Hanford Site Groundwater Monitoring for Fiscal Year 2000

Energy Technology Data Exchange (ETDEWEB)

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

2001-03-01

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

Soil water storage and groundwater behaviour in a catenary sequence beneath forest in central Amazonia: I. Comparisons between plateau, slope and valley floor

Directory of Open Access Journals (Sweden)

M. G. Hodnett

1997-01-01

Full Text Available Soil water storage was monitored in three landscape elements in the forest (plateau, slope and valley floor over a 3 year period to identify differences in sub-surface hydrological response. Under the plateau and slope, the changes of storage were very similar and there was no indication of surface runoff on the slope. The mean maximum seasonal storage change was 156 mm in the 2 m profile but it was clear that, in the dry season, the forest was able to take up water from below 3.6 m. Soil water availability was low. Soil water storage changes in the valley were dominated by the behaviour of a shallow water table which, in normal years, varied between 0.1 m below the surface at the end of the wet season and 0.8 m at the end of the dry season. Soil water storage changes were small because root uptake was largely replenished by groundwater flow towards the stream. The groundwater behaviour is controlled mainly by the deep drainage from beneath the plateau and slope areas. The groundwater gradient beneath the slope indicated that recharge beneath the plateau and slope commences only after the soil water deficits from the previous dry season have been replenished. Following a wet season with little recharge, the water table fell, ceasing to influence the valley soil water storage, and the stream dried up. The plateau and slope, a zone of very high porosity between 0.4 and 1.1 m, underlain by a less conductive layer, is a probable route for interflow during, and for a few hours after, heavy and prolonged rainfall.

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.

Fate of effluent-borne contaminants beneath septic tank drainfields overlying a Karst aquifer.

Science.gov (United States)

Katz, Brian G; Griffin, Dale W; McMahon, Peter B; Harden, Harmon S; Wade, Edgar; Hicks, Richard W; Chanton, Jeffrey P

2010-01-01

Groundwater quality effects from septic tanks were investigated in the Woodville Karst Plain, an area that contains numerous sinkholes and a thin veneer of sands and clays overlying the Upper Floridan aquifer (UFA). Concerns have emerged about elevated nitrate concentrations in the UFA, which is the source of water supply in this area of northern Florida. At three sites during dry and wet periods in 2007-2008, water samples were collected from the septic tank, shallow and deep lysimeters, and drainfield and background wells in the UFA and analyzed for multiple chemical indicators including nutrients, nitrate isotopes, organic wastewater compounds (OWCs), pharmaceutical compounds, and microbiological indicators (bacteria and viruses). Median NO3-N concentration in groundwater beneath the septic tank drainfields was 20 mg L(-1) (8.0-26 mg L(-1)). After adjusting for dilution, about 25 to 40% N loss (from denitrification, ammonium sorption, and ammonia volatilization) occurs as septic tank effluent moves through the unsaturated zone to the water table. Nitrogen loading rates to groundwater were highly variable at each site (3.9-12 kg N yr(-1)), as were N and chloride depth profiles in the unsaturated zone. Most OWCs and pharmaceutical compounds were highly attenuated beneath the drainfields; however, five Cs (caffeine, 1,7-dimethylxanthine, phenol, galaxolide, and tris(dichloroisotopropyl)phosphate) and two pharmaceutical compounds (acetaminophen and sulfamethoxazole) were detected in groundwater samples. Indicator bacteria and human enteric viruses were detected in septic tank effluent samples but only intermittently in soil water and groundwater. Contaminant movement to groundwater beneath each septic tank system also was related to water use and differences in lithology at each site.

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

Science.gov (United States)

McKenna, Owen P.; Sala, Osvaldo E.

2018-01-01

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

Hanford Site Groundwater Monitoring for Fiscal Year 2003

Energy Technology Data Exchange (ETDEWEB)

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

2004-04-12

This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 2003 (October 2002 through September 2003) on the U.S. Department of Energy's Hanford Site, Washington. The most extensive contaminant plumes in groundwater are tritium, iodine-129, and nitrate, which all had multiple sources and are very mobile in groundwater. The largest portions of these plumes are migrating from the central Hanford Site to the southeast, toward the Columbia River. Concentrations of tritium, nitrate, and some other contaminants continued to exceed drinking water standards in groundwater discharging to the river in some locations. However, contaminant concentrations in river water remained low and were far below standards. Carbon tetrachloride and associated organic constituents form a relatively large plume beneath the central part of the Hanford Site. Hexavalent chromium is present in smaller plumes beneath the reactor areas along the river and beneath the central part of the site. Strontium-90 exceeds standards beneath all but one of the reactor areas, and technetium-99 and uranium are present in the 200 Areas. Uranium exceeds standards in the 300 Area in the south part of the Hanford Site. Minor contaminant plumes with concentrations greater than standards include carbon-14, cesium-137, cis-1,2-dichloroethene, cyanide, fluoride, plutonium, and trichloroethene. Monitoring for the ''Comprehensive Environmental Response, Compensation, and Liability Act'' is conducted in 11 groundwater operable units. The purpose of this monitoring is to define and track plumes and to monitor the effectiveness of interim remedial actions. Interim groundwater remediation in the 100 Areas continued with the goal of reducing the amount of chromium (100-K, 100-D, and 100-H) and strontium-90 (100-N) reaching the Columbia River. The objective of two interim remediation systems in the 200 West Area is to prevent the spread of carbon

Investigation of Submarine Groundwater Discharge and Preferential Groundwater Flow-paths in a Coastal Karst Area using towed Marine and Terrestrial Electrical Resistivity

Science.gov (United States)

O'connell, Y.; Daly, E.; Duffy, G.; Henry, T.

2012-12-01

Large volumes of groundwater, containing nutrients and contaminants enter the coastal waters of southern Galway Bay on the west coast of Ireland through submarine groundwater discharge (SGD). The SGD occurs through karstified Carboniferous limestone in a major karst region comprising the Burren and Gort Lowlands. The Carboniferous limestones have experienced extensive dissolution resulting in the development of an underground network of conduits and fissures that define a trimodal groundwater flow pattern across the region. Groundwater discharge to the sea in this area is exclusively intertidal and submarine. Storage in the karst is limited and typical winter rainfall conditions result in the karst system becoming saturated. Temporary lakes (turloughs) form in lowlying areas and act as large reservoirs which provide storage to enable the transmission of the large volumes of water in the system to the sea. Between 2010 and 2012, terrestrial and shallow marine geophysical surveying has been undertaken to investigate preferential groundwater flow-paths and SGD locations in order to quantify the groundwater-seawater interactions in this coastal karst system. A report into the groundwater system of this karst region following a major flood event proposed a conceptual conduit model defined by extensive water tracing, water level monitoring, hydrochemical sampling, geological mapping and drilling. Limited information about the dimensions of the conduits was known. Electrical resistivity tomography (ERT) profiling to depths of 100m below ground level, with multiple array configurations, has been carried out to investigate the modes of groundwater flow in to and out of both temporary and permanent freshwater lakes in the system. Towed dipole-dipole profiles have been recorded to investigate conduits beneath a permanent lake exhibiting a tidal influence despite its location 5.5 km from the seashore. The ERT data indicates significant variations in subsurface resistivities

Estimating Groundwater Development area in Jianan Plain using Standardized Groundwater Index

Science.gov (United States)

Yu, Chang Hsiang; Haw, Lee Cheng

2017-04-01

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

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

International Nuclear Information System (INIS)

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

1993-06-01

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

Permeable Asphalt: A New Tool to Reduce Road Salt Contamination of Groundwater in Urban Areas.

Science.gov (United States)

Dietz, Michael E; Angel, Derek R; Robbins, Gary A; McNaboe, Lukas A

2017-03-01

Chloride contamination of groundwater in urban areas due to deicing is a well-documented phenomenon in northern climates. The objective of this study was to evaluate the effects of permeable pavement on degraded urban groundwater. Although low impact development practices have been shown to improve stormwater quality, no infiltration practice has been found to prevent road salt chlorides from entering groundwater. The few studies that have investigated chlorides in permeable asphalt have involved sampling directly beneath the asphalt; no research has looked more broadly at surrounding groundwater conditions. Monitoring wells were installed upgradient and downgradient of an 860 m 2 permeable asphalt parking lot at the University of Connecticut (Storrs, Connecticut). Water level and specific conductance were measured continuously, and biweekly samples were analyzed for chloride. Samples were also analyzed for sodium (Na), calcium (Ca), and magnesium (Mg). Analysis of variance analysis indicated a significantly (p monitoring revealed lower Cl concentrations downgradient than upgradient for the majority of the year. These results suggest that the use of permeable asphalt in impacted urban environments with high ambient chloride concentrations can be beneficial to shallow groundwater quality, although these results may not be generalizable to areas with low ambient chloride concentrations. © 2016, National Ground Water Association.

Numerical simulation of ground-water flow through glacial deposits and crystalline bedrock in the Mirror Lake area, Grafton County, New Hampshire

Science.gov (United States)

Tiedeman, Claire; Goode, Daniel J.; Hsieh, Paul A.

1997-01-01

recharge from precipitation to the water table is 26 to 28 cm/year. Hydraulic conductivities are 1.7 x 10-6 to 2.7 x 10-6 m/s for glacial deposits, about 3 x 10-7 m/s for bedrock beneath lower hillsides and valleys, and about 6x10-8 m/s for bedrock beneath upper hillsides and hilltops. Analysis of parameter uncertainty indicates that the above values are well constrained, at least within the context of regression analysis. In the regression, several attributes of the ground-water flow model are assumed perfectly known. The hydraulic conductivity for bedrock beneath upper hillsides and hilltops was determined from few data, and additional data are needed to further confirm this result. Model fit was not improved by introducing a 10-to-1 ration of horizontal-to-vertical anisotropy in the hydraulic conductivity of the glacial deposits, or by varying hydraulic conductivity with depth in the modeled part (uppermost 150m) of the bedrock. The calibrated model was used to delineate the Mirror Lake ground-water basin, defined as the volumes of subsurface through which ground water flows from the water table to Mirror Lake or its inlet streams. Results indicate that Mirror Lake and its inlet streams drain an area of ground-water recharge that is about 1.5 times the area of the surface-water basin. The ground-water basin extends far up the hillside on the northwestern part of the study area. Ground water from this area flows at depth under Norris Brook to discharge into Mirror Lake or its inlet streams. As a result, the Mirror Lake ground-water basin extends beneath the adjacent ground-water basin that drains into Norris Brook. Model simulation indicates that approximately 300,000 m3/year of precipitation recharges the Mirror Lake ground-water basin. About half the recharge enters the basin in areas where the simulated water table lies in glacial deposits; the other half enters the basin in areas where the simulated water table lies in be

F-Area Seepage Basins groundwater monitoring report -- third and fourth quarters 1993

International Nuclear Information System (INIS)

Butler, C.T.

1994-03-01

During the second half of 1993, the groundwater at the F-Area Seepage Basins (FASB) was monitored in compliance with Module 3, Section C, of South Carolina Hazardous Waste Permit SC1-890-008-989, effective November 2, 1992. The monitoring well network is composed of 87 FSB wells screened in the three hydrostratigraphic units that make up the uppermost aquifer beneath the FASB. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B post-closure care permit application for the F-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1990. Beginning in the first quarter of 1993, the standard for comparison became the SCDHEC Groundwater Protection Standard (GWPS) specified in the approved F-Area Seepage Basins Part B permit. Currently and historically, gross alpha, nitrate, nonvolatile beta, and tritium are among the primary constituents to exceed standards. Numerous other radionuclides and hazardous constituents also exceeded the GWPS in the groundwater at the FASB during the second half of 1993, notably aluminum, iodine-129, and zinc. The elevated constituents are found primarily in Aquifer Zone 2B 2 and Aquifer Zone 2B 1 wells. However, several Aquifer Unit 2A wells also contain elevated levels of constituents. Isoconcentration/isoactivity maps included in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units. Water-level maps indicate that the groundwater flow rates and directions at the FASB have remained relatively constant since the basins ceased to be active in 1988

Effects of stormwater infiltration on quality of groundwater beneath retention and detention basins

Science.gov (United States)

Fischer, D.; Charles, E.G.; Baehr, A.L.

2003-01-01

Infiltration of storm water through detention and retention basins may increase the risk of groundwater contamination, especially in areas where the soil is sandy and the water table shallow, and contaminants may not have a chance to degrade or sorb onto soil particles before reaching the saturated zone. Groundwater from 16 monitoring wells installed in basins in southern New Jersey was compared to the quality of shallow groundwater from 30 wells in areas of new-urban land use. Basin groundwater contained much lower levels of dissolved oxygen, which affected concentrations of major ions. Patterns of volatile organic compound and pesticide occurrence in basin groundwater reflected the land use in the drainage areas served by the basins, and differed from patterns in background samples, exhibiting a greater occurrence of petroleum hydrocarbons and certain pesticides. Dilution effects and volatilization likely decrease the concentration and detection frequency of certain compounds commonly found in background groundwater. High recharge rates in storm water basins may cause loading factors to be substantial even when constituent concentrations in infiltrating storm water are relatively low.

Preliminary report on the geology and ground-water supply of the Newark, New Jersey, area

Science.gov (United States)

Herpers, Henry; Barksdale, Henry C.

1951-01-01

In the Newark area, ground water is used chiefly for industrial cooling, air-conditioning, general processing, and for sanitary purposes. A small amount is used in the manufacture of beverages. Total ground-water pumpage in Newark is estimated at not less than 20,000,000 gallons daily. The Newark area is underlain by formations of Recent, Pleistocene and Triassic age, and the geology and hydrologic properties of these formations are discussed. Attention is called to the important influence of a buried valley in the rock floor beneath the Newark area on the yield of wells located within it. Data on the fluctuation of the water levels and the variation in pumpage are presented, and their significance discussed. The results of a pumping test made during the investigation were inconclusive. The beneficial results of artificially recharging the aquifers in one part of the area are described. The intrusion of salt water into certain parts of the ground-water body is described and graphically portrayed by a map showing the chloride concentration of the ground water in various parts of the City. Insofar as available data permit, the chemical quality of the ground water is discussed and records are given of the ground-water temperatures in various parts of the City. There has been marked lowering of the water table in the eastern part of the area, accompanied by salt water intrusion, indicating that the safe yield of the formations in this part of Newark has probably been exceeded. It is recommended that the study of the ground-water resources of this area be continued, and that artificial recharging of the aquifers be increased over as wide an area as possible.

Hydrologic assessment of the shallow groundwater flow system beneath the Shinnecock Nation tribal lands, Suffolk County, New York

Science.gov (United States)

Noll, Michael L.; Rivera, Simonette L.; Busciolano, Ronald J.

2016-12-02

Defining the distribution and flow of shallow groundwater beneath the Shinnecock Nation tribal lands in Suffolk County, New York, is a crucial first step in identifying sources of potential contamination to the surficial aquifer and coastal ecosystems. The surficial or water table aquifer beneath the tribal lands is the primary source of potable water supply for at least 6 percent of the households on the tribal lands. Oyster fisheries and other marine ecosystems are critical to the livelihood of many residents living on the tribal lands, but are susceptible to contamination from groundwater entering the embayment from the surficial aquifer. Contamination of the surficial aquifer from flooding during intense coastal storms, nutrient loading from fertilizers, and septic effluent have been identified as potential sources of human and ecological health concerns on tribal lands.The U.S. Geological Survey (USGS) facilitated the installation of 17 water table wells on and adjacent to the tribal lands during March 2014. These wells were combined with other existing wells to create a 32-well water table monitoring network that was used to assess local hydrologic conditions. Survey-grade, global-navigation-satellite systems provided centimeter-level accuracy for positioning wellhead surveys. Water levels were measured by the USGS during May (spring) and November (fall) 2014 to evaluate seasonal effects on the water table. Water level measurements were made at high and low tide during May 2014 to identify potential effects on the water table caused by changes in tidal stage (tidal flux) in Shinnecock Bay. Water level contour maps indicate that the surficial aquifer is recharged by precipitation and upgradient groundwater flow that moves from the recharge zone located generally beneath Sunrise Highway, to the discharge zone beneath the tribal lands, and eventually discharges into the embayment, tidal creeks, and estuaries that bound the tribal lands to the east, south, and

Remedial investigation concept plan for the groundwater operable units at the chemical plant area and the ordnance works area, Weldon Spring, Missouri

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-15

The U.S. Department of Energy (DOE) and the U.S. Department of the Army (DA) are conducting cleanup activities at two properties--the DOE chemical plant area and the DA ordnance works area (the latter includes the training area)--located in the Weldon Spring area in St. Charles County, Missouri. These areas are on the National Priorities List (NPL), and cleanup activities at both areas are conducted in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. DOE and DA are conducting a joint remedial investigation (RI) and baseline risk assessment (BRA) as part of the remedial investigation/feasibility study (RI/FS) for the groundwater operable units for the two areas. This joint effort will optimize further data collection and interpretation efforts and facilitate overall remedial decision making since the aquifer of concern is common to both areas. A Work Plan issued jointly in 1995 by DOE and the DA discusses the results of investigations completed at the time of preparation of the report. The investigations were necessary to provide an understanding of the groundwater system beneath the chemical plant area and the ordnance works area. The Work Plan also identifies additional data requirements for verification of the evaluation presented.

Remedial investigation concept plan for the groundwater operable units at the chemical plant area and the ordnance works area, Weldon Spring, Missouri

International Nuclear Information System (INIS)

1999-01-01

The U.S. Department of Energy (DOE) and the U.S. Department of the Army (DA) are conducting cleanup activities at two properties--the DOE chemical plant area and the DA ordnance works area (the latter includes the training area)--located in the Weldon Spring area in St. Charles County, Missouri. These areas are on the National Priorities List (NPL), and cleanup activities at both areas are conducted in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. DOE and DA are conducting a joint remedial investigation (RI) and baseline risk assessment (BRA) as part of the remedial investigation/feasibility study (RI/FS) for the groundwater operable units for the two areas. This joint effort will optimize further data collection and interpretation efforts and facilitate overall remedial decision making since the aquifer of concern is common to both areas. A Work Plan issued jointly in 1995 by DOE and the DA discusses the results of investigations completed at the time of preparation of the report. The investigations were necessary to provide an understanding of the groundwater system beneath the chemical plant area and the ordnance works area. The Work Plan also identifies additional data requirements for verification of the evaluation presented

F-Area Acid/Caustic Basin groundwater monitoring report. Second quarter 1994

International Nuclear Information System (INIS)

1994-09-01

During second quarter 1994, samples from the FAC monitoring wells at the F-Area Acid/Caustic Basin were collected and analyzed for herbicides/pesticides, indicator parameters, metals, nitrate, radionuclide indicators, volatile organic compounds, and other constituents. Piezometer FAC 5P and monitoring well FAC 6 were dry and could not be sampled. Analytical results that exceeded final Primary Drinking Water Standards (PDWS), other Savannah River Site (SRS) Flag 2 criteria, or the SRS turbidity standard of 50 NTU during the quarter were as follows: gross alpha exceeded the final PDWS and aluminum, iron, manganese, and total organic halogens exceeded the SRS Flag 2 criteria in one or more of the FAC wells. Turbidity exceeded the SRS standard in well FAC 3. Groundwater flow direction and rate in the water table beneath the F-Area Acid/Caustic Basin were similar to past quarters

100-N pilot project: Proposed consolidated groundwater monitoring program

International Nuclear Information System (INIS)

Borghese, J.V.; Hartman, M.J.; Lutrell, S.P.; Perkins, C.J.; Zoric, J.P.; Tindall, S.C.

1996-11-01

This report presents a proposed consolidated groundwater monitoring program for the 100-N Pilot Project. This program is the result of a cooperative effort between the Hanford Site contractors who monitor the groundwater beneath the 100-N Area. The consolidation of the groundwater monitoring programs is being proposed to minimize the cost, time, and effort necessary for groundwater monitoring in the 100-N Area, and to coordinate regulatory compliance activities. The integrity of the subprograms requirements remained intact during the consolidation effort. The purpose of this report is to present the proposed consolidated groundwater monitoring program and to summarize the process by which it was determined

H-Area Acid/Caustic Basin groundwater monitoring report. Second quarter 1994

International Nuclear Information System (INIS)

1994-09-01

During second quarter 1994, samples collected from the four HAC monitoring wells at the H-Area Acid/Caustic Basin received comprehensive analyses (exclusive of boron and lithium) and turbidity measurements. Monitoring results that exceeded the final Primary Drinking Water Standards (PDWS) or the Savannah River Site (SRS) flagging criteria or turbidity standard during the quarter are the focus of this report. Tritium exceeded the final PDWS in all four HAC wells during second quarter 1994. Carbon tetrachloride exceeded the final PDWS in well HAC 4. Aluminum exceeded its Flag 2 criterion in wells HAC 2, 3, and 4. Iron was elevated in wells HAC 1, 2, and 3. Manganese exceeded its Flag 2 criterion in well HAC 3. Specific conductance and total organic halogens were elevated in well HAC 2. No well samples exceeded the SRS turbidity standard. Groundwater flow direction in the water stable beneath the H-Area Acid/Caustic Basin was to the west during second quarter 1994. During previous quarters, the groundwater flow direction has been consistently to the northwest or the north-northwest. This apparent change in flow direction may be attributed to the lack of water elevations for wells HTF 16 and 17 and the anomalous water elevations for well HAC 2 during second quarter

Work plan for the remedial investigation/feasibility study for the groundwater operable units at the Chemical Plant Area and the Ordnance Works Area, Weldon Spring, Missouri

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

US Department of Energy (DOE) and the US Army Corps of Engineers (CE) are conducting cleanup activities at two properties, the chemical plant area and the ordnance works area, located adjacent to one another in St. Charles County, Missouri. In accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, DOE and CE are evaluating conditions and potential responses at the chemical plant area and at the ordnance works area, respectively, to address groundwater and surface water contamination. This work plan provides a comprehensive evaluation of areas that are relevant to the (GWOUs) of both the chemical plant and the ordnance works area. Following areas or media are addressed in this work plan: groundwater beneath the chemical plant area (including designated vicinity properties described in Section 5 of the RI for the chemical plant area [DOE 1992d]) and beneath the ordnance works area; surface water and sediment at selected springs, including Burgermeister Spring. The organization of this work plan is as follows: Chapter 1 discusses the objectives for conducting the evaluation, including a summary of relevant site information and overall environmental compliance activities to be undertaken; Chapter 2 presents a history and a description of the site and areas addressed within the GWOUs, along with currently available data; Chapter 3 presents a preliminary evaluation of areas included in the GWOUs, which is based on information given in Section 2, and discusses data requirements; Chapter 4 presents rationale for data collection or characterization activities to be carried out in the remedial investigation (RI) phase, along with brief summaries of supporting documents ancillary to this work plan; Chapter 5 discusses the activities planned for GWOUs under each of the 14 tasks for an remedial (RI/FS); Chapter 6 presents proposed schedules for RI/FS for the GWOUS; and Chapter 7 explains the project management structure.

Work plan for the remedial investigation/feasibility study for the groundwater operable units at the Chemical Plant Area and the Ordnance Works Area, Weldon Spring, Missouri

International Nuclear Information System (INIS)

1995-08-01

US Department of Energy (DOE) and the US Army Corps of Engineers (CE) are conducting cleanup activities at two properties, the chemical plant area and the ordnance works area, located adjacent to one another in St. Charles County, Missouri. In accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, DOE and CE are evaluating conditions and potential responses at the chemical plant area and at the ordnance works area, respectively, to address groundwater and surface water contamination. This work plan provides a comprehensive evaluation of areas that are relevant to the (GWOUs) of both the chemical plant and the ordnance works area. Following areas or media are addressed in this work plan: groundwater beneath the chemical plant area (including designated vicinity properties described in Section 5 of the RI for the chemical plant area [DOE 1992d]) and beneath the ordnance works area; surface water and sediment at selected springs, including Burgermeister Spring. The organization of this work plan is as follows: Chapter 1 discusses the objectives for conducting the evaluation, including a summary of relevant site information and overall environmental compliance activities to be undertaken; Chapter 2 presents a history and a description of the site and areas addressed within the GWOUs, along with currently available data; Chapter 3 presents a preliminary evaluation of areas included in the GWOUs, which is based on information given in Section 2, and discusses data requirements; Chapter 4 presents rationale for data collection or characterization activities to be carried out in the remedial investigation (RI) phase, along with brief summaries of supporting documents ancillary to this work plan; Chapter 5 discusses the activities planned for GWOUs under each of the 14 tasks for an remedial (RI/FS); Chapter 6 presents proposed schedules for RI/FS for the GWOUS; and Chapter 7 explains the project management structure

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

Recharge Area of Groundwater of Jakarta Basin

International Nuclear Information System (INIS)

Wandowo; Abidin, Zainal; Alip; Djiono

2002-01-01

Groundwater inside the earth contained in a porous and permeable layers called aquifers. Depend on the hydrogeological structure, the aquifers may be composed of independent layers separated each other by impermeable boundaries. Such a condition may effect the location of recharge where water is able to infiltrate and goes to the aquifers. The objective of this research is to find out and to locate the recharge area of Jakarta basin by utilizing stable isotopes 2H and 18O . The work was done by collecting shallow and deep groundwater samples throughout Jabotabek area and precipitations from different altitudes. Since the stable isotopes composition of precipitation is subject to the altitude, the recharge area would be able to be identified by assessing the correlation of stable isotopes composition of precipitation and corresponding groundwater population. The data obtained from this study suggested that shallow groundwater is originated from local recharge while deep groundwater is recharged from the area having altitude of 125 -230 meters, it correspond to the area between Depok and Bogor

A Transient Numerical Simulation of Perched Ground-Water Flow at the Test Reactor Area, Idaho National Engineering and Environmental Laboratory, Idaho, 1952-94

International Nuclear Information System (INIS)

Orr, B. R.

1999-01-01

Studies of flow through the unsaturated zone and perched ground-water zones above the Snake River Plain aquifer are part of the overall assessment of ground-water flow and determination of the fate and transport of contaminants in the subsurface at the Idaho National Engineering and Environmental Laboratory (INEEL). These studies include definition of the hydrologic controls on the formation of perched ground-water zones and description of the transport and fate of wastewater constituents as they moved through the unsaturated zone. The definition of hydrologic controls requires stratigraphic correlation of basalt flows and sedimentary interbeds within the saturated zone, analysis of hydraulic properties of unsaturated-zone rocks, numerical modeling of the formation of perched ground-water zones, and batch and column experiments to determine rock-water geochemical processes. This report describes the development of a transient numerical simulation that was used to evaluate a conceptual model of flow through perched ground-water zones beneath wastewater infiltration ponds at the Test Reactor Area (TRA)

Evaluation of ground-water flow and solute transport in the Lompoc area, Santa Barbara County, California

Science.gov (United States)

Bright, Daniel J.; Nash, David B.; Martin, Peter

1997-01-01

Ground-water quality in the Lompoc area, especially in the Lompoc plain, is only marginally acceptable for most uses. Demand for ground water has increased for municipal use since the late 1950's and has continued to be high for irrigation on the Lompoc plain, the principal agricultural area in the Santa Ynez River basin. As use has increased, the quality of ground water has deteriorated in some areas of the Lompoc plain. The dissolved-solids concentration in the main zone of the upper aquifer beneath most of the central and western plains has increased from less than 1,000 milligrams per liter in the 1940's to greater than 2,000 milligrams per liter in the 1960's. Dissolved- solids concentration have remained relatively constant since the 1960's. A three-dimensional finite-difference model was used to simulate ground-water flow in the Lompoc area and a two-dimensional finite-element model was used to simulate solute transport to gain a better understanding of the ground-water system and to evaluate the effects of proposed management plans for the ground-water basin. The aquifer system was simulated in the flow model as four horizontal layers. In the area of the Lompoc plain, the layers represent the shallow, middle, and main zones of the upper aquifer, and the lower aquifer. For the Lompoc upland and Lompoc terrace, the four layers represent the lower aquifer. The solute transport model was used to simulate dissolved-solids transport in the main zone of the upper aquifer beneath the Lompoc plain. The flow and solute-transport models were calibrated to transient conditions for 1941-88. A steady-state simulation was made to provide initial conditions for the transient-state simulation by using long-term average (1941-88) recharge rates. Model- simulated hydraulic heads generally were within 5 feet of measured heads in the main zone for transient conditions. Model-simulated dissolved- solids concentrations for the main zone generally differed less than 200milligrams

Yucca Mountain Area Saturated Zone Dissolved Organic Carbon Isotopic Data

International Nuclear Information System (INIS)

Thomas, James; Decker, David; Patterson, Gary; Peterman, Zell; Mihevc, Todd; Larsen, Jessica; Hershey, Ronald

2007-01-01

Groundwater samples in the Yucca Mountain area were collected for chemical and isotopic analyses and measurements of water temperature, pH, specific conductivity, and alkalinity were obtained at the well or spring at the time of sampling. For this project, groundwater samples were analyzed for major-ion chemistry, deuterium, oxygen-18, and carbon isotopes of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC). The U.S. Geological Survey (USGS) performed all the fieldwork on this project including measurement of water chemistry field parameters and sample collection. The major ions dissolved in the groundwater, deuterium, oxygen-18, and carbon isotopes of dissolved inorganic carbon (DIC) were analyzed by the USGS. All preparation and processing of samples for DOC carbon isotopic analyses and geochemical modeling were performed by the Desert Research Institute (DRI). Analysis of the DOC carbon dioxide gas produced at DRI to obtain carbon-13 and carbon-14 values was conducted at the University of Arizona Accelerator Facility (a NSHE Yucca Mountain project QA qualified contract facility). The major-ion chemistry, deuterium, oxygen-18, and carbon isotopes of DIC were used in geochemical modeling (NETPATH) to determine groundwater sources, f ow paths, mixing, and ages. The carbon isotopes of DOC were used to calculate groundwater ages that are independent of DIC model corrected carbon-14 ages. The DIC model corrected carbon-14 calculated ages were used to evaluate groundwater travel times for mixtures of water including water beneath Yucca Mountain. When possible, groundwater travel times were calculated for groundwater flow from beneath Yucca Mountain to down gradient sample sites. DOC carbon-14 groundwater ages were also calculated for groundwaters in the Yucca Mountain area. When possible, groundwater travel times were estimated for groundwater flow from beneath Yucca Mountain to down gradient groundwater sample sites using the DOC calculated

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-09-01

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

Nature and extent of lava-flow aquifers beneath Pahute Mesa, Nevada Test Site

Energy Technology Data Exchange (ETDEWEB)

Prothro, L.B.; Drellack, S.L. Jr.

1997-09-01

Work is currently underway within the Underground Test Area subproject of the US Department of Energy/Nevada Operations Office Environmental Restoration Program to develop corrective action plans in support of the overall corrective action strategy for the Nevada Test Site as established in the Federal Facility Agreement and Consent Order (FFACO, 1996). A closure plan is currently being developed for Pahute Mesa, which has been identified in the FFACO as consisting of the Western and Central Pahute Mesa Corrective Action Units. Part of this effort requires that hydrogeologic data be compiled for inclusion in a regional model that will be used to predict a contaminant boundary for these Corrective Action Units. Hydrogeologic maps have been prepared for use in the model to define the nature and extent of aquifers and confining units that might influence the flow of contaminated groundwater from underground nuclear tests conducted at Pahute Mesa. Much of the groundwater flow beneath Pahute Mesa occurs within lava-flow aquifers. An understanding of the distribution and hydraulic character of these important hydrogeologic units is necessary to accurately model groundwater flow beneath Pahute Mesa. This report summarizes the results of a study by Bechtel Nevada geologists to better define the hydrogeology of lava-flow aquifers at Pahute Mesa. The purpose of this study was twofold: (1) aid in the development of the hydrostratigraphic framework for Pahute Mesa, and (2) provide information on the distribution and hydraulic character of lava-flow aquifers beneath Pahute Mesa for more accurate computer modeling of the Western and Central Pahute Mesa Corrective Action Units.

Effects of 1992 farming systems on ground-water quality at the management systems evaluation area near Princeton, Minnesota

Science.gov (United States)

Delin, G.N.; Landon, M.K.; Lamb, J.A.; Dowdy, R.H.

1995-01-01

The Management Systems Evaluation Area (MSEA) program was a multiscale, interagency initiative to evaluate the effects of agricultural systems on water quality in the midwest corn belt. The primary objective of the Minnesota MSEA was to evaluate the effects of ridge-tillage practices in a corn and soybean farming system on ground-water quality. The 65-hectare Minnesota MSEA was located in the Anoka Sand Plain near the town of Princeton, Minnesota. Three fanning systems were evaluated: corn-soybean rotation with ridge-tillage (areas B and D), sweet corn-potato rotation (areas A and C), and field corn in consecutive years (continuous corn; area E). Water samples were collected four different times per year from a network of 22 multiport wells and 29 observation wells installed in the saturated zone beneath and adjacent to the cropped areas.

Isotope characteristics of groundwater in Beishan area

International Nuclear Information System (INIS)

Guo Yonghai; Liu Shufen; Lu Chuanhe

2004-01-01

Using the isotope techniques, the authors studied the origin, evolution and circulation of the groundwater in the potential site of China's high-level waste repository. The results indicate that both deep groundwater and shallow groundwater are mainly recharged by modern and local precipitation, and the deep groundwater in the site area is of meteoric origin. The shallow groundwater is mainly recharged by modern and local precipitation, and the deep groundwater originates from regional precipitation at higher elevation, or might be derived from the precipitation during the geological period of lower temperature. It is also known from the study that the deep underground is a system of very low-permeability where the groundwater flow rates are very low. (author)

Recent Advances in the Area of Groundwater

Science.gov (United States)

Bahr, J. M.

2017-12-01

Groundwater related papers published in Water Resources Research in the last year range from experimental and modeling studies of pore scale flow and reactive transport to assessments of changes in water storage at the scale of regional aquifers enabled by satellite observations. Important societal needs motivating these studies include sustainability of groundwater resources of suitable quantity and quality for human use, protection of groundwater-dependent ecosystems in streams, wetlands, lakes and coastal areas, and assessment of the feasibility of subsurface sequestration of carbon dioxide and long-lived radioactive wastes. Eight general areas that generated ten or more papers within the period July 2016 to June 2017 are the following: aquifer heterogeneity (including geostatistical and inverse methods for parameter estimation), flow and transport in the unsaturated zone (including recharge to and evaporative losses from aquifers), multiphase flow and transport (including processes relevant to carbon sequestration), groundwater-surface water interactions (particularly hyporheic exchange), flow and transport in fractured media, novel remote sensing and geophysical techniques for aquifer characterization and assessment of groundwater dynamics, freshwater-saltwater interactions (particularly in coastal aquifers), and reactive solute transport. This presentation will highlight selected findings in each of these areas.

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

Numerical simulation of groundwater and surface-water interactions in the Big River Management Area, central Rhode Island

Science.gov (United States)

Masterson, John P.; Granato, Gregory E.

2013-01-01

The Rhode Island Water Resources Board is considering use of groundwater resources from the Big River Management Area in central Rhode Island because increasing water demands in Rhode Island may exceed the capacity of current sources. Previous water-resources investigations in this glacially derived, valley-fill aquifer system have focused primarily on the effects of potential groundwater-pumping scenarios on streamflow depletion; however, the effects of groundwater withdrawals on wetlands have not been assessed, and such assessments are a requirement of the State’s permitting process to develop a water supply in this area. A need for an assessment of the potential effects of pumping on wetlands in the Big River Management Area led to a cooperative agreement in 2008 between the Rhode Island Water Resources Board, the U.S. Geological Survey, and the University of Rhode Island. This partnership was formed with the goal of developing methods for characterizing wetland vegetation, soil type, and hydrologic conditions, and monitoring and modeling water levels for pre- and post-water-supply development to assess potential effects of groundwater withdrawals on wetlands. This report describes the hydrogeology of the area and the numerical simulations that were used to analyze the interaction between groundwater and surface water in response to simulated groundwater withdrawals. The results of this analysis suggest that, given the hydrogeologic conditions in the Big River Management Area, a standard 5-day aquifer test may not be sufficient to determine the effects of pumping on water levels in nearby wetlands. Model simulations showed water levels beneath Reynolds Swamp declined by about 0.1 foot after 5 days of continuous pumping, but continued to decline by an additional 4 to 6 feet as pumping times were increased from a 5-day simulation period to a simulation period representative of long-term average monthly conditions. This continued decline in water levels with

Rational Exploitation and Utilizing of Groundwater in Jiangsu Coastal Area

Science.gov (United States)

Kang, B.; Lin, X.

2017-12-01

Jiangsu coastal area is located in the southeast coast of China, where is a new industrial base and an important coastal and Land Resources Development Zone of China. In the areas with strong human exploitation activities, regional groundwater evolution is obviously affected by human activities. In order to solve the environmental geological problems caused by groundwater exploitation fundamentally, we must find out the forming conditions of regional groundwater hydrodynamic field, and the impact of human activities on groundwater hydrodynamic field evolution and hydrogeochemical evolition. Based on these results, scientific management and reasonable exploitation of the regional groundwater resources can be provided for the utilization. Taking the coastal area of Jiangsu as the research area, we investigate and analyze of the regional hydrogeological conditions. The numerical simulation model of groundwater flow was established according to the water power, chemical and isotopic methods, the conditions of water flow and the influence of hydrodynamic field on the water chemical field. We predict the evolution of regional groundwater dynamics under the influence of human activities and climate change and evaluate the influence of groundwater dynamic field evolution on the environmental geological problems caused by groundwater exploitation under various conditions. We get the following conclusions: Three groundwater exploitation optimal schemes were established. The groundwater salinization was taken as the primary control condition. The substitution model was proposed to model groundwater exploitation and water level changes by BP network method.Then genetic algorithm was used to solve the optimization solution. Three groundwater exploitation optimal schemes were submit to local water resource management. The first sheme was used to solve the groundwater salinization problem. The second sheme focused on dual water supply. The third sheme concerned on emergency water

H-Area Seepage Basins groundwater monitoring report

International Nuclear Information System (INIS)

1992-09-01

During second quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Plant. This report gives the results of the analyses of groundwater from the H-Area Seepage Basin

Hydrogeologic and geochemical characterization of groundwater resources in Deep Creek Valley and adjacent areas, Juab and Tooele Counties, Utah, and Elko and White Pine Counties, Nevada

Science.gov (United States)

Gardner, Philip M.; Masbruch, Melissa D.

2015-09-18

The water resources of Deep Creek Valley were assessed during 2012–13 with an emphasis on better understanding the groundwater flow system and groundwater budget. Surface-water resources are limited in Deep Creek Valley and are generally used for agriculture. Groundwater is the predominant water source for most other uses and to supplement irrigation. Most groundwater withdrawal in Deep Creek Valley occurs from the unconsolidated basin-fill deposits, in which conditions are generally unconfined near the mountain front and confined in the lower-altitude parts of the valley. Productive aquifers are also present in fractured bedrock that occurs along the valley margins and beneath the basin-fill deposits. The consolidated-rock and basin-fill aquifers are hydraulically connected in many areas with much of the recharge occurring in the consolidated-rock mountain blocks and most of the discharge occurring from the lower-altitude basin-fill deposits.

Numerical simulation of groundwater flow at Puget Sound Naval Shipyard, Naval Base Kitsap, Bremerton, Washington

Science.gov (United States)

Jones, Joseph L.; Johnson, Kenneth H.; Frans, Lonna M.

2016-08-18

Information about groundwater-flow paths and locations where groundwater discharges at and near Puget Sound Naval Shipyard is necessary for understanding the potential migration of subsurface contaminants by groundwater at the shipyard. The design of some remediation alternatives would be aided by knowledge of whether groundwater flowing at specific locations beneath the shipyard will eventually discharge directly to Sinclair Inlet of Puget Sound, or if it will discharge to the drainage system of one of the six dry docks located in the shipyard. A 1997 numerical (finite difference) groundwater-flow model of the shipyard and surrounding area was constructed to help evaluate the potential for groundwater discharge to Puget Sound. That steady-state, multilayer numerical model with homogeneous hydraulic characteristics indicated that groundwater flowing beneath nearly all of the shipyard discharges to the dry-dock drainage systems, and only shallow groundwater flowing beneath the western end of the shipyard discharges directly to Sinclair Inlet.Updated information from a 2016 regional groundwater-flow model constructed for the greater Kitsap Peninsula was used to update the 1997 groundwater model of the Puget Sound Naval Shipyard. That information included a new interpretation of the hydrogeologic units underlying the area, as well as improved recharge estimates. Other updates to the 1997 model included finer discretization of the finite-difference model grid into more layers, rows, and columns, all with reduced dimensions. This updated Puget Sound Naval Shipyard model was calibrated to 2001–2005 measured water levels, and hydraulic characteristics of the model layers representing different hydrogeologic units were estimated with the aid of state-of-the-art parameter optimization techniques.The flow directions and discharge locations predicted by this updated model generally match the 1997 model despite refinements and other changes. In the updated model, most

Soil property control of biogeochemical processes beneath two subtropical stormwater infiltration basins.

Science.gov (United States)

O'Reilly, Andrew M; Wanielista, Martin P; Chang, Ni-Bin; Harris, Willie G; Xuan, Zhemin

2012-01-01

Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath two stormwater infiltration basins in north-central Florida. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median, 41% silt+clay) exhibited decreases in dissolved oxygen from 3.8 to 0.1 mg L and decreases in nitrate nitrogen (NO-N) from 2.7 mg L to soils (median, 2% silt+clay), aerobic conditions persisted from 2007 through 2009 (dissolved oxygen, 5.0-7.8 mg L), resulting in NO-N of 1.3 to 3.3 mg L in shallow groundwater. Enrichment of δN and δO of NO combined with water chemistry data indicates denitrification beneath the clayey basin and relatively conservative NO transport beneath the sandy basin. Soil-extractable NO-N was significantly lower and the copper-containing nitrite reductase gene density was significantly higher beneath the clayey basin. Differences in moisture retention capacity between fine- and coarse-textured soils resulted in median volumetric gas-phase contents of 0.04 beneath the clayey basin and 0.19 beneath the sandy basin, inhibiting surface/subsurface oxygen exchange beneath the clayey basin. Results can inform development of soil amendments to maintain elevated moisture content in shallow soils of stormwater infiltration basins, which can be incorporated in improved best management practices to mitigate NO impacts. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

H-Area Seepage Basins groundwater monitoring report

International Nuclear Information System (INIS)

Thompson, C.Y.

1992-06-01

During first quarter 1992, tritium, nitrate, nonvolatile beta, total alpha-emitting radium (radium-224 and radium-226), gross alpha, antimony, mercury, lead, tetrachloroethylene, arsenic, and cadmium exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the H-Area Seepage Basins (HASB) at the Savannah River Site. This report presents and discusses the groundwater monitoring results in the H-Area for first quarter 1992

Groundwater evolution of the granite area, Korea

International Nuclear Information System (INIS)

Kim, C.S.; Bae, D.S.; Koh, Y.K.; Kim, K.S.; Kim, G.Y.

