years. The particle size distribution can be described with the help of a power law or Pareto distribution. Comparing the measured particle size distribution with the Pareto distribution shows that particles with a diameter >7 microm are under-represented. As the particle size distribution is dependent on the flow velocity, so is the value of the "Pareto" slope beta. (c) 2009 Elsevier Ltd. All rights reserved.

Hanford wells

International Nuclear Information System (INIS)

Chamness, M.A.; Merz, J.K.

1993-08-01

Records describing wells located on or near the Hanford Site have been maintained by Pacific Northwest Laboratory and the operating contractor, Westinghouse Hanford Company. In support of the Ground-Water Surveillance Project, portions of the data contained in these records have been compiled into the following report, which is intended to be used by those needing a condensed, tabular summary of well location and basic construction information. The wells listed in this report were constructed over a period of time spanning almost 70 years. Data included in this report were retrieved from the Hanford Envirorunental Information System (HEIS) database and supplemented with information not yet entered into HEIS. While considerable effort has been made to obtain the most accurate and complete tabulations possible of the Hanford Site wells, omissions and errors may exist. This document does not include data on lithologic logs, ground-water analyses, or specific well completion details

Biogeochemical transport in the Loxahatchee River estuary, FL: The role of submarine groundwater discharge

Science.gov (United States)

Swarzenski, P.; Orem, B.; McPherson, B.; Baskaran, M.; Wan, Y.

2005-05-01

The distributions of dissolved organic carbon (DOC), silica, select trace elements (Mn, Fe, Ba, Sr, Co, V,) and a suite of naturally-occurring radionuclides in the U/Th decay series (222Rn, 223,224,226,228Ra, 238U) were studied during high and low discharge conditions in the Loxahatchee River estuary, Florida. The zero-salinity endmember of this still relatively pristine estuary may reflect not only river-borne constituents, but also those advected during active groundwater/surface-water discharge. During low discharge conditions, with the notable exception of Co, trace metals indicate nearly conservative mixing from a salinity of ~12 through the estuary (This statement contracdicts with what is said in p. 7). In contrast, of the trace metals studied, only Sr, Fe, U and V exhibited conservative estuarine mixing during high discharge. Dissolved organic carbon and Si concentrations were highest at zero salinities, and generally decreased with an increase in salinity during both discharge regimes, indicating removal of land-derived dissolved organic matter and silica in the estuary. Suspended particulate matter (SPM) concentrations were generally lowest ( 28 dpm L-1) at the freshwater endmember of the estuary, and appear to identify regions of the river most influenced by active submarine groundwater discharge (where is the data that show this?). Activities of four naturally-occurring isotopes of Ra (223,224,226,228Ra) in this estuary and select adjacent shallow groundwater wells indicate mean estuarine water mass residence times of less than 1 day; values in close agreement to those calculated by tidal prism and tidal period. A radium-based model for estimating submarine groundwater discharge to the Loxahatchee River estuary yielded an average of 1.03 V 3.84 x 105 m3 day-1, depending on river discharge stage as well as slight variations in the particular Ra models used. Such calculated flux estimates are in close agreement with results obtained from a 2-day

The transport of antibiotic resistance genes and residues in groundwater near swine production facilities

Science.gov (United States)

Lin, Y. F.; Yannarell, A. C.; Mackie, R. I.; Krapac, I. G.; Chee-Sanford, J. S.; Koike, S.

2008-12-01

The use of antibiotics at concentrated animal feeding operations (CAFOs) for disease prevention, disease treatment, and growth promotion can contribute to the spread of antibiotic compounds, their breakdown products, and antibiotic resistant bacteria and/or the genes that confer resistance. In addition, constitutive use of antibiotics at sub-therapeutic levels can select for antibiotic resistance among the bacteria that inhabit animal intestinal tracts, onsite manure treatment facilities, and any environments receiving significant inputs of manure (e.g. through waste lagoon leakage or fertilizer amendments to farm soils). If the antibiotic resistant organisms persist in these new environments, or if they participate in genetic exchanges with the native microflora, then CAFOs may constitute a significant reservoir for the spread of antibiotic resistance to the environment at large. Our results have demonstrated that leakage from waste treatment lagoons can influence the presence and persistence of tetracycline resistance genes in the shallow aquifer adjacent to swine CAFOs, and molecular phylogeny allowed us to distinguish "native" tetracycline resistance genes in control groundwater wells from manure-associated genes introduced from the lagoon. We have also been able to detect the presence of erythromycin resistance genes in CAFO surface and groundwater even though erythromycin is strictly reserved for use in humans and thus is not utilized at any of these sites. Ongoing research, including modeling of particle transport in groundwater, will help to determine the potential spatial and temporal extent of CAFO-derived antibiotic resistance.

Groundwater environmental capacity and its evaluation index.

Science.gov (United States)

Xing, Li Ting; Wu, Qiang; Ye, Chun He; Ye, Nan

2010-10-01

To date, no unified and acknowledged definition or well-developed evaluation index system of groundwater environment capacity can be found in the academia at home or abroad. The article explores the meaning of water environment capacity, and analyzes the environmental effects caused by the exploitation of groundwater resources. This research defines groundwater environmental capacity as a critical value in terms of time and space, according to which the groundwater system responds to the external influences within certain goal constraint. On the basis of observing the principles of being scientific, dominant, measurable, and applicable, six level 1 evaluation indexes and 11 constraint factors are established. Taking Jinan spring region for a case study, this research will adopt groundwater level and spring flow as constraint factors, and the allowable groundwater yield as the critical value of groundwater environmental capacity, prove the dynamic changeability and its indicating function of groundwater environmental capacity through calculation, and finally point out the development trends of researches on groundwater environmental capacity.

Characterization of shallow groundwater at TNX

International Nuclear Information System (INIS)

Nichols, R.L.

1993-01-01

The Savannah River Site (SRS), located on 300 square miles along the Savannah River near Aiken, South Carolina, is owned by the Department of Energy and operated by Westinghouse Savannah River Company. The site''s mission is to support the national security through the production of nuclear weapons material. With the recent reduction of the nation''s nuclear stockpile and the stronger focus on the cleanup of sites where nuclear operations activities have left behind soil and groundwater contamination, identifying and remediating all inactive wastes has become a primary goal.The TNX Area is located adjacent to the Savannah River in the western portion of SRS (Figure 1). The area is a pilot-scale test facility for the Savannah River Technology Center. Pilot-scale testing and evaluation of chemical processes at TNX have included support of the Defense Waste Processing Facility (DWPF), Separations Area, and fuel and target manufacturing areas. Wastewater generated during tests was discharged to unlined basins through a network of underground process sewers.A discussion of waste disposal activities for the TNX Area is included in this report to identify the major sources of contaminants that have impacted the groundwater

Soil and groundwater remediation using dual-phase extraction technology

International Nuclear Information System (INIS)

Miller, A.W.; Gan, D.R.