2001-01-01

The geochemistry and environmental isotopes of groundwater in the Cretaceous granite of the Yeongcheon area has been investigated. The hydrochemistry of groundwater belongs to the Ca-HCO 3 type. The oxygen-18 and deuterium data are clustered along the meteoric water line, indicating that the groundwater is of meteoric water origin. Tritium data show that the groundwaters were mostly recharged before pre-thermonuclear period and have been mixed with younger surface water flowing rapidly along fractured zones. Based on the mass balance and reaction simulation approaches using both the hydrochemistry of groundwater and the secondary mineralogy of fracture-filling materials, the low-temperature hydrogeochemical evolution of groundwater in the area has been modeled. The results of geochemical simulation show that the concentrations of Ca, Na and HCO 3 and pH of waters increase progressively owing to the dissolution of reactive minerals in flow paths. The concentrations of Mg and K first increase with the dissolution of reactant minerals, but later decrease when montmorillonite and illitic material are precipitated respectively. The continuous adding of reactive minerals, i. e. the progressively larger degrees of water/rock interaction, causes the formation of secondary minerals with the following sequence: hematite > gibbsite > kaolinite > montmorillonite > illitic material > microcline. The results of reaction simulation agree well with the observed water chemistry and secondary mineralogy, indicating the successful applicability of this simulation technique to delineate the complex hydrogeochemistry of bedrock groundwaters. (author)

Groundwater Monitoring Plan for the Z-Area Saltstone Facility

International Nuclear Information System (INIS)

Wells, D.

2002-01-01

Groundwater monitoring has been conducted at the Z-Area Saltstone Disposal Facility since 1987. At that time, groundwater monitoring was not required by the industrial landfill regulations, but a modest monitoring program was required by the operating permit. In 1996 SRS proposed a program based on direct push sampling. This program called for biennial direct push sampling within 25 feet of each waste-containing cell with additional samples being taken in areas where excessive cracking had been observed. The direct push proposal was accepted by The South Carolina Department of Health and Environmental Control (SCDHEC). The Industrial Solid Waste Landfill Regulations were revised in 1998 and now include requirements for groundwater monitoring. The major elements of those regulations and their application at Z-Area are discussed. These are a point of compliance, groundwater protection standards, the groundwater monitoring system, sampling and analysis, and data evaluation and reporting

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

Science.gov (United States)

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

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

Science.gov (United States)

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

2010-01-01

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

Hydrochemical Characteristics of Groundwater in an Agricultural Area in South Korea

Science.gov (United States)

Kim, N.; Hamm, S.; An, J.; Lee, J.; Jang, S.

2008-12-01

The study area, Sacheon-Hadong area, is located in the southern part of the Korean peninsula, which is bounded by the South Sea and surrounded by the Seomjin River in the west. The study area utilized for agricultural work for a long time. That resulted in vulnerable situation of groundwater due to contamination by fertilizer, insecticide and other human activities. In addition, groundwater is in the risk of seawater intrusion because of the study area's location nearby the South Sea. In Sacheon and Hadong area, the EC values were higher in alluvial aquifer than bedrock aquifer. The higher EC values in the alluvial groundwater than the bedrock groundwater were influenced by agricultural activity in near-surface. Water types of two groundwaters belong to Ca-Cl and Na-Cl types due to saline-water influence. EC values are raised, becoming close to the coast. The correlation analysis showed that EC had positive relationship with Na+, Ca2+, Mg2+, Fe2+, Mn2+, SO42-, and Cl-, indicating mixing with seawater. In Sacheon area, nitrogen isotope ratios in the alluvial groundwater ranged between -0.40 and 12.80‰, with 0.05~2.49 mg/l of NO3-N concentration; the range of nitrogen isotopes in the bedrock groundwater was between 3.30 and 17.60‰, with 0.12~2.14 mg/l of NO3-N concentration. Nitrogen was originated from organic source in soils, manures, and domestic wastes (Mueller and Helsel, 1996; Kim and Woo, 2003). In Hadong area, the nitrogen isotopes in the alluvial groundwater ranged from -0.50 to 19.10‰, and NO3-N concentration was between 0.63 and 6.68 mg/l. And these may be originated from anthropogenic pollutants (Mueller and Helsel, 1996). In Sacheon area, average δ18O and δD in alluvial groundwater were analyzed as - 6.77‰ and -47.50‰; average isotope ratios in bedrock groundwater were -7.73‰ and - 53.46‰. In Hadong area, average δ18O and δD in the alluvial groundwater were - 7.32‰ and -49.80‰; average isotope ratios in the bedrock groundwater

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

International Nuclear Information System (INIS)

Iwatsuki, Teruki; Hama, Katsuhiro; Yoshida, Hidekazu

1997-01-01

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

H-Area Hazardous Waste Management Facility Corrective Action Report, Third and Fourth Quarter 1998, Volumes I and II

International Nuclear Information System (INIS)

Chase, J.

1999-01-01

The groundwater in the uppermost aquifer beneath the H-Area Hazardous Waste Management Facility (HWMF), also known as the H-Area Seepage Basins, at the Savannah Site (SRS) is monitored periodically for selected hazardous and radioactive constituents. This report presents the results of the required groundwater monitoring program

Hydrochemical characterization of groundwater in the Akyem area, Ghana

Science.gov (United States)

Banoeng-Yakubo, B.; Yidana, S.M.; Anku, Y.; Akabzaa, T.; Asiedu, D.

2008-01-01

The Akyem area is a small farming community located in southeastern Ghana. Groundwater samples from wells in the area were analyzed for concentrations of the major ions, silica, electrical conductivity and pH. The objective was to determine the main controls on the hydrochemistry of ground-water. Mass balance modeling was used together with multivariate R-mode hierarchical cluster analysis to determine the significant sources of variation in the hydrochemistry. Two water types exist in this area. The first is influenced most by the weathering of silicate minerals from the underlying geology, and is thus rich in silica, sodium, calcium, bicarbonate, and magnesium ions. The second is water that has been influenced by the effects of fertilizers and other anthropogenic activities in the area. Mineral speciation and silicate mineral stability diagrams suggest that montmorillonite, probably derived from the incongruent dissolution of feldspars and micas, is the most stable silicate phase in the groundwaters. The apparent incongruent weathering of silicate minerals in the groundwater system has led to the enrichment of sodium, calcium, magnesium and bicarbonate ions as well as silica, leading to the supersaturation of calcite, aragonite, dolomite and quartz. Stability in the montmorillonite field suggests restricted flow conditions and a long groundwater residence time, leading to greater exposure of the rock to weathering. Cation exchange processes appear to play minor roles in the hydrochemistry of groundwater.

Isotope study of groundwater in Beishan area, Gansu province

International Nuclear Information System (INIS)

Guo Yonghai; Liu Shufen; Yang Tianxiao

2004-01-01

Using the isotope techniques, the groundwater origin, evolution and circulation in the potential site of China's high-level waste repository are studied. The results indicate that both shallow groundwaters are and deep groundwaters in the site area are of meteoric origin. The shallow groundwaters are mainly recharged by modern and local precipitation, and the deep groundwaters are originated from regional history period with lower temperature. Through the study we can also understand that the deep underground is a very low-permeability system where the groundwater flow-rates are very low. (author)

Surface water and groundwater interaction in Marala - Khanki area, Punjab

International Nuclear Information System (INIS)

Akram, W.; Ahmad, M.; Latif, Z.; Tariq, J.A.; Malik, M.R.

2011-07-01

Isotope hydrological investigations were carried out in two selected areas of Indus Basin viz. Haripur Area and Chashma- Taunsa Area for elucidating various aspects of surface water and groundwater interaction. Groundwater samples were collected on seasonal basis (low and high river discharge periods) while surface water samples were collected more frequently (weekly or monthly basis). Isotopic data suggested that there is no contribution of surface water to groundwater recharge in Haripur Area and rain is the prevailing source of groundwater recharge. The data further revealed that isotopic values of the Haripur pocket of Tarbela Lake are higher than those of Main Lake / Indus River meaning that there is a significant contribution of base flow in this pocket. Indus River appeared to be the dominant source of groundwater recharge at most of the locations in Chashma- Taunsa Area. Isotopic data of Indus River showed an increase at Taunsa as compared to Chashma in low flow period indicating the high contribution of base flow at this point in time. Stable isotopes were successfully used to quantify the base flow contribution. (author)

Groundwater Annual Status Report for Fiscal Year 1998

International Nuclear Information System (INIS)

A. K. Stoker; A. S. Johnson; B. D. Newman; B. M. Gallaher; C. L. Nylander; D. B. Rogers; D. E. Broxton; D. Katzman; E. H. Keating; G. L. Cole; K. A. Bitner; K. I. Mullen; P. Longmire; S. G. McLin; W. J. Stone

1999-01-01

Groundwater protection activities and hydrogeologic characterization studies are conducted at LANL annually. A summary of fiscal year 1998 results and findings shows increased understanding of the hydrogeologic environment beneath the Pajarito Plateau and significant refinement to elements of the LANL Hydrogeologic Conceptual Model pertaining to areas and sources of recharge to the regional aquifer. Modeling, drilling, monitoring, and data collection activities are proposed for fiscal year 1999

Groundwater evolution beneath Hat Yai, a rapidly developing city in Thailand

Science.gov (United States)

Lawrence, A. R.; Gooddy, D. C.; Kanatharana, P.; Meesilp, W.; Ramnarong, V.

2000-09-01

Many cities and towns in South and Southeast Asia are unsewered, and urban wastewaters are often discharged either directly to the ground or to surface-water canals and channels. This practice can result in widespread contamination of the shallow groundwater. In Hat Yai, southern Thailand, seepage of urban wastewaters has produced substantial deterioration in the quality of the shallow groundwater directly beneath the city. For this reason, the majority of the potable water supply is obtained from groundwater in deeper semi-confined aquifers 30-50 m below the surface. However, downward leakage of shallow groundwater from beneath the city is a significant component of recharge to the deeper aquifer, which has long-term implications for water quality. Results from cored boreholes and shallow nested piezometers are presented. The combination of high organic content of the urban recharge and the shallow depth to the water table has produced strongly reducing conditions in the upper layer and the mobilisation of arsenic. A simple analytical model shows that time scales for downward leakage, from the surface through the upper aquitard to the semi-confined aquifer, are of the order of several decades. Résumé. De nombreuses villes du sud et du sud-est de l'Asie ne possèdent pas de réseaux d'égouts et les eaux usées domestiques s'écoulent souvent directement sur le sol ou dans des canaux et des cours d'eau de surface. Ces pratiques peuvent provoquer une contamination dispersée de la nappe phréatique. A Hat Yai (sud de la Thaïlande), les infiltrations d'eaux usées domestiques sont responsables d'une détérioration notable de la qualité de la nappe phréatique directement sous la ville. Pour cette raison, la majorité de l'eau potable est prélevée dans des aquifères semi-captifs plus profonds, situés entre 30 et 50 m sous la surface. Cependant, une drainance à partir de la nappe phréatique sous la ville constitue une composante significative de la recharge

Sanitary Landfill Groundwater Monitoring Report, Fourth Quarter 1999 and 1999 Summary

International Nuclear Information System (INIS)

Chase, J.

2000-01-01

A maximum of thirty eight-wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill Area at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Water Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Iron (Total Recoverable), Chloroethene (Vinyl Chloride) and 1,1-Dichloroethane were the most widespread constituents exceeding the Final Primary Drinking Water Standards during 1999. Trichloroethylene, 1,1-Dichloroethylene, 1,2-Dichloroethane, 1,4-Dichlorobenzene, Aluminum (Total Recoverable), Benzene, cis-1,2-Dichloroethylene, Dichlorodifluoromethane, Dichloromethane (Methylene Chloride), Gross Alpha, Mercury (Total Recoverable), Nonvolatile Beta, Tetrachloroethylene, Total Organic Halogens, Trichlorofluoromethane, Tritium also exceeded standards in one or more wells. The groundwater flow direction in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill is to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 144.175 ft/year during first quarter 1999 and 145.27 ft/year during fourth quarter 1999

Heterogeneous Structure and Seismicity beneath the Tokyo Metropolitan Area

Science.gov (United States)

Nakagawa, S.; Kato, A.; Sakai, S.; Nanjo, K.; Panayotopoulos, Y.; Kurashimo, E.; Obara, K.; Kasahara, K.; Aketagawa, T.; Kimura, H.; Hirata, N.

2010-12-01

Beneath the Tokyo metropolitan area, the Philippine Sea Plate (PSP) subducts and causes damaged mega-thrust earthquakes. Sato et al. (2005) revealed the geometry of upper surface of PSP, and Hagiwara et al. (2006) estimated the velocity structure beneath Boso peninsula. However, these results are not sufficient for the assessment of the entire picture of the seismic hazards beneath the Tokyo metropolitan area including those due to an intra-slab M7+ earthquake. So, we launched the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan area (Hirata et al., 2009). Proving the more detailed geometry and physical properties (e.g. velocities, densities, attenuation) and stress field within PSP is very important to attain this issue. The core item of this project is a dense seismic array called Metropolitan Seismic Observation network (MeSO-net) for making observations in the metropolitan area (Sakai and Hirata, 2009; Kasahara et al., 2009). We deployed the 249 seismic stations with a spacing of 5 km. Some parts of stations construct 5 linear arrays at interval of 2 km such as Tsukuba-Fujisawa (TF) array, etc. The TF array runs from northeast to southwest through the center of Tokyo. In this study, we applied the tomography method to image the heterogeneous structure under the Tokyo metropolitan area. We selected events from the Japan Meteorological Agency (JMA) unified earthquake list. All data of MeSO-net were edited into event data by the selected JMA unified earthquake list. We picked the P and S wave arrival times. The total number of stations and events are 421 and 1,256, respectively. Then, we applied the double-difference tomography method (Zhang and Thurber, 2003) to this dataset and estimated the fine-scale velocity structure. The grid nodes locate 10 km interval in parallel with the array, 20 km interval in perpendicular to the array; and on depth direction, 5 km interval to a depth of less than 50 km and 10 km interval at a depth of more

Drought-induced recharge promotes long-term storage of porewater salinity beneath a prairie wetland

Science.gov (United States)

Levy, Zeno F.; Rosenberry, Donald O.; Moucha, Robert; Mushet, David M.; Goldhaber, Martin B.; LaBaugh, James W.; Fiorentino, Anthony J.; Siegel, Donald I.

2018-02-01

Subsurface storage of sulfate salts allows closed-basin wetlands in the semiarid Prairie Pothole Region (PPR) of North America to maintain moderate surface water salinity (total dissolved solids [TDS] from 1 to 10 g L-1), which provides critical habitat for communities of aquatic biota. However, it is unclear how the salinity of wetland ponds will respond to a recent shift in mid-continental climate to wetter conditions. To understand better the mechanisms that control surface-subsurface salinity exchanges during regional dry-wet climate cycles, we made a detailed geoelectrical study of a closed-basin prairie wetland (P1 in the Cottonwood Lake Study Area, North Dakota) that is currently experiencing record wet conditions. We found saline lenses of sulfate-rich porewater (TDS > 10 g L-1) contained in fine-grained wetland sediments 2-4 m beneath the bathymetric low of the wetland and within the currently ponded area along the shoreline of a prior pond stand (c. 1983). During the most recent drought (1988-1993), the wetland switched from a groundwater discharge to recharge function, allowing salts dissolved in surface runoff to move into wetland sediments beneath the bathymetric low of the basin. However, groundwater levels during this time did not decline to the elevation of the saline lenses, suggesting these features formed during more extended paleo-droughts and are stable in the subsurface on at least centennial timescales. We hypothesize a "drought-induced recharge" mechanism that allows wetland ponds to maintain moderate salinity under semiarid climate. Discharge of drought-derived saline groundwater has the potential to increase the salinity of wetland ponds during wet climate.

Groundwater Annual Status Report for Fiscal Year 1999

International Nuclear Information System (INIS)

Nylander, C.L.; Bitner, K.A.; Henning, K.; Johnson, A.S.; Keating, E.H.; Longmire, P.; Newman, B.D.; Robinson, B.; Rogers, D.B.; Stone, W.J.; Vaniman, D.

2000-01-01

Groundwater protection activities and hydrogeologic characterization studies are conducted at Los Alamos National Laboratory annually. A summary of fiscal year 1999 results and findings shows increased understanding of the hydrogeologic environment beneath the Pajarito Plateau and significant refinement to elements of the LANL. Hydrogeologic Conceptual Model pertaining to areas and sources of recharge to the regional aquifer. Modeling, drilling, monitoring, and data collection activities are proposed for fiscal year 2000

From groundwater baselines to numerical groundwater flow modelling for the Milan metropolitan area

Science.gov (United States)

Crosta, Giovanni B.; Frattini, Paolo; Peretti, Lidia; Villa, Federica; Gorla, Maurizio

2015-04-01

Contamination of major aquifers in highly densely populated areas is a major concern for stakeholders involved in the use and protection of groundwater resources. Sustainable groundwater withdrawal and management, and the identification of trends in groundwater contamination require a careful hydrochemical baseline characterization. This characterization is fundamental to investigate the presence and evolutionary trend of contaminants. In fact, it allows recovering and understanding: the spatial-temporal trend of contamination; the relative age of the contamination episodes; the reasons for anomalous behavior of some compounds during migration to and in the groundwater; the associations with which some contaminants can be found; the different behaviors in phreatic and semi-confined and confined aquifers. To attain such a characterization for the Milan metropolitan area (about 2,500 km2, ca 4.000.000 inhabitants, Lombardy, Italy), we carried out three main activities. (1) Collection of complete and reliable datasets concerning the geological, hydrogeological and hydrochemical (over 60,000 chemical analysis since 2003 to 2013) characteristics of the area and of the involved aquifers. This activity was very demanding because the available data are provided by different authorities (Lombardy Region, Provinces, Lombardy Environmental Agency - ARPA Lombardia, public own companies in charge of water system managements) in raw format and with different database standard, which required a large effort of manual verification and harmonization. (2) Completion of a hydrochemical characterization of the metropolitan area aquifers by classical statistical and multivariate statistical analyses, in order to define a baseline both for some major physical chemical characteristics and for the most relevant contaminants. (3) Development of a three dimensional hydrogeological model for the metropolitan area starting from the above listed datasets and existing models. This model will

Hydrological mediated denitrification in groundwater below a seasonal flooded restored riparian zone

DEFF Research Database (Denmark)

Jensen, Jannick Kolbjørn; Engesgaard, Peter; Johnsen, Anders R.

2017-01-01

nitrate removal in groundwater primarily by two mechanisms. First, by creating a stagnant flow zone beneath the flooded area thereby increasing the residence time and leaving more time for nitrate removal. Secondly, nitrate removal is increased by enhancing upward flow into the highly reactive organic......A restored riparian zone was characterized to understand the effects of flooding on subsurface hydrological flow paths and nitrate removal in groundwater. Field and laboratory investigations were combined with numerical modeling of dynamic flow and reactive nitrate transport. Flooding enhances...

Isotopic and geochemical evidence of recharge sources and water quality in the Quaternary aquifer beneath Jinchang city, NW China

International Nuclear Information System (INIS)

Ma Jinzhu; Pan Feng; Chen Lihua; Edmunds, W. Mike; Ding Zhenyu; He Jianhua; Zhou Kunpeng; Huang Tianming

2010-01-01

Multiple isotopic and hydrogeochemical tracers were utilized to understand the recharge sources and geochemical evolution of groundwater in the Quaternary aquifer beneath Jinchang city and the adjacent Gobi desert area. The groundwater shows markedly depleted stable isotopic composition compared to modern rainfall. The signature of groundwaters from Jinchang and the northern Gobi desert area differ clearly from that of the alluvial fan in the south Yongchang basin and modern rainfall, and has lower or non-detectable 3 H activity, implying that the aquifer is likely maintained by palaeowater. This groundwater in the Gobi desert has a 14 C age older than 12 ka, indicating that the groundwater resources are non-renewable. The build-up of dissolved solids through evaporation is a major control on groundwater composition, and the dominant anion species change systematically from HCO 3 - , SO 4 2- to Cl - , but cations from weathering of albite, calcite, dolomite and gypsum also make a significant contribution. The scientific results have important implications for groundwater management in Jinchang city and as well as in the Shiyang River basin under China's West Development Strategy. It is recommended that the water allocation program of diverting water from the Dongda river to the Minqin basin be reconsidered.

Groundwater Pollution Source Characterization of an Old Landfill

DEFF Research Database (Denmark)

Kjeldsen, Peter

1993-01-01

Only a few landfill investigations have focused on both the quantity and the quality of leachate as a source of groundwater pollution. The investigation of Vejen Landfill in Denmark included an introductionary historical survey (old maps, aerial photographs, interviews, etc.), leachate quality...... analysis, potential mapping of the groundwater surface below the landfill and leachate flow to surface waters and groundwater. The historical investigation showed that the original soil surface beneath the waste was a relatively heterogeneous mixture of boggy ground and sand soil areas. This indicated...... that the leaching from the landfill could be unevenly distributed. The main specific organic compounds observed in the leachate were aromatic hydrocarbons (mainly xylenes), phenols and the pesticide MCPP. Preliminary investigations of the leach from the landfill indicated, that both a northerly leach to a drainage...

Sampling and Hydrogeology of the Vadose Zone Beneath the 300 Area Process Ponds

International Nuclear Information System (INIS)

Bjornstad, Bruce N.

2004-01-01

Four open pits were dug with a backhoe into the vadose zone beneath the former 300 Area Process Ponds in April 2003. Samples were collected about every 2 feet for physical, chemical, and/or microbiological characterization. This reports presents a stratigraphic and geohydrologic summary of the four excavations

Low-Q structure beneath The Geysers area in the northern California

Science.gov (United States)

Matsubara, M.

2010-12-01

A large reservoir is located beneath The Geysers geothermal area, northern California. Seismic tomography revealed high-velocity (high-V) and low-Vp/Vs zones in the reservoir (Julian et al., 1996) and a decrease of Vp/Vs from 1991 to 1998 (Guasekera et al., 2003) due to withdrawal of steam from the reservoir. I build on these earlier studies by performing the attenuation tomography in this region to investigate the Q structure. The target region, 38.5-39.0°N and 122.5-123°W, covers The Geysers area. I use seismographs of Northern California Earthquake Data Center, which recorded 1235 earthquakes with magnitude larger than 2.0 and resolved focal mechanisms from 2002 to 2008. The band-pass filtered seismographs are analyzed for collecting the maximum amplitude data. Three kinds of Butterworth band-pass filters, such as 1-3, 3-7, and 7-15, correspond to the analysis of the Q structure for 2, 5, and 10 Hz, respectively. I use the P- and S-wave maximum amplitudes between the two seconds after the arrival of those waves in order to avoid the effects by coda. A total of 8980 P- and 1086 S-wave amplitude data for 949 earthquakes recorded at 48 stations are available for the analysis using the attenuation tomographic method (Zao et al., 1996). Extremely low-Qp and Qs zones are found at the northwestern (NW) of The Geysers area at sea level. These zones are consistent with the high-Vp and Vs and low-Vp/Vs zones located at the NW part of the reservoir. The low-Qs zone extends to the southeast (SE) and with approximately 15 km length and 5 km width and has another negative peak beneath the SE part of the reservoir. This low-Qs zone is also consistent with the high-Vp and Vs regions of the reservoir characterized by a low-Vp/Vs zone. However, Qp in the SE part is slightly high. Below sea level in The Geysers reservoir, there are a main greywacke layer and a felsite layer. Above sea level, there is a greenstone melange beneath the NW extremely low-Qp and Qs region and a

Investigation of heat flux processes governing the increase of groundwater temperatures beneath cities

Science.gov (United States)

Bayer, P.; Menberg, K.; Zhu, K.; Blum, P.

2012-12-01

In the subsurface of many cities there are widespread and persistent thermal anomalies. These so-called subsurface urban heat islands (UHIs), which also stimulate warming of urban aquifers, are triggered by various processes. Possible heat sources are basements of buildings, leakage of sewage systems, buried district heating networks, re-injection of cooling water and solar irradiation on paved surfaces. In the current study, the reported groundwater temperatures in several Central European cities, such as Berlin, Cologne (Germany) and Zurich (Switzerland) are compared. Available data sets are supplemented by temperature measurements and depth profiles in observation wells. Trend analyses are conducted with time series of groundwater temperatures, and three-dimensional groundwater temperature maps are provided. In all investigated cities, pronounced positive temperature anomalies are present. The distribution of groundwater temperatures appears to be spatially and temporally highly variable. Apparently, the increased heat input into the urban subsurface is controlled by very local and site-specific parameters. In the long-run, the combination of various heat sources results in an extensive temperature increase. In many cases, the maximum temperature elevation is found close to the city center. Regional groundwater temperature differences between the city center and the rural background are up to 5 °C, with local hot spots of even more pronounced anomalies. Particular heat sources, like cooling water injections or case-specific underground constructions, can cause local temperatures > 20 °C in the subsurface. Examination of the long-term variations in isotherm maps shows that temperatures have increased by about 1 °C in the city, as well as in the rural background areas over the last decades. This increase could be reproduced with trend analysis of temperature data gathered from several groundwater wells. Comparison between groundwater and air temperatures in the

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

International Nuclear Information System (INIS)

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

2005-01-01

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

Groundwater regimes and isotopic studies, Ranger mine area, Northern Territory

Energy Technology Data Exchange (ETDEWEB)

Ahmad, M; Green, D C

1986-12-01

Three types of groundwater occur in the area of the Ranger mine. Type A groundwater occurs in the loose sands and gravels occupying the present day stream channels, Type B in the weathering profile and Type C occurs in relatively fresh fractured bedrock occupying open fractures and other cavities. The three types of groundwater can be distinguished both chemically and isotopically. Light stable isotope data suggest that most early rains are lost by evapotranspiration and have no imprint on the groundwater. Later in the wet season, the ground is saturated and groundwater recharge occurs on a regional scale. This younger groundwater sits on the older waters. Mixing is probably minimal as before any large scale mixing could occur, most younger waters are lost by evapotranspiration. Stable isotope data suggest that Type B groundwater in certain areas has some connection with evaporated surface water bodies. Stable isotope measurements for the pollution monitoring bores around the tailings dam do not indicate any connection with the polluted pond waters at the time of sample collection.

Mixing-induced groundwater denitrification beneath a manured field in southern Alberta, Canada

International Nuclear Information System (INIS)

McCallum, J.E.; Ryan, M.C.; Mayer, B.; Rodvang, S.J.

2008-01-01

Contamination of shallow groundwater by NO 3 - from manure may occur under fields where manure is spread as fertilizer and for disposal. Attenuation of NO 3 - in groundwater occurs through denitrification under certain conditions, or NO 3 - -contaminated younger groundwater may mix with older groundwater, lowering the NO 3 - concentration. In this study, δ 15 N and δ 18 O values of NO 3 - , and δ 18 O and δ 2 H values in groundwater under a manured field were evaluated to determine if groundwater NO 3 - concentrations were influenced through mixing of shallower, manure-impacted groundwater with older groundwater, or if denitrification was reducing NO 3 - concentrations. The younger groundwater showed clear evidence of manure impact with elevated Cl - (∼85 mg L -1 ) and NO 3 - concentrations (∼50 mg NO 3 -N L -1 ), and δ 15 N and δ 18 O values of NO 3 - consistent with a manure source. Vertical hydraulic gradients and δ 18 O and δ 2 H values in groundwater suggest older, more reduced groundwater is upwelling locally and mixing with the shallow groundwater. Decreasing NO 3 :Cl ratios, decreasing dissolved O 2 concentrations, and increasing δ 15 N and δ 18 O values of NO 3 - suggest that denitrification occurs locally in the aquifer. The extent of denitrification is proportional to the fraction of deeper groundwater in the aquifer. Denitrification apparently does not proceed in the younger, manure-impacted groundwater in the absence of mixing

Stochastic simulation of regional groundwater flow in Beishan area

International Nuclear Information System (INIS)

Dong Yanhui; Li Guomin

2010-01-01

Because of the hydrogeological complexity, traditional thinking of aquifer characteristics is not appropriate for groundwater system in Beishan area. Uncertainty analysis of groundwater models is needed to examine the hydrologic effects of spatial heterogeneity. In this study, fast Fourier transform spectral method (FFTS) was used to generate the random horizontal permeability parameters. Depth decay and vertical anisotropy of hydraulic conductivity were included to build random permeability models. Based on high-performance computers, hundreds of groundwater flow models were simulated. Through stochastic simulations, the effect of heterogeneity to groundwater flow pattern was analyzed. (authors)

Uranium Contamination in the Subsurface Beneath the 300 Area, Hanford Site, Washington

Energy Technology Data Exchange (ETDEWEB)

Peterson, Robert E.; Rockhold, Mark L.; Serne, R. Jeffrey; Thorne, Paul D.; Williams, Mark D.

2008-02-29

This report provides a description of uranium contamination in the subsurface at the Hanford Site's 300 Area. The principal focus is a persistence plume in groundwater, which has not attenuated as predicted by earlier remedial investigations. Included in the report are chapters on current conditions, hydrogeologic framework, groundwater flow modeling, and geochemical considerations. The report is intended to describe what is known or inferred about the uranium contamination for the purpose of making remedial action decisions.

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

Science.gov (United States)

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

2010-03-01

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

Radionuclide inventories for the F- and H-area seepage basin groundwater plumes

Energy Technology Data Exchange (ETDEWEB)

Hiergesell, Robert A [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kubilius, Walter P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-05-01

Within the General Separations Areas (GSA) at the Savannah River Site (SRS), significant inventories of radionuclides exist within two major groundwater contamination plumes that are emanating from the F- and H-Area seepage basins. These radionuclides are moving slowly with groundwater migration, albeit more slowly due to interaction with the soil and aquifer matrix material. The purpose of this investigation is to quantify the activity of radionuclides associated with the pore water component of the groundwater plumes. The scope of this effort included evaluation of all groundwater sample analyses obtained from the wells that have been established by the Environmental Compliance & Area Completion Projects (EC&ACP) Department at SRS to monitor groundwater contamination emanating from the F- and H-Area Seepage Basins. Using this data, generalized groundwater plume maps for the radionuclides that occur in elevated concentrations (Am-241, Cm-243/244, Cs-137, I-129, Ni-63, Ra-226/228, Sr-90, Tc-99, U-233/234, U-235 and U-238) were generated and utilized to calculate both the volume of contaminated groundwater and the representative concentration of each radionuclide associated with different plume concentration zones.

Groundwater monitoring in the area of open cast Belchatow

International Nuclear Information System (INIS)

Zimnicki, R.; Soltyk, W.; Derda, M.; Chmielewski, A.G.; Owczarczyk, A.

2006-01-01

Groundwater analyses in the area of the open cast lignite mine Belchatow and Szczercow have been continued since 2000. The field work contains analyses of macro- and microion concentrations as well as measurements of tritium, 222 Rn and mean radioactivity ( 40 K). Complementary to these analyses, isotope ratios of δ 34 S/ 32 S and δ 18 O/ 16 O in SO 4 2- ion and δD in water have been investigated. In 2005 samples of water from boreholes and drains in the area of Szczercow open cast were taken and analyzed. It was found that the groundwater was not polluted, its quality and purity being in agreement with the approved groundwater purity standards

Qualitative risk assessment for the 100-KR-4 groundwater operable unit

Energy Technology Data Exchange (ETDEWEB)

Biggerstaff, R.L.

1994-06-30

This report provides the qualitative risk assessment (QRA) for the 100-KR-4 groundwater operable unit at the US Department of Energy`s (DOE) Hanford Site in southeastern Washington State. The extent of the groundwater beneath the 100 K Area is defined in the Remedial Investigation/Feasibility Study Work Plan for the 100-KR-4 Operable Unit (DOE-RL 1992a). The QRA is an evaluation or risk using a limited amount of data and a predefined set of human and environmental exposure scenarios and is not intended to replace or be a substitute for a baseline risk assessment.

Qualitative risk assessment for the 100-KR-4 groundwater operable unit

International Nuclear Information System (INIS)

Biggerstaff, R.L.

1994-01-01

This report provides the qualitative risk assessment (QRA) for the 100-KR-4 groundwater operable unit at the US Department of Energy's (DOE) Hanford Site in southeastern Washington State. The extent of the groundwater beneath the 100 K Area is defined in the Remedial Investigation/Feasibility Study Work Plan for the 100-KR-4 Operable Unit (DOE-RL 1992a). The QRA is an evaluation or risk using a limited amount of data and a predefined set of human and environmental exposure scenarios and is not intended to replace or be a substitute for a baseline risk assessment

Reconstructing the groundwater flow in the Baltic Basin during the Last glaciation

Science.gov (United States)

Saks, T.; Sennikovs, J.; Timuhins, A.; Kalvāns, A.

2012-04-01

In last decades it has been discussed that most large ice sheets tend to reside on warm beds even in harsh clima tic conditions and subglacial melting occurs due to geothermal heat flow and deformation heat of the ice flow. However the subglacial groundwater recharge and flow conditions have been addressed in only few studies. The aim of this study is to establish the groundwater flow pattern in the Baltic Basin below the Scandinavian ice sheet during the Late Weichselian glaciation. The calculation results are compared to the known distribution of the groundwater body of the glacial origin found in Cambrian - Vendian (Cm-V) aquifer in the Northern Estonia which is believed to have originated as a result of subglacial meltwater infiltration during the reoccurring glaciations. Steady state regional groundwater flow model of the Baltic Basin was used to simulate the groundwater flow beneath the ice sheet with its geometry adjusted to reflect the subglacial topography. Ice thickness modelling data (Argus&Peltier, 2010) was used for the setup of the boundary conditions: the meltwater pressure at the ice bed was assumed equal to the overlying ice mass. The modelling results suggest two main recharge areas of the Cm-V aquifer system, and reversed groundwater flow that persisted for at least 14 thousand years. Model results show that the groundwater flow velocities in the Cm-V aquifer in the recharge area in N-Estonia beneath the ice sheet exceeded the present velocities by a factor of 10 on average. The calculated meltwater volume recharged into the Cm-V aquifer system during the Late Weichselian corresponds roughly to the estimated, however, considering the fact, that the study area has been glaciated at least 4 times this is an overestimation. The modeling results attest the hypothesis of light dO18 groundwater glacial origin in the Cm-V aquifer system, however the volumes, timing and processes involved in the meltwater intrusion are yet to be explored. This study was

Groundwater impact assessment report for the 100-D Ponds

International Nuclear Information System (INIS)

Alexander, D.J.

1993-07-01

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

Hydrogeochemical characteristics of groundwater in selected areas of NWFP

International Nuclear Information System (INIS)

Akram, W.; Sajjad, M.I.; Sheikh, M.R.; Iqbal, M.Z.

1998-01-01

Chemical composition of ground water in selected area of NWFP (Pakistan) was investigated. Water samples were collected from existing open well, tube wells, springs and the river Indus. Important physico-chemical parameter like temperature, pH and electrical conductivity were measured in situ. All the collected samples were analysed for their dissolved chemical constituents (Na, K, Ca, Mg, Cl, HCO/sub 3/, NO/sub 3, SO/sub 4///0 in the laboratory. Different standard technique likes atomic absorption spectrophotometry, UV-visible spectrophotometry, ion selective electrodes and titrimetry were used for sample analyses. Data was used to study the recent trends of ground water chemistry in these areas. Chemical quality of groundwater was evaluated to determine its suitability for drinking purposes by comparing with WHO standards. It was found that groundwater in these areas meets the norms of good quality drinking water except in very few locations. Different compositional types of water were also identified. It was observed that Ca is the dominant cation at most of the locations which is balanced by HCO/sub 3/ giving rise to calcium bicarbonate type groundwater. At few locations groundwater of sodium sodium bicarbonate or mixed type was also encountered. (author)

Effects of acid conditions on element distribution beneath a sulphur basepad

International Nuclear Information System (INIS)

Sevigny, J.H.; Fennell, J.W.; Sharma, A.

1997-04-01

A reconnaissance-scale study was conducted to determine the extent of acid conditions beneath a sulphur basepad at Canadian Occidental's Balzac sour gas plant and to examine the effects of acid conditions on element distribution in the subsurface. Sulphur which is extracted from sour natural gas is stored in large blocks directly on the ground. The elemental sulphur will oxidize to H 2 SO 4 under aerobic conditions and with the proper microorganisms can result in possible removal of metals from the soil and transportation in the groundwater. The basepad at the sour gas plant is 36 years old and is covered by about 1 metre of elemental sulphur. EM31 terrain conductivity and electrical resistivity tomography geophysical surveys were conducted to determine aerial and subsurface bulk electrical conductivity. The objective was to locate the indurated layer using the geophysical techniques and soil boring. The extent of acid conditions beneath the sulphur block was determined. Migration rates for the site were also estimated. Results suggested that minimal soil and groundwater impact can be expected from sulphur blocks overlying properly buffered soils, and that synthetic liners beneath sulphur blocks may not be a necessary measure at sour gas plants in Alberta. 19 refs., 6 tabs., 6 figs., 5 appendices

Tracing recharge to aquifers beneath an Asian megacity with Cl/Br and stable isotopes: the example of Dhaka, Bangladesh

Science.gov (United States)

Hoque, M. A.; McArthur, J. M.; Sikdar, P. K.; Ball, J. D.; Molla, T. N.

2014-06-01

Dhaka, the capital of Bangladesh, is home to a population of 15 million people, whose water supply is 85% drawn from groundwater in aquifers that underlie the city. Values of Cl/Br >500 are common in groundwater beneath western Dhaka in areas leaking sewers and unsewered sanitation, and by river-bank infiltration from the Turag-Buriganga river system which bounds the western limit of the city. River-bank infiltration from other rivers around Dhaka is minor. Values of Cl/Br and Cl concentrations reveal that 23 % of wells sampled in Dhaka are influenced by saline connate water in amounts up to 1%. This residual natural salinity compromises the use of electrical conductivity of groundwater as a method for defining pathways of recharge by contaminated surface waters. Concentrations of As, B, Ba, Cd, Cu, F, Ni, NO3, Pb, Sb, Se and U in groundwater samples are less than WHO health-based guideline values for drinking water.

Groundwater quality around Tummalapalle area, Cuddapah District, Andhra Pradesh, India

Science.gov (United States)

Sreedhar, Y.; Nagaraju, A.

2017-11-01

The suitability of groundwater for drinking and irrigation was assessed in Tummalapalle area. Forty groundwater samples were analysed for major cations, anions and other parameters such as pH, electrical conductivity, total dissolved solids (TDS), total alkalinity and total hardness (TH). The parameters such as sodium adsorption ratio, adjusted sodium adsorption ratio (adj.SAR), per cent sodium, potential salinity, residual sodium carbonate, non-carbonate hardness, Kelly's ratio and permeability index were calculated for the evaluation of irrigation water quality. Groundwater chemistry was also analysed by statistical analysis, USSL, Wilcox, Doneen, Piper and Chadhas diagrams, to find out their suitability for irrigation. TDS and TH were used as main parameters to interpret the suitability of groundwater for drinking purpose. The correlation coefficient matrix between the hydrochemical parameters was carried out using Pearson's correlation to infer the possible water-rock interactions responsible for the variation of groundwater chemistry and this has been supported by Gibbs diagram. The results indicate that the groundwater in Tummalapalle area is alkaline in nature. Ca-Mg-HCO3 is the dominant hydrogeochemical facies. Water chemistry of the study area strongly reflects the dominance of weathering of rock-forming minerals such as bicarbonates and silicates. All parameters and diagrams suggest that the water samples of the study are good for irrigation, and the plots of TDS and TH suggest that 12.5% of the samples are good for human consumption.

The source of groundwater and solutes to Many Devils Wash at a former uranium mill site in Shiprock, New Mexico

Science.gov (United States)

Robertson, Andrew J.; Ranalli, Anthony J.; Austin, Stephen A.; Lawlis, Bryan R.

2016-04-21

from precipitation was calculated to be 0.0008 inches per year (in/yr) by using the mass-balance approach from reported seep discharge and 0.0011 in/yr using the chloride mass-balance approach.A conceptual model of groundwater quality beneath Many Devils Wash is presented to explain the source of solutes in the groundwater beneath Many Devils Wash. The major-ion concentrations and geochemical evolution in the groundwater beneath Many Devils Wash and across the study area support the conceptual model that the underlying Mancos Shale is the source of solutes. Differences in the major-ion composition between groundwater samples collected around the site, result from the degree of weathering to the Mancos Shale. The cation distribution appears to be an indicator of effects from the Mill, with samples from the Mill-affected wells largely having a calcium/magnesium-sulfate composition that resembles the reported compositions of more weathered shale; however, that composition could change if the Mill-processed water flowed into areas where the Mancos Shale was less weathered. On the basis of the widespread presence of uranium in the Mancos Shale and the distribution of aqueous uranium in the analog sites and other sites in the region, it appears likely that uranium in the groundwater of Many Devils Wash is naturally sourced from the Mancos Shale.

Assessment Methods of Groundwater Overdraft Area and Its Application

Science.gov (United States)

Dong, Yanan; Xing, Liting; Zhang, Xinhui; Cao, Qianqian; Lan, Xiaoxun

2018-05-01

Groundwater is an important source of water, and long-term large demand make groundwater over-exploited. Over-exploitation cause a lot of environmental and geological problems. This paper explores the concept of over-exploitation area, summarizes the natural and social attributes of over-exploitation area, as well as expounds its evaluation methods, including single factor evaluation, multi-factor system analysis and numerical method. At the same time, the different methods are compared and analyzed. And then taking Northern Weifang as an example, this paper introduces the practicality of appraisal method.

Microbes Characteristics in Groundwater Flow System in Mountainous Area

Science.gov (United States)

Yamamoto, Chisato; Tsujimura, Maki; Kato, Kenji; Sakakibara, Koichi; Ogawa, Mahiro; Sugiyama, Ayumi; Nagaosa, Kazuyo

2017-04-01

We focus on a possibility of microbes as a tracer for groundwater flow investigation. Some previous papers showed that the total number of prokaryotes in groundwater has correlation with depth and geology (Parkes et al., 1994; Griebler et al., 2009; Kato et al., 2012). However, there are few studies investigating both microbe characteristics and groundwater flow system. Therefore, we investigated a relationship between the total number of prokaryotes and age of spring water and groundwater. Intensive field survey was conducted at four mountainous areas, namely Mt. Fuji (volcano), a headwater at Mt. Setohachi, a headwater at River Oi and a headwater at River Nagano underlain by volcanic lava at Mt. Fuji, granite at Mt. Setohachi and sedimentary rock at River Oi and River Nagano. We collected totally 40 spring water/ groundwater samples in these mountainous areas in October 2015, August, October and November 2016 and analyzed concentration of inorganic ions, the stable isotopes of oxygen - 18, deuterium, CFCs and SF6. Also, we counted prokaryotic cells under the epifluorescence microscopy after fixation and filteration. The total number of prokaryotes in the spring water/ groundwater ranged from 1.0×102 to 7.0×103cells mL-1 at the Mt. Fuji, 1.3×104 to 2.7×105cells mL-1 at Mt. Setohachi, 3.1×104cells mL-1 at River Oi and 1.8×105 to 3.2×106cells mL-1 at River Nagano. The SF6 age of the spring water/ groundwater ranged from 8 to 64 years at Mt. Fuji, 2 to 32.5 years at Mt. Setohachi, 2.5 years at River Oi and 15 to 16 years at River Nagano. The total number of prokaryotes showed a clear negative correlation with residence time of spring water/ groundwater in all regions. Especially the prokaryotes number increased in the order of 102 cells mL-1 with decreasing of residence time in approximately 10 years in the groundwater and spring water with the age less than 15 years.