1995-01-01

A gasoline underground storage tank (UST) was formerly used to fuel vehicles for a hospital in Madison, Wisconsin. Elevated concentrations of gasoline range organics (GRO) were observed in soils and groundwater at the site during the tank removal and a subsequent site investigation. Based on the extent of soil and groundwater contamination, a dual-phase extraction technology was selected as the most cost effective alternative to remediate the site. The dual-phase extraction system includes one extraction well functioning both as a soil vapor extraction (SVE) and groundwater recovery well. After six months of operation, samples collected from the groundwater monitoring wells indicated that the groundwater has been cleaned up to levels below the Wisconsin preventative action limits. The dual-phase extraction system effectively remediated the site in a short period of time, saving both operation and maintenance costs and overall project cost

Hoe Creek groundwater restoration, 1989

Energy Technology Data Exchange (ETDEWEB)

Renk, R.R.; Crader, S.E.; Lindblom, S.R.; Covell, J.R.

1990-01-01

During the summer of 1989, approximately 6.5 million gallons of contaminated groundwater were pumped from 23 wells at the Hoe Creek underground coal gasification site, near Gillette, Wyoming. The organic contaminants were removed using activated carbon before the water was sprayed on 15.4 acres at the sites. Approximately 2647 g (5.8 lb) of phenols and 10,714 g (23.6 lb) of benzene were removed from the site aquifers. Phenols, benzene, toluene, ethylbenzene, and naphthalene concentrations were measured in 43 wells. Benzene is the only contaminant at the site exceeds the federal standard for drinking water (5 {mu}g/L). Benzene leaches into the groundwater and is slow to biologically degrade; therefore, the benzene concentration has remained high in the groundwater at the site. The pumping operation affected groundwater elevations across the entire 80-acre site. The water levels rebounded quickly when the pumping operation was stopped on October 1, 1989. Removing contaminated groundwater by pumping is not an effective way to clean up the site because the continuous release of benzene from coal tars is slow. Benzene will continue to leach of the tars for a long time unless its source is removed or the leaching rate retarded through mitigation techniques. The application of the treated groundwater to the surface stimulated plant growth. No adverse effects were noted or recorded from some 60 soil samples taken from twenty locations in the spray field area. 20 refs., 52 figs., 8 tabs.

Radionuclides in shallow groundwater at Solid Waste Storage Area 5 North, Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Ashwood, T.L.; Marsh, J.D. Jr.

1994-04-01

This report presents a compilation of groundwater monitoring data from Solid Waste Storage Area (SWSA) 5 North at Oak Ridge National Laboratory (ORNL) between November 1989 and September 1993. Monitoring data were collected as part of the Active Sites Environmental Monitoring Program that was implemented in 1989 in response to DOE Order 5820.2A. SWSA 5 North was established for the retrievable storage of transuranic (TRU) wastes in 1970. Four types of storage have been used within SWSA 5 North: bunkers, vaults, wells, and trenches. The fenced portion of SWSA 5 North covers about 3.7 ha (9 acres) in the White Oak Creek watershed south of ORNL. The area is bounded by White Oak Creek and two ephemeral tributaries of White Oak Creek. Since 1989, groundwater has been monitored in wells around SWSA 5 North. During that time, elevated gross alpha contamination (reaching as high as 210 Bq/L) has consistently been detected in well 516. This well is adjacent to burial trenches in the southwest corner of the area. Water level measurements in wells 516 and 518 suggest that water periodically inundates the bottom of some of those trenches. Virtually all of the gross alpha contamination is generated by Curium 244 and Americium 241. A special geochemical investigation of well 516 suggests that nearly all of the Curium 44 and Americium 241 is dissolved or associated with dissolved organic matter. These are being transported at the rate of about 2 m/year from the burial trenches, through well 516, to White Oak Creek, where Curium 244 has been detected in a few bank seeps. Concentrations at these seeps are near detection levels (<1 Bq/L)

Radionuclides in shallow groundwater at Solid Waste Storage Area 5 North, Oak Ridge National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Ashwood, T.L.; Marsh, J.D. Jr.

1994-04-01

This report presents a compilation of groundwater monitoring data from Solid Waste Storage Area (SWSA) 5 North at Oak Ridge National Laboratory (ORNL) between November 1989 and September 1993. Monitoring data were collected as part of the Active Sites Environmental Monitoring Program that was implemented in 1989 in response to DOE Order 5820.2A. SWSA 5 North was established for the retrievable storage of transuranic (TRU) wastes in 1970. Four types of storage have been used within SWSA 5 North: bunkers, vaults, wells, and trenches. The fenced portion of SWSA 5 North covers about 3.7 ha (9 acres) in the White Oak Creek watershed south of ORNL. The area is bounded by White Oak Creek and two ephemeral tributaries of White Oak Creek. Since 1989, groundwater has been monitored in wells around SWSA 5 North. During that time, elevated gross alpha contamination (reaching as high as 210 Bq/L) has consistently been detected in well 516. This well is adjacent to burial trenches in the southwest corner of the area. Water level measurements in wells 516 and 518 suggest that water periodically inundates the bottom of some of those trenches. Virtually all of the gross alpha contamination is generated by Curium 244 and Americium 241. A special geochemical investigation of well 516 suggests that nearly all of the Curium 44 and Americium 241 is dissolved or associated with dissolved organic matter. These are being transported at the rate of about 2 m/year from the burial trenches, through well 516, to White Oak Creek, where Curium 244 has been detected in a few bank seeps. Concentrations at these seeps are near detection levels (<1 Bq/L).

2013 Survey of Iowa groundwater and evaluation of public well vulnerability classifications for contaminants of emerging concern

Science.gov (United States)

Hruby, Claire E.; Libra, Robert D.; Fields, Chad L.; Kolpin, Dana W.; Hubbard, Laura E.; Borchardt, Mark R.; Spencer, Susan K.; Wichman, Michael D.; Hall, Nancy; Schueller, Michael D.; Furlong, Edward T.; Weyer, Peter J.

2015-01-01

Studies in Iowa have long documented the vulnerability of wells with less than 50 feet (15 meters) of confining materials above the source aquifer to contamination from nitrate and various pesticides. Recent studies in Wisconsin have documented the occurrence of viruses in untreated groundwater, even in wells considered to have little vulnerability to contamination from near-surface activities. In addition, sensitive methods have become available for analyses of pharmaceuticals and pesticides. This study represents the first comprehensive examination of contaminants of emerging concern in Iowa’s groundwater conducted to date, and one of the first conducted in the United States. Raw groundwater samples were collected from 66 public supply wells during the spring of 2013, when the state was recovering from drought conditions. Samples were analyzed for 206 chemical and biological parameters; including 20 general water-quality parameters and major ions, 19 metals, 5 nutrients, 10 virus groups, 3 species of pathogenic bacteria, 5 microbial indicators, 108 pharmaceuticals, 35 pesticides and pesticide degradates, and tritium. The wells chosen for this study represent a diverse range of ages, depths, confining material thicknesses, pumping rates, and land use settings. The most commonly detected contaminant group was pesticide compounds, which were present in 41% of the samples. As many as 6 pesticide compounds were found together in a sample, most of which were chloroacetanilide degradates. While none of the measured concentrations of pesticide compounds exceeded current benchmark levels, several of these compounds are listed on the U.S. Environmental Protection Agency’s Contaminant Candidate List and could be subject to drinking water standards in the future. Despite heavy use in the past decade, glyphosate was not detected, and its metabolite, aminomethylphosphonic acid, was only detected in two of 60 wells tested (3%) at the detection limit of 0.02 �

Y-12 Groundwater Protection Program Groundwater Monitoring Data Compendium, Revision 1

Energy Technology Data Exchange (ETDEWEB)

None

2006-12-01

This document is a compendium of water quality and hydrologic characterization data obtained through December 2005 from the network of groundwater monitoring wells and surface water sampling stations (including springs and building sumps) at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee that have been sampled since January 2003. The primary objectives of this document, hereafter referenced as the Y-12 Groundwater Protection Program (GWPP) Compendium, are to: (1) Serve as a single-source reference for monitoring data that meet the requirements of the Y-12 GWPP, as defined in the Y-12 GWPP Management Plan (BWXT Y-12 L.L.C. [BWXT] 2004); (2) Maintain a detailed analysis and evaluation of the monitoring data for each applicable well, spring, and surface water sampling station, with a focus on results for the primary inorganic, organic, and radiological contaminants in groundwater and surface water at Y-12; and (3) Ensure retention of ''institutional knowledge'' obtained over the long-term (>20-year) history of groundwater and surface water monitoring at Y-12 and the related sources of groundwater and surface water contamination. To achieve these goals, the Y-12 GWPP Compendium brings together salient hydrologic, geologic, geochemical, water-quality, and environmental compliance information that is otherwise disseminated throughout numerous technical documents and reports prepared in support of completed and ongoing environmental contamination assessment, remediation, and monitoring activities performed at Y-12. The following subsections provide background information regarding the overall scope and format of the Y-12 GWPP Compendium and the planned approach for distribution and revision (i.e., administration) of this ''living'' document.

Practical problems of groundwater model ages for groundwater protection studies

International Nuclear Information System (INIS)

Matthess, G.; Muennich, K.O.; Sonntag, C.

1976-01-01

Water authorities in the Federal Republic of Germany have established a system of protection zones for the protection of groundwater supplies from pollution. One zone (Zone II) is defined by an outer boundary from which the groundwater needs 50 days to flow to the well. 50 days is the period accepted for the elimination of pathogenic germs. However, within Zone II carbon-14 measurements of water may give model ages of several thousand years, which may lead to some confusion in the legal and practical aspects of this scheme. These model ages may result from uncertainties in the chemical model, or from mixing of waters of different ages, either within the aquifer or during extraction at the well. The paper discusses scientific aspects of the establishment of protection zones. Two processes affecting the model age determinations are examined in detail. First, the mechanism of diffusion transport downwards through porous, but impermeable, aquicludes is examined for stable trace substances and radioactive isotopes. Secondly, examples are given of model ages resulting from mixtures of new and old waters. It is recommended that such model ages should not be reported as 'ages' since they may be misinterpreted in groundwater protection applications. (author)

Investigating Groundwater Depletion and Aquifer Degradation in Central Valley California from Space

Science.gov (United States)

Ojha, C.; Shirzaei, M.; Werth, S.; Argus, D. F.

2017-12-01

The Central Valley in California includes one of the world's largest and yet most stressed aquifer systems. The large demand for groundwater, accelerated by population growth and extreme droughts, has been depleting the region's groundwater resources for decades. However, the lack of dense monitoring networks and inaccurate information on geophysical aquifer response pose serious challenges to water management efforts in the area and put the groundwater at high risk. Here, we performed a joint analysis of large SAR interferometric data sets acquired by ALOS L-band satellite in conjunction with the groundwater level observations across the Central Valley. We used 420 L-band SAR images acquired on the ascending orbit track during period Dec 24, 2006 - Jan 1, 2010, and generated more than 1600 interferograms with a pixel size of 100 m × 100 m. We also use data from 1600 observational wells providing continuous measurements of groundwater level within the study period for our analysis. We find that in the south and near Tulare Lake, north of Tule and south of Kaweah basin in San Joaquin valley, the subsidence rate is greatest at up to 20-25 cm/yr, while in Sacramento Valley the subsidence rate is lower at 1-3 cm/yr. From the characterization of the elastic and inelastic storage coefficients, we find that Kern, Tule, Tulare, Kaweah and Merced basins in the San Joaquin Valley are more susceptible to permanent compaction and aquifer storage loss. Kern County shows 0.23%-1.8% of aquifer storage loss during the study period, and has higher percentage loss than adjacent basins such as Tule and Tulare Lake with 0.15%-1.2% and 0.2 %-1.5% loss, respectively. Overall, we estimate that the aquifers across the valley lost a total of 28 km3 of groundwater and 2% of their storage capacity during the study period. Our unique observational evidence including valley-wide estimate of mechanical properties of aquifers and model results will not only facilitate monitoring water deficits

Geoelectrical mapping and groundwater contamination

Science.gov (United States)

Blum, Rainer

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

Water budgets and groundwater volumes for abandoned underground mines in the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania-Preliminary estimates with identification of data needs

Science.gov (United States)

Goode, Daniel J.; Cravotta,, Charles A.; Hornberger, Roger J.; Hewitt, Michael A.; Hughes, Robert E.; Koury, Daniel J.; Eicholtz, Lee W.

2011-01-01

levels and stream base flow, the latter at many locations composed primarily of discharge from mines. Automatic parameter estimation used MODFLOW-2000 with manual adjustments to constrain parameter values to realistic ranges. The calibrated model supports the conceptual model of high-permeability MCUs separated by low-permeability barriers and streamflow losses and gains associated with mine infiltration and discharge. The simulated groundwater levels illustrate low groundwater gradients within an MCU and abrupt changes in water levels between MCUs. The preliminary model results indicate that the primary result of increased pumping from the mine would be reduced discharge from the mine to streams near the pumping wells. The intact barriers limit the spatial extent of mine dewatering. Considering the simulated groundwater levels, depth of mining, and assumed bulk porosity of 11 or 40 percent for the mined seams, the water volume in storage in the mines of the Western Middle Anthracite Coalfield was estimated to range from 60 to 220 billion gallons, respectively. Details of the groundwater-level distribution and the rates of some mine discharges are not simulated well using the preliminary model. Use of the model results should be limited to evaluation of the conceptual model and its simulation using porous-media flow methods, overall water budgets for the Western Middle Anthracite Coalfield, and approximate storage volumes. Model results should not be considered accurate for detailed simulation of flow within a single MCU or individual flooded mine. Although improvements in the model calibration were possible by introducing spatial variability in permeability parameters and adjusting barrier properties, more detailed parameterizations have increased uncertainty because of the limited data set. The preliminary identification of data needs includes continuous streamflow, mine discharge rate, and groundwater levels in the mines and adjacent areas. Data collected whe