[Physical process based risk assessment of groundwater pollution in the mining area].

Science.gov (United States)

Sun, Fa-Sheng; Cheng, Pin; Zhang, Bo

2014-04-01

Case studies of groundwater pollution risk assessment at home and abroad generally start from groundwater vulnerability, without considering the influence of characteristic pollutants on the consequences of pollution too much. Vulnerability is the natural sensitivity of the environment to pollutants. Risk assessment of groundwater pollution should reflect the movement and distribution of pollutants in groundwater. In order to improve the risk assessment theory and method of groundwater pollution, a physical process based risk assessment methodology for groundwater pollution was proposed in a mining area. According to the sensitivity of the economic and social conditions and the possible distribution of pollutants in the future, the spatial distribution of risk levels in aquifer was ranged before hand, and the pollutant source intensity corresponding to each risk level was deduced accordingly. By taking it as the criterion for the classification of groundwater pollution risk assessment, the groundwater pollution risk in the mining area was evaluated by simulating the migration of pollutants in the vadose zone and aquifer. The result show that the risk assessment method of groundwater pollution based on physical process can give the concentration distribution of pollutants and the risk level in the spatial and temporal. For single punctuate polluted area, it gives detailed risk characterization, which is better than the risk assessment method that based on aquifer intrinsic vulnerability index, and it is applicable to the risk assessment of existing polluted sites, optimizing the future sites and providing design parameters for the site construction.

Groundwater Quality Assessment for Waste Management Area U: First Determination

Energy Technology Data Exchange (ETDEWEB)

Hodges, Floyd N.; Chou, Charissa J.

2000-08-04

As a result of the most recent recalculation one of the indicator parameters, specific conductance, exceeded its background value in downgradient well 299-W19-41, triggering a change from detection monitoring to groundwater quality assessment program. The major contributors to the higher specific conductance are nonhazardous constituents (i.e., sodium, calcium, magnesium, chloride, sulfate, and bicarbonate). Nitrate, chromium, and technetium-99 are present and are increasing; however, they are significantly below their drinking waster standards. Interpretation of groundwater monitoring data indicates that both the nonhazardous constituents causing elevated specific conductance in groundwater and the tank waste constituents present in groundwater at the waste management area are a result of surface water infiltration in the southern portion of the facility. There is evidence for both upgradient and waste management area sources for observed nitrate concentrations. There is no indication of an upgradient source for the observed chromium and technetium-99.

Seismic evidence of the lithosphere-asthenosphere boundary beneath Izu-Bonin area

Science.gov (United States)

Cui, H.; Gao, Y.; Zhou, Y.

2016-12-01

The lithosphere-asthenosphere boundary (LAB), separating the rigid lithosphere and the ductile asthenosphere layers, is the seismic discontinuity with the negative velocity contrast of the Earth's interior [Fischer et al., 2010]. The LAB has been also termed the Gutenberg (G) discontinuity that defines the top of the low velocity zone in the upper mantle [Gutenberg, 1959; Revenaugh and Jordan, 1991]. The seismic velocity, viscosity, resistivity and other physical parameters change rapidly with the depths across the boundary [Eaton et al., 2009]. Seismic detections on the LAB in subduction zone regions are of great help to understand the interactions between the lithosphere and asthenosphere layers and the geodynamic processes related with the slab subductions. In this study, the vertical broadband waveforms are collected from three deep earthquake events occurring from 2000 to 2014 with the focal depths of 400 600 km beneath the Izu-Bonin area. The waveform data is processed with the linear slant stack method [Zang and Zhou, 2002] to obtain the vespagrams in the relative travel-time to slowness domain and the stacked waveforms. The sP precursors reflected on the LAB (sLABP), which have the negative polarities with the amplitude ratios of 0.17 0.21 relative to the sP phases, are successfully extracted. Based on the one-dimensional modified velocity model (IASP91-IB), we obtain the distributions for six reflected points of the sLABP phases near the source region. Our results reveal that the LAB depths range between 58 and 65 km beneath the Izu-Bonin Arc, with the average depth of 62 km and the small topography of 7 km. Compared with the results of the tectonic stable areas in Philippine Sea [Kawakatsu et al., 2009; Kumar and Kawakatsu, 2011], the oceanic lithosphere beneath the Izu-Bonin Arc shows the obvious thinning phenomena. We infer that the lithospheric thinning is closely related with the partial melting, which is caused by the volatiles continuously released

Preliminary Groundwater Assessment using Electrical Method at Quaternary Deposits Area

Science.gov (United States)

Hazreek, Z. A. M.; Raqib, A. G. A.; Aziman, M.; Azhar, A. T. S.; Khaidir, A. T. M.; Fairus, Y. M.; Rosli, S.; Fakhrurrazi, I. M.; Izzaty, R. A.

2017-08-01

Alternative water sources using groundwater has increasingly demand in recent years. In the past, proper and systematic study of groundwater potential was varies due to several constraints. Conventionally, tube well point was drilled based on subjective judgment of several parties which may lead to the uncertainties of the project success. Hence, this study performed an electrical method to investigate the groundwater potential at quaternary deposits area particularly using resistivity and induced polarization technique. Electrical method was performed using ABEM SAS4000 equipment based on pole dipole array and 2.5 m electrode spacing. Resistivity raw data was analyzed using RES2DINV software. It was found that groundwater was able to be detected based on resistivity and chargeability values which varied at 10 - 100 Ωm and 0 - 1 ms respectively. Moreover, suitable location of tube well was able to be proposed which located at 80 m from the first survey electrode in west direction. Verification of both electrical results with established references has shown some good agreement thus able to convince the result reliability. Hence, the establishment of electrical method in preliminary groundwater assessment was able to assist several parties in term groundwater prospective at study area which efficient in term of cost, time, data coverage and sustainability.

Reassessment of Ground-Water Recharge and Simulated Ground-Water Availability for the Hawi Area of North Kohala, Hawaii

Science.gov (United States)

Oki, Delwyn S.

2002-01-01

An estimate of ground-water availability in the Hawi area of north Kohala, Hawaii, is needed to determine whether ground-water resources are adequate to meet future demand within the area and other areas to the south. For the Hawi area, estimated average annual recharge from infiltration of rainfall, fog drip, and irrigation is 37.5 million gallons per day from a daily water budget. Low and high annual recharge estimates for the Hawi area that incorporate estimated uncertainty are 19.9 and 55.4 million gallons per day, respectively. The recharge estimates from this study are lower than the recharge of 68.4 million gallons per day previously estimated from a monthly water budget. Three ground-water models, using the low, intermediate, and high recharge estimates (19.9, 37.5, and 55.4 million gallons per day, respectively), were developed for the Hawi area to simulate ground-water levels and discharges for the 1990?s. To assess potential ground-water availability, the numerical ground-water flow models were used to simulate the response of the freshwater-lens system to withdrawals at rates in excess of the average 1990?s withdrawal rates. Because of uncertainty in the recharge estimate, estimates of ground-water availability also are uncertain. Results from numerical simulations indicate that for appropriate well sites, depths, and withdrawal rates (1) for the low recharge estimate (19.9 million gallons per day) it may be possible to develop an additional 10 million gallons per day of fresh ground water from the Hawi area and maintain a freshwater-lens thickness of 160 feet near the withdrawal sites, (2) for the intermediate recharge estimate (37.5 million gallons per day) it may be possible to develop an additional 15 million gallons per day of fresh ground water from the Hawi area and maintain a freshwater-lens thickness of 190 feet near the withdrawal sites, and (3) for the high recharge estimate (55.4 million gallons per day) it may be possible to develop at

Groundwater Quality Assessment for Waste Management Area U: First Determination

Energy Technology Data Exchange (ETDEWEB)

FN Hodges; CJ Chou

2000-08-04

Waste Management Area U (TWA U) is located in the 200 West Area of the Hanford Site. The area includes the U Tank Farm, which contains 16 single-shell tanks and their ancillary equipment and waste systems. WMA U is regulated under the Resource Conservation and Recovery Act of 1976 (RCRA) as stipulated in 40 CFR Part 265, Subpart F, which is incorporated into the Washington State dangerous waste regulations (WAC 173-303400) by reference. Groundwater monitoring at WMA U has been guided by an interim status indicator evaluation program. As a result of changes in the direction of groundwater flow, background values for the WMA have been recalculated several times during its monitoring history. The most recent recalculation revealed that one of the indicator parameters, specific conductance, exceeded its background value in downgradient well 299-W19-41. This triggered a change from detection monitoring to a groundwater quality assessment program. The major contributors to the higher specific conductance are nonhazardous constituents, such as bicarbonate, calcium, chloride, magnesium, sodium and sulfate. Chromium, nitrate, and technetium-99 are present and are increasing; however, they are significantly below their drinking water standards. The objective of this study is to determine whether the increased concentrations of chromium, nitrate, and technetium-99 in groundwater are from WMA U or from an upgradient source. Interpretation of groundwater monitoring data indicates that both the nonhazardous constituents causing elevated specific conductance in groundwater and the tank waste constituents present in groundwater at the WMA are a result of surface water infiltration in the southern portion of the WMA. There is evidence that both upgradient and WMA sources contribute to the nitrate concentrations that were detected. There is no indication of an upgradient source for the chromium and technetium-99 that was detected. Therefore, a source of contamination appears to

Groundwater Quality Assessment for Waste Management Area U: First Determination

International Nuclear Information System (INIS)

FN Hodges; CJ Chou

2000-01-01

Waste Management Area U (TWA U) is located in the 200 West Area of the Hanford Site. The area includes the U Tank Farm, which contains 16 single-shell tanks and their ancillary equipment and waste systems. WMA U is regulated under the Resource Conservation and Recovery Act of 1976 (RCRA) as stipulated in 40 CFR Part 265, Subpart F, which is incorporated into the Washington State dangerous waste regulations (WAC 173-303400) by reference. Groundwater monitoring at WMA U has been guided by an interim status indicator evaluation program. As a result of changes in the direction of groundwater flow, background values for the WMA have been recalculated several times during its monitoring history. The most recent recalculation revealed that one of the indicator parameters, specific conductance, exceeded its background value in downgradient well 299-W19-41. This triggered a change from detection monitoring to a groundwater quality assessment program. The major contributors to the higher specific conductance are nonhazardous constituents, such as bicarbonate, calcium, chloride, magnesium, sodium and sulfate. Chromium, nitrate, and technetium-99 are present and are increasing; however, they are significantly below their drinking water standards. The objective of this study is to determine whether the increased concentrations of chromium, nitrate, and technetium-99 in groundwater are from WMA U or from an upgradient source. Interpretation of groundwater monitoring data indicates that both the nonhazardous constituents causing elevated specific conductance in groundwater and the tank waste constituents present in groundwater at the WMA are a result of surface water infiltration in the southern portion of the WMA. There is evidence that both upgradient and WMA sources contribute to the nitrate concentrations that were detected. There is no indication of an upgradient source for the chromium and technetium-99 that was detected. Therefore, a source of contamination appears to

Groundwater pollution by nitrates in irrigated areas with drainage

International Nuclear Information System (INIS)

Chandio, B.M.; Azam, M.; Abdullah, M.

2001-01-01

Field studies were conducted at three selected sites in irrigated areas of Pakistan to assess magnitude and severity of groundwater pollution by nitrates. The results of these studies indicate that concentration of nitrates in most of the samples collected from irrigated areas having drainage facility is much lower than threshold limit. The nitrate-nitrogen level within drainage projects ranges from 0.01-9.00 mg/l and in the area without drainage system ranges from 10.1-12.5 mg/l. The mineral fertilizers though are making contribution of NO3-N to the groundwater sources but that is much lower than threshold limits. The presence of septic tanks or farmyard manure dumps is also significant contributors of NO3-N to the groundwater. Thus drinking water sources near these polluting points are probable danger to human health. It is, therefore, concluded that still there is a lot of potential for fertilizer use in the agriculture but proper drainage facilities should be provided to minimize the potential threat of NO/sub 3/ pollution. (author)

Potential for saturated ground-water system contamination at the Lawrence Livermore National Laboratory

International Nuclear Information System (INIS)

Stone, R.; Ruggieri, M.R.; Rogers, L.L.; Emerson, D.O.; Buddemeier, R.W.

1982-01-01

A program of hydrogeologic investigation has been carried out to determine the likelihood of contaminant movement to the saturated zone from near the ground surface at Lawrence Livermore National Laboratory (LLNL). A companion survey of potential contaminant sources was also conducted at the LLNL. Water samples from selected LLNL wells were analyzed to test the water quality in the uppermost part of the saturated zone, which is from 14 to 48 m (45 to 158 ft) beneath the surface. Only nitrate and tritium were found in concentrations above natural background. In one well, the nitrate was slightly more concentrated than the drinking water limit. The nitrate source has not been found. The tritium in all ground-water samples from wells was found far less concentrated than the drinking water limit. The extent of infiltration of surface water was traced with environmental tritium. The thickness and stratigraphy of the unsaturated zone beneath the LLNL, and nearby area, was determined with specially constructed wells and boreholes. Well hydrograph analysis indicated where infiltration of surface water reached the saturated ground-water system. The investigation indicates that water infiltrating from the surface, through alluvial deposits, reaches the saturated zone along the course of Arroyo Seco, Arroyo Las Positas, and from the depression near the center of the site where seasonal water accumulates. Several potential contaminant sources were identified, and it is likely that contaminants could move from near the ground surface to the saturated zone beneath LLNL. Additional ground-water sampling and analysis will be performed and ongoing investigations will provide estimates of the speed with which potential contaminants can flow laterally in the saturated zone beneath LLNL. 34 references, 61 figures, 16 tables

Validation on groundwater flow model including sea level change. Modeling on groundwater flow in coastal granite area

International Nuclear Information System (INIS)

Hasegawa, Takuma; Miyakawa, Kimio

2009-01-01

It is important to verify the groundwater flow model that reproduces pressure head, water chemistry, and groundwater age. However, water chemistry and groundwater age are considered to be influenced by historical events. In this study, sea level change during glacial-interglacial cycle was taken into account for simulating salinity and groundwater age at coastal granite area. As a result of simulation, salinity movement could not catch up with sea level changes, and mixing zone was formed below the fresh-water zone. This mixing zone was observed in the field measurement, and the observed salinities were agreed with simulated results including sea level change. The simulated residence time including sea level change is one-tenth of steady state. The reason is that the saline water was washed out during regression and modern sea-water was infiltrated during transgression. As mentioned before, considering sea level change are important to reproduce salinity and helium age at coastal area. (author)

Management of groundwater in farmed pond area using risk-based regulation.

Science.gov (United States)

Huang, Jun-Ying; Liao, Chiao-Miao; Lin, Kao-Hung; Lee, Cheng-Haw

2014-09-01

Blackfoot disease (BFD) had occurred seriously in the Yichu, Hsuehchia, Putai, and Peimen townships of Chia-Nan District of Taiwan in the early days. These four townships are the districts of fishpond cultivation domestically in Taiwan. Groundwater becomes the main water supply because of short income in surface water. The problems of over pumping in groundwater may not only result in land subsidence and seawater intrusion but also be harmful to the health of human giving rise to the bioaccumulation via food chain in groundwater with arsenic (As). This research uses sequential indicator simulation (SIS) to characterize the spatial arsenic distribution in groundwater in the four townships. Risk assessment is applied to explore the dilution ratio (DR) of groundwater utilization, which is defined as the ratio showing the volume of groundwater utilization compared to pond water, for fish farming in the range of target cancer risk (TR) especially on the magnitude of 10(-4)~10(-6). Our study results reveal that the 50th percentile of groundwater DRs served as a regulation standard can be used to perform fish farm groundwater management for a TR of 10(-6). For a TR of 5 × 10(-6), we suggest using the 75th percentile of DR for groundwater management. For a TR of 10(-5), we suggest using the 95th percentile of the DR standard for performing groundwater management in fish farm areas. For the TR of exceeding 5 × 10(-5), we do not suggest establishing groundwater management standards under these risk standards. Based on the research results, we suggest that establishing a TR at 10(-5) and using the 95th percentile of DR are best for groundwater management in fish farm areas.

Activity concentration of uranium in groundwater from uranium mineralized areas and its neighborhood

International Nuclear Information System (INIS)

Arabi, S.A.; Funtua, I.I.; Dewu, B.B.M.; Alagbe, S.A.; Garba, M.L.; Kwaya, M.Y.; Baloga, A.D.

2013-01-01

Uranium mineralization in parts of northeastern Nigeria necessitated its exploration during early eighties by the Nigeria Uranium Mining Company (NUMCO) which was later abandoned. During their course of decay, uranium isotopes pass through radioactive decay stage and eventually into stable isotope of lead. The course of concern for soluble uranium in groundwater especially from the mineralized areas include ionizing radiation, chemical toxicity and reproductive defects for which ingested uranium has been implicated to have caused. This study is aimed at assessing the levels of concentration of uranium in groundwater to ascertain its compliance with the World Health Organization's (WHO) and the United State Environmental Protection Agency's (EPA) guideline for uranium in drinking water. Thirty five groundwater samples were collected using EPA's groundwater sampling protocol and analyzed at the Department of Geology, University of Cape Town using an Inductively Coupled Plasma Mass Spectrometric (ICP-MS) technique. Significant finding of this work was that there is radiological contamination of groundwater in the area. There is also an indication that the extent of radiological contamination is not much within the mineralized zones, therefore, there is likelihood that groundwater has acted as a medium of transporting and enhancing uranium in groundwater in an environment away from that of origin. About 5.7 % of the samples studied had uranium concentration above WHO and EPA's maximum contaminant level of 30 μg/L which is a major concern for inhabitants of the area. It was also apparent that radiological contamination at the southwestern part of the study area extends into the adjacent sheet (sheet 152). Uranium concentration above set standards in those areas might have originated from rocks around established mineralized zones but was transported to those contaminated areas by groundwater that leaches across the host rock and subsequently mobilizing soluble uranium

Simulation of the groundwater flow of the Kivetty area

International Nuclear Information System (INIS)

Taivassalo, V.; Meszaros, F.

1994-02-01

Teollisuuden Voima Oy (TVO) is preparing for the final disposal of spent nuclear fuel into crystalline bedrock in Finland. Groundwater flow modelling is a part of the preliminary site investigation work. The aim is to simulate groundwater flow as realistically as possible in view of the experimental data available. Three dimensional groundwater flow modelling is based on a conceptual bedrock model. The modelling results will be used in the site evaluation process. Observations from flow simulations will also be used to identify and study uncertainties included in the site characterization. First a conceptual flow model for the Kivetty site in Konginkangas was developed. As a second stage the flow model was calibrated. The goal was to increase the reality of the model. To evaluate the reality of the flow model, the values of the input and output parameters were compared with the field data. Finally groundwater flow simulation results were computed and groundwater flow at the Kivetty area was analysed. (50 refs., 78 figs., 7 tabs.)

Ground-water investigations of the Project Gnome area, Eddy and Lea Counties, New Mexico

Science.gov (United States)

Cooper, J.B.

1962-01-01

The U.S. Atomic Energy Commission, through the Office of Test Operations, Albuquerque Operations Office, plans to detonate a nuclear device in a massive salt bed 1,200 feet beneath the land surface. The project, known as Project Gnome, is an element of the Plowshare program--a study of peacetime applications of nuclear fission. The location of the proposed underground shot is in a sparsely-populated area in southeastern Eddy County, N. Mex., east of the Pecos River and about 25 miles southeast of the city of Carlsbad. The area is arid to Semiarid and ground water is a vital factor in the economic utilization of the land, which is primarily used for stock raising. An investigation of the Project Gnome site and surrounding area for the purposes of evaluating the ground-water resources and the possible effect upon them from the detonation of the nuclear shot was desired by the Commission. This report describes work done by the U.S. Geological Survey on behalf of the Commission and presents results of the investigation of the ground-water resources and geology of the area. The most intensive investigations were made within a 15-mile radius of the site of Project Gnome and mainly on the east side of the Pecos River. The total area of study of over 1,200 square miles includes parts of Eddy and Lea Counties, N. Mex. The Project Gnome site is in the sedimentary Delaware Basin. It is underlain by about 18,000 feet of sedimentary rocks ranging in age from Ordovician to Recent. Upper Permian evaporitic rocks, which contain the principal source of potash available in the United States, are worked in nearby mines. The potash minerals are found in a massive salt bed about 1,400 feet thick in the Salado Formation of Permian age. The land surface of the area is covered mostly by a wind-blown sand and caliche; however, rocks of the Rustler Formation of Permian age and younger rocks of Permian, Triassic, Pleistocene(?) and Recent age crop out at several localities. Solution by

Interaction between surface water areas and groundwater in Hanoi city, Viet Nam

Science.gov (United States)

Hayashi, T.; Kuroda, K.; Do Thuan, A.; Tran Thi Viet, N.; Takizawa, S.

2012-12-01

Hanoi is the capital of Viet Nam and the second largest city in this country (population: 6.45 million in 2009). Hanoi city has developed along the Red River and has many lakes, ponds and canals. However, recent rapid urbanization of this city has reduced number of natural water areas such as ponds and lakes by reclamation not only in the central area but the suburban area. Canals also have been reclaimed or cut into pieces. Contrary, number of artificial water areas such as fish cultivation pond has rapidly increased. On the other hand, various kind of waste water flows into these natural and artificial water areas and induces pollution and eutrophication. These waste waters also have possibility of pollution of groundwater that is one of major water resources in this city. In addition, groundwater in this area has high concentrations of Arsenic, Fe and NH4. Thus, groundwater use may causes re-circulation of Arsenic. However, studies on the interaction between surface water areas and groundwater and on the role of surface water areas for solute transport with water cycle are a few. Therefore, we focused on these points and took water samples of river, pond and groundwater from four communities in suburban areas: two communities are located near the Red River and other two are far from the River. Also, columnar sediment samples of these ponds were taken and pore water was abstracted. Major dissolved ions, metals and stable isotopes of oxygen and hydrogen of water samples were analyzed. As for water cycle, from the correlation between δ18O and δD, the Red River water (after GNIR) were distributed along the LMWL (δD=8.2δ18O+14.1, calculated from precipitation (after GNIP)). On the other hand, although the pond waters in rainy season were distributed along the LMWL, that in dry season were distributed along the local evaporation line (LEL, slope=5.6). The LEL crossed with the LMWL at around the point of weighted mean values of precipitation in rainy season and of

Denitrification in groundwater at uranium mill tailings sites

International Nuclear Information System (INIS)

Goering, Timothy J.; Groffman, Armando; Thomson, Bruce

1992-01-01

Nitrates are a major contaminant in groundwater at many Uranium Mill Tailings Remedial Action (UMTRA) sites. Microbial denitrification, the transformation of nitrate to nitrogen gas, may be occurring in groundwater at several UMTRA sites. Denitrification is a biologically mediated process whereby facultative anaerobes use nitrate for respiration under anaerobic conditions. Denitrifying bacteria are ubiquitous in soils, sediments, and water. Denitrification requires nitrate, organic carbon, oxygen-limiting conditions, and trace nutrients, especially phosphorus. The lack of organic carbon is the most common limiting factor for denitrification. Denitrification occurs under a limited range of temperature and pH. The uranium milling processes used at UMTRA sites provided a readily available source of carbon and nitrates for denitrifying bacteria. At the Maybell, Colorado, site, the denitrifying organisms Pseudomonas, Flavobacterium and Acinetobacter were identified in core samples of materials from beneath the tailings. In addition, microcosm experiments simulating aquifer conditions beneath the tailings pile showed an average 40 percent decrease in nitrate concentrations over 13 days. At the New Rifle, Colorado, site, aquifer conditions appear favorable for denitrification. Nitrate and organic carbon are readily available in the groundwater, and redox conditions beneath and downgradient of the tailings pile are relatively anoxic. Downgradient from the tailings, total nitrogen is being removed from the groundwater system at a greater rate than the geochemically conservative anion, chloride. This removal may be due to denitrification and adsorption of ammonium onto clay and silt particles. (author)

Denitrification in groundwater at uranium mill tailings sites

Energy Technology Data Exchange (ETDEWEB)

Goering, Timothy J [Jacobs Engineering Group, Inc., Albuquerque, NM (United States); Groffman, Armando [Roy F. Weston, Inc., Albuquerque, NM (United States); Thomson, Bruce [University of New Mexico, Albuquerque, NM (United States)

1992-07-01

Nitrates are a major contaminant in groundwater at many Uranium Mill Tailings Remedial Action (UMTRA) sites. Microbial denitrification, the transformation of nitrate to nitrogen gas, may be occurring in groundwater at several UMTRA sites. Denitrification is a biologically mediated process whereby facultative anaerobes use nitrate for respiration under anaerobic conditions. Denitrifying bacteria are ubiquitous in soils, sediments, and water. Denitrification requires nitrate, organic carbon, oxygen-limiting conditions, and trace nutrients, especially phosphorus. The lack of organic carbon is the most common limiting factor for denitrification. Denitrification occurs under a limited range of temperature and pH. The uranium milling processes used at UMTRA sites provided a readily available source of carbon and nitrates for denitrifying bacteria. At the Maybell, Colorado, site, the denitrifying organisms Pseudomonas, Flavobacterium and Acinetobacter were identified in core samples of materials from beneath the tailings. In addition, microcosm experiments simulating aquifer conditions beneath the tailings pile showed an average 40 percent decrease in nitrate concentrations over 13 days. At the New Rifle, Colorado, site, aquifer conditions appear favorable for denitrification. Nitrate and organic carbon are readily available in the groundwater, and redox conditions beneath and downgradient of the tailings pile are relatively anoxic. Downgradient from the tailings, total nitrogen is being removed from the groundwater system at a greater rate than the geochemically conservative anion, chloride. This removal may be due to denitrification and adsorption of ammonium onto clay and silt particles. (author)

Effects of groundwater-flow paths on nitrate concentrations across two riparian forest corridors

Science.gov (United States)

Speiran, Gary K.

2010-01-01

Groundwater levels, apparent age, and chemistry from field sites and groundwater-flow modeling of hypothetical aquifers collectively indicate that groundwater-flow paths contribute to differences in nitrate concentrations across riparian corridors. At sites in Virginia (one coastal and one Piedmont), lowland forested wetlands separate upland fields from nearby surface waters (an estuary and a stream). At the coastal site, nitrate concentrations near the water table decreased from more than 10 mg/L beneath fields to 2 mg/L beneath a riparian forest buffer because recharge through the buffer forced water with concentrations greater than 5 mg/L to flow deeper beneath the buffer. Diurnal changes in groundwater levels up to 0.25 meters at the coastal site reflect flow from the water table into unsaturated soil where roots remove water and nitrate dissolved in it. Decreases in aquifer thickness caused by declines in the water table and decreases in horizontal hydraulic gradients from the uplands to the wetlands indicate that more than 95% of the groundwater discharged to the wetlands. Such discharge through organic soil can reduce nitrate concentrations by denitrification. Model simulations are consistent with field results, showing downward flow approaching toe slopes and surface waters to which groundwater discharges. These effects show the importance of buffer placement over use of fixed-width, streamside buffers to control nitrate concentrations.

Geothermal properties and groundwater flow estimated with a three-dimensional geological model in a late Pleistocene terrace area, central Japan

Science.gov (United States)

Funabiki, A.; Takemura, T.; Hamamoto, S.; Komatsu, T.

2012-12-01

1. Introduction The ground source heat pump (GSHP) is a highly efficient and renewable energy technology for space heating and cooling, with benefits that include energy conservation and reductions in greenhouse gas emissions. One result of the huge Tohoku-oki earthquake and tsunami and the subsequent nuclear disasters is that GSHPs are receiving more attention from the media and they are being introduced by some local governments. Heat generated by underground GSHP installation, however, can pollute the geothermal environment or change groundwater flow patterns . In this study, we estimated possible effects from the use of GSHPs in the Tokyo area with a three-dimensional (3D) geological model. 2. Geological model The Tokyo Metropolitan Area is surrounded by the Late Pleistocene terraces called the Musashino uplands. The terrace surfaces are densely populated residential areas. One of these surfaces, the Shimosueyohi surface, formed along the Tama River during the last deglacial period. The CRE-NUCHS-1 core (Funabiki et al., 2011) was obtained from this surface, and the lithology, heat transfer coefficients, and chemical characteristics of the sediments were analyzed. In this study, we used borehole log data from a 5 km2 area surrounding the CRE-NUCHS-1 core site to create a 3D geological model. In this area, the Pleistocene Kazusa Group is overlain by terrace gravels and a volcanic ash layer called the Kanto Loam. The terrace gravels occur mainly beneath the Kanda, Kitazawa, and Karasuyama rivers , which flow parallel to the Tama River, whereas away from the rivers , the Kanto Loam directly overlies the Kazusa Group sediments. 3. Geothermal disturbance and groundwater flow Using the geological model, we calculated the heat transfer coefficients and groundwater flow velocities in the sediments. Within the thick terrace gravels, which are at relatively shallow depth (8-20 m), heat transfer coefficients were high and groundwater flow was relatively fast. The amount

hydrochemical assessment of groundwater quality in sagamu area ...

African Journals Online (AJOL)

ABDULRASHEED

alkaline indices (CAI), were calculated for irrigation purposes. The results were presented as spatial distribution maps for interpretation and further inferences. Comparison of the groundwater quality in the area with local and international ...

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-12-01

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

Review: Recharge rates and chemistry beneath playas of the High Plains aquifer, USA

Science.gov (United States)

Gurdak, Jason J.; Roe, Cassia D.

2010-12-01

Playas are ephemeral, closed-basin wetlands that are hypothesized as an important source of recharge to the High Plains aquifer in central USA. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on groundwater from the High Plains aquifer has prompted many questions regarding the contribution and quality of recharge from playas to the High Plains aquifer. As a result, there has been considerable scientific debate about the potential for water to infiltrate the relatively impermeable playa floors, travel through the unsaturated zone sediments that are tens of meters thick, and subsequently recharge the High Plains aquifer. This critical review examines previously published studies on the processes that control recharge rates and chemistry beneath playas. Reported recharge rates beneath playas range from less than 1.0 to more than 500 mm/yr and are generally 1-2 orders of magnitude higher than recharge rates beneath interplaya settings. Most studies support the conceptual model that playas are important zones of recharge to the High Plains aquifer and are not strictly evaporative pans. The major findings of this review provide science-based implications for management of playas and groundwater resources of the High Plains aquifer and directions for future research.

GIS-based evaluation of groundwater vulnerability in the Russeifa area, Jordan

OpenAIRE

El-Naqa, Ali; Hammouri, Nezar; Kuisi, Mustafa

2006-01-01

In recent years, groundwater quality has been deteriorating in many parts of Jordan as result of agriculture expansion, solid waste disposal, and industrialization. A preliminary assessment of vulnerability to groundwater contamination in Russeifa watershed area was undertaken because of the presence of the largest solid waste disposal site in Jordan, which is known as Russeifa landfill. The major geological and hydrogeological factors that affect and control groundwater contamination were in...

Management of groundwater in urban centers: A case study; Greater Dammam Metropolitan Area

International Nuclear Information System (INIS)

Abderrahman, Walid A.; Elamin, Abdalla S.; Al-Harazin, Ibrahim M.; Eqnaibi, Badie S.

2007-01-01

Effective management of groundwater resources in urban centers of arid regions is vital for sustainable development and groundwater protection especially with rapid growth of water demands under water stress conditions. Greater Dammam Metropolitan Area is a good example of rapid growing urban center due to comprehensive development and population growth. The water demand has increased by many times during the last three decades. Groundwater from local aquifers namely Dammam and Umm Er Radhuma, supplies more than 85% of the total water demands. The aquifers have been subjected to extensive and increasing groundwater pumping especially during last three decades. Negative impacts such as significant decline in water levels have been experienced in the area. A new groundwater management scheme in terms of improving the long-term water pumping policies is required for protection of the aquifers groundwater productivity. A special numerical simulation model of the multi-aquifer system including Dammam and Umm Er Radhuma aquifers has been developed to assess the behavior of the aquifer system under long term water stresses in Dammam Metropolitan Area. The developed numerical simulation model has been utilized to predict the responses of the aquifer system in terms of decline in terms of water level under different pumping schemes from the two aquifers during the next 30 years. The model results have postulated the importance of Umm Er Radhuma (UER) aquifer as a major water supply source to Dammam Metropolitan Area, as well as potential recharge source of more than 30% of the total water pumped from Dammam aquifer. These findings have been utilized in improving present and future groundwater management and conservation for the study area. Similar techniques can be used to improve the groundwater management in other parts of the country as well as other arid regions. (author)

Nevada Test 1999 Waste Management Monitoring Report, Area 3 and Area 5 radioactive waste management sites

International Nuclear Information System (INIS)

Yvonne Townsend

2000-01-01

Environmental monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site (NTS). These monitoring data include radiation exposure, air, groundwater, meteorology, vadose zone, and biota data. Although some of these media (radiation exposure, air, and groundwater) are reported in detail in other Bechtel Nevada reports (Annual Site Environmental Report [ASER], the National Emissions Standard for Hazardous Air Pollutants [NESHAP] report, and the Annual Groundwater Monitoring Report), they are also summarized in this report to provide an overall evaluation of RWMS performance and environmental compliance. Direct radiation monitoring data indicate that exposure at and around the RWMSs is not above background levels. Air monitoring data indicate that tritium concentrations are slightly above background levels, whereas radon concentrations are not above background levels. Groundwater monitoring data indicate that the groundwater in the alluvial aquifer beneath the Area 5 RWMS has not been affected by the facility. Meteorology data indicate that 1999 was a dry year: rainfall totaled 3.9 inches at the Area 3 RWMS (61 percent of average) and 3.8 inches at the Area 5 RWMS (75 percent of average). Vadose zone monitoring data indicate that 1999 rainfall infiltrated less than one foot before being returned to the atmosphere by evaporation. Soil-gas tritium data indicate very slow migration, and tritium concentrations in biota were insignificant. All 1999 monitoring data indicate that the Area 3 and Area 5 RWMSs are performing as expected at isolating buried waste

Surface water and groundwater interaction in selected areas of Indus basin

International Nuclear Information System (INIS)

Akram, W.; Ahmad, M.; Tariq, J.A.; Latif, Z.; Malik, M.R.

2011-08-01

Isotope hydrological investigations were carried out in Marala-Khanki Area of Punjab for elucidating various aspects of surface water and groundwater interaction. Groundwater samples were collected on seasonal basis (low and high river discharge periods) while surface water (Chenab River) samples were collected more frequently (weekly or monthly basis). Isotopic data suggested that there is no significant contribution of surface water to groundwater recharge in Marala-Khanki Area and rain is the prevailing source of groundwater recharge. The data further revealed that isotopic values of Tarbala lake are higher than those of main lake. Indus river meaning that there is significant contribution of base flow in this pocket. Isotopic data of Indus river showed an increase at Tunsa as compared to Chashma in flow period indicating the high contribution of base flow at this point in time. Stable isotopes were successfully used to quantify the base flow contribution. (author)

Methodology of determining soil structure in important groundwater areas: case studies in Kauvonkangas, Finnish Lapland

Science.gov (United States)

Kupila, Juho

2016-04-01

Finland is fully self-sufficient in clean groundwater and even has a capacity of exportation. There are approx. 6000 groundwater areas with a total yield of 5.4 million m3/day. Currently only 10% of this groundwater resource is in use. For the efficient and safe exploitation of these areas in the future, detailed modeling of soil structure is an important method in groundwater surveys. 3D -models improve the general knowledge of linkage between land use planning and groundwater protection. Results can be used as a base information in water supply service development and when performing the measures needed in case of environmental accidents. Also, when creating the groundwater flow models the collected information is utilized and is usually the main data source. Geological Survey of Finland has carried out soil structure studies in co-operation with authorities, municipalities and the local water suppliers. The main objectives of these projects are to determine the geological structure of groundwater area for estimating the validity of the present exclusion area, the quantity of ground water volume and recharge capability and possible risks to the groundwater. Research areas are usually under an active water supply service. Kauvonkangas groundwater area is located in the municipality of Tervola, in Southern part of Finnish Lapland. Extent of the area is 7.9 km2 and it is an important water source for the local and nearby population centers. There are two active water supply companies in the area. Field studies in the project will include general geological and hydrological mapping, soil drilling with observation pipe installation, test pumping and water sampling. Geophysical measures will play a key-role, including ground penetrating radar (GPR) and gravimetric measurements. Studies will be carried out in spring and summer 2016. The main results will be the models of the bedrock and groundwater level and main characteristics of the soil layers in the area. Results

A GIS/Remote Sensing-based methodology for groundwater potentiality assessment in Tirnavos area, Greece

Science.gov (United States)

Oikonomidis, D.; Dimogianni, S.; Kazakis, N.; Voudouris, K.

2015-06-01

The aim of this paper is to assess the groundwater potentiality combining Geographic Information Systems and Remote Sensing with data obtained from the field, as an additional tool to the hydrogeological research. The present study was elaborated in the broader area of Tirnavos, covering 419.4 km2. The study area is located in Thessaly (central Greece) and is crossed by two rivers, Pinios and Titarisios. Agriculture is one of the main elements of Thessaly's economy resulting in intense agricultural activity and consequently increased exploitation of groundwater resources. Geographic Information Systems (GIS) and Remote Sensing (RS) were used in order to create a map that depicts the likelihood of existence of groundwater, consisting of five classes, showing the groundwater potentiality and ranging from very high to very low. The extraction of this map is based on the study of input data such as: rainfall, potential recharge, lithology, lineament density, slope, drainage density and depth to groundwater. Weights were assigned to all these factors according to their relevance to groundwater potential and eventually a map based on weighted spatial modeling system was created. Furthermore, a groundwater quality suitability map was illustrated by overlaying the groundwater potentiality map with the map showing the potential zones for drinking groundwater in the study area. The results provide significant information and the maps could be used from local authorities for groundwater exploitation and management.

Preliminary analysis for model development of groundwater evolution in Horonobe area

International Nuclear Information System (INIS)

Yoshida, Yasushi; Yui, Mikazu

2003-03-01

The preliminary analysis for model development of groundwater evolution in Horonobe area was performed with data at D-1, HDB-1 and HDB-2 bore hole where hydrogen / oxygen isotope concentration, mineral property in sedimentary rock and physico-chemical parameters (pH, Eh and ionic concentrations) were measured. As a result of analysis for hydrogen and oxygen isotope concentration, saline water in marine sediment was diluted by the mixing with shallow groundwater and diffusion. And as a result of analysis for a concentration of bicarbonate from the difference of pH values measured between in-situ and under air, the estimated in-situ concentration of bicarbonate differs from that measured under air. And minerals which were assumed to be equilibrium with groundwater were selected by thermodynamic calculation. This report presents the results of preliminary analysis for groundwater evolution by using data derived from D-1, HDB-1 and HDB-2 boring research. In order to establish the model which interprets the groundwater evolution as a next step, data which satisfy the representative in-situ property of groundwater chemistry in Horonobe area are needed. Reliable measurements for physico-chemical parameter and property of minerals in sedimentary rock in dominant layer and at the variety of depth are also needed. (author)

Investigations of groundwater system and simulation of regional groundwater flow for North Penn Area 7 Superfund site, Montgomery County, Pennsylvania

Science.gov (United States)

Senior, Lisa A.; Goode, Daniel J.

2013-01-01

Groundwater in the vicinity of several industrial facilities in Upper Gwynedd Township and vicinity, Montgomery County, in southeast Pennsylvania has been shown to be contaminated with volatile organic compounds (VOCs), the most common of which is the solvent trichloroethylene (TCE). The 2-square-mile area was placed on the National Priorities List as the North Penn Area 7 Superfund site by the U.S. Environmental Protection Agency (USEPA) in 1989. The U.S. Geological Survey (USGS) conducted geophysical logging, aquifer testing, and water-level monitoring, and measured streamflows in and near North Penn Area 7 from fall 2000 through fall 2006 in a technical assistance study for the USEPA to develop an understanding of the hydrogeologic framework in the area as part of the USEPA Remedial Investigation. In addition, the USGS developed a groundwater-flow computer model based on the hydrogeologic framework to simulate regional groundwater flow and to estimate directions of groundwater flow and pathways of groundwater contaminants. The study area is underlain by Triassic- and Jurassic-age sandstones and shales of the Lockatong Formation and Brunswick Group in the Mesozoic Newark Basin. Regionally, these rocks strike northeast and dip to the northwest. The sequence of rocks form a fractured-sedimentary-rock aquifer that acts as a set of confined to partially confined layers of differing permeabilities. Depth to competent bedrock typically is less than 20 ft below land surface. The aquifer layers are recharged locally by precipitation and discharge locally to streams. The general configuration of the potentiometric surface in the aquifer is similar to topography, except in areas affected by pumping. The headwaters of Wissahickon Creek are nearby, and the stream flows southwest, parallel to strike, to bisect North Penn Area 7. Groundwater is pumped in the vicinity of North Penn Area 7 for industrial use, public supply, and residential supply. Results of field investigations

Isotopic study of the effect of Tarbela reservoir on the groundwater system in the downstream areas

International Nuclear Information System (INIS)

Sajjad, M.I.; Tasneem, M.A.; Hussain, S.D.; Khan, I.H.; Ali, M.; Latif, Z.

1994-04-01

Isotopic studies were carried out on the right side of river Indus, downstream of Tarbela dam to study the effect of Tarbela Reservoir on the groundwater system. The main objectives of the study were to determine the hydraulic connection, if any, between the Tarbela Lake and the groundwater appearing in the ponds near Gadon Amazai, see the effect of Tarbela dam on the groundwater system in the downstream areas, compute the relative contribution of different recharge sources towards groundwater system and to estimate residence time of groundwater in the area. Isotopic data reveals that the ponds near Gadoon Amazai area are being recharged by local rains and there is no contribution of Tarbela lake. The area around Gadoon Amazai, Topi and Kalabat is solely recharged by local rains while the area around Swabi, Zaida and Lahor has mixed recharge with major contribution from local canal system. Tritium data suggests that the residence time of groundwater in the study area varies from a few years to 30 years. Te groundwater in the area has low dissolved salt contents and is, generally, of good quality. (author) 19 figs

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

International Nuclear Information System (INIS)

Saka, David

2011-07-01

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

A comprehensive analysis of contaminant transport in the vadose zone beneath tank SX-109

International Nuclear Information System (INIS)

Ward, A.L.; Gee, G.W.; White, M.D.

1997-02-01

The Vadose Zone Characterization Project is currently investigating the subsurface distribution of gamma-emitting radionuclides in S and SX Waste Management Area (WMA-S-SX) located in the 200 West Area of the US Department of Energy's Hanford Site in southeastern Washington State. Spectral-gamma logging of boreholes has detected elevated 137 Cs concentrations as deep as 38 m, a depth considered excessive based on the assumed geochemistry of 137 Cs in Hanford sediments. Routine groundwater sampling under the Resource Conservation and Recovery Act (RCRA) have also detected elevated levels of site-specific contaminants downgradient of WMA-S-SX. The objective of this report is to explore the processes controlling the migration of 137 Cs, 99 Tc, and NO 3 through the vadose zone of WMA-S-SX, particularly beneath tank SX-109

Groundwater monitoring plan for the 300 Area process trenches

Energy Technology Data Exchange (ETDEWEB)

Lindberg, J.W.; Chou, C.J.; Johnson, V.G.

1995-05-23

This document describes the groundwater monitoring program for the Hanford Site 300 Area Process Trenches (300 APT). The 300 APT are a Resource Conservation and Recovery Act of 1976 (RCRA) regulated unit. The 300 APT are included in the Dangerous Waste Portion of the Resource Conservation and Recovery Act Permit for the Treatment, Storage, and Disposal of Dangerous Waste, Permit No. WA890008967, and are subject to final-status requirements for groundwater monitoring. This document describes a compliance monitoring program for groundwater in the uppermost aquifer system at the 300 APT. This plan describes the 300 APT monitoring network, constituent list, sampling schedule, statistical methods, and sampling and analysis protocols that will be employed for the 300 APT. This plan will be used to meet groundwater monitoring requirements from the time the 300 APT becomes part of the Permit and through the postclosure care period until certification of final closure.

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

International Nuclear Information System (INIS)

Thibault, J.J.

1999-01-01

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

General Separations Area (GSA) Groundwater Flow Model Update: Hydrostratigraphic Data

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-21

This document describes the assembly, selection, and interpretation of hydrostratigraphic data for input to an updated groundwater flow model for the General Separations Area (GSA; Figure 1) at the Department of Energy’s (DOE) Savannah River Site (SRS). This report is one of several discrete but interrelated tasks that support development of an updated groundwater model (Bagwell and Flach, 2016).

Development and validation of GWHEAD, a three-dimensional groundwater head computer code

International Nuclear Information System (INIS)

Beckmeyer, R.R.; Root, R.W.; Routt, K.R.

1980-03-01

A computer code has been developed to solve the groundwater flow equation in three dimensions. The code has finite-difference approximations solved by the strongly implicit solution procedure. Input parameters to the code include hydraulic conductivity, specific storage, porosity, accretion (recharge), and initial hydralic head. These parameters may be input as varying spatially. The hydraulic conductivity may be input as isotropic or anisotropic. The boundaries either may permit flow across them or may be impermeable. The code has been used to model leaky confined groundwater conditions and spherical flow to a continuous point sink, both of which have exact analytical solutions. The results generated by the computer code compare well with those of the analytical solutions. The code was designed to be used to model groundwater flow beneath fuel reprocessing and waste storage areas at the Savannah River Plant

Distribution of arsenic in groundwater in the area of Chalkidiki, Northern Greece

International Nuclear Information System (INIS)

Kouras, A.; Katsoyiannis, I.; Voutsa, D.

2007-01-01

An integrate study aiming at the occurrence and distribution of arsenic in groundwater in the area of Chalkidiki, Northern Greece has been carried out. Groundwater samples from public water supply wells and private wells were analysed for arsenic and other quality parameters (T, pH, EC, Ca, Mg, Na, K, Cl, HCO 3 , NO 3 , SO 4 , B, Fe, Mn). Arsenic showed high spatial variation; ranged from 0.001 to 1.840 mg/L. Almost 65% of the examined groundwaters exhibit arsenic concentrations higher than the maximum concentration limit of 0.010 mg/L, proposed for water intended for human consumption. Correlation analysis and principal component analysis were employed to find out possible relationships among the examined parameters and groundwater samples. Arsenic is highly correlated with potassium, boron, bicarbonate, sodium, manganese and iron suggesting common geogenic origin of these elements and conditions that enhance their mobility. Three groups of groundwater with different physicochemical characteristics were found in the study area: (a) groundwater with extremely high arsenic concentrations (1.6-1.9 mg/L) and high temperature (33-42 deg. C) from geothermal wells, (b) groundwater with relatively high arsenic concentrations (>0.050 mg/L), lower temperatures and relatively high concentrations of major ions, iron and manganese and, (c) groundwater with low arsenic concentrations that fulfil the proposed limits for dinking water

Physical analysis of groundwater at thickly populated area of Faisalabad by using GIS

International Nuclear Information System (INIS)

Nasir, A.; Arslan, C.; Sattar, A.

2012-01-01

Groundwater is the major source of drinking and soil pollution deteriorates its quality. The study was conducted in the area of Ghulam Muhammad Abad, the most thickly populated area of District Faisalabad, Pakistan. Primary information was collected by conducting the general survey of the area. Sampling was done by dividing the entire area into six zones. A total of 159 groundwater samples were collected from newly installed pumps at the depth of 90 ft. The samples were then tested for physical parameters as EC (electrical conductivity), pH, TDS (total dissolved solids), TS (total solids) and TSS (total suspended solids). Test results were compared with the guidelines given by WHO (World Health Organization), and standards drafted by PSI (Pakistan Standard Institution). GIS analysis was done by using ArcGIS v 9.2. These parameters were analyzed in drinking water with respect to drinking purpose. EC of samples ranged from 0.074 S/m to 6.044 S/m. Only 8 samples were found within the permissible limit given by WHO, i.e. 2.504 S/m. GIS analysis showed that most of the area have EC greater than permissible limit. pH value ranged from 2.19 to 6.20. All the samples were found below the permissible limit given by WHO, i.e. 6.5 to 8.5. GIS map for pH indicated that almost 80% area has the pH value ranging from 4.90 to 5.21. TDS in groundwater samples ranged from 309 mg/L to 3530 mg/L. Only 2 samples were found within the permissible limit given by PSI, i.e. 1500 mg/L. GIS analysis revealed that almost 50% area lies under high concentration of TDS. TSS in samples varied from 3 mg/L to 2222 mg/L. There were no guidelines for TSS in drinking water but are supposed to be near to 0 mg/L in groundwater. TS in groundwater samples varied from 400 mg/L to 5200 mg/L. High value of TS effect the value of EC and TDS. Hence, all the values of physical parameters revealed that the groundwater of the area is not suitable for drinking purpose and needs to improve the groundwater quality of

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

Directory of Open Access Journals (Sweden)

Dorota Porowska

2014-10-01

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

Groundwater quality in alluvial and prolluvial areas under the influence of irrigated agriculture activities.

Science.gov (United States)

Kovacevik, Biljana; Boev, Blazo; Panova, Vesna Zajkova; Mitrev, Sasa

2016-12-05

The aim of this study was to investigate the groundwater pollution from alluvial aquifers lying under surface agriculture activities in two geologically different areas: alluvial and prolluvial. The groundwater in investigated areas is neutral to alkaline (pH 7.05-8.45), and the major dissolved ions are bicarbonate and calcium. Groundwater samples from the alluvial area are characterized by nitrate concentration above the national maximum concentration limit (MCL) at 20.5% of samples [mean value (Me) 6.31 mg/L], arsenic concentrations greater than national MCL at 35.6% of investigated samples (Me 12.12 µg/L) and elevated concentrations of iron (Me 202.37 µg/L) and manganese (Me 355.22 µg/L) at 22.7% and 81% of investigated samples, respectively. Groundwater samples from the prolluvial area did not show significantly elevated concentrations of heavy metals, but the concentration of nitrate was considerably higher (Me 65.06 mg/L). Factor analysis positively correlates As with Mn and Fe, suggesting its natural origin. Nitrate was found in positive correlation with SO 4 2- and Ni but in negative with NH 4 + , suggesting its anthropogenic origin and the relationship of these ions in the process of denitrification. The t-test analysis showed a significant difference between nitrate pollution of groundwater from alluvial and prolluvial areas. According to the chemical composition of groundwater, the process of denitrification is considered to be the main reason for the reduced presence of nitrate in the groundwater lying under alluvial deposits represented by chalk and sandstones. Denitrification in groundwater lying under prolluvial deposits represented by magmatic and metamorphic rock formations was not observed.

Study Of Isotopic Technical Application To Estimate Origin Of Nitrogen Composition Of Groundwater In Hanoi Area

International Nuclear Information System (INIS)

Trinh Van Giap; Dinh Bich Lieu; Dang Anh Minh; Vo Thi Anh; Bui Dac Dung; Nguyen Thi Hong Thinh; Nguyen Manh Hung; Nguyen Van Hoan; Nguyen Van Hai

2007-01-01

Groundwater in Hanoi area as well as some other areas in Bac-Bo Delta is being contaminated by heavy metals and nitrogen compounds, especially arsenic and ammonium. The origin of nitrogen compounds in groundwater in Hanoi area is estimated in order to exploit and manage sustainable groundwater served for production and live. (author)

GIS based Hydrogeological Vulnerability Mapping of Groundwater Resources in Jerash Area-Jordan

Energy Technology Data Exchange (ETDEWEB)

Hammouri, N [Department of Earth and Environmental Sciences, Faculty of Natural Resources and Environment, Hashemite University, Zarqa (Jordan); El-Naqa, A [Department of Water Management and Environment, Faculty of Natural Resources and Environment, Hashemite University, Zarqa (Jordan)

2008-04-15

This paper presents groundwater vulnerability mapping for Jerash area, north Jordan generated using EPIK and DRASTIC models. These models have been implemented using GIS to delineate groundwater protection zones and to suggest a protection plan to improve groundwater quality of the major springs and wells. Most of the groundwater resources in the study area are polluted and bacteria and nitrate levels are high. Different sources of groundwater pollution have been identified. Domestic wastewater is considered as a major source of pollution. Urban runoff, fertilizers from agricultural return flows and solid waste disposal appear to be secondary sources. The most relevant vulnerability class of EPIK map is very high which accounts for about 41 % of the total area. While in the DRASTIC vulnerability map, areas with high vulnerability were only about 23 % of the total area. There is a good correlation between vulnerability maps obtained from both models with microbiological and chemical pollution evidences. There is also a good agreement between the areas classified as highly vulnerable and those that have high levels of pollution. [Spanish] El estudio de vulnerabilidad de aguas subterraneas en la region de Yerash, Jordania fue obtenido mediante las metodologias de EPIK y DRASTIC. Se uso GIS para mapear las zonas protegidas y para sugerir un plan de proteccion para mejorar la calidad del agua subterranea en los principales manantiales y pozos. Los niveles de contaminacion bacteriana y de nitratos son elevados. El efluente domestico es la fuente mas importante de contaminacion; vienen en segundo lugar la precipitacion en zonas urbanas, los fertilizantes agricolas y los desechos solidos. En el mapa de EPIK, la vulnerabilidad extrema abarca hasta 41% del area total; en cambio, en el mapa de DRASTIC las areas de alta vulnerabilidad ocupan solo un 23% del area. La correlacion de los datos de contaminacion microbiana y quimica con ambos mapas der vulnerabilidad es buena

Simulating Lake-Groundwater Interactions During Decadal Climate Cycles: Accounting For Variable Lake Area In The Watershed

Science.gov (United States)

Virdi, M. L.; Lee, T. M.

2009-12-01

The volume and extent of a lake within the topo-bathymetry of a watershed can change substantially during wetter and drier climate cycles, altering the interaction of the lake with the groundwater flow system. Lake Starr and other seepage lakes in the permeable sandhills of central Florida are vulnerable to climate changes as they rely exclusively on rainfall and groundwater for inflows in a setting where annual rainfall and recharge vary widely. The groundwater inflow typically arrives from a small catchment area bordering the lake. The sinkhole origin of these lakes combined with groundwater pumping from underlying aquifers further complicate groundwater interactions. Understanding the lake-groundwater interactions and their effects on lake stage over multi-decadal climate cycles is needed to manage groundwater pumping and public expectation about future lake levels. The interdependence between climate, recharge, changing lake area and the groundwater catchment pose unique challenges to simulating lake-groundwater interactions. During the 10-year study period, Lake Starr stage fluctuated more than 13 feet and the lake surface area receded and expanded from 96 acres to 148 acres over drier and wetter years that included hurricanes, two El Nino events and a La Nina event. The recently developed Unsaturated Zone Flow (UZF1) and Lake (LAK7) packages for MODFLOW-2005 were used to simulate the changing lake sizes and the extent of the groundwater catchment contributing flow to the lake. The lake area was discretized to occupy the largest surface area at the highest observed stage and then allowed to change size. Lake cells convert to land cells and receive infiltration as receding lake area exposes the underlying unsaturated zone to rainfall and recharge. The unique model conceptualization also made it possible to capture the dynamic size of the groundwater catchment contributing to lake inflows, as the surface area and volume of the lake changed during the study

Ground-water monitoring under RCRA

International Nuclear Information System (INIS)

Coalgate, J.

1993-11-01

In developing a regulatory strategy for the disposal of hazardous waste under the Resource Conservation and Recovery Act (RCRA), protection of ground-water resources was the primary goal of the Environmental Protection Agency (EPA). EPA's ground-water protection strategy seeks to minimize the potential for hazardous wastes and hazardous constituents in waste placed in land disposel units to migrate into the environment. This is achieved through liquids management (limiting the placement of liquid wastes in or on the land, requiring the use of liners beneath waste, installing leachate collection systems and run-on and run-off controls, and covering wastes at closure). Ground-water monitoring serves to detect any failure in EPA's liquids management strategy so that ground-water contamination can be detected and addressed as soon as possible

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-11-01

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

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

International Nuclear Information System (INIS)

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

1993-11-01

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

Recharge beneath low-impact design rain gardens and the influence of El Niño Southern Oscillation on urban, coastal groundwater resources

Science.gov (United States)

Newcomer, M. E.; Gurdak, J. J.

2011-12-01

Groundwater resources in urban, coastal environments are highly vulnerable to increased human pressures and climate variability. Impervious surfaces, such as buildings, roads, and parking lots prevent infiltration, reduce recharge to underlying aquifers, and increase contaminants in surface runoff that often overflow sewage systems. To mitigate these effects, cities worldwide are adopting low impact design (LID) approaches that direct runoff into natural vegetated systems, such as rain gardens that reduce, filter, and slow stormwater runoff, and are hypothesized to increase infiltration and recharge rates to aquifers. The effects of LID on recharge rates and quality is unknown, particularly during intense precipitation events for cities along the Pacific coast in response to interannual variability of the El Niño Southern Oscillation (ENSO). Using vadose zone monitoring sensors and instruments, I collected and monitored soil, hydraulic, and geochemical data to quantify the rates and quality of infiltration and recharge to the California Coastal aquifer system beneath a LID rain garden and traditional turf-lawn setting in San Francisco, CA. The data were used to calibrate a HYDRUS-3D model to simulate recharge rates under historical and future variability of ENSO. Understanding these processes has important implications for managing groundwater resources in urban, coastal environments.

Edible Oil Barriers for Treatment of Chlorinated Solvent and Perchlorate-Contaminated Groundwater

Science.gov (United States)

2010-02-01

The groundwater potentiometric surface beneath SWMU 17 is relatively flat with some tidal influence resulting in fluctuating groundwater flow...after its application, the pH within most of the aquifer would be expected to vary between background (~5) and 9. A titration experiment determined

Pavement Subsidence in the Cumberland Gap Tunnel, USA: A Story of Groundwater Chemistry

Science.gov (United States)

Zhu, J.; Currens, J. C.; Webb, S. E.; Rister, B. W.

2014-12-01

Cumberland Gap Tunnel was constructed in 1996 to improve highway travel between southeastern Kentucky and northeastern Tennessee and to restore Cumberland Gap to its historical appearance. About five years after construction, the concrete pavement in the tunnel began to exhibit noticeable signs of subsidence. Ground penetrating radar surveys detected voids in many areas of the limestone roadbed aggregate beneath the pavement. Field investigations conducted by the Kentucky Geological Survey and Kentucky Transportation Center from 2006 to 2008 discovered that groundwater was flowing from the bedrock invert into the aggregate along many parts of the tunnel. Average groundwater discharge from the tunnel was measured at approximately 1700 m3/d. We analyzed 265 groundwater samples collected from aggregate in different parts of the tunnel roadbed during low and high flow conditions. Calculated calcite saturation indices indicated that the groundwater was geochemically aggressive and capable of continuously dissolving calcite in the limestone aggregate although pH values of these water samples were near neutral. We also conducted an in-situ dissolution experiment by placing eight baskets filled with limestone aggregate beneath the roadbed in different locations in the tunnel for 178 days. At the end of the experiment, the limestone aggregate in contact with groundwater exhibited visual signs of dissolution and lost mass, and the highest mass loss recorded was 3.4 percent. Mass loss calculations based on kinetic models of calcite mineral and water samples taken near the baskets matched well with the actual measured mass losses, confirming that dissolution of calcite by the groundwater was the primary cause of the roadbed subsidence problem. Based on these findings, we suggested the limestone aggregate be replaced with noncarbonate (granite) aggregate to mitigate future road subsidence. The suggestion was adopted, and the repair was completed in early 2014.

Regional assessment of groundwater resources (hydrogeological map of Younggwang area, Korea vol.8)

Energy Technology Data Exchange (ETDEWEB)

Choi, S H; Kim, Y K; Hong, Y K; Cho, M J; Lee, D W; Bae, D J; Lee, C W; Kim, H C; Kim, S J; Park, S W; Lee, P K; Yum, B W; Moon, S H; Lee, S K; Lee, S R; Park, Y S; Lim, M T; Sung, K S; Park, I H; Ham, S Y; Kim, Y J; Woo, N C [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1997-12-01

This study is objected to characterize groundwater resources, to assess groundwater contamination, and to produce hydrogeological and related thematic maps of the study area. The study area, Younggwang County, Chonnam Province, covers the area of 460 km{sup 2}. To accomplish the objectives various studies have been carried out including general and structural geology, GIS, hydrogeology, geophysics and hydrogeochemical analysis. Geophysical explorations, dipole-dipole resistivity, Schulumberger sounding and magnetic method, were executed for investigating geologic structure and determining test borehole sites. Some test boreholes such as, Honggok, Donggan, Weolsan and Seolmae hit aquifer structures. Geophysical logging, such as gamma ray, temperature, water conductivity, electrical resistivity, self-potential were also executed for petrological differentiation and in out flow of groundwater. The recharge rate of granitic region is more than the others, which derived by the analysis of 7 low-flow measurements in 10 small watersheds in the area. The recharge rate has been estimated at 7.2%(99.3 mm/year) in the vicinity. Well inventory of the area included 197 deep wells and 43 shallow wells. In addition, 10 stream samples and one spring were surveyed for water level, water temperature, pH, EC, TDS and the concentration of dissolved oxygen(DO). Regional groundwater pollution susceptibility was analyzed using GIS technique. A standard method, `DRASTIC` developed by US EPA, was applied to evaluate groundwater pollution potential and aquifer susceptibility. Resulting DRASTIC indices ranged from 52 to 141, and the Pesticide indices from 61 to 187. Seawater intrusion phenomena in Sangsari-Hasari are considered and evaluated by well inventory and the selected borehole`s electric conductivity(EC) logging. Seawater intrusion to the vulnerable coastal alluvium aquifers is generally depleted with time. The amount of potential groundwater resources in the study area is estimated

Applying Environmental Isotope Theory to Groundwater Recharge in the Jiaozuo Mining Area, China

Directory of Open Access Journals (Sweden)

Pinghua Huang

2017-01-01

Full Text Available This study establishes the surface water evaporation line in theory and numerically simulates the δD and δ18O value distribution interval of the recharge source of deep groundwater in the Jiaozuo mining area. The recharge elevation is calculated based on hydrogen and oxygen isotope tracer theory. Theoretical calculation and experimental data indicate that the surface water evaporation line in the study area in theory is almost the same as the measured surface data-fitting line. A significant linear relationship is identified between δ18O and the elevation of spring outcrop. The topography increases per 100 m, and the δ18O value reduces by 0.23‰ on average. The δ18O value is converted into formula to calculate the groundwater recharge elevation, which is approximately from 400 to 800 m. The measured tritium values of karst groundwater are greater than 3 TU. The second factor score is a fraction distribution in shallow groundwater and negative fraction distribution in spring and deep groundwater, which indicates that the Northern Taihang Mountain is the main recharge area, where carbonate-exposed areas exist. The research conclusion holds a certain value for the flood evaluation of local coal mines.

Development of a Groundwater Management Model for the Project Shoal Area

Energy Technology Data Exchange (ETDEWEB)

G. Lamorey; S. Bassett; R. Schumer; D. Boyle; G. Pohll; J. Chapman

2006-09-01

This document describes the development of a user-friendly and efficient groundwater management model of the Project Shoal Area (PSA and surrounding area that will allow the U.S. Department of Energy and State of Nevada personnel to evaluate the impact of proposed water-use scenarios. The management model consists of a simple hydrologic model within an interactive groundwater management framework. This framework is based on an object user interface that was developed by the U.S. Geological Survey and has been used by the Desert Research Institute researchers and others to couple disparate environmental resource models, manage temporal and spatial data, and evaluate model results for management decision making. This framework was modified and applied to the PSA and surrounding Fairview Basin. The utility of the management model was demonstrated through the application of hypothetical future scenarios including mineral mining, regional expansion of agriculture, and export of water to large urban areas outside the region. While the results from some of the scenarios indicated potential impacts to groundwater levels near the PSA and others did not, together they demonstrate the utility of the management tool for the evaluation of proposed changes in groundwater use in or near the PSA.

Hanford Site Groundwater Monitoring for Fiscal Year 1998

Energy Technology Data Exchange (ETDEWEB)

Hartman, M.J. [and others

1999-03-24

This report presents the results of groundwater and vadose-zone monitoring and remediation for fiscal year (FY) 1998 on the Word Site, Washington. Soil-vapor extraction in the 200-West Area removed 777 kg of carbon tetrachloride in FY 1998, for a total of 75,490 kg removed since remediation began in 1992. Spectral gamma logging and evaluation of historical gross gamma logs near tank farms and liquid-disposal sites in the 200 Areas provided information on movement of contaminants in the vadose zone. Water-level monitoring was performed to evaluate groundwater-flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Water levels over most of the Hanford Site continued to decline between June 1997 and June 1998. The most widespread radiological contaminant plumes in groundwater were tritium and iodine-129. Concentrations of technetium-99, uranium, strontium-90, and carbon-14 also exceeded drinking water standards in smaller plumes. Plutonium and cesium-137 exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in U.S. Department of Energy Order 5400.5 were exceeded for tritium, uranium, strontium-90, and plutonium in small plumes or single wells. One well completed in the basalt-confined aquifer beneath the 200-East Area exceeded the drinking water standard for technetium-99. Nitrate is the most extensive chemical contaminant. Carbon tetrachloride, chloroform, chromium, cis-l, Z-dichloroethylene, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Cyanide concentrations were elevated in one area but were below the maximum contaminant level. Tetrachloroethylene exceeded its maximum contaminant level in several wells in the 300 Area for the first time since the 1980s. Metals such as aluminum, cadmium, iron, manganese, and nickel exceeded their maximum contaminant levels in filtered samples from numerous

Deployment of phytoremediation at the 317/319 area at Argonne National Laboratory - East

International Nuclear Information System (INIS)

Negri, M. C.; Hinchman, R. R.; Quinn, J.; Wozniak, J.

2000-01-01

The 317 and 319 Areas are located on the extreme southern end of the ANL-E site, immediately adjacent to the DuPage County Waterfall Glen Forest Preserve. The 317 Area is an active hazardous and radioactive waste processing and storage area. In the late 1950s, liquid waste was placed in the unit known as the French Drain. Since that time, this waste has migrated into underlying soil and groundwater. The principal environmental concern in the 317 Area is the presence of several VOCs in the soil and groundwater and low levels of tritium in the groundwater beneath and down gradient of the site. The 319 Area Landfill and French Drain are located immediately adjacent to the 317 Area. The principal environmental concern in the 319 Area is the presence of radioactive materials in the waste mound, in the leachate in the mound, and in the shallow groundwater immediately down gradient of the landfill. Several interim actions have already been implemented in this area, to reduce the VOC and tritium releases from these areas, as the result of the Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) conducted from December 1994 through September 1996

Groundwater Study of the Rocky Mountain Arsenal and Some Surrounding Area, 1974 - 1975

Science.gov (United States)

1975-01-01

Table 3. From the sampling, Lake F was found to contain a l~er concentration of OCPD than that found in the groundwaters. In addition, very high copper...be the influent area to Lake F. (3) Reclamation of the groundwater for DIMP Is reco..ended. (4) Reclmatlon of OCPD frca, tli, groundwater appears

A study on groundwater infiltration in the Horonobe area, northern Hokkaido, Japan

International Nuclear Information System (INIS)

Yokota, Hideharu; Yamamoto, Yoichi; Maekawa, Keisuke; Hara, Minoru

2011-01-01

In the Horonobe area of northern Hokkaido, the Japan Atomic Energy Agency has been carrying out various hydrological observations to estimate the recharge rate. Subsurface earth temperature and soil moisture content have been observed at HGW-1 site (GL-0.7m to GL-2.3m, since 2005) and Hokushin Meteorological Station (GL-0.1m to GL-1.1m, since 2008). The results have revealed groundwater infiltration and recharge occurring throughout year, the shallow groundwater-infiltration velocity depending on the depth and the position of the Zero Flux Plane. For the estimation of boundary conditions in groundwater flow simulation, in this study, the shallow groundwater-flow system has been examined qualitatively on the basis of the variation of the subsurface earth temperature and the soil moisture content. In the future, it is necessary to quantitatively assess the shallow groundwater infiltration and recharge rate, the intermediate runoff, and the evapotranspiration based on the observed data of the weighing lysimeter, and the other measurement stations in the area. (author)

Groundwater Pathway Model for the Los Alamos National Laboratory Technical Area 54, Area G, Revision 1

Energy Technology Data Exchange (ETDEWEB)

Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chu, Shaoping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Miller, Terry A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Strobridge, Daniel M. [Neptune Inc., Los Alamos, NM (United States); Cole, Gregory L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Birdsell, Kay H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Robinson, Bruce Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gable, Carl Walter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Broxton, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Springer, Everett P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schofield, Tracy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-10

This report consists of four major sections, including this introductory section. Section 2 provides an overview of previous investigations related to the development of the current sitescale model. The methods and data used to develop the 3-D groundwater model and the techniques used to distill that model into a form suitable for use in the GoldSim models are discussed in Section 3. Section 4 presents the results of the model development effort and discusses some of the uncertainties involved. Eight attachments that provide details about the components and data used in this groundwater pathway model are also included with this report. The groundwater modeling effort reported here is a revision of the work that was conducted in 2005 (Stauffer et al., 2005a) in support of the 2008 Area G performance assessment and composite analysis (LANL, 2008). The revision effort was undertaken primarily to incorporate new geologic information that has been collected since 2003 at, and in the vicinity of, Area G. The new data were used to create a more accurate geologic framework model (GFM) that forms the basis of the numerical modeling of the site’s long-term performance. The groundwater modeling uses mean hydrologic properties of the geologic strata underlying Area G; this revision includes an evaluation of the impacts that natural variability in these properties may have on the model projections.

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

Directory of Open Access Journals (Sweden)

M. Spizzico

2005-01-01

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

Groundwater Vulnerability Assessment of the Tarkwa Mining Area ...

African Journals Online (AJOL)

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

hydrochemical evolution of groundwater in jimeta- yola area ...

African Journals Online (AJOL)

DJFLEX

development of groundwater resources for water supply ... water business has led to the proliferation of shallow ... Areas liable to flooding ...... by salinization process of the aquifer which act ..... Malaysia. Environmental Geology 56(8): 1721-. 1732. Barcelona, M. J., Gibb, J. P., Helfrich, .... World Health Organization, 1993.

Alternative designs for petroleum product storage tanks for groundwater protection.

Science.gov (United States)

Oke Adeleke, Samson

In developing countries, there are numerous occurrences of petroleum product spillage in groundwater. The current practice of burying storage tanks beneath the surface without adequate safety devices facilitates this phenomenon. Underground tanks rust and leak, and spilled petroleum products migrate downward. The movement of the oil in the soil depends on its viscosity and quantity, the permeability of the soil/rock, and the presence of fractures within the rock. The oil spreads laterally in the form of a thin pancake due to its lower specific gravity, and soluble components dissolve in water. The pollution plume of petroleum products and dissolved phases moves in the direction of groundwater flow in the aquifer within the pores of soil and sediments or along fractures in basement complex areas. Most communities reply heavily on groundwater for potable and industrial supplies. However, the sustainability of this resource is under threat in areas where there are filling stations as a result of significant groundwater contamination from petroleum product spillage. Drinking water becomes unpalatable when it contains petroleum products in low concentrations, and small quantities may contaminate large volumes of water. Considering the losses incurred from spillage, the cost of cleaning the aquifer, and the fact that total cleansing and attenuation is impossible, the need to prevent spillage and if it happens to prevent it from getting into the groundwater system is of paramount importance. This paper proposes alternative design procedures with a view to achieving these objectives.

Decadal variations in groundwater quality

DEFF Research Database (Denmark)

Jessen, Søren; Postma, Dieke; Thorling, Lærke

2017-01-01

Twenty-five years of groundwater quality monitoring in a sandy aquifer beneath agricultural fields showed large temporal and spatial variations in major ion groundwater chemistry, which were linked closely to the nitrate (NO3) content of agricultural recharge. Between 1988 and 2013, the NO3 content...... of water in the oxidized zone of the aquifer nearly halved, following implementation of action plans to reduce N leaching from agriculture. However, due to denitrification by pyrite oxidation in the aquifer, a plume of sulfate-rich water migrates through the aquifer as a legacy of the historical NO3...... loading. Agriculture thus is an important determinant of major ion groundwater chemistry. Temporal and spatial variations in the groundwater quality were simulated using a 2D reactive transport model, which combined effects of the historical NO3 leaching and denitrification, with dispersive mixing...

Remedial Investigation/Feasibility Study Work Plan for the 200-UP-1 Groundwater Operable Unit, Hanford Site, Richland, Washington

International Nuclear Information System (INIS)

1994-01-01

This work plan identifies the objectives, tasks, and schedule for conducting a Remedial Investigation/Feasibility Study for the 200-UP-1 Groundwater Operable Unit in the southern portion of the 200 West Groundwater Aggregate Area of the Hanford Site. The 200-UP-1 Groundwater Operable Unit addresses contamination identified in the aquifer soils and groundwater within its boundary, as determined in the 200 West Groundwater Aggregate Area Management Study Report (AAMSR) (DOE/RL 1992b). The objectives of this work plan are to develop a program to investigate groundwater contaminants in the southern portion of the 200 West Groundwater Aggregate Area that were designated for Limited Field Investigations (LFIs) and to implement Interim Remedial Measures (IRMs) recommended in the 200 West Groundwater AAMSR. The purpose of an LFI is to evaluate high priority groundwater contaminants where existing data are insufficient to determine whether an IRM is warranted and collect sufficient data to justify and implement an IRM, if needed. A Qualitative Risk Assessment (QRA) will be performed as part of the LFI. The purpose of an IRM is to develop and implement activities, such as contaminant source removal and groundwater treatment, that will ameliorate some of the more severe potential risks of groundwater contaminants prior to the RI and baseline Risk Assessment (RA) to be conducted under the Final Remedy Selection (FRS) at a later date. This work plan addresses needs of a Treatability Study to support the design and implementation of an interim remedial action for the Uranium- 99 T c -Nitrate multi-contaminant IRM plume identified beneath U Plant

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

Science.gov (United States)

Jeong, Chan Ho

2001-11-01

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

Nevada Test Site 2001 Waste Management Monitoring Report Area 3 and Area 5 Radioactive Waste Management Sites

International Nuclear Information System (INIS)

Y. E. Townsend

2002-06-01

Environmental monitoring data, subsidence monitoring data, and meteorology monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site (NTS) (refer to Figure 1). These monitoring data include radiation exposure, air, groundwater, meteorology, vadose zone, subsidence, and biota data. Although some of these media (radiation exposure, air, and groundwater) are reported in detail in other Bechtel Nevada (BN) reports (Annual Site Environmental Report [ASER], the National Emissions Standard for Hazardous Air Pollutants [NESHAP] report, and the Annual Groundwater Monitoring Report), they are also summarized in this report to provide an overall evaluation of RWMS performance and environmental compliance. Direct radiation monitoring data indicate that exposure at and around the RWMSs is not above background levels. Air monitoring data indicate that tritium concentrations are slightly above background levels. Groundwater monitoring data indicate that the groundwater in the uppermost aquifer beneath the Area 5 RWMS has not been affected by the facility. Meteorology data indicate that 2001 was an average rainfall year: rainfall totaled 150 mm (5.9 in) at the Area 3 RWMS and 120 mm (4.7 in) at the Area 5 RWMS. Vadose zone monitoring data indicate that 2001 rainfall infiltrated less than one meter (3 ft) before being returned to the atmosphere by evaporation. Soil-gas tritium monitoring data indicate slow subsurface migration, and tritium concentrations in biota were lower than in previous years. All 2001 monitoring data indicate that the Area 3 and Area 5 RWMSs are performing within expectations of the model and parameter assumptions for the facility performance assessments

Current Conditions Risk Assessment for the 300-FF-5 Groundwater Operable Unit

Energy Technology Data Exchange (ETDEWEB)

Miley, Terri B.; Bunn, Amoret L.; Napier, Bruce A.; Peterson, Robert E.; Becker, James M.

2007-11-01

This report updates a baseline risk assessment for the 300 Area prepared in 1994. The update includes consideration of changes in contaminants of interest and in the environment that have occurred during the period of interim remedial action, i.e., 1996 to the present, as well as the sub-regions, for which no initial risk assessments have been conducted. In 1996, a record of decision (ROD) stipulated interim remedial action for groundwater affected by releases from 300 Area sources, as follows: (a) continued monitoring of groundwater that is contaminated above health-based levels to ensure that concentrations continue to decrease, and (b) institutional controls to ensure that groundwater use is restricted to prevent unacceptable exposure to groundwater contamination. In 2000, the groundwater beneath the two outlying sub-regions was added to the operable unit. In 2001, the first 5-year review of the ROD found that the interim remedy and remedial action objectives were still appropriate, although the review called for additional characterization activities. This report includes a current conditions baseline ecological and human health risk assessment using maximum concentrations in the environmental media of the 300-FF-5 Operable Unit and downstream conditions at the City of Richland, Washington. The scope for this assessment includes only current measured environmental concentrations and current use scenarios. Future environmental concentrations and future land uses are not considered in this assessment.

100-D Ponds groundwater quality assessment

International Nuclear Information System (INIS)

Hartman, M.J.

1996-01-01

The 100-D Ponds facility is regulated under the Resource Conservation and Recovery Act of 1976. The pH of groundwater in a downgradient well is statistically different than local background, triggering an assessment of groundwater contamination under 40 CFR 265.93. Results of a similar assessment, conducted in 1993, show that the elevated pH is caused by the presence of alkaline ash sediments beneath the ponds, which are not part of the RCRA unit. The 100-D Ponds should remain in indicator evaluation monitoring

Interim Sanitary Landfill Groundwater Monitoring Report. 1997 Annual Report

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-01

Eight wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Interim Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled semiannually to comply with the South Carolina Department of Health and Environmental Control Modified Municipal Solid Waste Permit 025500-1120 (formerly dWP-087A) and as part of the SRS Groundwater Monitoring Program.

Groundwater monitoring program evaluation For A/M Area, Savannah River Site

International Nuclear Information System (INIS)

Hiergesell, R.A.; Bollinger, J.S.

1996-01-01

This investigation was undertaken with the primary purpose of assessing the groundwater monitoring program within the A/M Area to identify ways in which the monitoring program could be improved. The task was difficult due to the large number of wells located within the A/M Area and the huge database of analytical data. It was recognized early in this investigation that one of the key tasks was to develop a way to gain access to the groundwater databases so that recommendations could be made. To achieve this, geographic information systems (GIS) technology was used to extract pertinent groundwater quality information from the Geochemical Information Management System (GIMS) groundwater database and display the extracted information spatially. GIS technology was also used to determine the location of well screen and annular material zones within the A/M Area hydrostratigraphy and to identify wells that may breach confining units. Recommendations developed from this study address: (1) wells that may not be providing reliable data but continue to be routinely sampled (2) wells that may be inappropriately located but continue to be routinely sampled and (3) further work that should be undertaken, including well development, evaluation of wells that may be breaching confining units, and development of an automated link to GIMS using GIS so that GIMS data can easily be accessed and displayed geographically

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

Science.gov (United States)

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

2017-04-01

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

Occurrence of fungicides and other pesticides in surface water, groundwater, and sediment from three targeted-use areas in the United States, 2009

Science.gov (United States)

Orlando, James L.; Smalling, Kelly L.; Reilly, Timothy J.; Boehlke, Adam; Meyer, Michael T.; Kuivila, Kathryn

2013-01-01

Surface-water, groundwater, and suspended- and bedsediment samples were collected in three targeted-use areas in the United States where potatoes were grown during 2009 and analyzed for an extensive suite of fungicides and other pesticides by gas chromatograph/mass spectrometry and liquid chromatography with tandem mass spectrometry. Fungicides were detected in all environmental matrices sampled during the study. The most frequently detected fungicides were azoxystrobin, boscalid, chlorothalonil, and pyraclostrobin. Other pesticides that were detected frequently included amino phosphonic acid (AMPA), atrazine, metolaclor, and the organochlorine insecticide p,p’-DDT and its degradates p,p’-DDD and p,p’-DDE. A greater number of pesticides were detected in surface water relative to the other environmental matrices sampled, and at least one pesticide was detected in 62 of the 63 surfacewater samples. The greatest numbers of pesticides and the maximum observed concentrations for most pesticides were measured in surface-water samples from Idaho. In eight surface- water samples (six from Idaho and two from Wisconsin), concentrations of bifenthrin, metolachlor, or malathion exceeded U.S. Environmental Protection Agency freshwater aquatic-life benchmarks for chronic toxicity to invertebrates. Thirteen pesticides, including seven fungicides, were detected in groundwater samples. Shallow groundwater samples collected beneath recently harvested potato fields contained more pesticides and had higher concentrations of pesticides than samples collected from other groundwater sources sampled during the study. Generally, pesticide concentrations were lower in groundwater samples than in surfacewater or sediment samples, with the exception of the fungicide boscalid, which was found to have its highest concentration in a shallow groundwater sample collected in Wisconsin. Thirteen pesticides, including four fungicides, were detected in suspended-sediment samples. The most

Sanitary landfill groundwater monitoring report. Fourth quarter 1994 and 1994 summary

International Nuclear Information System (INIS)

1995-02-01

Eighty-nine wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Waste Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Dichloromethane, a common laboratory contaminant, and trichloroethylene were the most widespread constituents exceeding standards during 1994. Benzene, chloroethene (vinyl chloride), 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-dichloropropane, gross alpha, mercury, nonvolatile beta, tetrachloroethylene, and tritium also exceeded standards in one or more wells. The groundwater flow direction in the Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill was to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 140 ft/year during first and fourth quarters 1994

Nevada Test Site 2001 Waste Management Monitoring Report Area 3 and Area 5 Radioactive Waste Management Sites; TOPICAL

International Nuclear Information System (INIS)

Y. E. Townsend

2002-01-01

Environmental monitoring data, subsidence monitoring data, and meteorology monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site (NTS) (refer to Figure 1). These monitoring data include radiation exposure, air, groundwater, meteorology, vadose zone, subsidence, and biota data. Although some of these media (radiation exposure, air, and groundwater) are reported in detail in other Bechtel Nevada (BN) reports (Annual Site Environmental Report[ASER], the National Emissions Standard for Hazardous Air Pollutants[NESHAP] report, and the Annual Groundwater Monitoring Report), they are also summarized in this report to provide an overall evaluation of RWMS performance and environmental compliance. Direct radiation monitoring data indicate that exposure at and around the RWMSs is not above background levels. Air monitoring data indicate that tritium concentrations are slightly above background levels. Groundwater monitoring data indicate that the groundwater in the uppermost aquifer beneath the Area 5 RWMS has not been affected by the facility. Meteorology data indicate that 2001 was an average rainfall year: rainfall totaled 150 mm (5.9 in) at the Area 3 RWMS and 120 mm (4.7 in) at the Area 5 RWMS. Vadose zone monitoring data indicate that 2001 rainfall infiltrated less than one meter (3 ft) before being returned to the atmosphere by evaporation. Soil-gas tritium monitoring data indicate slow subsurface migration, and tritium concentrations in biota were lower than in previous years. All 2001 monitoring data indicate that the Area 3 and Area 5 RWMSs are performing within expectations of the model and parameter assumptions for the facility performance assessments

Geohydrology of the Gallup's Quarry area, Plainfield, Connecticut

Science.gov (United States)

Melvin, Robert L.; Stone, Janet Radway; Craft, Patrick A.; Lane, John W.

1995-01-01

The geohydrology of the Gallup's Quarry area in Plainfield, Connecticut was characterized by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to provide a preliminary framework for future remedial efforts. Gallup's Quarry, an inactive sand and gravel pit, was the site of unregulated disposal of an unknown volume of chemical wastes from at least the summer of 1977 until January 1978. Existing information collected for the Connecticut Department of Environmental Protection during 1978-82 showed that ground water beneath Gallup's Quarry and adjacent land to the northwest was contaminated by organic and inorganic compounds. There is also some evidence for contamination of Mill Brook, which is located north and northwest of the disposal areas. Geologic mapping and subsurface data show that unconsolidated surficial materials up to 90 feet thick overlie fractured crystalline bedrock in most of the Gallup's Quarry area. The surficial materials consist primarily of stratified drift and till. Texture changes vertically and laterally within the stratified drift; grain size ranges from very coarse to fine. Till blankets the bedrock surface beneath the stratified drift and is a few feet to as much as 25 feet thick. Bedrock is exposed at land surface in a hill in the southeastern part of the quarry and slopes to depths of up to 90 feet beneath the area west and north of the disposal sites. The bedrock is a dark, fine-grained, fractured and jointed blastomylonite and hornblende gneiss of the Quinebaug Formation. It is likely that a west- northwest-trending fault is present in the bedrock beneath Gallup's Quarry; this fault, if present, may provide a preferential pathway for ground-water flow and contaminant transport. The principal horizontal direction of ground-water flow and movement of dissolved contaminants in the stratified drift was to the northwest of the waste-disposal areas toward Mill Brook in 1978. Estimates of average annual

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

International Nuclear Information System (INIS)

Goswami, D.