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

Science.gov (United States)

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

2014-01-01

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

Characteristics and factors of groundwater contamination in Asian coastal megacities

Science.gov (United States)

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

2017-12-01

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

Understanding similarity of groundwater systems with empirical copulas

Science.gov (United States)

Haaf, Ezra; Kumar, Rohini; Samaniego, Luis; Barthel, Roland

2016-04-01

Within the classification framework for groundwater systems that aims for identifying similarity of hydrogeological systems and transferring information from a well-observed to an ungauged system (Haaf and Barthel, 2015; Haaf and Barthel, 2016), we propose a copula-based method for describing groundwater-systems similarity. Copulas are an emerging method in hydrological sciences that make it possible to model the dependence structure of two groundwater level time series, independently of the effects of their marginal distributions. This study is based on Samaniego et al. (2010), which described an approach calculating dissimilarity measures from bivariate empirical copula densities of streamflow time series. Subsequently, streamflow is predicted in ungauged basins by transferring properties from similar catchments. The proposed approach is innovative because copula-based similarity has not yet been applied to groundwater systems. Here we estimate the pairwise dependence structure of 600 wells in Southern Germany using 10 years of weekly groundwater level observations. Based on these empirical copulas, dissimilarity measures are estimated, such as the copula's lower- and upper corner cumulated probability, copula-based Spearman's rank correlation - as proposed by Samaniego et al. (2010). For the characterization of groundwater systems, copula-based metrics are compared with dissimilarities obtained from precipitation signals corresponding to the presumed area of influence of each groundwater well. This promising approach provides a new tool for advancing similarity-based classification of groundwater system dynamics. Haaf, E., Barthel, R., 2015. Methods for assessing hydrogeological similarity and for classification of groundwater systems on the regional scale, EGU General Assembly 2015, Vienna, Austria. Haaf, E., Barthel, R., 2016. An approach for classification of hydrogeological systems at the regional scale based on groundwater hydrographs EGU General Assembly

Interpretation of stable isotope, denitrification, and groundwater age data for samples collected from Sandia National Laboratories /New Mexico (SNL/NM) Burn Site Groundwater Area of Concern

Energy Technology Data Exchange (ETDEWEB)

Madrid, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Singleton, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Visser, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Esser, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-06-02

This report combines and summarizes results for two groundwater-sampling events (October 2012 and October/November 2015) from the Sandia National Laboratories/New Mexico (SNL/NM) Burn Site Groundwater (BSG) Area of Concern (AOC) located in the Lurance Canyon Arroyo southeast of Albuquerque, NM in the Manzanita Mountains. The first phase of groundwater sampling occurred in October 2012 including samples from 19 wells at three separate sites that were analyzed by the Environmental Radiochemistry Laboratory at Lawrence Livermore National Laboratory as part of a nitrate Monitored Natural Attenuation (MNA) evaluation. The three sites (BSG, Technical Area-V, and Tijeras Arroyo) are shown on the regional hydrogeologic map and described in the Sandia Annual Groundwater Monitoring Report. The first phase of groundwater sampling included six monitoring wells at the Burn Site, eight monitoring wells at Technical Area-V, and five monitoring wells at Tijeras Arroyo. Each groundwater sample was analyzed using the two specialized analytical methods, age-dating and denitrification suites. In September 2015, a second phase of groundwater sampling took place at the Burn Site including 10 wells sampled and analyzed by the same two analytical suites. Five of the six wells sampled in 2012 were resampled in 2015. This report summarizes results from two sampling events in order to evaluate evidence for in situ denitrification, the average age of the groundwater, and the extent of recent recharge of the bedrock fracture system beneath the BSG AOC.

Interpretation of stable isotope, denitrification, and groundwater age data for samples collected from Sandia National Laboratories /New Mexico (SNL/NM) Burn Site Groundwater Area of Concern

International Nuclear Information System (INIS)

Madrid, V.; Singleton, M. J.; Visser, A.; Esser, B.

2016-01-01

This report combines and summarizes results for two groundwater-sampling events (October 2012 and October/November 2015) from the Sandia National Laboratories/New Mexico (SNL/NM) Burn Site Groundwater (BSG) Area of Concern (AOC) located in the Lurance Canyon Arroyo southeast of Albuquerque, NM in the Manzanita Mountains. The first phase of groundwater sampling occurred in October 2012 including samples from 19 wells at three separate sites that were analyzed by the Environmental Radiochemistry Laboratory at Lawrence Livermore National Laboratory as part of a nitrate Monitored Natural Attenuation (MNA) evaluation. The three sites (BSG, Technical Area-V, and Tijeras Arroyo) are shown on the regional hydrogeologic map and described in the Sandia Annual Groundwater Monitoring Report. The first phase of groundwater sampling included six monitoring wells at the Burn Site, eight monitoring wells at Technical Area-V, and five monitoring wells at Tijeras Arroyo. Each groundwater sample was analyzed using the two specialized analytical methods, age-dating and denitrification suites. In September 2015, a second phase of groundwater sampling took place at the Burn Site including 10 wells sampled and analyzed by the same two analytical suites. Five of the six wells sampled in 2012 were resampled in 2015. This report summarizes results from two sampling events in order to evaluate evidence for in situ denitrification, the average age of the groundwater, and the extent of recent recharge of the bedrock fracture system beneath the BSG AOC.

Windows of Opportunity for Groundwater Management

Science.gov (United States)

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

2015-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-12-01

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

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

International Nuclear Information System (INIS)

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

2000-12-01

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

F-Area Seepage Basins groundwater monitoring report

International Nuclear Information System (INIS)

1992-09-01

This progress report from the Savannah River Plant for second quarter 1992 includes discussion on the following topics: description of facilities; hydrostratigraphic units; monitoring well nomenclature; integrity of the monitoring well network; groundwater monitoring data; analytical results exceeding standards; tritium, nitrate, and pH time-trend data; water levels; groundwater flow rates and directions; upgradient versus downgradient results

F-Area Seepage Basins groundwater monitoring report

International Nuclear Information System (INIS)

1992-06-01

This progress report from the Savannah River Plant for first quarter 1992 includes discussion on the following topics: description of facilities; hydrostratigraphic units; monitoring well nomenclature; integrity of the monitoring well network; groundwater monitoring data; analytical results exceeding standards; tritium, nitrate, and pH time-trend data; water levels; groundwater flow rates and directions; upgradient versus downgradient results

Simulated effects of impoundment of lake seminole on ground-water flow in the upper Floridan Aquifer in southwestern Georgia and adjacent parts of Alabama and Florida

Science.gov (United States)

Jones, L. Elliott; Torak, Lynn J.