1996-01-01

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

Groundwater quality in the shallow aquifers of the Tulare, Kaweah, and Tule Groundwater Basins and adjacent highlands areas, Southern San Joaquin Valley, California

Science.gov (United States)

Fram, Miranda S.

2017-01-18

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. The shallow aquifers of the Tulare, Kaweah, and Tule groundwater basins and adjacent highlands areas of the southern San Joaquin Valley constitute one of the study units being evaluated.

Decomposition of groundwater level fluctuations using transfer modelling in an area with shallow to deep unsaturated zones

Science.gov (United States)

Gehrels, J. C.; van Geer, F. C.; de Vries, J. J.

1994-05-01

Time series analysis of the fluctuations in shallow groundwater levels in the Netherlands lowlands have revealed a large-scale decline in head during recent decades as a result of an increase in land drainage and groundwater withdrawal. The situation is more ambiguous in large groundwater bodies located in the eastern part of the country, where the unsaturated zone increases from near zero along the edges to about 40 m in the centre of the area. As depth of the unsaturated zone increases, groundwater level reacts with an increasing delay to fluctuations in climate and influences of human activities. The aim of the present paper is to model groundwater level fluctuations in these areas using a linear stochastic transfer function model, relating groundwater levels to estimated precipitation excess, and to separate artificial components from the natural groundwater regime. In this way, the impact of groundwater withdrawal and the reclamation of a 1000 km 2 polder area on the groundwater levels in the adjoining higher ground could be assessed. It became evident that the linearity assumption of the transfer functions becomes a serious drawback in areas with the deepest groundwater levels, because of non-linear processes in the deep unsaturated zone and the non-synchronous arrival of recharge in the saturated zone. Comparison of the results from modelling the influence of reclamation with an analytical solution showed that the lowering of groundwater level is partly compensated by reduced discharge and therefore is less than expected.

Spreading of Groundwater Contamined by Leached in the Surrounding Area of Piyungan Landfill Bantul District, Yogyakarta Province

Directory of Open Access Journals (Sweden)

J Sartohadi

2017-07-01

Full Text Available The objectives of this research are: (1 to study the characteristics of aquifer, distribution and chemical types of groundwater in the research area; (2 to measure the consentration of major elements (HC03-, Cl-, S042-, Ca2+, Mg2+, Na+, K+ and minor elements (S2-, NH4+ as indicators of leached contamination in the groundwater; and (3 to establish the spreading of contamined groundwater by leached. The grid sampling method was applied in this research. The grid dimension is 1 cm x 1 cm measured in the 1:25000 scale of Indonesian Topographic Map. The groundwater samples were taken randomly within the grid. Not the whole study area covered by the map was grided but only the surrounding area of Piyungan Landfill and the area lower than Piyungan landfill were grided. The groundwater samples were taken during the rainy season because during the rainy season there were more leached produced from Piyungan Landfill. The groundwater samples were examined their physical and chemical qualities using the legal standard quality in Yogyakarta Province. Spatial analysis using maps and graphics were applied to examine the spreading of contimined groundwater by leached. The spreading of unconfined groundwater in the study area was not equal distributed but it seems to be controlled by the landforms. There were an increasing elements content of Cl-, Ca2+, Mg2+ and HCO3-, as well as dissolved oxygen, NO3- and S2- in the groundwater contamined by leached. The zonation of the spreading of groundwater contamined by leached was categorized into three class, i.e., central (location of landfill, well number 1 0, transisional (well number: 11, 12, 13, 15, and primary (well number: 8, 14, 16, 17, 25, 26 zones. The zonation of groundwater matched with the analysis of groundwater quality by the distance from the Piyungan Landfill.

Pickering Nuclear site wide groundwater monitoring system

International Nuclear Information System (INIS)

DeWilde, J.; Chin-Cheong, D.; Lledo, C.; Wootton, R.; Belanger, D.; Hansen, K.

2001-01-01

Ontario Power Generation Inc. (OPG) is continuing its efforts to understand the chemical and physical characteristics of the groundwater flow systems beneath the Pickering Nuclear Generating Station (PNGS). To this end, OPG constructed a site-wide Groundwater Monitoring System (GMS) at the PNGS to provide support to other ongoing environmental investigations and to provide a means to monitor current and future groundwater environmental issues. This paper will present the results of this work, including the development of a state-of-the-art data management system for storage and retrieval of environmental data for the site, which has applications for other power generation facilities. (author)

Fracture detection and groundwater flow characterization in poorly exposed ground using helium and radon in soil gases

International Nuclear Information System (INIS)

Gascoyne, M.; Wuschke, D.M.

1991-05-01

Radon and helium in soil gases have been used to identify locations of groundwater discharge and the presence of fractures outcropping beneath overburden in two areas near the Underground Research Laboratory (URL), Lac du Bonnet, Manitoba, Canada. In particular, groundwater discharge from a known, inclined fracture zone at the URL was clearly identified by a helium excess in overlying soil gases. A model was developed to describe gas phase flow in bedrock and overburden at this location, from gas injection in an adjacent borehole. Predictions were made of gas transport pathway and breakthrough time at the surface, in preparation for a gas injection test

Geochemical Characteristics of Shallow Groundwater in Jiaoshiba Shale Gas Production Area: Implications for Environmental Concerns

Directory of Open Access Journals (Sweden)

Yiman Li

2016-11-01

Full Text Available The geochemical characteristics of shallow groundwater are essential for environmental impact studies in the shale gas production area. Jiaoshiba in the Sichuan basin is the first commercial-scale shale gas production area in China. This paper studied the geochemical and isotopic characteristics of the shallow groundwater of the area for future environmental concerns. Results show that the average pH of the shallow groundwater is 7.5 and the total dissolved solids (TDS vary from 150 mg/L to 350 mg/L. The main water types are HCO3-Ca and HCO3-Ca·Mg due to the carbonates dissolution equilibrium in karst aquifers. The concentrations of major ions and typical toxic elements including Mn, Cr, Cu, Zn, Ba, and Pb are below the drinking water standard of China and are safe for use as drinking water. The high nitrate content is inferred to be caused by agricultural pollution. The shallow groundwater is recharged by local precipitation and flows in the vertical circulation zone. Evidences from low TDS, water isotopes, and high 3H and 14C indicate that the circulation rate of shallow groundwater is rapid, and the lateral groundwater has strong renewability. Once groundwater pollution from deep shale gas production occurs, it will be recovered soon by enough precipitation.

200 West Groundwater Aggregate Area management study report

International Nuclear Information System (INIS)

1993-01-01

This report presents the results of an aggregate area management study (AAMS) for the 200 West Groundwater Aggregate Area in the 200 Areas of the US Department of Energy (DOE) Hanford Site in Washington State. This scoping level study provides the basis for initiating Remedial Investigation/Feasibility Study (RI/FS) activities under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or Resource Conservation and Recovery Act (RCRA), Facility Investigations (Rlq) and Corrective Measures Studies (CMS) under RCRA. This report also integrates select RCRA treatment, storage or disposal (TSD) closure activities with CERCLA and RCRA past practice investigations

Nevada Test Site 2000 Waste Management Monitoring Report Area 3 and Area 5 Radioactive Waste Management Sites

International Nuclear Information System (INIS)

Yvonne Townsend

2001-01-01

Environmental monitoring data, subsidence monitoring data, and meteorology monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site (NTS) (refer to Figure 1). These monitoring data include radiation exposure, air, groundwater, meteorology, vadose zone, subsidence, and biota data. Although some of these media (radiation exposure, air, and groundwater) are reported in detail in other Bechtel Nevada reports (Annual Site Environmental Report [ASER], the National Emissions Standard for Hazardous Air Pollutants [NESHAP] report, and the Annual Groundwater Monitoring Report), they are also summarized in this report to provide an overall evaluation of RWMS performance and environmental compliance. Direct radiation monitoring data indicate that exposure at and around the RWMSs is not above background levels. Air monitoring data indicate that tritium concentrations are slightly above background levels, whereas radon concentrations are not above background levels. Groundwater monitoring data indicate that the groundwater in the uppermost aquifer beneath the Area 5 RWMS has not been affected by the facility. Meteorology data indicate that 2000 was an average rainfall year: rainfall totaled 167 mm (6.6 in) at the Area 3 RWMS (annual average is 156 mm [6.5 in]) and 123 mm (4.8 in) at the Area 5 RWMS (annual average is 127 mm [5.0 in]). Vadose zone monitoring data indicate that 2000 rainfall infiltrated less than one meter (3 ft) before being returned to the atmosphere by evaporation. Soil-gas tritium monitoring data indicate slow subsurface migration, and tritium concentrations in biota were lower than in previous years. All 2000 monitoring data indicate that the Area 3 and Area 5 RWMSs are performing well at isolating buried waste

Integrating geochemical investigations and geospatial assessment to understand the evolutionary process of hydrochemistry and groundwater quality in arid areas.

Science.gov (United States)

El Alfy, Mohamed; Alharbi, Talal; Mansour, Basma

2018-04-12

Groundwater is the key for life in arid areas. Aquifer overexploitation and climatic conditions can significantly deteriorate groundwater quality. The Al-Qassim area in central Saudi Arabia is characterized by dense agricultural use and is irrigated mainly by fossil groundwater from the Saq Aquifer. Understanding the area's hydrochemistry, major factors governing groundwater quality, and alternative uses of the groundwater are the main goals of this study. Groundwater samples were collected and examined for major, minor, and trace elements. Ionic relationships, hydrochemical facies, geospatial distributions, and multivariate analyses were conducted to assess the hydrochemical processes at play. The salinity and nitrate concentrations of the Saq Aquifer's groundwater were found to increase in the outcrop areas more than the confined areas. The spatial distributions were fragmented by three main factors: (i) modern recharge by relatively brackish water, (ii) irrigation return flow in intensive farming areas, and (iii) overexploitation and draining of deep and relatively saline zones of the aquifer. Seven water types were found representing the alkaline water with a predominance of sulfate-chloride ions and earth alkaline water with a predominance of sulfate and chloride. Mixing between fresh and brackish water, dissolution of mineral phases, silicate weathering, and reverse ion exchange were recognized as the evolutionary processes, while evaporation played a minor role. Cluster analyses characterized the fresh groundwater zone, modern groundwater recharge zone, and anthropogenic influence zone. In the confined areas, nearly all the groundwater was appropriate for domestic use and irrigation. In the outcrop areas, some limitations were found due to unsuitable conditions.

Real - time Dynamic Simulation and Prediction of Groundwater in Typical Arid Area Based on SPASS Improvement

Science.gov (United States)

Wang, Xiao-ming

2018-03-01

The establishment of traditional groundwater numerical simulation model, parameter identification and inspection process, especially the water level fitting and the actual observation of the value obtained compared to a large error. Based on the SPASS software, a large number of statistical analysis of the numerical simulation results show that the complexity of the terrain in the study area, the distribution of lithology and the influence of the parameters on the groundwater level in the study area have great influence on the groundwater level. Through the multi-factor analysis and adjustment, the simulated groundwater flow and the actual observation are similar. Then, the final result is taken as the standard value, and the groundwater in the study area is simulated and predicted in real time. The simulation results provide technical support for the further development and utilization of the local water resources.

Hydrochemistry, origin and residence time of deep groundwater in the Yuseong area

International Nuclear Information System (INIS)

Koh, Yong Kwon; Kim, Geon Young; Bae, Dae Seok; Park, Kyung Woo

2005-01-01

As a part of the radioactive waste disposal research program in Korea, the geological, hydrogeological and hydrogeochemical investigations have been carried out in the Yuseong area (KAERI). The temperature or groundwater is measured up to 24 .deg. C and thermal gradient is obtained, to 0.26 .deg. C/100m. pH of groundwater at upper section shows about 7 and the pH of groundwater of 200m below surface reaches almost constant value as 9.9∼10.3. The redox potential of groundwater varied with depth and more negative values were recognized in deep groundwater. The redox potential of deep groundwater, main factor of U solubility, was measured up to -150 mV. These high pH and reduced conditions indicates that the maximum U concentration in groundwater would be limited by the equilibrium solubility of U minerals. The chemistry of shallow groundwater shows Ca-HCO 3 or Ca-Na-HCO 3 type, whereas the deep groundwater belongs to typical Na-HCO 3 type. The chemistry of groundwater below 250m from the surface is constant with depth, indicating that the extent of water-rock reaction is almost unique, which is controlled by the residence time of groundwater. The carbon isotope data (δ 13 C) of groundwater show the contribution of carbon from either that microbial oxidation of organic matter or carbon dioxide from plant respiration. The measurement and interpretation of C-14 indicate that the residence time of borehole deep groundwater ranges from about 2,000 to 6,000 yr BP. The high δ 34 S so4 value of groundwater indicate that the sulfate reduction might be occurred in the deep environment

Identifying the Prospective Area of Sulfide Groundwater within the Area of Palvantash Oil and Gas Deposit

Directory of Open Access Journals (Sweden)

M. R. Zhurayev

2014-03-01

Full Text Available This paper describes the methodology of prospecting for sulfide groundwater in the area of Palvantash oil fields. In result of study allowed determining the favorable conditions for the sulfide waters formation, and mapping the areas of different sulfide water concentration. The relatively permeable areas were established and the water borehole positions were recommended.

Seismic Constraints on the Lithosphere-Asthenosphere Boundary Beneath the Izu-Bonin Area: Implications for the Oceanic Lithospheric Thinning

Science.gov (United States)

Cui, Qinghui; Wei, Rongqiang; Zhou, Yuanze; Gao, Yajian; Li, Wenlan

2018-01-01

The lithosphere-asthenosphere boundary (LAB) is the seismic discontinuity with negative velocity contrasts in the upper mantle. Seismic detections on the LAB are of great significance in understanding the plate tectonics, mantle convection and lithospheric evolution. In this paper, we study the LAB in the Izu-Bonin subduction zone using four deep earthquakes recorded by the permanent and temporary seismic networks of the USArray. The LAB is clearly revealed with sP precursors (sdP) through the linear slant stacking. As illustrated by reflected points of the identified sdP phases, the depth of LAB beneath the Izu-Bonin Arc (IBA) is about 65 km with a range of 60-68 km. The identified sdP phases with opposite polarities relative to sP phases have the average relative amplitude of 0.21, which means a 3.7% velocity drop and implies partial melting in the asthenosphere. On the basis of the crustal age data, the lithosphere beneath the IBA is located at the 1100 °C isotherm calculated with the GDH1 model. Compared to tectonically stable areas, such as the West Philippine Basin (WPB) and Parece Vela Basin (PVB) in the Philippine Sea, the lithosphere beneath the Izu-Bonin area shows the obvious lithospheric thinning. According to the geodynamic and petrological studies, the oceanic lithospheric thinning phenomenon can be attributed to the strong erosion of the small-scale convection in the mantle wedge enriched in volatiles and melts.

Uranium series disequilibrium: application to studies of the groundwater regime of the Harwell region

International Nuclear Information System (INIS)

Ivanovich, M.; Alexander, J.

1985-03-01

Regional groundwater systems incorporating argillaceous formations beneath the Harwell site have been studied as part of a national research programme of investigation into the feasibility of disposal of low and intermediate radioactive wastes into argillaceous rocks. The principal aim of the programme is to establish the groundwater flow patterns using hydrogeological and geochemical methods in association with isotope contents and uranium series disequilibrium and thus provide an independent approach to the study of effective permeabilities of clay lithologies in a sedimentary sequence. Thirty four groundwater samples derived from the high permeability formations in the Harwell region have been analysed for uranium and thorium content and 234 U/ 238 U, 230 Th/ 234 U and 230 Th/ 232 Th activity ratios. The uranium isotopic signatures have been interpreted in terms of the regional groundwater circulation and mixing patterns. The most significant zones of groundwater mixing determined from uranium isotopic data are situated just beneath the edge of the confined strata. These zones coincide with the locations of hydraulic lows in the Great Oolite and the Corallian formations towards which the regional groundwaters move. It is concluded that the uranium isotopic signatures can be used to identify water masses and to evaluate mixing of groundwaters in a sedimentary sequence on a regional scale. (author)

Modeling contribution of shallow groundwater to evapotranspiration and yield of maize in an arid area.

Science.gov (United States)

Gao, Xiaoyu; Huo, Zailin; Qu, Zhongyi; Xu, Xu; Huang, Guanhua; Steenhuis, Tammo S

2017-02-21

Capillary rise from shallow groundwater can decrease the need for irrigation water. However, simple techniques do not exist to quantify the contribution of capillary flux to crop water use. In this study we develop the Agricultural Water Productivity Model for Shallow Groundwater (AWPM-SG) for calculating capillary fluxes from shallow groundwater using readily available data. The model combines an analytical solution of upward flux from groundwater with the EPIC crop growth model. AWPM-SG was calibrated and validated with 2-year lysimetric experiment with maize. Predicted soil moisture, groundwater depth and leaf area index agreed with the observations. To investigate the response of model, various scenarios were run in which the irrigation amount and groundwater depth were varied. Simulations shows that at groundwater depth of 1 m capillary upward supplied 41% of the evapotranspiration. This reduced to 6% at groundwater depth of 2 m. The yield per unit water consumed (water productivity) was nearly constant for 2.3 kg/m 3 . The yield per unit water applied (irrigation water productivity) increased with decreasing irrigation water because capillary rise made up in part for the lack of irrigation water. Consequently, using AWPM-SG in irrigation scheduling will be beneficial to save more water in areas with shallow groundwater.

An appraisal of the geologic structure beneath the Ikogosi warm spring in south-western Nigeria using integrated surface geophysical methods

Directory of Open Access Journals (Sweden)

J.S Ojo

2011-06-01

Full Text Available An integrated surface geophysical investigation involving resistivity and magnetic methods was carried out in the immediate vicinity of the Ikogosi warm spring situated in south-western Nigeria with a view to delineating its subsurface geological sequence and evaluating the structural setting beneath the warmspring. Total field magnetic measurements and vertical electrical sounding (VES data were acquired along five N-S traverses. Magnetic and VES data interpretation
involved inverse modelling. The inverse magnetic models delineated fractured quartzite/faulted areas within fresh massive quartzite at varying depths and beneath all traverses. The geoelectrical sections developed from VESinterpretation results also delineated a subsurface sequence consisting of a topsoil/weathered layer, fresh quartzite, fractured/faulted quartzite and fresh quartzite bedrock. It was deduced that the fractured/faulted quartzite may have acted as conduit for the
movement of warm groundwater from profound depths to the surface while the spring outlet was located on a geological interface  (lineament.

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

International Nuclear Information System (INIS)

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

1993-04-01

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

Field Implementation Plan for the In-Situ Bioremediation Treatability Study at the Technical Area-V Groundwater Area of Concern

Energy Technology Data Exchange (ETDEWEB)

Li, Jun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-10-31

This Field Implementation Plan (FIP) was prepared by Sandia National Laboratories, New Mexico (SNL/NM) and provides instruction on conducting a series of in-situ bioremediation (ISB) tests as described in the Revised Treatability Study Work Plan for In-Situ Bioremediation at the Technical Area-V Groundwater Area of Concern, referred to as the Revised Work Plan in this FIP. The Treatability Study is designed to gravity inject an electron-donor substrate and bioaugmentation bacteria into groundwater via three injection wells to perform bioremediation of the constituents of concern (COCs), nitrate and trichloroethene (TCE), in the regions with the highest concentrations at the Technical Area-V Groundwater (TAVG) Area of Concern (AOC). The Treatability Study will evaluate the effectiveness of bioremediation solution delivery and COC treatment over time. This FIP is designed for SNL/NM work planning and management. It is not intended to be submitted for regulator’s approval. The technical details presented in this FIP are subject to change based on field conditions, availability of equipment and materials, feasibility, and inputs from Sandia personnel and Aboveground Injection System contractor.

Field Implementation Plan for the In-Situ Bioremediation Treatability Study at the Technical Area-V Groundwater Area of Concern

International Nuclear Information System (INIS)

Li, Jun

2016-01-01

This Field Implementation Plan (FIP) was prepared by Sandia National Laboratories, New Mexico (SNL/NM) and provides instruction on conducting a series of in-situ bioremediation (ISB) tests as described in the Revised Treatability Study Work Plan for In-Situ Bioremediation at the Technical Area-V Groundwater Area of Concern, referred to as the Revised Work Plan in this FIP. The Treatability Study is designed to gravity inject an electron-donor substrate and bioaugmentation bacteria into groundwater via three injection wells to perform bioremediation of the constituents of concern (COCs), nitrate and trichloroethene (TCE), in the regions with the highest concentrations at the Technical Area-V Groundwater (TAVG) Area of Concern (AOC). The Treatability Study will evaluate the effectiveness of bioremediation solution delivery and COC treatment over time. This FIP is designed for SNL/NM work planning and management. It is not intended to be submitted for regulator's approval. The technical details presented in this FIP are subject to change based on field conditions, availability of equipment and materials, feasibility, and inputs from Sandia personnel and Aboveground Injection System contractor.

INVESTIGATION OF STABLE ISOTOPE OF 18O AND 2H IN SHALLOW GROUNDWATER FROM KARAWANG AREA

Directory of Open Access Journals (Sweden)

E. Ristin Pujiindiyati

2010-06-01

Full Text Available Karawang area is well known as an agriculture area and 2% area is utilized for industries. Clean water demands increase due to developing industry development and population increasement. The origin of groundwater is necessary to keep the sustainability of water resources in this area. Stable isotopes such as 18O and 2H can be used as a parameter to trace the ground water origin. The methods used were Epstein-Mayeda and Zinc reduction for analysis 18O and 2H, respectively. Sampling period was conducted in major dry season in year 2002. The result showed that evaporation effect had influenced to the content of both isotopes in its shallow groundwater that caused a slope shift from its local meteoric line. The origin of its shallow groundwater was from rainwater infiltrating directly in less than 10 m altitude. Citarum River showed more depleted values in both isotopes compared to shallow groundwater and it indicated that its water might originate from spring at the altitude of 600 m.     Keywords: oxygene-18, deuterium, groundwater, isotope

Corrective measures evaluation report for technical area-v groundwater.

Energy Technology Data Exchange (ETDEWEB)

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

2005-07-01

This Corrective Measures Evaluation Report was prepared as directed by the Compliance Order on Consent issued by the New Mexico Environment Department to document the process of selecting the preferred remedial alternative for contaminated groundwater at Technical Area V. Supporting information includes background information about the site conditions and potential receptors and an overview of work performed during the Corrective Measures Evaluation. Evaluation of remedial alternatives included identification and description of four remedial alternatives, an overview of the evaluation criteria and approach, qualitative and quantitative evaluation of remedial alternatives, and selection of the preferred remedial alternative. As a result of the Corrective Measures Evaluation, it was determined that monitored natural attenuation of all contaminants of concern (trichloroethene, tetrachloroethene, and nitrate) was the preferred remedial alternative for implementation as the corrective measure to remediate contaminated groundwater at Technical Area V of Sandia National Laboratories/New Mexico. Finally, design criteria to meet cleanup goals and objectives and the corrective measures implementation schedule for the preferred remedial alternative are presented.

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

Science.gov (United States)

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

2017-09-05

Water levels during 2003 through 2013 were less than mean water levels for the period 1925–2013 for several lakes in the northeast Twin Cities Metropolitan Area in Minnesota. Previous periods of low lake-water levels generally were correlated with periods with less than mean precipitation. Increases in groundwater withdrawals and land-use changes have brought into question whether or not recent (2003–13) lake-water-level declines are solely caused by decreases in precipitation. A thorough understanding of groundwater and surface-water exchanges was needed to assess the effect of water-management decisions on lake-water levels. To address this need, the U.S. Geological Survey, in cooperation with the Metropolitan Council and the Minnesota Department of Health, developed and calibrated a three-dimensional, steady-state groundwater-flow model representing 2003–13 mean hydrologic conditions to assess groundwater and lake-water exchanges, and the effects of groundwater withdrawals and precipitation on water levels of 96 lakes in the northeast Twin Cities Metropolitan Area.Lake-water budgets for the calibrated groundwater-flow model indicated that groundwater is flowing into lakes in the northeast Twin Cities Metropolitan Area and lakes are providing water to underlying aquifers. Lake-water outflow to the simulated groundwater system was a major outflow component for Big Marine Lake, Lake Elmo, Snail Lake, and White Bear Lake, accounting for 45 to 64 percent of the total outflows from the lakes. Evaporation and transpiration from the lake surface ranged from 19 to 52 percent of the total outflow from the four lakes. Groundwater withdrawals and precipitation were varied from the 2003‒13 mean values used in the calibrated model (30-percent changes in groundwater withdrawals and 5-percent changes in precipitation) for hypothetical scenarios to assess the effects of groundwater withdrawals and precipitation on water budgets and levels in Big Marine Lake, Snail Lake

Assessment of groundwater contamination risk in an agricultural area in north Italy

Directory of Open Access Journals (Sweden)

Georgios Bartzas

2015-09-01

Full Text Available In the present study a specific approach is followed, considering the Pesticide DRASTIC and Susceptibility index (SI methods and a GIS framework, to assess groundwater vulnerability in the agricultural area of Albenga, in north Italy. The results indicate “high” to “very high” vulnerability to groundwater contamination along the coastline and the middle part of the Albenga plain, for almost 49% and 56% of the total study area for Pesticide DRASTIC and SI methods, respectively. These sensitive regions depict characteristics such as shallow depth to groundwater, extensive deposits of alluvial silty clays, flat topography and intensive agricultural activities. The distribution of nitrates concentration in groundwater in the study area is slightly better correlated with the SI (0.728 compared to Pesticide DRASTIC (0.693, thus indicating that both methods are characterized by quite good accuracy. Sensitivity analysis was also performed to acknowledge statistical uncertainty in the estimation of each parameter used, assess its impact and thus identify the most critical parameters that require further investigation in the future. Depth to water is the parameter that exhibited the largest impact on the Pesticide DRASTIC vulnerability index followed by the impact of the vadose zone and topography. On the other hand, the SI method is more sensitive to the removal of the topography parameter followed by the aquifer media and the depth to water parameters.

Conceptual geohydrological model of the separations area

International Nuclear Information System (INIS)

Root, R.W.; Marine, I.W.

1977-01-01

Subsurface drilling in and around the Separations Areas (F-Area and H-Area of the Savannah River Plant) is providing detailed information for a conceptual model of the geology and hydrology underlying these areas. This conceptual model will provide the framework needed for a mathematical model of groundwater movement beneath these areas. Existing information substantiates the presence of two areally extensive clay layers and several discontinuous clay and sandy-clay layers. These layers occur in and between beds of clayey and silty sand that make up most of the subsurface material. Within these sand beds are geologic units of differing hydraulic conductivity. For the present scale of the model, the subsurface information is considered adequate in H-Area, but additional drilling is planned in F-Area

Hydrochemical and microbiological quality of groundwater in the Merdja area, Tébessa, North-East of Algeria

Science.gov (United States)

Fehdi, Chemseddine; Rouabhia, Abdelkader; Mechai, Abdelbasset; Debabza, Manel; Abla, Khalida; Voudouris, Kostas

2016-03-01

The aim of this study was to perform a preliminary assessment of the hydrochemical and microbial groundwater quality of the Merdja plain (Tébessa area). Twenty samples of groundwater collected from Bekkaria (Site 1) to Ain Chabro (Site 2) were assessed for their suitability for human consumption. Groundwater from the aquifer in the Merdja area can be divided into two major groups according to geographical locations and chemical compositions. Water in the center part of the study area is characterized by the dominance of chloride, sulfate, sodium, and potassium; whereas waters in the limestone aquifers in the west are dominated by the same cations but have higher concentrations of bicarbonate. Microbiological parameters were determined in 13 groundwater samples collected from the study area. Total coliforms, thermotolerant coliforms, E. coli, Enterococcus spp., Salmonella sp., Staphylococcus spp., and P. aeruginosa were detected in 96.36, 88.18, 100, 47.5, 97.27, 96.7, and 75 % of the groundwater samples, respectively. The pollution of groundwater comes from a variety of sources, Ouadi El Kebir River, including land application of agricultural chemicals and organic wastes, infiltration of irrigation water, septic tanks, and infiltration of effluent from sewage treatment plants, pits, lagoons, and ponds used for storage.

Groundwater flow simulation of the Savannah River Site general separations area

Energy Technology Data Exchange (ETDEWEB)

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

2017-09-07

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

Geohydrology of Big Bear Valley, California: phase 1--geologic framework, recharge, and preliminary assessment of the source and age of groundwater

Science.gov (United States)

Flint, Lorraine E.; Brandt, Justin; Christensen, Allen H.; Flint, Alan L.; Hevesi, Joseph A.; Jachens, Robert; Kulongoski, Justin T.; Martin, Peter; Sneed, Michelle

2012-01-01

The Big Bear Valley, located in the San Bernardino Mountains of southern California, has increased in population in recent years. Most of the water supply for the area is pumped from the alluvial deposits that form the Big Bear Valley groundwater basin. This study was conducted to better understand the thickness and structure of the groundwater basin in order to estimate the quantity and distribution of natural recharge to Big Bear Valley. A gravity survey was used to estimate the thickness of the alluvial deposits that form the Big Bear Valley groundwater basin. This determined that the alluvial deposits reach a maximum thickness of 1,500 to 2,000 feet beneath the center of Big Bear Lake and the area between Big Bear and Baldwin Lakes, and decrease to less than 500 feet thick beneath the eastern end of Big Bear Lake. Interferometric Synthetic Aperture Radar (InSAR) was used to measure pumping-induced land subsidence and to locate structures, such as faults, that could affect groundwater movement. The measurements indicated small amounts of land deformation (uplift and subsidence) in the area between Big Bear Lake and Baldwin Lake, the area near the city of Big Bear Lake, and the area near Sugarloaf, California. Both the gravity and InSAR measurements indicated the possible presence of subsurface faults in subbasins between Big Bear and Baldwin Lakes, but additional data are required for confirmation. The distribution and quantity of groundwater recharge in the area were evaluated by using a regional water-balance model (Basin Characterization Model, or BCM) and a daily rainfall-runoff model (INFILv3). The BCM calculated spatially distributed potential recharge in the study area of approximately 12,700 acre-feet per year (acre-ft/yr) of potential in-place recharge and 30,800 acre-ft/yr of potential runoff. Using the assumption that only 10 percent of the runoff becomes recharge, this approach indicated there is approximately 15,800 acre-ft/yr of total recharge in

Field Evidence for Co-Metabolism of Trichloroethene Stimulated by Addition of Electron Donor to Groundwater

Energy Technology Data Exchange (ETDEWEB)

Conrad, Mark E.; Brodie, Eoin L.; Radtke, Corey W.; Bill, Markus; Delwiche, Mark E.; Lee, M. Hope; Swift, Dana L.; Colwell, Frederick S.

2010-05-17

For more than 10 years, electron donor has been injected into the Snake River aquifer beneath the Test Area North site of the Idaho National Laboratory for the purpose of stimulating microbial reductive dechlorination of trichloroethene (TCE) in groundwater. This has resulted in significant TCE removal from the source area of the contaminant plume and elevated dissolved CH4 in the groundwater extending 250 m from the injection well. The delta13C of the CH4 increases from 56o/oo in the source area to -13 o/oo with distance from the injection well, whereas the delta13C of dissolved inorganic carbon decreases from 8 o/oo to -13 o/oo, indicating a shift from methanogenesis to methane oxidation. This change in microbial activity along the plume axis is confirmed by PhyloChip microarray analyses of 16S rRNA genes obtained from groundwater microbial communities, which indicate decreasing abundances of reductive dechlorinating microorganisms (e.g., Dehalococcoides ethenogenes) and increasing CH4-oxidizing microorganisms capable of aerobic co-metabolism of TCE (e.g., Methylosinus trichosporium). Incubation experiments with 13C-labeled TCE introduced into microcosms containing basalt and groundwater from the aquifer confirm that TCE co-metabolism is possible. The results of these studies indicate that electron donor amendment designed to stimulate reductive dechlorination of TCE may also stimulate co-metabolism of TCE.

Nevada Test Site 2000 Annual Data Report: Groundwater Monitoring Program Area 5 Radioactive Waste Management Site

Energy Technology Data Exchange (ETDEWEB)

Y. E.Townsend

2001-02-01

This report is a compilation of the calendar year 2000 groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS). Contamination indicator data are presented in control chart and tabular form with investigation levels (IL) indicated. Gross water chemistry data are presented in graphical and tabular form. Other information in the report includes, the Cumulative Chronology for Area 5 RWMS Groundwater Monitoring Program, a brief description of the site hydrogeology, and the groundwater sampling procedure.

Nevada Test Site 2000 Annual Data Report: Groundwater Monitoring Program Area 5 Radioactive Waste Management Site

International Nuclear Information System (INIS)

Y. E.Townsend

2001-01-01

This report is a compilation of the calendar year 2000 groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS). Contamination indicator data are presented in control chart and tabular form with investigation levels (IL) indicated. Gross water chemistry data are presented in graphical and tabular form. Other information in the report includes, the Cumulative Chronology for Area 5 RWMS Groundwater Monitoring Program, a brief description of the site hydrogeology, and the groundwater sampling procedure

An investigation on groundwater recovery rate within sub sea floor tunnels at closed coal mines

International Nuclear Information System (INIS)

Nakata, Eiji; Suenaga, Hiroshi; Oyama, Takahiro; Nomura, Tokisada; Ichihara, Yoshihisa

2008-01-01

The groundwater recovery rate investigated at the closed coal mines extended within sub sea floor tunnels. The Ikeshima and the Taiheiyo coal mine companies exploited the deep coal-bearing strata beneath the ocean. Ikeshima coal mine, excavated S.L. -650m to 6km offshore from Ikeshima island, was closed at November 2002, and Taiheiyo coal mine, excavated S.L. -720m to 9km offshore from Hokkaido, was stopped to excavate from the deep area at January 2003. After closing and stopping of development, we began the investigation of the groundwater recovery rate at both coal mines. The groundwater level of Ikeshima coal mine raised +405m per 1.8 years at the main shaft. The permeability coefficient estimated between 10 - 8 m /s and 10 -6 m/s to use the water recovery rate at the shaft. Otherwise, at Taiheiyo coal mine, we measured the air pressure in tubes used by 3.5km 2.5km, and 1.5km length 2mm diameters tubes to estimate the groundwater recovery level at the 3.2km offshore plug site. Groundwater didn't reach 4.7km (1.5+3.2km) area until November 2004. There were breakdown of shotcleate and rock mass from the roof of tunnel at 5.3km from offshore line. In this paper, we try to show the groundwater recovery rate of these sub sea floor collieries. (author)

Interim sanitary landfill groundwater monitoring report. 1996 Annual report

International Nuclear Information System (INIS)

Bagwell, L.A.

1997-01-01

Eight wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Interim Sanitary Landfill at the Savannah River Site. These wells are sampled semiannually to comply with the South Carolina Department of Health and Environmental Control Modified Municipal Solid Waste Permit 025500-1120 and as part of the SRS Groundwater Monitoring Program. Trichlorofluoromethane and 1,1,1-trichloroethane were elevated in one sidegradient well and one downgradient well during 1996. Zinc was elevated in three downgradient wells and also was detected in the associated laboratory blanks for two of those wells. Specific conductance was elevated in one background well and one sidegradient well. Barium and copper exceeded standards in one sidegradient well, and dichloromethane (a common laboratory contaminant) was elevated in another sidegradient well. Barium, copper, and dichloromethane were detected in the associated blanks for these wells, also. The groundwater flow direction in the Steed Pond Acquifer (Water Table) beneath the Interim Sanitary Landfill was to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 210 ft/year during first quarter 1996 and 180 ft/yr during third quarter 1996

Approximating dose and risk for contaminants in groundwater from the underground nuclear test areas of the Nevada National Security Site (NNSS)

Energy Technology Data Exchange (ETDEWEB)

Daniels, Jeffrey I. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Chapman, Jenny [Desert Research Inst. (DRI), Las Vegas, NV (United States); Pohlmann, Karl F. [Desert Research Inst. (DRI), Las Vegas, NV (United States)

2015-03-01

As part of the Environmental Management Program at the Nevada National Security Site (NNSS), the Underground Test Area (UGTA) Activity investigates the potential impacts of radionuclides that were introduced into groundwater from the underground nuclear tests conducted near or below the NNSS water table between 1951 and 1992. Groundwater models are being used to simulate contaminant transport and forecast contaminant boundaries that encompass areas where the groundwater has a five percent or greater probability of containing contaminants above the Safe Drinking Water Act Maximum Contaminant Levels (SDWA MCLs) at any time during the next 1,000 years. Transport modeling conducted for the Frenchman Flat Corrective Action Unit (CAU) at the NNSS identified the beta/photon-emitting radionuclides tritium (3H), carbon-14 (14C), chlorine-36 (36Cl), technetium-99 (99Tc), and iodine-129 (129I) as having the greatest influence in defining the farthest extent of the modeled CAU contaminant boundary. These same radionuclides are assumed here as the contaminants of concern (COCs) for all underground nuclear tests at the NNSS because models are not yet complete for the other CAUs.Potential public exposure to the COCs will only occur and be of concern if the COCs migrate into the groundwater beneath public or private lands at levels that exceed either individual SDWA MCLs or dose and risk limits. Groundwater flow directions strongly suggest that any contaminant boundary predicted by contaminant fate and transport modeling to overlap public or private lands is more likely to occur to the west and/or southwest of the NNSS and the adjacent Nevada Test and Training Range (NTTR). Well-established, rural communities exist in these directions. Estimates of representative activity concentrations at the applicable SDWA MCL were developed for the five COCs. It is assumed that these COC concentrations may collectively occur at some public or private location in the future, but that situation

Ground-water recharge from small intermittent streams in the western Mojave Desert, California: Chapter G in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

Science.gov (United States)

Izbicki, John A.; Johnson, Russell U.; Kulongoski, Justin T.; Predmore, Steven; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Population growth has impacted ground-water resources in the western Mojave Desert, where declining water levels suggest that recharge rates have not kept pace with withdrawals. Recharge from the Mojave River, the largest hydrographic feature in the study area, is relatively well characterized. In contrast, recharge from numerous smaller streams that convey runoff from the bounding mountains is poorly characterized. The current study examined four representative streams to assess recharge from these intermittent sources. Hydraulic, thermal, geomorphic, chemical, and isotopic data were used to study recharge processes, from streamflow generation and infiltration to percolation through the unsaturated zone. Ground-water movement away from recharge areas was also assessed.Infiltration in amounts sufficient to have a measurable effect on subsurface temperature profiles did not occur in every year in instrumented study reaches. In addition to streamflow availability, results showed the importance of sediment texture in controlling infiltration and eventual recharge. Infiltration amounts of about 0.7 meters per year were an approximate threshold for the occurrence of ground-water recharge. Estimated travel times through the thick unsaturated zones underlying channels reached several hundred years. Recharging fluxes were influenced by stratigraphic complexity and depositional dynamics. Because of channel meandering, not all water that penetrates beneath the root zone can be assumed to become recharge on active alluvial fans.Away from study washes, elevated chloride concentrations and highly negative water potentials beneath the root zone indicated negligible recharge from direct infiltration of precipitation under current climatic conditions. In upstream portions of washes, generally low subsurface chloride concentrations and near-zero water potentials indicated downward movement of water toward the water table, driven primarily by gravity. Recharging conditions did not

Rainwater lens dynamics and mixing between infiltrating rainwater and upward saline groundwater seepage beneath a tile-drained agricultural field

NARCIS (Netherlands)

Louw, de P.G.B.; Eeman, S.; Oude Essink, G.H.P.; Vermue, E.; Post, V.E.A.

2013-01-01

Thin rainwater lenses (RW-lenses) near the land surface are often the only source of freshwater in agricultural areas with regionally-extensive brackish to saline groundwater. The seasonal and inter-annual dynamics of these lenses are poorly known. Here this knowledge gap is addressed by

Management of water resources to control groundwater levels in the southern area of the western Nile delta, Egypt

Directory of Open Access Journals (Sweden)

Mohamed M. Sobeih

2017-10-01

Full Text Available The present study was initiated with the objective of simulating and predicting the effect of future development on the groundwater flow and levels. This supports applications for future planning and wise management of water resources. The study area extends south of El Nubariya canal including Sadat City area and its vicinities in the western Nile delta region. A numerical groundwater flow model (MODFLOW has been employed to simulate flow and get the budget of groundwater in the study area. The model showed that about 28,101,041 m3/day of surface water is infiltrated to groundwater dominantly from canals and excess irrigation water. About the same quantity (28,101,052 m3/day, is discharged from groundwater through production wells, open drains and through some reaches of canals. Three development scenarios were simulated to give predictions of the impact of future increasing recharge, construction of new canal and new open drains, and also increased pumping on the groundwater levels in the study area.

An isotope-aided study on the interaction between surface water and groundwater in the KAERI area

International Nuclear Information System (INIS)

Ahn, Jong Sung; Kim, Jong Hoon; Yun, Si Tae; Jeong, Chan Ho; Kim, Kae Nam

1988-01-01

The basement rocks of the KAERI area are compose421d of two mica granite and schistose granite. The groundwater in these fresh crystalline rocks appears to be restricted within the zones developing the fractures. The groundwater in this area occurs mainly in the weathered zones of granitic rocks, with a thickness of 5-20 m. On the results of environmental isotopes analyses, it was proved that surface water and precipitation infiltrated rapidly through the subsurface media into the weathered zone. The high environmental isotopes level found in some groundwater samples are ascribed to the impermeable layer such as clay and silt around the sampling points. Consequently, the groundwater flow in this area is controlled by the heterogeneity of weathered materials. The water types classified by the piper diagram are attributed to the Ca-Cl and Ca-HCO 3 types

Microbial community of high arsenic groundwater in agricultural irrigation area of Hetao Plain, Inner Mongolia

Directory of Open Access Journals (Sweden)

Yanhong Wang

2016-12-01

Full Text Available Microbial communities can play important role in arsenic release in groundwater aquifers. To investigate the microbial communities in high arsenic groundwater aquifers in agricultural irrigation area, 17 groundwater samples with different arsenic concentrations were collected along the agricultural drainage channels of Hangjinhouqi County, Inner Mongolia and examined by illumina Miseq sequencing approach targeting the V4 region of the 16S rRNA gene. Both principal component analysis and hierarchical clustering results indicated that these samples were divided into two groups (high and low arsenic groups according to the variation of geochemical characteristics. Arsenic concentrations showed strongly positive correlations with NH4+ and TOC. Sequencing results revealed that a total of 329-2823 OTUs were observed at the 97% OTU level. Microbial richness and diversity of high arsenic groundwater samples along the drainage channels were lower than those of low arsenic groundwater samples but higher than those of high arsenic groundwaters from strongly reducing areas. The microbial community structure in groundwater along the drainage channels was different from those in strongly reducing As-rich aquifers of Hetao Plain and other high As groundwater aquifers including Bangladesh, West Bengal and Vietnam. Acinetobacter and Pseudomonas dominated with high percentages in both high and low arsenic groundwaters. Alishewanella, Psychrobacter, Methylotenera and Crenothrix showed relatively high abundances in high arsenic groundwater, while Rheinheimera and the unidentified OP3 were predominant populations in low arsenic groundwater. Archaeal populations displayed a low occurrence and mainly dominated by methanogens such as Methanocorpusculum and Methanospirillum. Microbial community compositions were different between high and low arsenic groundwater samples based on the results of principal coordinate analysis and co-inertia analysis. Other geochemical

Radio-Ecological Conditions of Groundwater in the Area of Uranium Mining and Milling Facility - 13525

International Nuclear Information System (INIS)

Titov, A.V.; Semenova, M.P.; Seregin, V.A.; Isaev, D.V.; Metlyaev, E.G.; Glagolev, A.V.; Klimova, T.I.; Sevtinova, E.B.; Zolotukhina, S.B.; Zhuravleva, L.A.

2013-01-01

Manmade chemical and radioactive contamination of groundwater is one of damaging effects of the uranium mining and milling facilities. Groundwater contamination is of special importance for the area of Priargun Production Mining and Chemical Association, JSC 'PPMCA', because groundwater is the only source of drinking water. The paper describes natural conditions of the site, provides information on changes of near-surface area since the beginning of the company, illustrates the main trends of contaminators migration and assesses manmade impact on the quality and mode of near-surface and ground waters. The paper also provides the results of chemical and radioactive measurements in groundwater at various distances from the sources of manmade contamination to the drinking water supply areas. We show that development of deposits, mine water discharge, leakages from tailing dams and cinder storage facility changed general hydro-chemical balance of the area, contributed to new (overlaid) aureoles and flows of scattering paragenetic uranium elements, which are much smaller in comparison with natural ones. However, increasing flow of groundwater stream at the mouth of Sukhoi Urulyungui due to technological water infiltration, mixing of natural water with filtration streams from industrial reservoirs and sites, containing elevated (relative to natural background) levels of sulfate-, hydro-carbonate and carbonate- ions, led to the development and moving of the uranium contamination aureole from the undeveloped field 'Polevoye' to the water inlet area. The aureole front crossed the southern border of water inlet of drinking purpose. The qualitative composition of groundwater, especially in the southern part of water inlet, steadily changes for the worse. The current Russian intervention levels of gross alpha activity and of some natural radionuclides including 222 Rn are in excess in drinking water; regulations for fluorine and manganese concentrations are also in excess

Radio-Ecological Conditions of Groundwater in the Area of Uranium Mining and Milling Facility - 13525

Energy Technology Data Exchange (ETDEWEB)

Titov, A.V.; Semenova, M.P.; Seregin, V.A.; Isaev, D.V.; Metlyaev, E.G. [FSBU SRC A.I.Burnasyan Federal Medical Biophysical Center of FMBA of Russia, Zhivopisnaya Street, 46, Moscow (Russian Federation); Glagolev, A.V.; Klimova, T.I.; Sevtinova, E.B. [FSESP ' Hydrospecgeologiya' (Russian Federation); Zolotukhina, S.B.; Zhuravleva, L.A. [FSHE ' Centre of Hygiene and Epidemiology no. 107' under FMBA of Russia (Russian Federation)

2013-07-01

Manmade chemical and radioactive contamination of groundwater is one of damaging effects of the uranium mining and milling facilities. Groundwater contamination is of special importance for the area of Priargun Production Mining and Chemical Association, JSC 'PPMCA', because groundwater is the only source of drinking water. The paper describes natural conditions of the site, provides information on changes of near-surface area since the beginning of the company, illustrates the main trends of contaminators migration and assesses manmade impact on the quality and mode of near-surface and ground waters. The paper also provides the results of chemical and radioactive measurements in groundwater at various distances from the sources of manmade contamination to the drinking water supply areas. We show that development of deposits, mine water discharge, leakages from tailing dams and cinder storage facility changed general hydro-chemical balance of the area, contributed to new (overlaid) aureoles and flows of scattering paragenetic uranium elements, which are much smaller in comparison with natural ones. However, increasing flow of groundwater stream at the mouth of Sukhoi Urulyungui due to technological water infiltration, mixing of natural water with filtration streams from industrial reservoirs and sites, containing elevated (relative to natural background) levels of sulfate-, hydro-carbonate and carbonate- ions, led to the development and moving of the uranium contamination aureole from the undeveloped field 'Polevoye' to the water inlet area. The aureole front crossed the southern border of water inlet of drinking purpose. The qualitative composition of groundwater, especially in the southern part of water inlet, steadily changes for the worse. The current Russian intervention levels of gross alpha activity and of some natural radionuclides including {sup 222}Rn are in excess in drinking water; regulations for fluorine and manganese

Electrical resistivity dynamics beneath a fractured sedimentary bedrock riverbed in response to temperature and groundwater–surface water exchange

Directory of Open Access Journals (Sweden)

C. M. Steelman

2017-06-01

Full Text Available Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwater–surface water exchange. In this study, surface electrical methods were used as a non-invasive technique to assess the scale and temporal variability of riverbed temperature and groundwater–surface water interaction beneath a sedimentary bedrock riverbed. Conditions were monitored at a semi-daily to semi-weekly interval over a full annual period that included a seasonal freeze–thaw cycle. Surface electromagnetic induction (EMI and electrical resistivity tomography (ERT methods captured conditions beneath the riverbed along a pool–riffle sequence of the Eramosa River in Canada. Geophysical datasets were accompanied by continuous measurements of aqueous specific conductance, temperature, and river stage. Time-lapse vertical temperature trolling within a lined borehole adjacent to the river revealed active groundwater flow zones along fracture networks within the upper 10 m of rock. EMI measurements collected during cooler high-flow and warmer low-flow periods identified a spatiotemporal riverbed response that was largely dependent upon riverbed morphology and seasonal groundwater temperature. Time-lapse ERT profiles across the pool and riffle sequence identified seasonal transients within the upper 2 and 3 m of rock, respectively, with spatial variations controlled by riverbed morphology (pool versus riffle and dominant surficial rock properties (competent versus weathered rock rubble surface. While the pool and riffle both exhibited a dynamic resistivity through seasonal cooling and warming cycles, conditions beneath the pool were more variable, largely due to the formation of river

Biosensor-based diagnostics of contaminated groundwater: assessment and remediation strategy

International Nuclear Information System (INIS)

Bhattacharyya, Jessica; Read, David; Amos, Sean; Dooley, Stephen; Killham, Kenneth; Paton, Graeme I.

2005-01-01

Shallow groundwater beneath a former airfield site in southern England has been heavily contaminated with a wide range of chlorinated solvents. The feasibility of using bacterial biosensors to complement chemical analysis and enable cost-effective, and focussed sampling has been assessed as part of a site evaluation programme. Five different biosensors, three metabolic (Vibrio fischeri, Pseudomonas fluorescens 10568 and Escherichia coli HB101) and two catabolic (Pseudomonas putida TVA8 and E. coli DH5α), were employed to identify areas where the availability and toxicity of pollutants is of most immediate environmental concern. The biosensors used showed different sensitivities to each other and to the groundwater samples tested. There was generally a good agreement with chemical analyses. The potential efficacy of remediation strategies was explored by coupling sample manipulation to biosensor tests. Manipulation involved sparging and charcoal treatment procedures to simulate remediative engineering solutions. Sparging was sufficient at most locations. - Luminescent bacteria complement chemical analysis and support remediation technology

A highly attennuative zone beneath the Tokyo Metropolitan area.

Science.gov (United States)

Panayotopoulos, Y.; Hirata, N.; Sakai, S.; Nakagawa, S.; Kasahara, K.

2014-12-01

The intensities of seismic waves observed at the dense seismic array of the Tokyo Metropolitan Seismic Observation network (MeSO-net) inside the Kanto basin, display unusual distribution patterns. In several occasions, the highest intensities are not observed in the area above an earthquakes hypocenter but appear sifted more than 20 km away. In order to understand the source of this unusual intensity distribution pattern, it is crucial to understand how the waves attenuate before they reach the surface. The attenuation of seismic waves along their path is represented by the t∗ attenuation operator that can be obtained by fitting the observed seismic wave spectrum to a theoretical spectrum using an ω2 model. In order to create a high quality dataset, only 1449 earthquakes that are recorded with intensity greater than 0 in the Japan Meteorological Agency (JMA) intensity scale are selected from the JMA unified earthquake list from April 1st 2008 to October 2nd 2013. A grid search method is applied to determine the t∗ values by matching the observed and theoretical spectra. The t∗ data where then inverted to estimate a 3D Q structure with grid points set at a 10 km spacing. We implemented the 3D velocity model estimated by Nakagawa et al., 2012 and in addition we set the initial Q values at 100 for the 0 km grids and to 400 for the grids below them. The obtained model suggests average Q values of 50˜100 inside the Kanto basin. Furthermore, a low Q zone is observed in the area where the Philippine Sea plate meets the upper part of the Pacific sea plate. This area is located at approximately 40 km depth, beneath the north-east Tokyo and west Chiba prefectures and is represented by Q values Earthquakes occurring on the Pacific plate pass through this low Q area inside the Philippine sea plate and are attenuated significantly. The estimated attenuation distribution at the MeSO-net station for these earthquakes implementing our 3D Q model greatly coincides with the

Application of a Groundwater Modeling Tool for Managing Hydrologically Connected Area in State of Nebraska, US

Science.gov (United States)

Li, R.; Flyr, B.; Bradley, J.; Pun, M.; Schneider, J.; Wietjes, J.; Chinta, S.

2014-12-01

Determination of the nature and degree of hydrologically connected groundwater and surface water resources is of paramount importance to integrated water management within the State of Nebraska to understand the impact of water uses on available supplies, such as depletion of streams and aquifers caused by groundwater pumping. The ability to quantify effects of surface water-groundwater hydrologic connection and interactions, is regarded as one of the most important steps towards effectively managing water resources in Nebraska and provides the basis for designating management areas. Designation of management areas allows the state and other management entities to focus various efforts and resources towards those projects that have the greatest impact to water users. Nebraska Department of Natural Resources (NDNR) developed a groundwater modeling tool, Cycle Well Analysis, to determine the areas defined to have a high degree of connectivity between groundwater and surface water (in accordance with the state regulations). This tool features two graphic user interfaces to allow the analysis to be fully compatible with most MODFLOW-based numerical groundwater models currently utilized by NDNR. Case studies showed that the tool, in combination of Geographic Information Systems (GIS), can be used to quantify the degree of stream depletion and delineate the boundary of hydrologically connected areas within different political boundaries and subbasins in Nebraska. This approach may be applied to other regions with similar background and need for integrated water management.

Nitrogen and carbon dynamics beneath on-site wastewater treatment systems in Pitt County, North Carolina.

Science.gov (United States)

Del Rosario, Katie L; Humphrey, Charles P; Mitra, Siddhartha; O'Driscoll, Michael A

2014-01-01

On-site wastewater treatment systems (OWS) are a potentially significant non-point source of nutrients to groundwater and surface waters, and are extensively used in coastal North Carolina. The goal of this study was to determine the treatment efficiency of four OWS in reducing total dissolved nitrogen (TDN) and dissolved organic carbon (DOC) concentrations before discharge to groundwater and/or adjacent surface water. Piezometers were installed for groundwater sample collection and nutrient analysis at four separate residences that use OWS. Septic tank effluent, groundwater, and surface water samples (from an adjacent stream) were collected four times during 2012 for TDN and DOC analysis and pH, temperature, electrical conductivity, and dissolved oxygen measurements. Treatment efficiencies from the tank to the groundwater beneath the drainfields ranged from 33 to 95% for TDN and 45 to 82% for DOC, although dilution accounted for most of the concentration reductions. There was a significant positive correlation between nitrate concentration and separation distance from trench bottom to water table and a significant negative correlation between DOC concentration and separation distance. The TDN and DOC transport (>15 m) from two OWS with groundwater saturated drainfield trenches was significant.

Groundwater and quaternary geological studies of potential peat production areas - useful tool for sustainable peat production

Energy Technology Data Exchange (ETDEWEB)

Valpola, S.E.; Paalijaervi, M. (Geological Survey of Finland, Kokkola (Finland)), Email: samu.valpola@gtk.fi, Email: miikka.paalijarvi@gtk.fi

2009-07-01

Potential peat production areas in Finland are often situated in vicinity of eskers or other quaternary (glaciofluvial) formations. Frequently these formations are also important groundwater resources and it is essential for sustainable peat production to assure that these resources will not be endangered. The Geological Survey of Finland (GTK) has concluded several quaternary geological studies on potential peat production areas, which are connected to locally important groundwater areas. These studies have been made using mainly ground penetrating radar (GPR) and light drilling equipment. The main objective of these studies has been to establish the local groundwater flow directions and the quality and extent of quaternary deposits. The increasing need of peat production areas has created an evident demand of cost-effective and fast research methods which can be used for providing reliable information for planning of new production areas. (orig.)

Leachable 226Ra in Philippine phosphogypsum and its implication in groundwater contamination in Isabel, Leyte Philippines

International Nuclear Information System (INIS)

Canete, Socrates Jose P.; Palad, Lorna Jean H.; Enriquez, Eliza B.; Garcia, Teofilo Y.; Yulo-Nazarea, Teresa

2007-01-01

Phosphogypsum (PG), the major waste material in phosphate fertilizer processing, has been known to contain enhanced levels of naturally-occurring radionuclides especially 226 Ra. The lack of radioactivity data regarding Philippine phosphogypsum and its environmental behavior in the Philippine setting has brought concern on possible contamination of groundwater beneath the phosphogypsum ponds in Isabel, Leyte, Philippines. The radioactivity of Philippine phosphogypsum was determined and the leaching of 226 Ra from phosphogypsum and through local soil was quantified. Level of 226 Ra in groundwater samples in Isabel, Leyte, Philippines was also quantified to address the primary concern. It was found that the 226 Ra activity in Philippine phosphogypsum is distributed in a wide range from 91.5 to 935 Bq/kg. As much as 5% of 226 Ra can be leached from Philippine PG with deionized water. In vitro soil leach experiments suggest that the soil in the phosphate fertilizer plant area would be able to deter the intrusion of 226 Ra into the water table. Compared to reported values of natural groundwater levels of 226 Ra, the concentration of this radionuclide in Isabel, Leyte groundwater suggest that there is no 226 Ra intrusion brought about by the presence of phosphogypsum ponds in the area. (Authors)

Flow and geochemistry along shallow ground-water flowpaths in an agricultural area in southeastern Wisconsin

Science.gov (United States)

Saad, D.A.; Thorstenson, D.C.

1998-01-01

Water-quality and geohydrologic data were collected from 19 monitor wells and a stream in an agricultural area in southeastern Wisconsin. These sites were located along a 2,700-ft transect from a local ground-water high to the stream. The transect is approximately parallel to the horizontal direction of ground-water flow at the water table. Most of the wells were installed in unconsolidated deposits at five locations along the transect and include an upgradient well nest, a midgradient well nest, a downgradient well nest, wells in the lowland area near the stream, and wells installed in the stream bottom. The data collected from this study site were used to describe the water quality and geohydrology of the area and to explain and model the variations in water chemistry along selected ground-water flowpaths.

Geophysical investigation of seepage beneath an earthen dam.

Science.gov (United States)

Ikard, S J; Rittgers, J; Revil, A; Mooney, M A

2015-01-01

A hydrogeophysical survey is performed at small earthen dam that overlies a confined aquifer. The structure of the dam has not shown evidence of anomalous seepage internally or through the foundation prior to the survey. However, the surface topography is mounded in a localized zone 150 m downstream, and groundwater discharges from this zone periodically when the reservoir storage is maximum. We use self-potential and electrical resistivity tomography surveys with seismic refraction tomography to (1) determine what underlying hydrogeologic factors, if any, have contributed to the successful long-term operation of the dam without apparent indicators of anomalous seepage through its core and foundation; and (2) investigate the hydraulic connection between the reservoir and the seepage zone to determine whether there exists a potential for this success to be undermined. Geophysical data are informed by hydraulic and geotechnical borehole data. Seismic refraction tomography is performed to determine the geometry of the phreatic surface. The hydro-stratigraphy is mapped with the resistivity data and groundwater flow patterns are determined with self-potential data. A self-potential model is constructed to represent a perpendicular profile extending out from the maximum cross-section of the dam, and self-potential data are inverted to recover the groundwater velocity field. The groundwater flow pattern through the aquifer is controlled by the bedrock topography and a preferential flow pathway exists beneath the dam. It corresponds to a sandy-gravel layer connecting the reservoir to the downstream seepage zone. © 2014, National Ground Water Association.

Potential Magma Chambers beneath the Tatun Volcanic Area, Taiwan: Results from Magnetotelluric Survey and Monitoring

Science.gov (United States)

Chen, C.

2013-12-01

Previous earthquakes analysis indicated existing seismicity anomaly beneath Tatun volcano, Taiwan, possibly caused by the fluid activity of the volcano. Helium isotope studies also indicated that over 60% of the fumarolic gases and vapors originated from deep mantle in the Tatun volcano area. The chemistry of the fumarolic gases and vapors and seismicity anomaly are important issues in view of possible magma chamber in the Tatun volcano, where is in the vicinity of metropolitan Taipei, only 15 km north of the capital city. In this study magnetotelluric (MT) soundings and monitoring were deployed to understand the geoelectric structures in the Tatun volcano as Electromagnetic methods are sensitive to conductivity contrasts and can be used as a supplementary tool to delineate reservoir boundaries. An anticline extending more than 10 km beneath the Chih-Shin-Shan and Da-You-Kan areas was recognized. Low resistivity at a shallow and highly porous layer 500m thick might indicate circulation of heated water. However, a high resistivity layer at depth between 2 and 6 km was detected. This layer could be associated with high micro-earthquakes zone. The characteristics of this layer produced by either the magma chamber or other geothermal activity were similar to that of some other active volcanic areas in the world. At 6 km underground was a dome structure of medium resistivity. This structure could be interpreted as a magma chamber in which the magma is possibly cooling down, as judged by its relatively high resistivity. The exact attributes of the magma chamber were not precisely determined from the limited MT soundings. At present, a joint monitors including seismic activity, ground deformation, volcanic gases, and changes in water levels and chemistry are conducted by universities and government agencies. When unusual activity is detected, a response team may do more ground surveys to better determine if an eruption is likely.

Recharge behavior to groundwater in the command area of Heran distributary, Sanghar, Sindh

International Nuclear Information System (INIS)

Lashari, B.K.

2004-01-01

Determination of net recharge to the groundwater is of prime importance while managing irrigation and drainage system of the area. Without knowing the groundwater and recharge both systems irrigation and drainage, are two sides of one coin may mislead. In order to determine net recharge to the groundwater, the data of important parameters such as irrigation delivery at head of the channel, total losses, crop water requirement, water table fluctuation, operation hours of tube wells and surface drain discharge and shallow as well as deep ground water quality were measured for Rabi season (November, 1999 to March, 2000). Using different approaches such as actual observation of inflow and outflow components, change of water table and SURFER (Software), the net recharge was determined. Results have shown that in Rabi season, the groundwater is recharged except in the month of January (canal closure period) and March, depending on various irrigation and drainage factors, which are complex. Shallow groundwater quality was observed good and use able due to recharge by surface water. About 41 % of command area was under shallow water table with salinity of water 300-800 ppm, 29 % was under water quality of 800-1300 ppm, 9% was between 1800-2300 ppm and rest 12% of the area was observed more than 2300 ppm. The quality of fresh water pump lifting water from the depth of 40 ft was up to 2400 ppm and deeper pump water quality was about 25000 ppm in scavenger and saline tube wells. Average water table was about 3.0 ft and fluctuation was between 2.38-3.8 feet in spite of running the tube wells.(author)

Thermal footprints in groundwater of central European cities

Science.gov (United States)

Bayer, P.; Menberg, K.; Blum, P.

2014-12-01

Atmospheric thermal pollution in densely populated areas is recognized as a severe problem with consequences for human health, and considerable efforts are being taken to mitigate heat stress in cities. However, anthropogenic activities also influence the thermal environment beneath the ground level, with commonly growing temperatures that affect groundwater ecology and geothermal use efficiency. In our work, we identify the controlling mechanisms for the long-term evolution of such urban heat islands. The shallow groundwater temperatures in several central European cities such as Cologne, Karlsruhe, Munich, Berlin and Zurich were mapped at high spatial and temporal resolution. Thermal anomalies were found to be highly heterogeneous with local hot spots showing temperatures of more than 20°C. Accordingly, these urban regions show a considerable groundwater warming in comparison to undisturbed temperatures of 8-11°C. Examination of potential heat sources by analytical modelling reveals that increased ground surface temperatures and basements of buildings act as dominant drivers for the anthropogenic heat input into the groundwater. The factors are revealed to be case-specific and they may have pronounced local or regional effects. Typical local factors are for example buried district heating networks. In selected cities we find that the average urban heat flux is around one order of magnitude higher than the elevated ground heat flux due to recent climate change. Additionally, such as observed in Zurich, naturally controlled temperature variations can be substantial and they are shown to wash out anthropogenic thermal footprints.

Multivariate statistical evaluation of trace elements in groundwater in a coastal area in Shenzhen, China

International Nuclear Information System (INIS)

Chen Kouping; Jiao, Jiu J.; Huang Jianmin; Huang Runqiu

2007-01-01

Multivariate statistical techniques are efficient ways to display complex relationships among many objects. An attempt was made to study the data of trace elements in groundwater using multivariate statistical techniques such as principal component analysis (PCA), Q-mode factor analysis and cluster analysis. The original matrix consisted of 17 trace elements estimated from 55 groundwater samples colleted in 27 wells located in a coastal area in Shenzhen, China. PCA results show that trace elements of V, Cr, As, Mo, W, and U with greatest positive loadings typically occur as soluble oxyanions in oxidizing waters, while Mn and Co with greatest negative loadings are generally more soluble within oxygen depleted groundwater. Cluster analyses demonstrate that most groundwater samples collected from the same well in the study area during summer and winter still fall into the same group. This study also demonstrates the usefulness of multivariate statistical analysis in hydrochemical studies. - Multivariate statistical analysis was used to investigate relationships among trace elements and factors controlling trace element distribution in groundwater

Groundwater Monitoring Plan for the Z-Area Saltstone Disposal Facility, Revision 3

International Nuclear Information System (INIS)

WELLS, DANIEL

2005-01-01

Groundwater monitoring has been conducted at the Z-Area Saltstone Disposal Facility since 1987. At that time, groundwater monitoring was not required by the industrial landfill regulations, but a modest monitoring program was required by the operating permit. At the time of the 1996 permit renewal, it was determined that a more robust monitoring program was needed. The draft permit required new monitoring wells within 25 feet of each active disposal cell. As an alternative, SRS proposed a program based on direct push sampling. This program called for biennial direct push sampling within 25 feet of each waste-containing cell with additional samples being taken in areas where excessive cracking had been observed. The direct push proposal was accepted by The South Carolina Department of Health and Environmental Control (SCDHEC), and was incorporated by reference into the Z-Area Saltstone Industrial Solid Waste Permit, No.025500-1603. The Industrial Solid Waste Landfill Regulations were revised in 1998 and now include specific requirements for groundwater monitoring. SRS's plan for complying with those regulations is discussed below. The plan calls for a return to traditional monitoring with permanent wells. It also proposes a more technically sound monitoring list based on the actual composition of saltstone

P-wave velocity structure beneath the northern Antarctic Peninsula

Science.gov (United States)

Park, Y.; Kim, K.; Jin, Y.

2010-12-01

We have imaged tomographically the tree-dimensional velocity structure of the upper mantle beneath the northern Antarctic Peninsula using teleseismic P waves. The data came from the seven land stations of the Seismic Experiment in Patagonia and Antarctica (SEPA) campaigned during 1997-1999, a permanent IRIS/GSN station (PMSA), and 3 seismic stations installed at scientific bases, Esperanza (ESPZ), Jubany (JUBA), and King Sejong (KSJ), in South Shetland Islands. All of the seismic stations are located in coast area, and the signal to noise ratios (SNR) are very low. The P-wave model was inverted from 95 earthquakes resulting in 347 ray paths with P- and PKP-wave arrivals. The inverted model shows a strong low velocity anmaly beneath the Bransfield Strait, and a fast anomaly beneath the South Shetland Islands. The low velocity anomaly beneath the Bransfield might be due to a back arc extension, and the fast velocity anomaly beneath the South Shetland Islands could indicates the cold subducted slab.

Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona—2013–2015

Science.gov (United States)

Macy, Jamie P.; Mason, Jon P.

2017-12-07

The Navajo (N) aquifer is an extensive aquifer and the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use by a growing population and because of low precipitation in the arid climate of the Black Mesa area. Precipitation in the area typically is between 6 and 16 inches per year.The U.S. Geological Survey water-monitoring program in the Black Mesa area began in 1971 and provides information about the long-term effects of groundwater withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected as part of the monitoring program in the Black Mesa area from January 2013 to December 2015. The monitoring program includes measurements of (1) groundwater withdrawals (pumping), (2) groundwater levels, (3) spring discharge, (4) surface-water discharge, and (5) groundwater chemistry.In 2013, total groundwater withdrawals were 3,980 acre-feet (ft), in 2014 total withdrawals were 4,170 acre-ft, and in 2015 total withdrawals were 3,970 acre-ft. From 2013 to 2015 total withdrawals varied by less than 5 percent.From 2014 to 2015, annually measured water levels in the Black Mesa area declined in 9 of 15 wells that were available for comparison in the unconfined areas of the N aquifer, and the median change was -0.1 feet. Water levels declined in 3 of 16 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.6 feet. From the prestress period (prior to 1965) to 2015, the median water-level change for 34 wells in both the confined and unconfined areas was -13.2 feet; the median water-level changes were -1.7 feet for 16 wells measured in the unconfined areas and -42.3 feet for 18 wells measured in the confined area.Spring flow was measured at four springs in 2014. Flow fluctuated during the

Assessment of the Impact of Industrial Effluents on Groundwater Quality in Okhla Industrial Area, New Delhi, India

Directory of Open Access Journals (Sweden)

Wequar Ahmad Siddiqui

2009-01-01

Full Text Available In the present study physicochemical parameters like pH, hardness, TDS, chloride, sulphate, nitrate, fluoride, DO, COD and conductivity of some important heavy metals such as iron, cobalt, cadmium, lead, mercury, chromium, selenium and arsenic were first analyzed in effluent water of Okhla industrial area phase-II and then groundwater of near by areas. Obtained values of effluent water were compared with ISI standard for effluent water discharge and groundwater values were compared with ISI and WHO drinking water standards. The result shows that discharge of untreated effluents by the industries is leading to contamination of groundwater of the surrounding areas. Lead, mercury, fluoride, TDS, sulphate was above the desirable limit in effluent water (ISI standard for effluent water discharge. Subsequent analysis of groundwater of nearby areas was rated as unacceptable for drinking because of presence of fluoride in all the samples above the desirable limit. Lead, mercury, cadmium, chloride was also detected in many samples.

RESULTS OF TRITIUM TRACKING AND GROUNDWATER MONITORING AT THE HANFORD SITE 200 AREA STATE APPROVED LAND DISPOSAL SITE. FISCAL YEAR 2008

International Nuclear Information System (INIS)

Erb, D.B.

2008-01-01

The Hanford Site's 200 Area Effluent Treatment Facility (ETF) processes contaminated aqueous wastes derived from Hanford Site facilities. The treated wastewater occasionally contains tritium, which cannot be removed by the ETF prior to the wastewater being discharged to the 200 Area State-Approved Land Disposal Site (SALDS). During the first 11 months of fiscal year 2008 (FY08) (September 1, 2007, to July 31, 2008), approximately 75.15 million L (19.85 million gal) of water were discharged to the SALDS. Groundwater monitoring for tritium and other constituents, as well as water-level measurements, is required for the SALDS by State Waste Discharge Permit Number ST-4500 (Ecology 2000). The current monitoring network consists of three proximal (compliance) monitoring wells and nine tritium-tracking wells. Quarterly sampling of the proximal wells occurred in October 2007 and in January/February 2008, April 2008, and August 2008. The nine tritium-tracking wells, including groundwater monitoring wells located upgradient and downgradient of the SALDS, were sampled in January through April 2008. Water-level measurements taken in the three proximal SALDS wells indicate that a small groundwater mound is present beneath the facility, which is a result of operational discharges. The mound increased in FY08 due to increased ETF discharges from treating groundwater from extraction wells at the 200-UP-l Operable Unit and the 241-T Tank Farm. Maximum tritium activities increased by an order of magnitude at well 699-48-77A (to 820,000 pCi/L in April 2008) but remained unchanged in the other two proximal wells. The increase was due to higher quantities of tritium in wastewaters that were treated and discharged in FY07 beginning to appear at the proximal wells. The FY08 tritium activities for the other two proximal wells were 68,000 pCi/L at well 699-48-77C (October 2007) and 120,000 pCi/L at well 699-48-77D (October 2007). To date, no indications of a tritium incursion from the

S-wave attenuation structure beneath the northern Izu-Bonin arc

Science.gov (United States)

Takahashi, Tsutomu; Obana, Koichiro; Kodaira, Shuichi

2016-04-01

To understand temperature structure or magma distribution in the crust and uppermost mantle, it is essential to know their attenuation structure. This study estimated the 3-D S-wave attenuation structure in the crust and uppermost mantle at the northern Izu-Bonin arc, taking into account the apparent attenuation due to multiple forward scattering. In the uppermost mantle, two areas of high seismic attenuation (high Q -1) imaged beneath the volcanic front were mostly colocated with low-velocity anomalies. This coincidence suggests that these high- Q -1 areas in low-velocity zones are the most likely candidates for high-temperature regions beneath volcanoes. The distribution of random inhomogeneities indicated the presence of three anomalies beneath the volcanic front: Two were in high- Q -1 areas but the third was in a moderate- Q -1 area, indicating a low correlation between random inhomogeneities and Q -1. All three anomalies of random inhomogeneities were rich in short-wavelength spectra. The most probable interpretation of such spectra is the presence of volcanic rock, which would be related to accumulated magma intrusion during episodes of volcanic activity. Therefore, the different distributions of Q -1 and random inhomogeneities imply that the positions of hot regions in the uppermost mantle beneath this arc have changed temporally; therefore, they may provide important constraints on the evolutionary processes of arc crust and volcanoes.

Groundwater Engineering in an Environmentally Sensitive Urban Area: Assessment, Landuse Change/Infrastructure Impacts and Mitigation Measures

Directory of Open Access Journals (Sweden)

Yohannes Yihdego

2017-07-01

Full Text Available A rise in the shallow unconfined groundwater at a site in Australia is causing water logging of the underground facility in the affected area. Realizing this problem, a study was conducted to identify the source of water that is causing the rise and to develop an implementation and operation plan of the mitigation (dewatering system. Modelling was undertaken using MODFLOW-SURFACT code, within the framework of Visual MODFLOW, to assess the spatial and temporal groundwater level at the site. The study undertaken incorporates compilation and assessment of available data, including a list of factual information reviewed, development of a conceptual groundwater model for the site and modelling of the pre and post development conditions. The outcomes of the assessment indicate water level rises due to the construction of the embankment are likely less than 0.12 m and changes in land, such as affected area burial, may change aquifer characteristics more significantly than the embankment. It is concluded that the elevated groundwater levels in the affected area are most likely a result of above average rainfall since 2007 and long term cumulative land use changes. The embankment construction is just one of many land use changes that have occurred both within and surrounding the affected area and likely only a minor contributor to the elevated water levels. Greater contribution may be attributed to re-direction of the natural flow paths the railway culvert weir reducing the overland flow gradient and ongoing changes (burial within the affected area and including the embankment. The model findings gives answers on what factors may be/are causing/contributing to, the higher than usual groundwater levels in the study area. A combination of drainage and/or pumping (dewatering system is suggested as a solution to overcome the problem of rising groundwater levels at the site. Further, the model output can aid in assessing mitigation options, including

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.

2016 Waste Management Monitoring Report Area 3 and Area 5 Radioactive Waste Management Sites

Energy Technology Data Exchange (ETDEWEB)

Black, David [National Security Technologies, LLC. (NSTec), Mercury, NV (United States)

2017-08-30

Environmental monitoring data are collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) within the Nevada National Security Site (NNSS). These data include direct radiation exposure, as well as radiation from the air, groundwater, meteorology, and vadose zone. This report summarizes the 2016 environmental data to provide an overall evaluation of RWMS performance and to support environmental compliance and performance assessment (PA) activities. Some of these data (e.g., radiation exposure, air, and groundwater) are presented in other reports, developed by National Security Technologies, LLC Direct radiation monitoring data indicate exposure levels at the RWMSs are within the range of background levels measured at the NNSS. Slightly elevated exposure levels outside the Area 3 RWMS are attributed to nearby historical aboveground nuclear weapons tests. Air monitoring data show that tritium concentrations in water vapor and americium and plutonium concentrations in air particles are below Derived Concentration Standards for these radionuclides. Groundwater monitoring data indicate the groundwater in the uppermost aquifer beneath the Area 5 RWMS is not impacted by RWMS operations. Results of groundwater analysis from wells around the Area 5 RWMS were all below established investigation levels. Leachate samples collected from the leachate collection system at the mixed low-level waste cell were below established contaminant regulatory limits. During 2016, precipitation at the Area 3 RWMS was 8% below average, and precipitation at the Area 5 RWMS was 8% above average. Water balance measurements indicate that evapotranspiration from the vegetated weighing lysimeter dries the soil and prevents downward percolation of precipitation more effectively than evaporation as measured from the bare-soil weighing lysimeter. Vadose zone monitoring on Area 5 and Area 3 RWMS cell covers shows no evidence of precipitation percolating through the covers

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

Science.gov (United States)

Beretta, Giovanni Pietro; Terrenghi, Jacopo

2017-05-01

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

Stakeholder and expert-guided scenarios for agriculture and landscape development in a groundwater proction area

DEFF Research Database (Denmark)

Vejre, Henrik; Vesterager, Jens Peter; Kristensen, Lone Søderkvist

2011-01-01

Nitrate and pesticide leaching led to the designation of groundwater protection zones in Denmark. The protective measures in these zones often clash with local interests in agriculture. Scenarios were used to evaluate the development of a groundwater protection zone in a farming area. Stakeholders...

H-O isotopic and chemical characteristics of a precipitation-lake water-groundwater system in a desert area

Science.gov (United States)

Jin, Ke; Rao, Wenbo; Tan, Hongbing; Song, Yinxian; Yong, Bin; Zheng, Fangwen; Chen, Tangqing; Han, Liangfeng

2018-04-01

The recharge mechanism of groundwater in the Badain Jaran Desert, North China has been a focus of research and still disputable in the past two decades. In this study, the chemical and hydrogen (H) and oxygen (O) isotopic characteristics of shallow groundwater, lake water and local precipitation in the Badain Jaran Desert and neighboring areas were investigated to reveal the relationships between various water bodies and the recharge source of shallow groundwater. Isotopic and hydrogeochemical results show that (1) shallow groundwater was associated with local precipitation in the Ayouqi and Yabulai regions, (2) lake water was mainly recharged by groundwater in the desert hinterland, (3) shallow groundwater of the desert hinterland, Yabulai Mountain and Gurinai Grassland had a common recharge source. Shallow groundwater of the desert hinterland had a mean recharge elevation of 1869 m a.s.l. on the basis of the isotope-altitude relationship and thus originated chiefly from lateral infiltration of precipitation in the Yabulai Mountain. It is further concluded that shallow groundwater flowed towards the Gurinai Grassland according to the groundwater table contour map. Along the flow pathway, the H-O isotopic variations were primarily caused by the evaporation effect but chemical variations of shallow groundwater were affected by multiple factors, e.g., evaporation effect, dilution effect of occasional heavy-precipitation and dissolution of aquifer evaporites. Our findings provide new insight into the groundwater cycle and benefit the management of the limited water resources in the arid desert area.

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

Simulated effects of increased groundwater withdrawals in the Cave Springs area, Hixson, Tennessee

Science.gov (United States)

Haugh, Connor J.

2014-01-01

Concern for future water supplies in Tennessee has grown in recent years as a result of increased awareness of competing needs, the impact of droughts, and the need for more water to support growing populations. The U.S. Geological Survey conducts investigations to improve the knowledge about interactions of geology, climate, humans, and ecosystems with the water cycle, which is critical to understanding and optimizing water availability. The Hixson Utility District in Hamilton County, Tennessee, uses groundwater resources in the Cave Springs area as a water supply, withdrawing water from two well fields located at Cave Springs and Walkers Corner. Historically, Hixson Utility District has withdrawn about 5 million gallons per day (Mgal/d) at the Cave Springs well field and between 2 and 3 Mgal/d at the Walkers Corner well field. To assess the capacity of the groundwater resources in the Cave Springs area to meet future demands, four different scenarios of increased groundwater withdrawals were analyzed using computer model simulations.

Environmental isotopes, chemical composition and groundwater sources in Al-Maghara area, Sinai, Egypt

International Nuclear Information System (INIS)

Nada, A.A.; Awad, M.A.; Froehlich, K.; El Behery, M.

1991-01-01

Groundwater samples collected from a number of localities, in Al-Maghara area, north central part of Sinai, were subject to various chemical and isotopic analysis. The purpose of the study is to determine whether the groundwaters are recently recharged or not in order to adopt an efficient water management policy. The hydrochemical results indicate that they are mainly of primary marine origin, dilution of this water by meteoric water changes its chemical composition to be mixed water type, which has the major chemical components: KCl, NaCl, Na 2 SO 4 , MgSO 4 , Mg(HCO 3 ) 2 and Ca(HCO 3 ) 2 . The tritium content confirm the meteoric water recharge recently especially for wells with high tritium content. The stable environmental isotopic composition of the groundwater reflects the isotopic composition of precipitation and flooding with some evaporation enrichment prior to infiltration. There is also mixing with palaeowater (water recharge in the past cooler climate periods), by leaking through faulting in the area. (orig.) [de

Three-Dimensional Groundwater Models of the 300 Area at the Hanford Site, Washington State

Energy Technology Data Exchange (ETDEWEB)

Williams, Mark D.; Rockhold, Mark L.; Thorne, Paul D.; Chen, Yousu

2008-09-01

Researchers at Pacific Northwest National Laboratory developed field-scale groundwater flow and transport simulations of the 300 Area to support the 300-FF-5 Operable Unit Phase III Feasibility Study. The 300 Area is located in the southeast portion of the U.S. Department of Energy’s Hanford Site in Washington State. Historical operations involving uranium fuel fabrication and research activities at the 300 Area have contaminated engineered liquid-waste disposal facilities, the underlying vadose zone, and the uppermost aquifer with uranium. The main objectives of this research were to develop numerical groundwater flow and transport models to help refine the site conceptual model, and to assist assessment of proposed alternative remediation technologies focused on the 300 Area uranium plume.

Metal concentrations and mobility in marine sediment and groundwater in coastal reclamation areas: A case study in Shenzhen, China

International Nuclear Information System (INIS)

Chen Kouping; Jiao, Jiu J.

2008-01-01

The concentrations of metals in the buried marine sediment and groundwater were differently affected by land reclamation. Nine metals (V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb) in sediment and coastal groundwater from reclamation areas in Shenzhen were examined. The gradually decreased concentrations (V, Cr, Mn, Ni, Cu, Zn) in sediment and relatively higher concentrations (V, Cr, Mn, Co, Ni, Cu and Cd) in groundwater within reclamation areas were observed. The increase of V, Cr, Mn, Ni, Cu and Cd concentrations in groundwater within reclamation areas subsequently after land reclamation should be resulted from the mobilization of these metals accumulated in the sediment. These metals appear to be easily mobilized from solid phase to solution phase after reclamation. The physico-chemical changes such as reduction in pH and salinity in water environment induced by land reclamation appear to be responsible for metal mobility in the sediment-groundwater system. - Metals in coastal groundwater and marine sediment are affected by land reclamation

Isotope hydrology applied to evaluation of groundwater in arid areas

International Nuclear Information System (INIS)

Froehlich, K.; Geyh, M.A.; Verhagen, B.T.; Wirth, K.

1987-01-01

Capture of underground water in arid or semi-arid areas in developing countries is essential to safeguarding life. In order to realize in time, or to prevent, endangerment of exploitable groundwater resources due to pollution or excess exploitation, isotope hydrology offers low-cost methods that are applied along with other methods. Their results contribute to determine the origin, mixing, residence time (or age), and pollution of endangered groundwater resources. The research report in hand uses the results of hydrochemical analyses and isotope hydrological data from hydrogeological studies made over some years by the Bundesanstalt fuer Geowissenschaften und Rohstoffe in six selected countries: Jordan, Cyprus, Brazil, Sudan, Djibouti, Senegal. It also uses data of recent analyses of the years 1985 and 1986. Data evaluation is done applying modern, qualitative and quantitative methods of interpretation. The available long-term series of isotopic data are scanned for any early information on water quality deterioration that is not otherwise detected. The information thus obtained is a prerequisite of urgently needed measures for protecting the groundwater reserves. (orig./HP) [de

Revised model of regional groundwater flow in the Whiteshell research area

International Nuclear Information System (INIS)

Ophori, D.U.; Brown, A.; Chan, T.; Davison, C.C.; Gascoyne, M.; Scheier, N.W.; Stanchell, F.W.; Stevenson, D.R.

1996-08-01

Steady-state regional groundwater flow of the Whiteshell Research Area (WRA) has been simulated in order to evaluate alternate locations for a hypothetical nuclear fuel waste disposal vault that maximize the retention of vault contaminants in long, slow groundwater flow paths through the geosphere. A revised conceptual model of the hydrogeologic conditions was constructed using all the information obtained from field investigations at the WRA between 1977 and 1994. All the simulations were performed using AECL's three-dimensional finite element code, MOTIF. A base-case simulation was performed using average value estimates of hydraulic parameters obtained from the field data, and freshwater was assumed to occur in the entire groundwater flow region. The simulated freshwater heads did not compare favourably with the freshwater beads that were derived from the field data. The simulated equivalent freshwater heads for the final calibrated model compared reasonably well with measured heads in the network of boreholes at the WRA. The simulated recharge rate for the final model was 4.8 mm/a Most of the groundwater flow in the model occurred in local systems between ground surface and a depth of 1000 m. A particle tracking code, TRACK3D, was used to determine the pathways, travel times and exit locations of particles released from different depths in the groundwater velocity field of the calibrated model. The exit locations of these pathways were found to be controlled by the network of regional fracture zones in the model. These results were used to select a location for a hypothetical nuclear fuel waste disposal vault in the regional groundwater flow model that maximizes the retention of vault contaminants in long, slow groundwater flow paths. A smaller region of about 75 km 2 was identified around this location for the development of a local geosphere model. (author). 32 refs., 4 tabs., 29 figs

Origin and distribution of saline groundwaters in the upper Miocene aquifer system, coastal Rhodope area, northeastern Greece

Science.gov (United States)

Petalas, C. P.; Diamantis, I. B.