2004-01-01

Hydrologic implications of the impoundment of Lake Seminole in southwest Georgia and its effect on components of the surface- and ground-water flow systems of the lower Apalachicola?Chattahoochee?Flint (ACF) River Basin were investigated using a ground-water model. Comparison of simulation results of postimpoundment drought conditions (October 1986) with results of hypothetical preimpoundment conditions (a similar drought prior to 1955) provides a qualitative measure of the changes in hydraulic head and ground-water flow to and from streams and Lake Seminole, and across State lines caused by the impoundment. Based on the simulation results, the impoundment of Lake Seminole changed ground-water flow directions within about 20?30 miles of the lake, reducing the amount of ground water flowing from Florida to Georgia southeast of the lake. Ground-water storage was increased by the impoundment, as indicated by a simulated increase of as much as 26 feet in the water level in the Upper Floridan aquifer. The impoundment of Lake Seminole caused changes to simulated components of the ground-water budget, including reduced discharge from the Upper Floridan aquifer to streams (315 million gallons per day); reduced recharge from or increased discharge to regional ground-water flow at external model boundaries (totaling 183 million gallons per day); and reduced recharge from or increased discharge to the undifferentiated overburden (totaling 129 million gallons per day).

Distribution of Redox-Sensitive Groundwater Quality Parameters Downgradient of a Landfill (Grindsted, Denmark)

DEFF Research Database (Denmark)

Bjerg, Poul Løgstrup; Rügge, Kirsten; Pedersen, Jørn K.

1995-01-01

The leachate plume stretching 300 m downgradient from the Grindsted Landfill (Denmark) has been characterized in terms of redox-sensitive groundwater quality parameters along two longitudinal transects (285 samples). Variations in the levels of methane, sulfide, iron(ll), manganese(ll), ammonium......, dinitrogen oxide, nitrite, nitrate, and oxygen in the groundwater samples indicate that methane production, sulfate reduction, iron reduction, manganese reduction, and nitrate reduction take place in the plume. Adjacent to the landfill, methanogenic and sulfatereducing zones were identified, while aerobic...... environments were identified furthest away from the landfill. In between, different redox environments, including apparent transition zones, were identified in a sequence in accordance with the thermodynamic principles. The redox zones are believed to constitute an important chemical framework...

Handbook: Collecting Groundwater Samples from Monitoring Wells in Frenchman Flat, CAU 98

Energy Technology Data Exchange (ETDEWEB)

Chapman, Jenny [Desert Research Inst. (DRI), Reno, NV (United States); Lyles, Brad [Desert Research Inst. (DRI), Reno, NV (United States); Cooper, Clay [Desert Research Inst. (DRI), Reno, NV (United States); Hershey, Ron [Desert Research Inst. (DRI), Reno, NV (United States); Healey, John [Desert Research Inst. (DRI), Reno, NV (United States)

2015-06-01

CAU. The sampling plan is designed to ensure that monitoring activities occur in compliance with the UGTA Quality Assurance Plan (DOE, 2012). The sampling plan should be referenced for Quality Assurance (QA) elements and procedures governing sampling activities. The NNSS Integrated Sampling Plan specifies the groundwater monitoring that will occur in CAU 98 until the long-term monitoring program is approved in the Closure Report. The plan specifies the wells that must be monitored and categorizes them by their sampling objective with the associated analytical requirements and frequency. Possible sample collection methods and required standard operating procedures are also presented. The intent of this handbook is to augment the NNSS Integrated Sampling Plan by providing well-specific details for the sampling professional implementing the Sampling Plan in CAU 98, Frenchman Flat. This handbook includes each CAU 98 well designated for sampling in the NNSS Integrated Sampling Plan. The following information is provided in the individual well sections: 1. The purpose of sampling. 2. A physical description of the well. 3. The chemical characteristics of the formation water. 4. Recommended protocols for purging and sampling. The well-specific information has been gathered from numerous historical and current sources cited in each section, but two particularly valuable resources merit special mention. These are the USGS NNSS website (http://nevada.usgs.gov/doe_nv/ntsarea5.cfm) and the UGTA Field Operations website (https://ugta.nv.doe.gov/sites/Field%20Operations/default.aspx). 2 Land surface elevation and measuring point for water level measurements in Frenchman Flat were a focus during CAU investigations (see Appendix B, Attachment 1 in Navarro-Intera, 2014). Both websites listed above provide information on the accepted datum for each well. A summary is found on the home page for the well on the USGS website. Additional information is available through a link in the �

Results of groundwater monitoring and vegetation sampling at Everest, Kansas, in 2009 .

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M.; Environmental Science Division

2010-05-13

effectively, identified by the existing network of monitoring points and have not changed significantly during the CCC/USDA investigation program. The carbon tetrachloride distribution within the plume has continued to evolve, however, with relatively constant or apparently decreasing contaminant levels at most sampling locations. In response to these findings, the KDHE requested that the CCC/USDA develop a plan for annual monitoring of the groundwater and surface water at Everest, to facilitate continued tracking of the carbon tetrachloride plume at this site (KDHE 2009a). A recommendation for annual sampling (for analyses of VOCs) of 16 existing groundwater monitoring points within and near the identified contaminant migration pathway and surface water sampling at 5 locations along the intermittent creek west (downgradient) of the identified plume was presented by the CCC/USDA (Appendix A) and approved by the KDHE (2009b) for implementation. The monitoring wells will be sampled according to the low-flow procedure, and sample preservation, shipping, and analysis activities will be consistent with previous work at Everest. The annual sampling will continue until identified conditions at the site indicate a technical justification for a change. This report summarizes the results of sampling and monitoring activities conducted at the Everest site since completion of the April 2008 groundwater sampling event (Argonne 2008). The investigations performed during the current review period (May 2008 to October 2009) were as follows: (1) With one exception, the KDHE-approved groundwater and surface water monitoring points were sampled on April 24-27, 2009. In this event, well PT1 was inadvertently sampled instead of the adjacent well MW04. This investigation represents the first groundwater and surface water sampling event performed under the current plan for annual monitoring approved by the KDHE. (2) Ongoing monitoring of the groundwater levels at Everest is performed with KDHE

Modeling irrigation behavior in groundwater systems

Science.gov (United States)

Foster, Timothy; Brozović, Nicholas; Butler, Adrian P.

2014-08-01

Integrated hydro-economic models have been widely applied to water management problems in regions of intensive groundwater-fed irrigation. However, policy interpretations may be limited as most existing models do not explicitly consider two important aspects of observed irrigation decision making, namely the limits on instantaneous irrigation rates imposed by well yield and the intraseasonal structure of irrigation planning. We develop a new modeling approach for determining irrigation demand that is based on observed farmer behavior and captures the impacts on production and water use of both well yield and climate. Through a case study of irrigated corn production in the Texas High Plains region of the United States we predict optimal irrigation strategies under variable levels of groundwater supply, and assess the limits of existing models for predicting land and groundwater use decisions by farmers. Our results show that irrigation behavior exhibits complex nonlinear responses to changes in groundwater availability. Declining well yields induce large reductions in the optimal size of irrigated area and irrigation use as constraints on instantaneous application rates limit the ability to maintain sufficient soil moisture to avoid negative impacts on crop yield. We demonstrate that this important behavioral response to limited groundwater availability is not captured by existing modeling approaches, which therefore may be unreliable predictors of irrigation demand, agricultural profitability, and resilience to climate change and aquifer depletion.

IN SITU DESTRUCTION OF CHLORINATED HYDROCARBON COMPOUNDS IN GROUNDWATER USING CATALYTIC REDUCTIVE REDUCTIVE DEHALOGENATION IN A REACTIVE WELL: TESTING AND OPERATIONAL EXPERIENCES. (R825421)

Science.gov (United States)

A groundwater treatment technology based on catalytic reductive dehalogenation has been developed to efficiently destroy chlorinated hydrocarbons in situ using a reactive well approach. The treatment process utilizes dissolved H2 as an electron donor, in...

Understanding shallow groundwater contamination in Bwaise slum, Kampala, Uganda

Science.gov (United States)

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

2012-04-01

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

Groundwater conditions in Georgia, 2010–2011

Science.gov (United States)

Peck, Michael F.; Gordon, Debbie W.; Painter, Jaime A.

2013-01-01

The U.S. Geological Survey collects groundwater data and conducts studies to monitor hydrologic conditions, better define groundwater resources, and address problems related to water supply, water use, and water quality. In Georgia, water levels were monitored continuously at 186 wells during calendar year 2010 and at 181 wells during calendar year 2011. Because of missing data or short periods of record (less than 3 years) for several of these wells, a total of 168 wells are discussed in this report. These wells include 17 in the surficial aquifer system, 19 in the Brunswick aquifer system and equivalent sediments, 70 in the Upper Floridan aquifer, 16 in the Lower Floridan aquifer and underlying units, 10 in the Claiborne aquifer, 1 in the Gordon aquifer, 11 in the Clayton aquifer, 14 in the Cretaceous aquifer system, 2 in Paleozoic-rock aquifers, and 8 in crystalline-rock aquifers. Data from the well network indicate that water levels generally declined during the 2010 through 2011 calendar-year period, with water levels declining in 158 wells and rising in 10. Water levels declined over the period of record at 106 wells, increased at 56 wells, and remained relatively constant at 6 wells. In addition to continuous water-level data, periodic water-level measurements were collected and used to construct potentiometric-surface maps for the Upper Floridan aquifer in Camden, Charlton, and Ware Counties, Georgia, and adjacent counties in Florida during May–June 2010, and in the following areas in Georgia: the Brunswick area during August 2010 and August 2011, in the Albany–Dougherty County area during November 2010 and November 2011, and in the Augusta–Richmond County area during October 2010 and August 2011. In general, water levels in these areas were lower during 2011 than during 2010; however, the configuration of the potentiometric surfaces in each of the areas showed little change. Groundwater quality in the Floridan aquifer system is monitored in the

Hydrogeological characterisation of groundwater over Brazil using remotely sensed and model products.

Science.gov (United States)

Hu, Kexiang; Awange, Joseph L; Khandu; Forootan, Ehsan; Goncalves, Rodrigo Mikosz; Fleming, Kevin

2017-12-01

For Brazil, a country frequented by droughts and whose rural inhabitants largely depend on groundwater, reliance on isotope for its monitoring, though accurate, is expensive and limited in spatial coverage. We exploit total water storage (TWS) derived from Gravity Recovery and Climate Experiment (GRACE) satellites to analyse spatial-temporal groundwater changes in relation to geological characteristics. Large-scale groundwater changes are estimated using GRACE-derived TWS and altimetry observations in addition to GLDAS and WGHM model outputs. Additionally, TRMM precipitation data are used to infer impacts of climate variability on groundwater fluctuations. The results indicate that climate variability mainly controls groundwater change trends while geological properties control change rates, spatial distribution, and storage capacity. Granular rocks in the Amazon and Guarani aquifers are found to influence larger storage capability, higher permeability (>10 -4 m/s) and faster response to rainfall (1 to 3months' lag) compared to fractured rocks (permeability 3months) found only in Bambui aquifer. Groundwater in the Amazon region is found to rely not only on precipitation but also on inflow from other regions. Areas beyond the northern and southern Amazon basin depict a 'dam-like' pattern, with high inflow and slow outflow rates (recharge slope > 0.75, discharge slope 30cm). Amazon's groundwater declined between 2002 and 2008 due to below normal precipitation (wet seasons lasted for about 36 to 47% of the time). The Guarani aquifer and adjacent coastline areas rank second in terms of storage capacity, while the northeast and southeast coastal regions indicate the smallest storage capacity due to lack of rainfall (annual average is rainfall <10cm). Copyright © 2017 Elsevier B.V. All rights reserved.

Treatment of Chlorinated Solvents in Groundwater Beneath an Occupied Building at the Young-Rainey STAR Center, Pinellas, FL

Energy Technology Data Exchange (ETDEWEB)

Daniel, Joe [Navarro Research and Engineering; Surovchak, Scott [Dept. of Energy (DOE), Legacy Management; Tabor, Charles [Navarro Research and Engineering

2016-03-01

Groundwater contamination, consisting of two dissolved-phase plumes originating from chlorinated solvent source areas, in the southeastern portion of the Young- Rainey Star Center (also known as the Pinellas County, Florida, Site) in Largo, Florida, has migrated beyond the property boundary, beneath the roadways, and beneath adjacent properties to the south and east. Groundwater contamination will persist as long as the onsite contaminant source remains. The origin of the contamination appears to be multiple long-term point sources beneath Building 100, a 4.5 ha (11 acre) building that housed manufacturing facilities during US DOE operations at the site. The site is now owned by Pinellas County, and most of the space inside the building is leased to private companies, so DOE chose not to conduct characterization or remediation through the floor of the building, instead choosing to conduct all work from outside the building. Injection of emulsified soybean oil and a microbial culture has been used at other areas of the site to accelerate naturally occurring bacterial processes that degrade groundwater contaminants to harmless compounds, and that same approach was chosen for this task. The technical approach consisted of installing horizontal wells from outside the building footprint, extending through and around the identified subsurface treatment areas, and terminating beneath the building. Two 107 m (350 ft) long wells, two 122 m (400 ft) long wells, and four 137 m (450 ft) long wells have been installed to intersect the inferred source areas and confirmed contaminant plumes beneath the building. DOE then injected emulsified vegetable oil and a microbial culture into the horizontal wells at each of several target areas beneath the building where the highest groundwater contaminant concentrations have been detected. The target areas are the northwest corner of the building between the old drum storage pad locations and monitoring well PIN12-S35B, the vicinity of

The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines

Science.gov (United States)

Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, Amarisa; 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 (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.