1999-06-01

This paper describes the origins and distribution of saline groundwaters in the coastal area of Rhodope, Greece. The aquifer system includes two aquifers within coarse-grained alluvial sediments in the coastal part of the study area. Two major water-quality groups occur in the study area, namely Ca2+-rich saline groundwater and Ca2+-poor, almost fresh groundwater. The main process controlling the groundwater chemistry is the exchange of calcium and sodium between the aquifer matrix and intruding seawater. The natural salt water in the study area is probably residual water that infiltrated the aquifer system during repeated marine transgressions in late Pleistocene time. Seawater intrusion into the coastal aquifer system occurs as a result of overpumping in two seawater wedges separated vertically by a low-permeability layer. The rate of intrusion averages 0.8 m/d and is less than expected due to a decline of the aquifer's permeability at the interface with the seawater. The application of several hydrochemical techniques (Piper and Durov diagrams; Na+/Cl-, Ca2+/Cl-, Mg2+/Cl-, and Br-/Cl- molar ratios; Ca2+/Mg2+ weight ratio; and chloride concentrations), combined with field observations, may lead to a better explanation of the origin of the saline groundwater.

Site characterization plan for groundwater in Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

Lee, R.R.; Curtis, A.H.; Houlberg, L.M.; Purucker, S.T.; Singer, M.L.; Tardiff, M.F.; Wolf, D.A.

1994-07-01

The Waste Area Grouping (WAG) 1 Groundwater Operable Unit (OU) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, is undergoing a site characterization to identify environmental contamination that may be present. This document, Site Characterization Report for Groundwater in Waste Area Grouping I at Oak Ridge National Laboratory, Oak Ridge, Tennessee, identifies areas of concern with respect to WAG 1 groundwater and presents the rationale, justification, and objectives for conducting this continuing site characterization. This report summarizes the operations that have taken place at each of the areas of concern in WAG 1, summarizes previous characterization studies that have been performed, presents interpretations of previously collected data and information, identifies contaminants of concern, and presents an action plan for further site investigations and early actions that will lead to identification of contaminant sources, their major groundwater pathways, and reduced off-site migration of contaminated groundwater to surface water. Site characterization Activities performed to date at WAG I have indicated that groundwater contamination, principally radiological contamination, is widespread. An extensive network of underground pipelines and utilities have contributed to the dispersal of contaminants to an unknown extent. The general absence of radiological contamination in surface water at the perimeter of WAG 1 is attributed to the presence of pipelines and underground waste storage tank sumps and dry wells distributed throughout WAG 1 which remove more than about 40 million gal of contaminated groundwater per year.

Site characterization plan for groundwater in Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Lee, R.R.; Curtis, A.H.; Houlberg, L.M.; Purucker, S.T.; Singer, M.L.; Tardiff, M.F.; Wolf, D.A.

1994-07-01

The Waste Area Grouping (WAG) 1 Groundwater Operable Unit (OU) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, is undergoing a site characterization to identify environmental contamination that may be present. This document, Site Characterization Report for Groundwater in Waste Area Grouping I at Oak Ridge National Laboratory, Oak Ridge, Tennessee, identifies areas of concern with respect to WAG 1 groundwater and presents the rationale, justification, and objectives for conducting this continuing site characterization. This report summarizes the operations that have taken place at each of the areas of concern in WAG 1, summarizes previous characterization studies that have been performed, presents interpretations of previously collected data and information, identifies contaminants of concern, and presents an action plan for further site investigations and early actions that will lead to identification of contaminant sources, their major groundwater pathways, and reduced off-site migration of contaminated groundwater to surface water. Site characterization Activities performed to date at WAG I have indicated that groundwater contamination, principally radiological contamination, is widespread. An extensive network of underground pipelines and utilities have contributed to the dispersal of contaminants to an unknown extent. The general absence of radiological contamination in surface water at the perimeter of WAG 1 is attributed to the presence of pipelines and underground waste storage tank sumps and dry wells distributed throughout WAG 1 which remove more than about 40 million gal of contaminated groundwater per year

Investigation of Geochemical Characteristics and Controlling Processes of Groundwater in a Typical Long-Term Reclaimed Water Use Area

Directory of Open Access Journals (Sweden)

Yong Xiao

2017-10-01

Full Text Available The usage of reclaimed water can efficiently mitigate water crises, but it may cause groundwater pollution. To clearly understand the potential influences of long-term reclaimed water usage, a total of 91 samples of shallow and deep groundwater were collected from a typical reclaimed water use area during the dry and rainy seasons. The results suggest both shallow and deep groundwater are mainly naturally alkaline freshwater, which are composed mainly of Ca-HCO3, followed by mixed types such as Ca-Na-HCO3 and Ca-Mg-HCO3. A seasonal desalination trend was observed in both shallow and deep aquifers due to dilution effects in the rainy season. Groundwater chemical compositions in both shallow and deep aquifers are still dominantly controlled by natural processes such as silicate weathering, minerals dissolution and cation exchange. Human activities are also the factors influencing groundwater chemistry. Urbanization has been found responsible for the deterioration of groundwater quality, especially in shallow aquifers, because of the relative thin aquitard. Reclaimed water usage for agricultural irrigation and landscape purposes has nearly no influences on groundwater quality in rural areas due to thick aquitards. Therefore, reclaimed water usage should be encouraged in arid and semiarid areas with proper hydrogeological condition.

Coordination of groundwater activities in the 100 N Area

International Nuclear Information System (INIS)

Hartman, M.J.

1995-09-01

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

Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

Science.gov (United States)

Yu, Liang; Rozemeijer, Joachim; van Breukelen, Boris M.; Ouboter, Maarten; van der Vlugt, Corné; Broers, Hans Peter

2018-01-01

The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN), total phosphorus (TP), NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type) for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban-agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs) in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88) between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate from the decomposition of

Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

Science.gov (United States)

Jones, Perry M.; Trost, Jared J.; Erickson, Melinda L.

2016-10-19

OverviewThis study assessed lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes applying three approaches: statistical analysis, field study, and groundwater-flow modeling.  Statistical analyses of lake levels were completed to assess the effect of physical setting and climate on lake-level fluctuations of selected lakes. A field study of groundwater and surface-water interactions in selected lakes was completed to (1) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (2) estimate general ages for waters extracted from the wells, and (3) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake.  Groundwater flow was simulated using a steady-state, groundwater-flow model to assess regional groundwater and surface-water exchanges and the effects of groundwater withdrawals, climate, and other factors on water levels of northeast Twin Cities Metropolitan Area lakes.

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

F-Area Hazardous Waste Management Facility groundwater monitoring report, Third and fourth quarters 1995: Volume 1

International Nuclear Information System (INIS)

1996-03-01

Groundwater at the F-Area Hazardous Waste Management Facility (HWMF) is monitored in compliance with applicable regulations. Monitoring results are compared to the South Carolina Department of Health and Environmental Control (SCDHEC) Groundwater Protection Standard (GWPS). Historically and currently, gross alpha, nitrates, nonvolatile beta, and tritium are among the primary constituents to exceed standards. Numerous other radionuclides and hazardous constituents also exceed the GWPS in the groundwater during the second half of 1995, notably cadmium, lead, radium-226, radium-228, strontium-90, and total alpha-emitting radium. The elevated constituents were found primarily in the water table (aquifer zone IIB 2 ), however, several other aquifer unit monitoring wells contained elevated levels of constituents. Water-level maps indicate that the groundwater flow rates and directions at the F-Area HWMF have remained relatively constant since the basins ceased to be active in 1988

Hydrogeological and Groundwater Flow Model for C, K, L, and P Reactor Areas, Savannah River Site, Aiken, South Carolina

International Nuclear Information System (INIS)

Flach, G.P.

1999-01-01

A regional groundwater flow model encompassing approximately 100 mi 2 surrounding the C, K. L. and P reactor areas has been developed. The Reactor flow model is designed to meet the planning objectives outlined in the General Groundwater Strategy for Reactor Area Projects by providing a common framework for analyzing groundwater flow, contaminant migration and remedial alternatives within the Reactor Projects team of the Environmental Restoration Department

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

Science.gov (United States)

Moran, Edward H.; Galloway, Devin L.

2006-01-01

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

Paleohydrology of the southern Great Basin, with special reference to water table fluctuations beneath the Nevada Test Site during the late(?) Pleistocene

Science.gov (United States)

Winograd, Isaac Judah; Doty, Gene C.

1980-01-01

Knowledge of the magnitude of water-table rise during Pleistocene pluvial climates, and of the resultant shortening of groundwater flow path and reduction in unsaturated zone thickness, is mandatory for a technical evaluation of the Nevada Test Site (NTS) or other arid zone sites as repositories for high-level or transuranic radioactive wastes. The distribution of calcitic veins filling fractures in alluvium, and of tufa deposits between the Ash Meadows spring discharge area and the Nevada Test Site indicates that discharge from the regional Paleozoic carbonate aquifer during the Late( ) Pleistocene pluvial periods may have occurred at an altitude about 50 meters higher than at present and 14 kilometers northeast of Ash Meadows. Use of the underflow equation (relating discharge to transmissivity, aquifer width, and hydraulic gradient), and various assumptions regarding pluvial recharge, transmissivity, and altitude of groundwater base level, suggest possible rises in potentiometric level in the carbonate aquifer of about -90 meters beneath central Frenchman Flat. During Wisconsin time the rise probably did not exceed 30 meters. Water-level rises beneath Frenchman Flat during future pluvials are unlikely to exceed 30 meters and might even be 10 meters lower than modern levels. Neither the cited rise in potentiometric level in the regional carbonate aquifer, nor the shortened flow path during the Late( ) Pleistocene preclude utilization of the NTS as a repository for high-level or transuranic-element radioactive wastes provided other requisite conditions are met as this site. Deep water tables, attendant thick (up to several hundred meter) unsaturated zones, and long groundwater flow paths characterized the region during the Wisconsin Stage and probably throughout the Pleistocene Epoch and are likely to so characterize it during future glacial periods. (USGS)

Analog model study of the ground-water basin of the Upper Coachella Valley, California

Science.gov (United States)

Tyley, Stephen J.

1974-01-01

continue to provide the most significant supply of ground water for the upper valley. The total ground-water storage depletion for the entire upper valley for 1986-67 was about 600,000 acre-feet, an average storage decrease of about 25,000 acre-feet per year since 1945. Transmissivity for the Whitewater River subbasin ranges from 860,000 gallons per day per foot (near Point Happy) to 50,000 gallons per day per foot, with most of the subbasin about 800,000 gallons per day per foot. In contrast, the transmissivities of the Desert Hot Springs, Mission Creek, and Garnet Hill subbasins generally range from 2,000 to 100,000, but the highest value, beneath the Mission Creek streambed deposits, is 200,000 gallons per day per foot; the transmissivity for most of the area of th6 three subbasins is 80,000 gallons per day per foot. The storage coefficients are representative of water-table conditions, ranging from 0.18 beneath the Mission Creek stream deposits to 0.06 in the Palm Springs area. The model indicated that the outflow at Point Happy decreased from 50,000 acre-feet in 1936 to 30,000 acre-feet by 1967 as a result of the rising water levels in the lower valley. The most logical area to recharge the Colorado River water is the Windy Point-Whitewater area, where adequate percolation rates of 2-4 acre-feet per acre per day are probable. The Whitewater River bed may be the best location to spread the water if the largest part of the imported water can be recharged during low-flow periods. The area in sec. 21, T. 2 S., R. 4 E., would be adequate for the smaller quantities of recharge proposed for the Mission Creek area. Projected pumpage for the period 1968-2000 was programmed on the model with the proposed recharge of Colorado River water for the same period. The model indicated a maximum water-level increase of 200 feet above the 1967 water level at Windy Point, the proposed recharge site, by the year 2000, a 130-foot increase by 1990, and a 20-foot increas

Pollution of shallow groundwater in urban areas of developing countries; a comparative case study of Enugu and Aba towns of southeastern Nigeria

International Nuclear Information System (INIS)

Uma, K. O.; Ezeigbo, H. I.

2000-07-01

Field studies involving hydrochemical sampling of the groundwater in dug wells and shallow boreholes were carried out in the towns of Enugu (underlain by laterized clay aquifers) and Aba (underlain by loose sandstones). The results suggested generally similar enrichment pattern of some sewage sensitive geochemical parameters (Cl - , NO 3 , electric conductivity, HCO -3 and p H). There is, for instance, a clear elevation of the concentration of nitrates and chlorides above background values of zero and 10 mg/l respectively and these could be correlated with the intensity of urbanization in both towns. A significant observation was the relatively higher concentration of the sensitive parameters in the laterized clay aquifer beneath Enugu with respect to the sandy aquifer beneath Aba. The median concentration values of nitrates and chlorides were 20 mg/l and 16 mg/l at Aba whereas the values at Enugu were 27 mg/l and 72 mg/I respectively. The average electric conductance at Aba (300 mS/cm) was only about 50% of the corresponding value at Enugu, (610 mS/cm). There was also a more uniform concentration range at Enugu whereas outlier values were more common at Aba. The explanation for this could be found in both the matrix lithology and aquifer hydraulics in the areas. It is projected from the findings that thin laterized clay aquifers in hilly terrains could provide a highly conducive environment for rapid contaminant distribution. Such a hydrogeologic environment may even pose greater danger than that of a permeable sandy aquifer in flat terrains

Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona: 2011-2012

Science.gov (United States)

Macy, Jamie P.; Unema, Joel A.

2014-01-01

The Navajo (N) aquifer is an extensive aquifer and the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use by a growing population and because of low precipitation in the arid climate of the Black Mesa area. Precipitation in the area typically is between 6 and 14 inches per year. The U.S. Geological Survey water-monitoring program in the Black Mesa area began in 1971 and provides information about the long-term effects of groundwater withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected as part of the monitoring program in the Black Mesa area from January 2011 to September 2012. The monitoring program includes measurements of (1) groundwater withdrawals, (2) groundwater levels, (3) spring discharge, (4) surface-water discharge, and (5) groundwater chemistry. In 2011, total groundwater withdrawals were 4,480 acre-ft, industrial withdrawals were 1,390 acre-ft, and municipal withdrawals were 3,090 acre-ft. Total withdrawals during 2011 were about 39 percent less than total withdrawals in 2005 because of Peabody Western Coal Company’s discontinued use of water to transport coal in a slurry. From 2010 to 2011 total withdrawals increased by 11 percent; industrial withdrawals increased by approximately 19 percent, and total municipal withdrawals increased by 8 percent. From 2011 to 2012, annually measured water levels in the Black Mesa area declined in 8 of 15 wells that were available for comparison in the unconfined areas of the N aquifer, and the median change was -0.1 feet. Water levels declined in 9 of 18 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.0 feet. From the prestress period (prior to 1965) to 2012, the median water-level change for 34 wells in both

Groundwater quality in a mining activity area (The Bierzo Basin-Leon)

International Nuclear Information System (INIS)

Losa, A. de la; Moreno, L.; Nunez, I.

2010-01-01

The Bierzo Basin presents large coal mining structures without restore where the air exposition of metallic sulphurs could become a source of heavy metal pollution and acification of waters. This paper presents the results of a research focused on groundwater quality affected by the mining activity. A sampling campaign of both ground and surface waters was carried out. Altogether, 37 sampling points has been selected including 26 springs, 7 shallow wells for agricultural use and 4 river water samples, all of them directly or indirectly connected to groundwater. The interpretation of results is based on the multivariate analysis application. Sulphate is the dominant anion in both water types, and it is related, in most cases, to oxidation of sulphurs, widely represented in the study area. However, the main conclusion is that surface water and groundwater samples have no high abnormal contents of heavy metals due to the induced alteration by mining activity. (Author) 15 refs.

Simulation of the Groundwater-Flow System in Pierce, Polk, and St. Croix Counties, Wisconsin

Science.gov (United States)

Juckem, Paul F.

2009-01-01

Groundwater is the sole source of residential water supply in Pierce, Polk, and St. Croix Counties, Wisconsin. A regional three-dimensional groundwater-flow model and three associated demonstration inset models were developed to simulate the groundwater-flow systems in the three-county area. The models were developed by the U.S. Geological Survey in cooperation with the three county governments. The objectives of the regional model of Pierce, Polk, and St. Croix Counties were to improve understanding of the groundwaterflow system and to develop a tool suitable for evaluating the effects of potential water-management programs. The regional groundwater-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, groundwater/surface-water interactions, and groundwater withdrawals from high-capacity wells. Results from the regional model indicate that about 82 percent of groundwater in the three counties is from recharge within the counties; 15 percent is from surface-water sources, consisting primarily of recirculated groundwater seepage in areas with abrupt surface-water-level changes, such as near waterfalls, dams, and the downgradient side of reservoirs and lakes; and 4 percent is from inflow across the county boundaries. Groundwater flow out of the counties is to streams (85 percent), outflow across county boundaries (14 percent), and pumping wells (1 percent). These results demonstrate that the primary source of groundwater withdrawn by pumping wells is water that recharges within the counties and would otherwise discharge to local streams and lakes. Under current conditions, the St. Croix and Mississippi Rivers are groundwater discharge locations (gaining reaches) and appear to function as 'fully penetrating' hydraulic boundaries such that groundwater does not cross between Wisconsin and Minnesota beneath them. Being hydraulic boundaries, however, they can change in response to

Regional groundwater flow model for C, K. L. and P reactor areas, Savannah River Site, Aiken, SC

Energy Technology Data Exchange (ETDEWEB)

Flach, G.P.

2000-02-11

A regional groundwater flow model encompassing approximately 100 mi2 surrounding the C, K, L, and P reactor areas has been developed. The reactor flow model is designed to meet the planning objectives outlined in the General Groundwater Strategy for Reactor Area Projects by providing a common framework for analyzing groundwater flow, contaminant migration and remedial alternatives within the Reactor Projects team of the Environmental Restoration Department. The model provides a quantitative understanding of groundwater flow on a regional scale within the near surface aquifers and deeper semi-confined to confined aquifers. The model incorporates historical and current field characterization data up through Spring 1999. Model preprocessing is automated so that future updates and modifications can be performed quickly and efficiently. The CKLP regional reactor model can be used to guide characterization, perform scoping analyses of contaminant transport, and serve as a common base for subsequent finer-scale transport and remedial/feasibility models for each reactor area.

Regional groundwater flow model for C, K. L. and P reactor areas, Savannah River Site, Aiken, SC

International Nuclear Information System (INIS)

Flach, G.P.

2000-01-01

A regional groundwater flow model encompassing approximately 100 mi2 surrounding the C, K, L, and P reactor areas has been developed. The reactor flow model is designed to meet the planning objectives outlined in the General Groundwater Strategy for Reactor Area Projects by providing a common framework for analyzing groundwater flow, contaminant migration and remedial alternatives within the Reactor Projects team of the Environmental Restoration Department. The model provides a quantitative understanding of groundwater flow on a regional scale within the near surface aquifers and deeper semi-confined to confined aquifers. The model incorporates historical and current field characterization data up through Spring 1999. Model preprocessing is automated so that future updates and modifications can be performed quickly and efficiently. The CKLP regional reactor model can be used to guide characterization, perform scoping analyses of contaminant transport, and serve as a common base for subsequent finer-scale transport and remedial/feasibility models for each reactor area

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

International Nuclear Information System (INIS)

Meyer, K.A. Jr.

1988-01-01

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

Determining the impacts of experimental forest plantation on groundwater recharge in the Nebraska Sand Hills (USA) using chloride and sulfate

Science.gov (United States)

Adane, Z. A.; Gates, J. B.

2015-02-01

Although impacts of land-use changes on groundwater recharge have been widely demonstrated across diverse environmental settings, most previous research has focused on the role of agriculture. This study investigates recharge impacts of tree plantations in a century-old experimental forest surrounded by mixed-grass prairie in the Northern High Plains (Nebraska National Forest), USA. Recharge was estimated using solute mass balance methods from unsaturated zone cores beneath 10 experimental plots with different vegetation and planting densities. Pine and cedar plantation plots had uniformly lower moisture contents and higher solute concentrations than grasslands. Cumulative solute concentrations were greatest beneath the plots with the highest planting densities (chloride concentrations 225-240 % and sulfate concentrations 175-230 % of the grassland plot). Estimated recharge rates beneath the dense plantations (4-10 mm yr-1) represent reductions of 86-94 % relative to the surrounding native grassland. Relationships between sulfate, chloride, and moisture content in the area's relatively homogenous sandy soils confirm that the unsaturated zone solute signals reflect partitioning between drainage and evapotranspiration in this setting. This study is among the first to explore afforestation impacts on recharge beneath sandy soils and sulfate as a tracer of deep drainage.

Relationship between water quality of deep-groundwater and geology in non-volcanic areas in Japan

International Nuclear Information System (INIS)

Oyama, Yoichi; Takahashi, Masaaki; Tsukamoto, Hitoshi; Kazahaya, Kohei; Yasuhara, Masaya; Takahashi, Hiroshi; Morikawa, Noritoshi; Ohwada, Michiko; Shibahara, Akihiko; Inamura, Akihiko

2011-01-01

Geochemical characteristics in groundwater such as groundwater chemistry and physicochemical parameters are affected by their source and the interaction with rocks and minerals. We observed the relationships between groundwater chemistry of the deep-groundwater and the geology in non-volcanic areas in Japan using about 9300 of deep-groundwater data. A Geographical Information System (GIS) was used to extract data in non-volcanic areas and numbers of water data are about 5200. The data were further classified into four types of geology (sedimentary rock, accretionary complex, volcanic rock and plutonic rock). The pH, temperature and major ion concentrations among deep-groundwaters in each geology have been statistically analysed. Result shows that the total cation concentration of deep-groundwaters are significantly different between geology, and the average values are decreased in the order of the sedimentary rock (66.7 meq l -1 ), volcanic rock (43.0 meq l -1 ), accretionary complex (24.6 meq l -1 ), and plutonic rock (11.0 meq l -1 ). The average pH does not show the major difference between geology whereas the highest average temperature is found in volcanic rock. In addition, the all four major cations (Na, K, Mg, and Ca) show the highest average concentrations in sedimentary rock, within the highest average concentrations of major anions for Cl, SO 4 , and HCO 3 are found in sedimentary rock, volcanic rock and accretionary complex, respectively, indicating the difference of the influence on the anions varied with geology. The distribution of deep-groundwater that are dominated by each major anions implied that SO 4 -type groundwater in volcanic rocks are formed by the influence of Neogene volcanic rock (Green tuff). In addition, HCO 3 -type groundwater in accretionary complex found from Kinki to Shikoku regions are formed by the addition of CO 2 gases supplying not only from surface soil and carbonate minerals but from deep underground. (author)

Status of remedial investigation activities in the Hanford Site 300 Area groundwater operable unit

International Nuclear Information System (INIS)

Hulstrom, L.C.; Innis, B.E.; Frank, M.A.

1993-09-01

The Phase 1 remedial investigation (RI) and Phase 1 and 2 feasibility studies (FS) for the 300-FF-5 groundwater operable unit underlying the 300 Area on the Hanford Site have been completed. Analysis and evaluation of soil, sediment, and surface water, and biotic sampling data, groundwater chemistry, and radiological data gathered over the past 3 years has been completed. Risk assessment calculations have been performed. Use of the data gathered, coupled with information from an automated water level data collection system, has enabled engineers to track three plumes that represent the most significant contamination of the groundwater

Assessment of groundwater quality in the coastal area of Sindh province, Pakistan.

Science.gov (United States)

Alamgir, Aamir; Khan, Moazzam Ali; Schilling, Janpeter; Shaukat, S Shahid; Shahab, Shoaib

2016-02-01

Groundwater is a highly important resource, especially for human consumption and agricultural production. This study offers an assessment of groundwater quality in the coastal areas of Sindh province in Pakistan. Fifty-six samples of groundwater were taken at depths ranging from 30 to 50 m. Bacteriological and physico-chemical analyses were performed using the Standard Methods for the Examination of Water and Wastewater. These were supplemented with expert interviews and observations to identify the usage of water and potential sources of pollution. The quality of the groundwater was found to be unsuitable for human consumption, despite being used for this purpose. The concentrations of sulfate and phosphate were well within the tolerance limits. Most critical were the high levels of organic and fecal pollution followed by turbidity and salinity. Metal concentrations (As, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn) were also determined, and Ni and Pb strongly exceeded health standards. The study stresses the need for significant improvements of the irrigation, sanitation, and sewage infrastructure.

Estimating groundwater recharge in the outcrop area of the Guarani Aquifer System; Estimativa de recarga subterranea en area de afloramento do Sistema Aquifero Guarani

Energy Technology Data Exchange (ETDEWEB)

Lucas, M. C.; Guanabara, R. C.; Wendland, E.

2012-11-01

The Guarani aquifer system (GAS) is one of the most important groundwater reservoirs in South America. Its main groundwater recharge occurs in the outcrop areas of the Botucatu and Piramboia formations. In these areas groundwater input, such as the infiltration of precipitation, is controlled mainly by climatic characteristics, soil proprieties and land use in the area. We provide here an estimation of the annual recharge into the Ribeirao da Onca basin, located in an outcrop area of the GAS, resulting from data collected during monitoring from September 2004 until August 2011. Fluctuations in the water table were measured at 11 piezometers, sited in different crops areas. Processing techniques for multispectral images were used to map land use. Recharge was estimated by a local-scale method (water-table fluctuation, WTF). Recharge estimates for areas with citrus and eucalyptus proved to be lower than for areas under grassland and sugar cane. Annual recharge rates estimated for the entire watershed ranged from 80 mm to 359 mm for annual precipitations of 1,175.5 mm and 1,807.7 mm. The assessment of recharge in outcrop areas is essential for a suitable future exploitation of the GAS. (Author)

The use of environmental isotopes on groundwater hydrology in the selected areas in Thailand

International Nuclear Information System (INIS)

Buapeng, S.

1990-11-01

A detailed environmental isotope investigation (using 0-18, H-2, H-3, C-14 and C-13 isotopes) has been carried out in a multi-layer aquifer system of the Chao-Phraya basin in Thailand. The main emphasis of the applied field research has been placed on the delineation of genesis of water and on studying the regional replenishment and flow characteristics of the groundwater in the lower Chao-Phraya basin (Bangkok Metropolitan Area). The results of isotope data gathered have been evaluated along with hydrochemical and basic hydrogeological data, to provide quantitative information on the replenishment characteristics of the groundwater and on the cause and processes involved in the increase of salinity being observed in the groundwater system of the Bangkok area. The report provides all the isotopic results and other relevant data together with interpretation and evaluation of the results. Refs, figs and tabs

Hydrogeological and Groundwater Flow Model for C, K, L, and P Reactor Areas, Savannah River Site, Aiken, South Carolina

Energy Technology Data Exchange (ETDEWEB)

Flach, G.P.

1999-02-24

A regional groundwater flow model encompassing approximately 100 mi{sup 2} surrounding the C, K. L. and P reactor areas has been developed. The Reactor flow model is designed to meet the planning objectives outlined in the General Groundwater Strategy for Reactor Area Projects by providing a common framework for analyzing groundwater flow, contaminant migration and remedial alternatives within the Reactor Projects team of the Environmental Restoration Department.

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

International Nuclear Information System (INIS)

Jackson, D.G. Jr.

2000-01-01

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

Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

Directory of Open Access Journals (Sweden)

L. Yu

2018-01-01

Full Text Available The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN, total phosphorus (TP, NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban–agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88 between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate

Comparative study on change in groundwaters of rural and urban areas in Korea: effects of climate change

Science.gov (United States)

Yun, Sang Woong; Seul Kim, Ye; Kim, Dong Hyun; Kim, Ho Chul; Shin, Min Cheol; Park, Jae Yong; Kim, Heejung; Lee, Jin-Yong

2013-04-01

Groundwater occupies a considerable proportion of the world's water resources and is affected by climate change. It is important to understand how water budget responds to future precipitation variability for sustainable management of groundwater resources. In order to evaluate the effects of climate change on groundwater resources in the future, it is necessary to not only collect field data but also predict groundwater change using some groundwater numerical modelling. In this study, a relevant climate change scenario (RCP 4.5) was adopted and Visual MODFLOW was used as a main tool for predicting water budget. The predicted precipitation and air temperature data were obtained from Climate Change Information Center (CCIC) of Korea. By using the data on the scenario from 2011 to 2100, the future water budget was calculated using groundwater numerical modelling for both Wonju (WJ: urban area) and Yanggu (YG: rural area) of Gangwon Province in Korea. The model calibration was done by the groundwater level measured at 10 monitoring wells. For the numerical prediction, the groundwater recharge (WJ: 10.1%, YG: 13.3%) was estimated using watertable fluctuation (WTF) method and a concept of threshold precipitation (WJ: 240.5 mm, YG: 363.8 mm) was applied. Consequently, the water levels in both Wonju and Yanggu showed gradually increasing trends and ranged from 3.0 to 10.8 m, from 0.5 to 1.8 m in 2100, respectively. Under annual precipitation fluctuation on the scenario (2011-2100), water budget IN-OUT value (-0.87~1.07 m3/day) in Wonju city gradually increases while that (-0.73~0.46 m3/day) of Yanggu county does not. However, its annual difference is enlarged with year for both areas. The results indicate that securing groundwater resource and its management will be difficult because of frequent annual change of the groundwater storage. This work was supported by Science High School R&E program (No. C1008804-01-01) and the National Research Foundation of Korea (NRF) grant

Estimates of Nutrient Loading by Ground-Water Discharge into the Lynch Cove Area of Hood Canal, Washington

Science.gov (United States)

Simonds, F. William; Swarzenski, Peter W.; Rosenberry, Donald O.; Reich, Christopher D.; Paulson, Anthony J.

2008-01-01

Low dissolved oxygen concentrations in the waters of Hood Canal threaten marine life in late summer and early autumn. Oxygen depletion in the deep layers and landward reaches of the canal is caused by decomposition of excess phytoplankton biomass, which feeds on nutrients (primarily nitrogen compounds) that enter the canal from various sources, along with stratification of the water column that prevents mixing and replenishment of oxygen. Although seawater entering the canal is the largest source of nitrogen, ground-water discharge to the canal also contributes significant quantities, particularly during summer months when phytoplankton growth is most sensitive to nutrient availability. Quantifying ground-water derived nutrient loads entering an ecologically sensitive system such as Hood Canal is a critical component of constraining the total nutrient budget and ultimately implementing effective management strategies to reduce impacts of eutrophication. The amount of nutrients entering Hood Canal from ground water was estimated using traditional and indirect measurements of ground-water discharge, and analysis of nutrient concentrations. Ground-water discharge to Hood Canal is variable in space and time because of local geology, variable hydraulic gradients in the ground-water system adjacent to the shoreline, and a large tidal range of 3 to 5 meters. Intensive studies of ground-water seepage and hydraulic-head gradients in the shallow, nearshore areas were used to quantify the freshwater component of submarine ground-water discharge (SGD), whereas indirect methods using radon and radium geochemical tracers helped quantify total SGD and recirculated seawater. In areas with confirmed ground-water discharge, shore-perpendicular electrical resistivity profiles, continuous electromagnetic seepage-meter measurements, and continuous radon measurements were used to visualize temporal variations in ground-water discharge over several tidal cycles. The results of these

Radiological and hydrochemical study of thermal and fresh groundwater samples of northern Euboea and Sperchios areas, Greece: insights into groundwater natural radioactivity and geology.

Science.gov (United States)

Kanellopoulos, C; Mitropoulos, P; Argyraki, A

2018-04-04

A radiological and hydrochemical study has been conducted on thermal and fresh groundwater samples of northern Euboea Island and eastern central Greece. Both areas are characterized by complex geology and are renowned since antiquity for their hot springs, that are exploited for therapeutic spa purposes until today. The aim of the study was to combine radiological and hydrochemical data in order to achieve a holistic water quality assessment with insights into the geology of the study areas. All samples were characterized with respect to their major and trace ion and element composition, as well as activity concentrations of 222 Rn, 226 Ra, 228 Ra, 228 Th, and 40 K. The samples demonstrated elevated natural radioactivity and U concentrations, especially in some locations of the Kamena Vourla area, reaching 179 Bq/L 222 Rn, 2.2 Bq/L 226 Ra, 2.9 Bq/L 228 Ra, and 17 μg/L U. The estimated circulation depth of thermal groundwater ranges between 250 m in central Greece and 1240 m in north Euboea study area, whereas the calculated water residence times range between 27 and 555 years. Our data suggest the possible presence of an unknown until know U-rich plutonic rock formation in Kamena Vourla area and immiscibility of the fresh and thermal groundwaters in the studied areas.

RCRA Assessment Plan for Single-Shell Tank Waste Management Area S-SX at the Hanford Site

International Nuclear Information System (INIS)

Chou, C.J.; Johnson, V.G.

1999-01-01

A groundwater quality assessment plan was prepared for waste management area S-SX at the Hanford Site. Groundwater monitoring is conducted at this facility in accordance with Title 40, Code of Federal Regulation (CFR) Part 265, Subpart F [and by reference of Washington Administrative Code (WAC) 173-303-400(3)]. The facility was placed in assessment groundwater monitoring program status after elevated waste constituents and indicator parameter measurements (i.e., chromium, technetium-99 and specific conductance) in downgradient monitoring wells were observed and confirmed. A first determination, as allowed under 40 CFR 265.93(d), provides the owner/operator of a facility an opportunity to demonstrate that the regulated unit is not the source of groundwater contamination. Based on results of the first determination it was concluded that multiple source locations in the waste management area could account for observed spatial and temporal groundwater contamination patterns. Consequently, a continued investigation is required. This plan, developed using the data quality objectives process, is intended to comply with the continued investigation requirement. Accordingly, the primary purpose of the present plan is to determine the rate and extent of dangerous waste (hexavalent chromium and nitrate) and radioactive constituents (e.g., technetium-99) in groundwater and to determine their concentrations in groundwater beneath waste management area S-SX. Comments and concerns expressed by the Washington State Department of Ecology on the initial waste management area S-SX assessment report were addressed in the descriptive narrative of this plan as well as in the planned activities. Comment disposition is documented in a separate addendum to this plan

Hydrogeology, groundwater seepage, nitrate distribution, and flux at the Raleigh hydrologic research station, Wake County, North Carolina, 2005-2007

Science.gov (United States)

McSwain, Kristen Bukowski; Bolich, Richard E.; Chapman, Melinda J.

2013-01-01

gradients in the groundwater discharge area near the Neuse River were complex and were affected by fluctuations in river stage, with the exception of a well completed in a diabase dike. Water-quality data from the wells and surface-water sites at the RHRS were collected continuously as well as during periodic sampling events. Surface-water samples collected from a tributary were most similar in chemical composition to groundwater found in the regolith and transition zone. Nitrate (measured as nitrite plus nitrate, as nitrogen) concentrations in the sampled wells and tributary ranged from about 5 to more than 120 milligrams per liter as nitrogen. Waterborne continuous resistivity profiling conducted on the Neuse River in the area of the RHRS measured areas of low apparent resistivity that likely represent groundwater contaminated by high concentrations of nitrate. These areas were located on either side of a diabase dike and at the outfall of two unnamed tributaries. The diabase dike preferentially directed the discharge of groundwater to the Neuse River and may isolate groundwater movement laterally. Discrete temperature measurements made within the pore water beneath the Neuse River revealed seeps of colder groundwater discharging into warmer surface water near a diabase dike. Water-quality samples collected from the pore water beneath the Neuse River indicated that nitrate was present at concentrations as high as 80 milligrams per liter as nitrogen on the RHRS side of the river. The highest concentrations of nitrate were located within pore water collected from an area near a diabase dike that was identified as a suspected seepage area. Hydraulic head was measured and pore water samples were collected from two 140-centimeter-deep (55.1-inch-deep) multiport piezometers that were installed in bed sediments on opposite sides of a diabase dike. The concentration of nitrate in pore water at a suspected seepage area ranged from 42 to 82 milligrams per liter as nitrogen with a

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

concentrations larger than 40 milligrams per liter. The chloride concentration of ground water in the alluvial aquifer reflects several sources, including precipitation, water from the Missouri River, water in the aquifer, and the treated effluent. Chloride concentrations from precipitation, the Missouri River, and water in the alluvial aquifer were less than 40 milligrams per liter. These monitoring wells affected by effluent are located in two general areas - adjacent to treatment wetland unit 1 and near the ground-water high on and north of the Eagle Bluffs Conservation Area. The probable source of the large chloride concentrations in well samples adjacent to treatment wetland unit 1 is leakage from the unit. The source for the large chloride concentrations in the other monitoring well samples is the effluent mixed with ground water and Missouri River water that is used to fill pools on the Eagle Bluffs Conservation Area. One monitoring well had a single sample with a chloride concentration larger than 40 milligrams per liter. That sample may have been affected by the use of road salt because of the presence of ice and snow immediately before the sample was collected. Lateral ground-water flow was dominated by the presence of a persistent ground-water high beneath the Eagle Bluffs Conservation Area and the presence of a cone of depression centered around the city of Columbia well field in the northern part of the study area. Ground-water flow was radially away from the apex of the ground-water high; west and south of the high, flow was toward the Missouri River, east of the high, flow was toward Perche Creek, and north of the high, flow was to the north toward the cone of depression around the city of Columbia well field. Another permanent feature on the water-level maps was a ground-water high beneath treatment wetland unit 1. Although the ground-water high was present throughout the study period, the subsurface expression of the high changed depending on hydrolo

Resistivity-Chemistry Integrated Approaches for Investigating Groundwater Salinity of Water Supply and Agricultural Activity at Island Coastal Area

Science.gov (United States)

Baharuddin, M. F. T.; Masirin, M. I. M.; Hazreek, Z. A. M.; Azman, M. A. A.; Madun, A.

2018-04-01

Groundwater suitability for water supply and agriculture in an island coastal area may easily be influenced by seawater intrusion. The aim of this study was to investigate seawater intrusion to the suitability of the groundwater for water supply and oil palm cultivation on Carey Island in Malaysia. This is the first study that used integrated method of geo-electrical resistivity and hydrogeochemical methods to investigate seawater intrusion to the suitability of groundwater for water supply and oil palm cultivation at two different surface elevation and land cover. The relationship between earth resistivity, total dissolved solids and earth conductivity was derived with water type classifications and crop suitability classification according to salinity, used to identify water types and also oil palm tolerance to salinity. Results from the contour resistivity and conductivity maps showed that the area facing severe coastal erosion (east area) exhibited unsuitable groundwater condition for water supply and oil palm at the unconfined aquifer thickness of 7.8 m and 14.1 m, respectively. Comparing to the area that are still intact with mangrove (west area), at the same depth, groundwater condition exhibits suitable usage for both socioeconomic activities. Different characteristics of surface elevation and land cover are paramount factors influencing saltwater distribution at the west and east area. By the end of the twenty-first century there will no longer be suitable water for supply and oil palm plantation based on the local sea-level rise prediction and Ghyben–Herzberg assumption (sharp interface), focusing on the severe erosion area of the study site.

Summary of groundwater-recharge estimates for Pennsylvania

Science.gov (United States)

Stuart O. Reese,; Risser, Dennis W.

2010-01-01

Groundwater recharge is water that infiltrates through the subsurface to the zone of saturation beneath the water table. Because recharge is a difficult parameter to quantify, it is typically estimated from measurements of other parameters like streamflow and precipitation. This report provides a general overview of processes affecting recharge in Pennsylvania and presents estimates of recharge rates from studies at various scales.The most common method for estimating recharge in Pennsylvania has been to estimate base flow from measurements of streamflow and assume that base flow (expressed in inches over the basin) approximates recharge. Statewide estimates of mean annual groundwater recharge were developed by relating base flow to basin characteristics of HUC10 watersheds (a fifth-level classification that uses 10 digits to define unique hydrologic units) using a regression equation. The regression analysis indicated that mean annual precipitation, average daily maximum temperature, percent of sand in soil, percent of carbonate rock in the watershed, and average stream-channel slope were significant factors in the explaining the variability of groundwater recharge across the Commonwealth.Several maps are included in this report to illustrate the principal factors affecting recharge and provide additional information about the spatial distribution of recharge in Pennsylvania. The maps portray the patterns of precipitation, temperature, prevailing winds across Pennsylvania’s varied physiography; illustrate the error associated with recharge estimates; and show the spatial variability of recharge as a percent of precipitation. National, statewide, regional, and local values of recharge, based on numerous studies, are compiled to allow comparison of estimates from various sources. Together these plates provide a synopsis of groundwater-recharge estimations and factors in Pennsylvania.Areas that receive the most recharge are typically those that get the most

H-Area Seepage Basins groundwater monitoring report -- third and fourth quarters 1993

International Nuclear Information System (INIS)

Butler, C.T.

1994-03-01

During the second half of 1993, the groundwater at the H-Area Seepage Basins (HASB) was monitored in compliance with the September 30, 1992, modification of South Carolina Hazardous Waste Permit SC1-890-008-989. A detailed description of the uppermost aquifer is included in the Resource Conservation and Recovery Act Part B post-closure care permit application for the H-Area Hazardous Waste Management Facility submitted to the South Carolina Department of Health and Environmental Control (SCDHEC) in December 1990. Beginning first quarter 1993, the HASB's Groundwater Protection Standard (GWPS), established in Appendix 3D-A of the cited permit, became the standard for comparison. Historically as well as currently, nitrate, nonvolatile beta, and tritium have been among the primary constituents to exceed standards. Other radionuclides and hazardous constitutents also exceeded the GWPS in the groundwater at the HASB (notably aluminum, iodine-129, strontium-90, technetium-99, and zinc) during the second half of 1993. Elevated constituents were found primarily in Aquifer Zone 2B 2 and in the upper portion of Aquifer Zone 2B 1 . However, constituents exceeding standards also occurred in several wells screened in the lower portion of Aquifer Zone 2B 1 and Aquifer Unit 2A. Isoconcentration/isoactivity maps include in this report indicate both the concentration/activity and extent of the primary contaminants in each of the three hydrostratigraphic units during the second half of 1993. Water-level maps indicate that the groundwater flow rates and directions at the HASB have remained relatively constant since the basins ceased to be active in 1988

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.

Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China.