Defining an optimum pumping-time requirement for sampling ground-water wells on the Hanford site

International Nuclear Information System (INIS)

Scharnhorst, N.L.

1982-04-01

The objective was to determine the optimum time period necessary to pump water from a well before a representative sample of the ground water can be obtained. It was assumed that a representative sample has been collected if the concentration of chemical parameters is the same in a number of samples taken consecutively, so that the concentration of parameters does not vary with time of collection. Ground-water samples used in this project were obtained by pumping selected wells on the Hanford Site. At each well, samples were taken at two minute intervals, and on each sample various chemical analyses were performed. Samples were checked for pH, sulfate, iron, specific conductivity, chloride, nitrate and alkalinity. The data showed that pH, alkalinity, sulfate and specific conductivity levels stabilized almost immediately after pumping of the well began. In many wells, the chloride and nitrate levels were unstable throughout the 38-minute sampling period. Iron levels, however, did not behave in either fashion. The concentration of iron in the samples was high when pumping began but dropped rapidly as pumping continued. The best explanation for this is that iron is flushed from the sides of the casing into the well when pumping begins. After several minutes of pumping, most of the dissolved iron is washed from the well casing and the iron concentration reaches a stable plateau representative of the iron concentration in the ground water.Since iron concentration takes longest to stabilize, the optimum pumping time for a well is based on the iron stabilization time for that well

Assessing biosynthetic potential of agricultural groundwater through metagenomic sequencing: A diverse anammox community dominates nitrate-rich groundwater.

Directory of Open Access Journals (Sweden)

William B Ludington

Full Text Available Climate change produces extremes in both temperature and precipitation causing increased drought severity and increased reliance on groundwater resources. Agricultural practices, which rely on groundwater, are sensitive to but also sources of contaminants, including nitrate. How agricultural contamination drives groundwater geochemistry through microbial metabolism is poorly understood.On an active cow dairy in the Central Valley of California, we sampled groundwater from three wells at depths of 4.3 m (two wells and 100 m (one well below ground surface (bgs as well as an effluent surface water lagoon that fertilizes surrounding corn fields. We analyzed the samples for concentrations of solutes, heavy metals, and USDA pathogenic bacteria of the Escherichia coli and Enterococcus groups as part of a long term groundwater monitoring study. Whole metagenome shotgun sequencing and assembly revealed taxonomic composition and metabolic potential of the community.Elevated nitrate and dissolved organic carbon occurred at 4.3m but not at 100m bgs. Metagenomics confirmed chemical observations and revealed several Planctomycete genomes, including a new Brocadiaceae lineage and a likely Planctomycetes OM190, as well novel diversity and high abundance of nano-prokaryotes from the Candidate Phyla Radiation (CPR, the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, Nanohaloarchaea (DPANN and the Thaumarchaeota, Aigarchaeota, Crenarchaeota, Korarchaeota (TACK superphyla. Pathway analysis suggests community interactions based on complimentary primary metabolic pathways and abundant secondary metabolite operons encoding antimicrobials and quorum sensing systems.The metagenomes show strong resemblance to activated sludge communities from a nitrogen removal reactor at a wastewater treatment plant, suggesting that natural bioremediation occurs through microbial metabolism. Elevated nitrate and rich secondary metabolite biosynthetic capacity suggest

Groundwater/surface-water interaction in central Sevier County, Tennessee, October 2015–2016

Science.gov (United States)

Carmichael, John K.; Johnson, Gregory C.

2017-12-14

The U.S. Geological Survey evaluated the interaction of groundwater and surface water in the central part of Sevier County, Tennessee, from October 2015 through October 2016. Stream base flow was surveyed in December 2015 and in July and October 2016 to evaluate losing and gaining stream reaches along three streams in the area. During a July 2016 synoptic survey, groundwater levels were measured in wells screened in the Cambrian-Ordovician aquifer to define the potentiometric surface in the area. The middle and lower reaches of the Little Pigeon River and the middle reaches of Middle Creek and the West Prong Little Pigeon River were gaining streams at base-flow conditions. The lower segments of the West Prong Little Pigeon River and Middle Creek were losing reaches under base-flow conditions, with substantial flow losses in the West Prong Little Pigeon River and complete subsurface diversion of flow in Middle Creek through a series of sinkholes that developed in the streambed and adjacent flood plain beginning in 2010. The potentiometric surface of the Cambrian-Ordovician aquifer showed depressed water levels in the area where loss of flow occurred in the lower reaches of West Prong Little Pigeon River and Middle Creek. Continuous dewatering activities at a rock quarry located in this area appear to have lowered groundwater levels by as much as 180 feet, which likely is the cause of flow losses observed in the two streams, and a contributing factor to the development of sinkholes at Middle Creek near Collier Drive.

River-groundwater connectivity in a karst system, Wellington, New South Wales, Australia

Science.gov (United States)

Keshavarzi, Mohammadreza; Baker, Andy; Kelly, Bryce F. J.; Andersen, Martin S.

2017-03-01

The characterization of river-aquifer connectivity in karst environments is difficult due to the presence of conduits and caves. This work demonstrates how geophysical imaging combined with hydrogeological data can improve the conceptualization of surface-water and groundwater interactions in karst terrains. The objective of this study is to understand the association between the Bell River and karst-alluvial aquifer at Wellington, Australia. River and groundwater levels were continuously monitored, and electrical resistivity imaging and water quality surveys conducted. Two-dimensional resistivity imaging mapped the transition between the alluvium and karst. This is important for highlighting the proximity of the saturated alluvial sediments to the water-filled caves and conduits. In the unsaturated zone the resistivity imaging differentiated between air- and sediment-filled karst features, and in the saturated zone it mapped the location of possible water- and sediment-filled caves. Groundwater levels are dynamic and respond quickly to changes in the river stage, implying that there is a strong hydraulic connection, and that the river is losing and recharging the adjacent aquifer. Groundwater extractions (1,370 ML, megalitres, annually) from the alluvial aquifer can cause the groundwater level to fall by as much as 1.5 m in a year. However, when the Bell River flows after significant rainfall in the upper catchment, river-leakage rapidly recharges the alluvial and karst aquifers. This work demonstrates that in complex hydrogeological settings, the combined use of geophysical imaging, hydrograph analysis and geochemical measurements provide insights on the local karst hydrology and groundwater processes, which will enable better water-resource and karst management.

Simulating groundwater-peatland interactions in depression and slope peatlands in southern Quebec (Canada)

Science.gov (United States)

Larocque, M.; Quillet, A.; Paniconi, C.

2013-12-01

It is crucial to understand hydrogeological interactions between aquifers and peatlands in order to grasp the influence of aquifers in peatland water budgets, to understand the role of groundwater in the evolution or organic matter deposition, and to quantify how a peatland can sustain groundwater levels in a superficial aquifer. These questions have rarely been addressed in literature and there is currently no understanding of which process dominates aquifer-peatland exchanges in different geomorphological settings. The main purpose of the study was to use groundwater flow modeling to answer these questions in two contrasted geological contexts of southern Quebec (Canada). During a three-year study, six peatlands have been instrumented in the Becancour (Centre-du-Quebec) and Amos (Abitibi-Temiscamingue) regions of southern Quebec (Canada). At each site, either one or two transects of six piezometer nests (at 1.20 m depth in the organic deposits and in the mineral deposits below the peat) have been installed, for a total of twelve aquifer-peatland transects of approximately 500 m. The stratigraphy and geometry of the peatland-aquifer system, as well as the hydrodynamic properties of the organic and mineral deposits have been measured at all sites. Groundwater levels have been recorded from autumn 2010 to summer 2012. The Becancour peatlands have developed in depressions while the Amos peatlands have developed through the paludification of esker slopes. The maximum peat thickness measured in the Bécancour peatlands is 6.4 m while it is 4.5 m in the Amos region. In both regions, peatlands are fringed by sandy deposits that extend at least partly under the organic deposits. The thickness of these underlying deposits is not well defined, but available data suggests a metric scale thickness in areas close to the adjacent superficial aquifer. Field data is used to create 2D numerical models in Modflow to simulate flow between the shallow groundwater and the peatland on

Expediting Groundwater Sampling at Hanford and Making It Safer

International Nuclear Information System (INIS)

Connell, Carl W. Jr.; Carr, Jennifer S.; Hildebrand, R. Douglas; Schatz, Aaron L.; Conley, S. F.; Brown, W. L.

2013-01-01

The CH2M HILL Plateau Remediation Company (CHPRC) manages the groundwater monitoring programs at the Department of Energy's 586-square-mile Hanford site in southeastern Washington state. These programs are regulated by the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), and the Atomic Energy Act (AEA). The purpose of monitoring is to track existing groundwater contamination from past practices, as well as other potential contamination that might originate from RCRA treatment, storage, and disposal (TSD) facilities. An integral part of the groundwater-monitoring program involves taking samples of the groundwater and measuring the water levels in wells scattered across the site. Each year, more than 1,500 wells are accessed for a variety of reasons

Groundwater quality in the Mojave area, California

Science.gov (United States)

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Four groundwater basins along the Mojave River make up one of the study areas being evaluated. The Mojave study area is approximately 1,500 square miles (3,885 square kilometers) and includes four contiguous groundwater basins: Upper, Middle, and Lower Mojave River Groundwater Basins, and the El Mirage Valley (California Department of Water Resources, 2003). The Mojave study area has an arid climate, and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). Land use in the study area is approximately 82 percent (%) natural (mostly shrubland), 4% agricultural, and 14% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Victorville, Hesperia, and Apple Valley (2010 populations of 116,000, 90,000 and 69,000, respectively). Groundwater in these basins is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in the Mojave study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in the Mojave study area are completed to depths between 200 and 600 feet (18 to 61 meters), consist of solid casing from the land surface to a depth of 130 to 420 feet (40 to 128 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the mountains to the south, mostly through the Mojave River channel. The primary sources

Questa baseline and pre-mining ground-water quality investigation. 5. Well installation, water-level data, and surface- and ground-water geochemistry in the Straight Creek drainage basin, Red River Valley, New Mexico, 2001-03

Science.gov (United States)

Naus, Cheryl A.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Donohoe, Lisa C.; Hunt, Andrew G.; Paillet, Frederick L.; Morin, Roger H.; Verplanck, Philip L.

2005-01-01

The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, northern New Mexico. The primary approach is to determine the processes controlling ground-water chemistry at an unmined, off-site, proximal analog. The Straight Creek drainage basin, chosen for this purpose, consists of the same quartz-sericite-pyrite altered andesitic and rhyolitic volcanic rock of Tertiary age as the mine site. The weathered and rugged volcanic bedrock surface is overlain by heterogeneous debris-flow deposits that interfinger with alluvial deposits near the confluence of Straight Creek and the Red River. Pyritized rock in the upper part of the drainage basin is the source of acid rock drainage (pH 2.8-3.3) that infiltrates debris-flow deposits containing acidic ground water (pH 3.0-4.0) and bedrock containing water of circumneutral pH values (5.6-7.7). Eleven observation wells were installed in the Straight Creek drainage basin. The wells were completed in debris-flow deposits, bedrock, and interfingering debris-flow and Red River alluvial deposits. Chemical analyses of ground water from these wells, combined with chemical analyses of surface water, water-level data, and lithologic and geophysical logs, provided information used to develop an understanding of the processes contributing to the chemistry of ground water in the Straight Creek drainage basin. Surface- and ground-water samples were routinely collected for determination of total major cations and selected trace metals; dissolved major cations, selected trace metals, and rare-earth elements; anions and alkalinity; and dissolved-iron species. Rare-earth elements were determined on selected samples only. Samples were collected for determination of dissolved organic carbon, mercury, sulfur isotopic composition (34S and 18O of sulfate), and water isotopic composition (2H and 18O) during

A systematic review of definitions and classification systems of adjacent segment pathology.

Science.gov (United States)

Kraemer, Paul; Fehlings, Michael G; Hashimoto, Robin; Lee, Michael J; Anderson, Paul A; Chapman, Jens R; Raich, Annie; Norvell, Daniel C

2012-10-15

Systematic review. To undertake a systematic review to determine how "adjacent segment degeneration," "adjacent segment disease," or clinical pathological processes that serve as surrogates for adjacent segment pathology are classified and defined in the peer-reviewed literature. Adjacent segment degeneration and adjacent segment disease are terms referring to degenerative changes known to occur after reconstructive spine surgery, most commonly at an immediately adjacent functional spinal unit. These can include disc degeneration, instability, spinal stenosis, facet degeneration, and deformity. The true incidence and clinical impact of degenerative changes at the adjacent segment is unclear because there is lack of a universally accepted classification system that rigorously addresses clinical and radiological issues. A systematic review of the English language literature was undertaken and articles were classified using the Grades of Recommendation Assessment, Development, and Evaluation criteria. RESULTS.: Seven classification systems of spinal degeneration, including degeneration at the adjacent segment, were identified. None have been evaluated for reliability or validity specific to patients with degeneration at the adjacent segment. The ways in which terms related to adjacent segment "degeneration" or "disease" are defined in the peer-reviewed literature are highly variable. On the basis of the systematic review presented in this article, no formal classification system for either cervical or thoracolumbar adjacent segment disorders currently exists. No recommendations regarding the use of current classification of degeneration at any segments can be made based on the available literature. A new comprehensive definition for adjacent segment pathology (ASP, the now preferred terminology) has been proposed in this Focus Issue, which reflects the diverse pathology observed at functional spinal units adjacent to previous spinal reconstruction and balances