Science.gov (United States)

Han, Dongmei; Cao, Guoliang; McCallum, James; Song, Xianfang

2015-12-15

Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33-521mg/L) in NO3(-) concentrations. Elevated nitrate concentrations, in addition to seawater intrusion in the Daweijia well field, both attributable to anthropogenic activities, may impact future water-management practices. Chemical and stable isotopic (δ(18)O, δ(2)H) analysis, (3)H and CFCs methods were applied to provide a better understanding of the relationship between the distribution of groundwater mean residence time (MRT) and nitrate transport, and to identify sources of nitrate concentrations in the complex coastal aquifer systems. There is a relatively narrow range of isotopic composition (ranging from -8.5 to -7.0‰) in most groundwater. Generally higher tritium contents observed in the wet season relative to the dry season may result from rapid groundwater circulation in response to the rainfall through the preferential flow paths. In the well field, the relatively increased nitrate concentrations of groundwater, accompanied by the higher tritium contents in the wet season, indicate the nitrate pollution can be attributed to domestic wastes. The binary exponential and piston-flow mixing model (BEP) yielded feasible age distributions based on the conceptual model. The good inverse relationship between groundwater MRTs (92-467years) and the NO3(-) concentrations in the shallow Quaternary aquifers indicates that elevated nitrate concentrations are attributable to more recent recharge for shallow groundwater. However, there is no significant relationship between the MRTs (8-411years) and the NO3(-) concentrations existing in the carbonate aquifer system, due to the complex hydrogeological conditions, groundwater age distributions and the range of contaminant source areas. Nitrate in the groundwater system without denitrification effects could accumulate and be transported for tens of years, through the complex carbonate

Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China

International Nuclear Information System (INIS)

Han, Dongmei; Cao, Guoliang; McCallum, James; Song, Xianfang

2015-01-01

Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33–521 mg/L) in NO_3"− concentrations. Elevated nitrate concentrations, in addition to seawater intrusion in the Daweijia well field, both attributable to anthropogenic activities, may impact future water-management practices. Chemical and stable isotopic (δ"1"8O, δ"2H) analysis, "3H and CFCs methods were applied to provide a better understanding of the relationship between the distribution of groundwater mean residence time (MRT) and nitrate transport, and to identify sources of nitrate concentrations in the complex coastal aquifer systems. There is a relatively narrow range of isotopic composition (ranging from − 8.5 to − 7.0‰) in most groundwater. Generally higher tritium contents observed in the wet season relative to the dry season may result from rapid groundwater circulation in response to the rainfall through the preferential flow paths. In the well field, the relatively increased nitrate concentrations of groundwater, accompanied by the higher tritium contents in the wet season, indicate the nitrate pollution can be attributed to domestic wastes. The binary exponential and piston-flow mixing model (BEP) yielded feasible age distributions based on the conceptual model. The good inverse relationship between groundwater MRTs (92–467 years) and the NO_3"− concentrations in the shallow Quaternary aquifers indicates that elevated nitrate concentrations are attributable to more recent recharge for shallow groundwater. However, there is no significant relationship between the MRTs (8–411 years) and the NO_3"− concentrations existing in the carbonate aquifer system, due to the complex hydrogeological conditions, groundwater age distributions and the range of contaminant source areas. Nitrate in the groundwater system without denitrification effects could accumulate and be transported for tens of years, through the

Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China

Energy Technology Data Exchange (ETDEWEB)

Han, Dongmei [Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Cao, Guoliang [National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Center for Water Research, College of Engineering, Peking University, Beijing 100871 (China); McCallum, James [National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); School of the Environment, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Song, Xianfang [Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China)

2015-12-15

Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33–521 mg/L) in NO{sub 3}{sup −} concentrations. Elevated nitrate concentrations, in addition to seawater intrusion in the Daweijia well field, both attributable to anthropogenic activities, may impact future water-management practices. Chemical and stable isotopic (δ{sup 18}O, δ{sup 2}H) analysis, {sup 3}H and CFCs methods were applied to provide a better understanding of the relationship between the distribution of groundwater mean residence time (MRT) and nitrate transport, and to identify sources of nitrate concentrations in the complex coastal aquifer systems. There is a relatively narrow range of isotopic composition (ranging from − 8.5 to − 7.0‰) in most groundwater. Generally higher tritium contents observed in the wet season relative to the dry season may result from rapid groundwater circulation in response to the rainfall through the preferential flow paths. In the well field, the relatively increased nitrate concentrations of groundwater, accompanied by the higher tritium contents in the wet season, indicate the nitrate pollution can be attributed to domestic wastes. The binary exponential and piston-flow mixing model (BEP) yielded feasible age distributions based on the conceptual model. The good inverse relationship between groundwater MRTs (92–467 years) and the NO{sub 3}{sup −} concentrations in the shallow Quaternary aquifers indicates that elevated nitrate concentrations are attributable to more recent recharge for shallow groundwater. However, there is no significant relationship between the MRTs (8–411 years) and the NO{sub 3}{sup −} concentrations existing in the carbonate aquifer system, due to the complex hydrogeological conditions, groundwater age distributions and the range of contaminant source areas. Nitrate in the groundwater system without denitrification effects could accumulate and be

Perched-Water Evaluation for the Deep Vadose Zone Beneath the B, BX, and BY Tank Farms Area of the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

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

2013-06-28

Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located a few meters above the water table within the B, BX, and BY Tank Farms area. The perched water contains elevated concentrations of uranium and technetium-99. This perched-water zone is important to consider in evaluating the future flux of contaminated water into the groundwater. The study described in this report was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and 3) associated groundwater impact.

Simulation of Groundwater Movement for Nuclear Research Center at AlTuwaitha Area in Baghdad City, Iraq

Directory of Open Access Journals (Sweden)

Ayad Sleibi Mustafa

2017-07-01

Full Text Available The simulation of groundwater movement has been carried out by using MODFLOW model in order to show the impact of change of water surface elevation of the Tigris river on layers of the aquifer system for Nuclear Research Center at Al-Tuwaitha area, in addition to evaluate the ability of the proposed pumping well to collect groundwater and change the direction of flow at steady-state. The results of the study indicated that there is a good match between the values of groundwater levels that calculated in the model and measured in the field, where mean error is 0.09 m.The study also showed that the increasing of water surface elevation of the Tigris river led to increase in the hydraulic head of observed wells, while the use proposed pumping well reduced the hydraulic head and intercepted the movement of groundwater flow. The flow direction is toward the Tigris river, and the velocity of flow is clear in the third layer identified medium sand which is 0.0015 m/day. The using of the proposed pumping well has changed the direction of groundwater, especially in the area around the well.

Management of Brackish Groundwater Extraction, San Diego-Tijuana area, USA and Mexico

Science.gov (United States)

Danskin, W. R.

2017-12-01

Management of brackish groundwater extraction from coastal sediment in the transboundary San Diego-Tijuana area, USA and Mexico, involves monitoring storage depletion, seawater intrusion, and land subsidence. In 2017, five additional extraction wells were installed, doubling capacity of the Reynolds Groundwater Desalination Facility. Environmental permits to expand capacity of the facility, and the recently-enacted Sustainable Groundwater Management Act (SGMA) by the State of California require monitoring the possible adverse effects of the additional extraction. Fortuitously, over the past 14 years, 12 deep multiple-depth, monitoring-well sites were installed by the United States Geological Survey (USGS) to aid in mapping the coastal geology and groundwater conditions. Now these sites are being used for groundwater management. Storage depletion is monitored daily via water levels measured using transducers installed permanently in each of the 4-6 piezometers at each site and transmitted automatically to the Internet. Seawater intrusion is tracked annually via electromagnetic geophysical logging in the deepest piezometer at each site, 500-800 meters below land surface, about twice the depth of the extraction wells. Land subsidence is determined annually from surveys of reference points installed at the well sites and from Interferometric Synthetic Aperature Radar (InSAR) satellite data. Management also involves use of a regional hydrologic model to simulate the likely location and timing of future storage depletion, seawater intrusion, and land subsidence.

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

Science.gov (United States)

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

2016-09-01

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

Numerical simulation of groundwater flow, resource optimization, and potential effects of prolonged drought for the Citizen Potawatomi Nation Tribal Jurisdictional Area, central Oklahoma

Science.gov (United States)

Ryter, Derek W.; Kunkel, Christopher D.; Peterson, Steven M.; Traylor, Jonathan P.

2015-08-13

A hydrogeological study including two numerical groundwater-flow models was completed for the Citizen Potawatomi Nation Tribal Jurisdictional Area of central Oklahoma. One numerical groundwater-flow model, the Citizen Potawatomi Nation model, encompassed the jurisdictional area and was based on the results of a regional-scale hydrogeological study and numerical groundwater flow model of the Central Oklahoma aquifer, which had a geographic extent that included the Citizen Potawatomi Nation Tribal Jurisdictional Area. The Citizen Potawatomi Nation numerical groundwater-flow model included alluvial aquifers not in the original model and improved calibration using automated parameter-estimation techniques. The Citizen Potawatomi Nation numerical groundwater-flow model was used to analyze the groundwater-flow system and the effects of drought on the volume of groundwater in storage and streamflow in the North Canadian River. A more detailed, local-scale inset model was constructed from the Citizen Potawatomi Nation model to estimate available groundwater resources for two Citizen Potawatomi Nation economic development zones near the North Canadian River, the geothermal supply area and the Iron Horse Industrial Park.

Estimation of the sources and flow system of groundwater in Fuji-Gotenba area by stable isotopic analysis and groundwater flow simulation

International Nuclear Information System (INIS)

Tomiyama, Shingo; Miyaike, Shusaku; Ii, Hiroyuki; Hattori, Ryota; Ito, Yuji

2009-01-01

Understanding the source and chemical character of the groundwater provides an important strategy for the quality management of mineral water and food materials. In order to identify a source and the flow paths of groundwater used for mineral water, the water quality and stable isotopes of hydrogen and oxygen of well water in Gotenba city were studied. The electrical conductivity and chemical character of sampled water are similar to those of well water and spring water discharged elsewhere around Mt. Fuji. The hydrogen and oxygen isotopic ratios of water samples indicate their origin to be solely meteoric and the oxygen isotopic ratios suggest that the groundwater mainly originated from the mountain-side of Mt. Fuji at altitudes of from 1500 m to 2300 m. A subsequent simulation of groundwater showed that the distribution of the total head and the Darcy velocity are down streamlines from mountain-sides toward the study area in Gotenba city. The altitudes of discharge obtained by the simulation are above 2000 m, and these correspond well with altitudes estimated from δ 18 O values of the samples. (author)

Sanitary Landfill groundwater monitoring report. Fourth quarterly report and summary 1993

Energy Technology Data Exchange (ETDEWEB)

1994-02-01

Fifty-seven wells of the LFW series monitor groundwater quality in Steed Pond Aquifer (Water Table) beneath the Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled quarterly to comply with the South Carolina Department of Health and Environmental Control Domestic Waste Permit DWP-087A and as part of the SRS Groundwater Monitoring Program. Dichloromethane a common laboratory contaminant, and trichloroethylene were the most widespread constituents exceeding standards during 1993. Benzene, chlorobenzene, chloroethene 1,2 dichloroethane, 1,1-dichloroethylene, 1,2-dichloropropane, gross alpha, lindane, mercury, tetrachloroethylene, and tritium also exceeded standards in one or more wells. No groundwater contaminants were observed in wells screened in the lower section of Steed Pond Aquifer.

Summary of the results and interpretation of tritium and noble gas measurements on groundwater samples from the Perch Lake Basin Area

International Nuclear Information System (INIS)

Kotzer, T.G.

1999-02-01

Along the west-central margin of the Lower Perch Lake Basin, a limited number of groundwaters have been sampled from piezometers at depths of between 8 and 17 m and distances of between 100 and 900 m downgradient from their recharge location near Area A. Concentrations of tritium in these groundwaters varied between approximately 100 and 2800 TU. Measurements of dissolved gases in these groundwaters indicate concentrations of 4 He and neon approximating those in recently recharged groundwaters; however, the concentrations of 3 He are as much as 100 times higher, indicating the waters have accumulated tritiogenic 3 He. Using the 3 H/ 3 He dating technique, groundwater residence times on the order of 29 ± 8 years and groundwater velocities on the order of 0.1 m/day have been calculated for the flow system in the middle sand unit between Area A recharge and Perch Lake. These results, although based on a very small number of groundwater analyses, are comparable to earlier estimates of groundwater residence times and velocities obtained using Darcy calculations, borehole dilution experiments and tracer-test results from previous hydrogeologic studies in the area. (author)

Final Record of Decision for the South Post Impact Area and Area of Contamination 41 Groundwater and Areas of Contamination 25, 26, and 27

National Research Council Canada - National Science Library

1996-01-01

.... This Record of Decision (ROD) addresses AOCs 25 (the Explosives Ordnance Disposal (EOD) Range), 26 (Zulu Ranges), and 27 (Hotel Range) and a subset of the groundwater within the South Post Impact Area...

Shallow groundwater quality and associated non-cancer health risk in agricultural areas (Poyang Lake basin, China).

Science.gov (United States)

Soldatova, Evgeniya; Sun, Zhanxue; Maier, Sofya; Drebot, Valeriia; Gao, Bai

2018-03-24

Owing to their accessibility, shallow groundwater is an essential source of drinking water in rural areas while usually being used without control by authorities. At the same time, this type of water resource is one of the most vulnerable to pollution, especially in regions with extensive agricultural activity. These factors increase the probability of adverse health effects in the population as a result of the consumption of shallow groundwater. In the present research, shallow groundwater quality in the agricultural areas of Poyang Lake basin was assessed according to world and national standards for drinking water quality. To evaluate non-cancer health risk from drinking groundwater, the hazard quotient from exposure to individual chemicals and hazard index from exposure to multiple chemicals were applied. It was found that, in shallow groundwater, the concentrations of 11 components (NO 3 - , NH 4 + , Fe, Mn, As, Al, rare NO 2 - , Se, Hg, Tl and Pb) exceed the limits referenced in the standards for drinking water. According to the health risk assessment, only five components (NO 3 - , Fe, As, rare NO 2 - and Mn) likely provoke non-cancer effects. The attempt to evaluate the spatial distribution of human health risk from exposure to multiple chemicals shows that the most vulnerable area is associated with territory characterised by low altitude where reducing or near-neutral conditions are formed (lower reaches of Xiushui and Ganjiang Rivers). The largest health risk is associated with the immune system and adverse dermal effects.

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

International Nuclear Information System (INIS)

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

1995-03-01

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

Seasonal coefficient of performance for ground source heat pump and groundwater one in Białystok

Science.gov (United States)

Gajewski, Andrzej

2017-11-01

European Economic Area (EEA) states declare to contain greenhouse gases emissions at 20% by 2020, whereas European Union (EU) does 40% before 2030, which result in encouragement to apply low-carbon technologies. Coefficient of Performance (COP) and Seasonal Coefficient of Performance (SCOPnet) are obtained using temperature measurement done by The Institute of Meteorology and Water Management - National Research Institute (IMGW-PIB) at the weather station in Bialystok for ten-year period. The first variant is ground source heat pump (GSHP) and the second one is groundwater source heat pump (WSHP) which can be equipped with separating heat exchanger (SHE) optionally. In both cases heat is generated for heating system only. Ground temperature is determined from Baggs (1983) formula using Oleśkowicz-Popiel et. al. (2002) adaptation to Polish climate and substituting the local constants achieved by Biernacka (2010). Water temperature in a groundwater basin is obtained from Kowalski (2007) equation. Estimation is done in each hour of heating season. All COP values are higher than 3.5 required by EU (2013). SCOPnet are as follows: 6.12, 5.86, 5.03 for WSHP, WSHP+SHE, GSHP respectively. Insomuch as WSHP needs only two boreholes it is recommended to the areas beneath ones a groundwater basin is located.

Seasonal coefficient of performance for ground source heat pump and groundwater one in Białystok

Directory of Open Access Journals (Sweden)

Gajewski Andrzej

2017-01-01

Full Text Available European Economic Area (EEA states declare to contain greenhouse gases emissions at 20% by 2020, whereas European Union (EU does 40% before 2030, which result in encouragement to apply low-carbon technologies. Coefficient of Performance (COP and Seasonal Coefficient of Performance (SCOPnet are obtained using temperature measurement done by The Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB at the weather station in Bialystok for ten-year period. The first variant is ground source heat pump (GSHP and the second one is groundwater source heat pump (WSHP which can be equipped with separating heat exchanger (SHE optionally. In both cases heat is generated for heating system only. Ground temperature is determined from Baggs (1983 formula using Oleśkowicz-Popiel et. al. (2002 adaptation to Polish climate and substituting the local constants achieved by Biernacka (2010. Water temperature in a groundwater basin is obtained from Kowalski (2007 equation. Estimation is done in each hour of heating season. All COP values are higher than 3.5 required by EU (2013. SCOPnet are as follows: 6.12, 5.86, 5.03 for WSHP, WSHP+SHE, GSHP respectively. Insomuch as WSHP needs only two boreholes it is recommended to the areas beneath ones a groundwater basin is located.

Groundwater flow and heterogeneous discharge into a seepage lake

DEFF Research Database (Denmark)

Kazmierczak, Jolanta; Müller, Sascha; Nilsson, B.

2016-01-01

with the lake remained under seemingly steady state conditions across seasons, a high spatial and temporal heterogeneity in the discharge to the lake was observed. The results showed that part of the groundwater flowing from the west passes beneath the lake and discharges at the eastern shore, where groundwater......Groundwater discharge into a seepage lake was investigated by combining flux measurements, hydrochemical tracers, geological information, and a telescopic modeling approach using first two-dimensional (2-D) regional then 2-D local flow and flow path models. Discharge measurements and hydrochemical...... tracers supplement each other. Discharge measurements yield flux estimates but rarely provide information about the origin and flow path of the water. Hydrochemical tracers may reveal the origin and flow path of the water but rarely provide any information about the flux. While aquifer interacting...

Geophysical work for the feasibility birthing study of groundwater in Florida area

International Nuclear Information System (INIS)

Costa, H

1996-01-01

Geological studies were carried out on the soil to determine the existence of groundwater as well as the type of rocks to can drill the zone. The area is conformed by granitic rocks of medium or coarse grain with different degrees of alteration.

Unraveling Health Risk and Speciation of Arsenic from Groundwater in Rural Areas of Punjab, Pakistan.

Science.gov (United States)

Shakoor, Muhammad Bilal; Niazi, Nabeel Khan; Bibi, Irshad; Rahman, Mohammad Mahmudur; Naidu, Ravi; Dong, Zhaomin; Shahid, Muhammad; Arshad, Muhammad

2015-10-05

This study determined the total and speciated arsenic (As) concentrations and other health-related water quality parameters for unraveling the health risk of As from drinking water to humans. Groundwater samples (n = 62) were collected from three previously unexplored rural areas (Chichawatni, Vehari, Rahim Yar Khan) of Punjab in Pakistan. The mean and median As concentrations in groundwater were 37.9 and 12.7 µg·L(-1) (range = 1.5-201 µg·L(-1)). Fifty three percent groundwater samples showed higher As value than WHO safe limit of 10 µg·L(-1). Speciation of As in groundwater samples (n = 13) showed the presence of inorganic As only; arsenite (As(III)) constituted 13%-67% of total As and arsenate (As(V)) ranged from 33% to 100%. For As health risk assessment, the hazard quotient and cancer risk values were 11-18 and 46-600 times higher than the recommended values of US-EPA (i.e., 1.00 and 10(-6), respectively). In addition to As, various water quality parameters (e.g., electrical conductivity, Na, Ca, Cl(-), NO₃(-), SO₄(2-), Fe, Mn, Pb) also enhanced the health risk. The results show that consumption of As-contaminated groundwater poses an emerging health threat to the communities in the study area, and hence needs urgent remedial and management measures.

Unraveling Health Risk and Speciation of Arsenic from Groundwater in Rural Areas of Punjab, Pakistan

Directory of Open Access Journals (Sweden)

Muhammad Bilal Shakoor

2015-10-01

Full Text Available This study determined the total and speciated arsenic (As concentrations and other health-related water quality parameters for unraveling the health risk of As from drinking water to humans. Groundwater samples (n = 62 were collected from three previously unexplored rural areas (Chichawatni, Vehari, Rahim Yar Khan of Punjab in Pakistan. The mean and median As concentrations in groundwater were 37.9 and 12.7 µg·L−1 (range = 1.5–201 µg·L−1. Fifty three percent groundwater samples showed higher As value than WHO safe limit of 10 µg·L−1. Speciation of As in groundwater samples (n = 13 showed the presence of inorganic As only; arsenite (As(III constituted 13%–67% of total As and arsenate (As(V ranged from 33% to 100%. For As health risk assessment, the hazard quotient and cancer risk values were 11–18 and 46–600 times higher than the recommended values of US-EPA (i.e., 1.00 and 10−6, respectively. In addition to As, various water quality parameters (e.g., electrical conductivity, Na, Ca, Cl−, NO3−, SO42−, Fe, Mn, Pb also enhanced the health risk. The results show that consumption of As-contaminated groundwater poses an emerging health threat to the communities in the study area, and hence needs urgent remedial and management measures.

The Study of Groundwater Age in Semarang Area Considering Beta Activityof Tritium

International Nuclear Information System (INIS)

F, Wisjachudin; Agus-Sulistiyono; Fajar-Budi Haendrapratikto

2000-01-01

The groundwater age in Semarang regency, they are Genuk, Pedurungan,North Semarang, Urban Semarang, Mijen, Mangkang, Manyaran, Tembalang, Sekaranconsidering tritium content inside has been done. Tritium content ingroundwater given pretreatment that is enriching tritium content usingsynthesize technique by benzene synthesizer (H 2 O converted into C 6 H 6 ).Tritium activity in C 6 H 6 was analyzed using liquid scintillation counterPackard 2000 CA/LL. Optimum condition of volume ratio between cocktail(picofluor) and sample solution is reached ratio of 10 : 10. Efficiencydetection (ε) = 42.16 %, while merit factor = 1.981.10 5 . From twolocations that can be detected show that analysis on groundwater age onManyaran location (damar formation) is younger than Urban Semarang (alluviumsediment), which is match to geological analysis considering geological layershows that on geology layer of volcanic breksi layer is younger than damarformation area and the oldest is the alluvium sediment area. (author)

Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona—2012–2013

Science.gov (United States)

Macy, Jamie P.; Truini, Margot

2016-03-02

The Navajo (N) aquifer is an extensive aquifer and the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use by a growing population and because of low precipitation in the arid climate of the Black Mesa area. Precipitation in the area typically is between 6 and 14 inches per year.The U.S. Geological Survey water-monitoring program in the Black Mesa area began in 1971 and provides information about the long-term effects of groundwater withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected as part of the monitoring program in the Black Mesa area from January 2012 to September 2013. The monitoring program includes measurements of (1) groundwater withdrawals, (2) groundwater levels, (3) spring discharge, (4) surface-water discharge, and (5) groundwater chemistry.In calendar year 2012, total groundwater withdrawals were 4,010 acre-ft, industrial withdrawals were 1,370 acre-ft, and municipal withdrawals were 2,640 acre-ft. Total withdrawals during 2012 were about 45 percent less than total withdrawals in 2005 because of Peabody Western Coal Company’s discontinued use of water to transport coal in a coal slurry pipeline. From 2011 to 2012 total withdrawals decreased by 10 percent; industrial withdrawals decreased by approximately 1 percent, and total municipal withdrawals decreased by 15 percent.From 2012 to 2013, annually measured water levels in the Black Mesa area declined in 6 of 16 wells that were available for comparison in the unconfined areas of the N aquifer, and the median change was 0.8 feet. Water levels declined in 5 of 16 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.3 feet. From the prestress period (prior to 1965) to 2013, the median water

Nevada National Security Site 2014 Data Report: Groundwater Monitoring Program Area 5 Radioactive Waste Management Site

Energy Technology Data Exchange (ETDEWEB)

Hudson, David [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States)

2015-02-01

This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site, Nye County, Nevada. Groundwater samples from the aquifer immediately below the Area 5 RWMS have been collected and analyzed and static water levels have been measured in this aquifer since 1993. This report updates these data to include the 2014 results. Analysis results for leachate contaminants collected from the mixed-waste cell at the Area 5 RWMS (Cell 18) are also included. During 2014, groundwater samples were collected and static water levels were measured at three wells surrounding the Area 5 RWMS. Groundwater samples were collected at wells UE5PW-1, UE5PW-2, and UE5PW-3 on March 11 and August 12, 2014, and static water levels were measured at each of these wells on March 10, June 2, August 11, and October 14, 2014. Groundwater samples were analyzed for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. General water chemistry (cations and anions) was also measured. Results from samples collected in 2014 are within the limits established by agreement with the Nevada Division of Environmental Protection for each analyte. The data from the shallow aquifer indicate that there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS, and there were no significant changes in measured groundwater parameters compared to previous years. Leachate from above the primary liner of Cell 18 drains into a sump and is collected in a tank at the ground surface. Cell 18 began receiving waste in January 2011. Samples were collected from the tank when the leachate volume approached the 3,000-gallon tank capacity. Leachate samples have been collected 16 times since January 2011. During 2014, samples were collected on February 25, March 5, May 20, August 12, September 16, November 11, and December 16. Each leachate sample was

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

Science.gov (United States)

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

2014-12-01

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

Seasonal Variation in Fluoride Content in Groundwaters of Langtang Area, Northcentral Nigeria

Science.gov (United States)

Dibal, H. U.; Dajilak, W. N.; Lekmang, I. C.; Nimze, L. W.; Yenne, E. Y.

2017-06-01

Thirty groundwater samples were collected at the peak of the rainy season and analysed for fluoride and other cations and anions in drinking water sources of Langtang area. For comparative purposes, thirty seven groundwater samples were collected in the dry season. The aim of the study was to determine variation in fluoride content with respect to the seasons. Fluoride in water was determined by the Ion Selective Electrode (ISE) and the cations by the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The anion (sulphate) was determined by Multi - Ion Colorimeter, bicarbonate and chloride by titration method. In addition fluorine content in aquifer materials from a borehole section were determined by Fusion method. The two seasons show variation in content of fluoride in groundwater. Fluoride content in groundwater is higher in the dry season ranging from 0.13 - 10.3 mg/l compared to the 0.06 - 4.60 mg/l values in the rainy season. Content of fluorine (0.01 wt %) in the aquifer materials (sands) is low from depth of 0 to 7.95 m. However, fluorine content increases with depth, from 7.95 to 10.60 m with concentration of 0.04 wt %, 0.05 wt % from 10.60 to 13.25m, and 0.07 wt % from 13.25 to 15.70 m, the content of fluorine however, decreased at depth 15.70 to18.55m with concentration of 0.02 wt % even with fluorite mineral in the aquifer material at this depth. Dilution of fluoride ion as a result of rain input which recharges the aquifer may be the main reason for lower values recorded in the rainy season. Over fifty and sixty percent of waters in both dry and rainy season have fluoride concentration above the WHO upper limit of 1.5 mg/l. Consumption of these elevated values of fluoride in groundwater of the study area, clearly manifests as symptoms of dental fluorosis.

Seasonal Variation in Fluoride Content in Groundwaters of Langtang Area, Northcentral Nigeria

Directory of Open Access Journals (Sweden)

Dibal H.U.

2017-06-01

Full Text Available Thirty groundwater samples were collected at the peak of the rainy season and analysed for fluoride and other cations and anions in drinking water sources of Langtang area. For comparative purposes, thirty seven groundwater samples were collected in the dry season. The aim of the study was to determine variation in fluoride content with respect to the seasons. Fluoride in water was determined by the Ion Selective Electrode (ISE and the cations by the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES. The anion (sulphate was determined by Multi – Ion Colorimeter, bicarbonate and chloride by titration method. In addition fluorine content in aquifer materials from a borehole section were determined by Fusion method. The two seasons show variation in content of fluoride in groundwater. Fluoride content in groundwater is higher in the dry season ranging from 0.13 – 10.3 mg/l compared to the 0.06 – 4.60 mg/l values in the rainy season. Content of fluorine (0.01 wt % in the aquifer materials (sands is low from depth of 0 to 7.95 m. However, fluorine content increases with depth, from 7.95 to 10.60 m with concentration of 0.04 wt %, 0.05 wt % from 10.60 to 13.25m, and 0.07 wt % from 13.25 to 15.70 m, the content of fluorine however, decreased at depth 15.70 to18.55m with concentration of 0.02 wt % even with fluorite mineral in the aquifer material at this depth. Dilution of fluoride ion as a result of rain input which recharges the aquifer may be the main reason for lower values recorded in the rainy season. Over fifty and sixty percent of waters in both dry and rainy season have fluoride concentration above the WHO upper limit of 1.5 mg/l. Consumption of these elevated values of fluoride in groundwater of the study area, clearly manifests as symptoms of dental fluorosis.

Revised ground-water monitoring compliance plan for the 300 area process trenches

Energy Technology Data Exchange (ETDEWEB)

Schalla, R.; Aaberg, R.L.; Bates, D.J.; Carlile, J.V.M.; Freshley, M.D.; Liikala, T.L.; Mitchell, P.J.; Olsen, K.B.; Rieger, J.T.

1988-09-01

This document contains ground-water monitoring plans for process-water disposal trenches located on the Hanford Site. These trenches, designated the 300 Area Process Trenches, have been used since 1973 for disposal of water that contains small quantities of both chemicals and radionuclides. The ground-water monitoring plans contained herein represent revision and expansion of an effort initiated in June 1985. At that time, a facility-specific monitoring program was implemented at the 300 Area Process Trenches as part of a regulatory compliance effort for hazardous chemicals being conducted on the Hanford Site. This monitoring program was based on the ground-water monitoring requirements for interim-status facilities, which are those facilities that do not yet have final permits, but are authorized to continue interim operations while engaged in the permitting process. The applicable monitoring requirements are described in the Resource Conservation and Recovery Act (RCRA), 40 CFR 265.90 of the federal regulations, and in WAC 173-303-400 of Washington State's regulations (Washington State Department of Ecology 1986). The program implemented for the process trenches was designed to be an alternate program, which is required instead of the standard detection program when a facility is known or suspected to have contaminated the ground water in the uppermost aquifer. The plans for the program, contained in a document prepared by the US Department of Energy (USDOE) in 1985, called for monthly sampling of 14 of the 37 existing monitoring wells at the 300 Area plus the installation and sampling of 2 new wells. 27 refs., 25 figs., 15 tabs.

Profiling oil sands mixtures from industrial developments and natural groundwaters for source identification.

Science.gov (United States)

Frank, Richard A; Roy, James W; Bickerton, Greg; Rowland, Steve J; Headley, John V; Scarlett, Alan G; West, Charles E; Peru, Kerry M; Parrott, Joanne L; Conly, F Malcolm; Hewitt, L Mark

2014-01-01

The objective of this study was to identify chemical components that could distinguish chemical mixtures in oil sands process-affected water (OSPW) that had potentially migrated to groundwater in the oil sands development area of northern Alberta, Canada. In the first part of the study, OSPW samples from two different tailings ponds and a broad range of natural groundwater samples were assessed with historically employed techniques as Level-1 analyses, including geochemistry, total concentrations of naphthenic acids (NAs) and synchronous fluorescence spectroscopy (SFS). While these analyses did not allow for reliable source differentiation, they did identify samples containing significant concentrations of oil sands acid-extractable organics (AEOs). In applying Level-2 profiling analyses using electrospray ionization high resolution mass spectrometry (ESI-HRMS) and comprehensive multidimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF/MS) to samples containing appreciable AEO concentrations, differentiation of natural from OSPW sources was apparent through measurements of O2:O4 ion class ratios (ESI-HRMS) and diagnostic ions for two families of suspected monoaromatic acids (GC × GC-TOF/MS). The resemblance between the AEO profiles from OSPW and from 6 groundwater samples adjacent to two tailings ponds implies a common source, supporting the use of these complimentary analyses for source identification. These samples included two of upward flowing groundwater collected <1 m beneath the Athabasca River, suggesting OSPW-affected groundwater is reaching the river system.

First and second quarters 1999 - TNX Area groundwater and effectiveness monitoring strategy data only report

International Nuclear Information System (INIS)

Chase, J.

1999-01-01

This report presents data of groundwater monitoring conducted during the first and second quarters of 1999 in support of the Interim Remedial Action. The data is from groundwater monitoring wells described in this report as the primary, secondary, and recovery wells of the initial operation of the Effectiveness Monitoring Strategy (EMS) as stipulated in Revision 1.3 (WSRC, 1996), the proposed wells for the full operation of the EMS as described in Revision 1.5 (WSRC, 1999), and general wells pertinent to the report. Also included are data from SRTC projects in the TNX Area that are deemed useful for groundwater characterization

Ground water in selected areas in the Klamath Basin, Oregon

Science.gov (United States)

Leonard, A.R.; Harris, A.B.

1973-01-01

GROUNDWATER FEATURES OF SIX LOWLAND AREAS IN THE KLAMATH BASIN OF OREGON--KLAMATH MARSH AREA, AND SPRAGUE RIVER, SWAN LAKE, YONNA, POE, AND LANGELL VALLEYS--ARE DESCRIBED. RUGGED MOUNTAINS AND RIDGES SURROUND AND SEPARATE THESE LOWLANDS WHERE FLOORS RANGE IN ALTITUDE FROM 4,100 FEET IN POE VALLEY TO 4,600 FEET NORTH OF KLAMATH MARSH. THE SIX AREAS EXTEND OVER A NORTH-SOUTH DISTANCE OF 70 MILES, AN EAST-WEST DISTANCE OF 40 MILES, AND INCLUDE AN AREA OF APPROXIMATELY 600 SQUARE MILES. THE AREA IS SEMIARID AND RECEIVED ABOUT 14 TO 18 INCHES OF PRECIPITATION A YEAR. EXTINCT VOLCANOES AND THEIR EXTRUSIONS CHARACTERIZE THE AREA. MOST WELLS TAP PERMEABLE BASALT OR CINDERY RUBBLE BENEATH THE LACUSTRINE BEDS. THE DEPTHS OF WELLS RANGE FROM LESS THAN 50 TO NEARLY 2,000 FEET--MOST ARE BETWEEN 100 AND 1,000 FEET DEEP. FLOWING WELLS OCCUR IN ALL AREAS EXCEPT SWAN LAKE VALLEY. THE MOST EXTENSIVE AREA OF FLOWING WELLS IS IN THE SPRAGUE RIVER VALLEY, WHERE ABOUT 25 WELLS, SOME FLOWING MORE THAN 2,000 GPM, SUPPLY WATER FOR IRRIGATION. WATER LEVELS IN WELLS FLUCTUATE SEASONALLY FROM 1 TO 4 FEET. GROUNDWATER IN THE BASIN IS OF EXCELLENT QUALITY FOR DRINKING, IRRIGATION, AND MOST INDUSTRIAL USES.

Groundwater recharge mechanism in an integrated tableland of the Loess Plateau, northern China: insights from environmental tracers

Science.gov (United States)

Huang, Tianming; Pang, Zhonghe; Liu, Jilai; Ma, Jinzhu; Gates, John

2017-11-01

Assessing groundwater recharge characteristics (recharge rate, history, mechanisms (piston and preferential flow)) and groundwater age in arid and semi-arid environments remains a difficult but important research frontier. Such assessments are particularly important when the unsaturated zone (UZ) is thick and the recharge rate is limited. This study combined evaluations of the thick UZ with those of the saturated zone and used multiple tracers, such as Cl, NO3, Br, 2H, 18O, 13C, 3H and 14C, to study groundwater recharge characteristics in an integrated loess tableland in the Loess Plateau, China, where precipitation infiltration is the only recharge source for shallow groundwater. The results indicate that diffuse recharge beneath crops, as the main land use of the study area, is 55-71 mm yr-1 based on the chloride mass balance of soil profiles. The length of time required for annual precipitation to reach the water table is 160-400 yrs. The groundwater is all pre-modern water and paleowater, with corrected 14C age ranging from 136 to 23,412 yrs. Most of the water that eventually becomes recharge originally infiltrated in July-September. The Cl and NO3 contents in the upper UZ are considerably higher than those in the deep UZ and shallow groundwater because of recent human activities. The shallow groundwater has not been in hydraulic equilibrium with present near-surface boundary conditions. The homogeneous material of the UZ and relatively old groundwater age imply that piston flow is the dominant recharge mechanism for the shallow groundwater in the tableland.

Estimation of Groundwater Recharge in a Japanese Headwater Area by Intensive Collaboration of Field Survey and Modelling Work

Science.gov (United States)

Yano, S.; Kondo, H.; Tawara, Y.; Yamada, T.; Mori, K.; Yoshida, A.; Tada, K.; Tsujimura, M.; Tokunaga, T.

2017-12-01

It is important to understand groundwater systems, including their recharge, flow, storage, discharge, and withdrawal, so that we can use groundwater resources efficiently and sustainably. To examine groundwater recharge, several methods have been discussed based on water balance estimation, in situ experiments, and hydrological tracers. However, few studies have developed a concrete framework for quantifying groundwater recharge rates in an undefined area. In this study, we established a robust method to quantitatively determine water cycles and estimate the groundwater recharge rate by combining the advantages of field surveys and model simulations. We replicated in situ hydrogeological observations and three-dimensional modeling in a mountainous basin area in Japan. We adopted a general-purpose terrestrial fluid-flow simulator (GETFLOWS) to develop a geological model and simulate the local water cycle. Local data relating to topology, geology, vegetation, land use, climate, and water use were collected from the existing literature and observations to assess the spatiotemporal variations of the water balance from 2011 to 2013. The characteristic structures of geology and soils, as found through field surveys, were parameterized for incorporation into the model. The simulated results were validated using observed groundwater levels and resulted in a Nash-Sutcliffe Model Efficiency Coefficient of 0.92. The results suggested that local groundwater flows across the watershed boundary and that the groundwater recharge rate, defined as the flux of water reaching the local unconfined groundwater table, has values similar to the level estimated in the `the lower soil layers on a long-term basis. This innovative method enables us to quantify the groundwater recharge rate and its spatiotemporal variability with high accuracy, which contributes to establishing a foundation for sustainable groundwater management.

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.

Investigation of ground-water contamination at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

Science.gov (United States)

Vroblesky, Don A.; Casey, Clifton C.

2007-01-01

The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.

H-Area Hazardous Waste Management Facility groundwater monitoring report, Third and fourth quarters 1995: Volume 1

International Nuclear Information System (INIS)

1996-03-01

Groundwater at the H-Area Hazardous Waste Management Facility (HWMF) is monitored in compliance with applicable regulations. Monitoring results are compared to the South Carolina Department of Health and Environmental control (SCDHEC) Groundwater Protection Standard (GWPS). Historically as well as currently, nitrate-nitrite as nitrogen, nonvolatile beta, and tritium have been among the primary constituents to exceed standards. Other radionuclides and hazardous constituents also exceeded the GWPS in the second half of 1995. Elevated constituents were found primarily in the water table (Aquifer Zone IIB 2 ), however, constitutents exceeding standards also occurred in several different aquifer zones monitoring wells. Water-level maps indicate that the groundwater flow rates and directions at the H-Area HWMF have remained relatively constant since the basins ceased to be active in 1988

Analysis of pumping-induced unsaturated regions beneath aperennial river

Energy Technology Data Exchange (ETDEWEB)

Su, G.W.; Jasperse, J.; Seymour, D.; Constantz, J.; Zhou, Q.

2007-05-15

The presence of an unsaturated region beneath a streambedduring groundwater pumping near streams reduces the pumping capacity whenit reaches the well screens, changes flow paths, and alters the types ofbiological transformations in the streambed sediments. Athree-dimensional, multi-phase flow model of two horizontal collectorwells along the Russian River near Forestville, California was developedto investigate the impact of varying the ratio of the aquifer tostreambed permeability on (1) the formation of an unsaturated regionbeneath the stream, (2) the pumping capacity, (3) stream-water fluxesthrough the streambed, and (4) stream-water travel times to the collectorwells. The aquifer to streambed permeability ratio at which theunsaturated region was initially observed ranged from 10 to 100. The sizeof the unsaturated region beneath the streambed increased as the aquiferto streambed permeability ratio increased. The simulations also indicatedthat for a particular aquifer permeability, decreasing the streambedpermeability by only a factor of 2-3 from the permeability wheredesaturation initially occurred resulted in reducing the pumpingcapacity. In some cases, the stream-water fluxes increased as thestreambed permeability decreased. However, the stream water residencetimes increased and the fraction of stream water that reached that thewells decreased as the streambed permeability decreased, indicating thata higher streambed flux does not necessarily correlate to greaterrecharge of stream water around the wells.

Effects of the proposed EPA groundwater standards on the Uranium Mill Tailings Remedial Action Project

International Nuclear Information System (INIS)

Titus, F.B.

1988-01-01

Potential groundwater contamination beneath the 24 tailings piles that are to be stabilized under the UMTRA Project was intended in early project plans to be minimized by placing disposal piles over thick stratigraphic sequences of tight (minimally permeable) formations, and by designing covers that contained low permeability soil/clay infiltration barriers. The court-ordered revision of the UMTRA groundwater standards by EPA (proposed standards of September 1987) include very low Maximum Concentration Limits (MCLs), which are based mostly on Primary Drinking Water Standards. EPA also mandates that the designs should control radioactivity and hazardous constituents...for up to one thousand years, to the extends reasonably achievable, and, in any case, for at least two hundred years.... In order to accommodate this stipulation, transport modeling of water and contaminants in both the vadose and saturated zones beneath the piles is run until steady state conditions are reached. The early decision to locate stabilized piles over tight formations now exacerbates the problem of complying with the standards, since the contaminants percolate to groundwater that moves only slowly through strata having low permeabilities. Innovative solutions have been evaluated that are aimed at further minimizing long-term infiltration, geochemically fixing contaminants in place before they reach groundwater, or otherwise minimizing contaminant flux

Determination of pharmaceuticals in groundwater collected in five cemeteries' areas (Portugal).

Science.gov (United States)

Paíga, P; Delerue-Matos, C

2016-11-01

There are growing public attention and concern about the possibility of ecosystem and human health effects from pharmaceuticals in environment. Several types of environmental samples were target of studies by the scientific community, namely drinking water, groundwater, surface water (river, ocean), treated water (influent and effluent), soils, and sediments near to Wastewater Treatment Plants or near to others potential sources of contaminations. Normally, studies in the cemeteries areas are for historical and architectural research and questions of the potential risk for adverse impact of cemeteries in environment have never received enough attention. However, this risk may exist when cemeteries are placed in areas that are vulnerable to contamination. The objective of the present work was the determination of pharmaceuticals (nonsteroidal anti-inflammatory/analgesics, antibiotics and psychiatric drugs) in groundwater samples collected inside of the cemeteries areas. Acetaminophen, salicylic acid, ibuprofen, ketoprofen, nimesulide, carbamazepine, fluoxetine, and sertraline were the pharmaceuticals achieved in the analysed samples. None of the studied antibiotics were detected. The highest concentration was obtained for salicylic acid (in the range of 33.7 to 71.0ng/L) and carbamazepine (between 20.0 and 22.3ng/L), respectively. By the cluster analysis similarity between carbamazepine and fluoxetine was achieved. Copyright © 2016. Published by Elsevier B.V.

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

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

Science.gov (United States)

Miguez-Macho, Gonzalo; Fan, Ying

2010-05-01

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

Investigations into Pb isotope signatures in groundwater and sediments in a uranium-mineralized area

Energy Technology Data Exchange (ETDEWEB)

Vecchia, Adriana Monica Dalla; Rodrigues, Paulo Cesar Horta; Rios, Francisco Javier; Ladeira, Ana Claudia Queiroz, E-mail: amdvc@cdtn.br, E-mail: acql@cdtn.br, E-mail: javier@cdtn.br, E-mail: pchr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-01-15

This work presents the investigation in an environment that contains uranium deposits by using Pb isotope signatures. The study area, southeast of Brazil, is characterized by the lack of surface water and, as a consequence, the groundwater plays an important role in the economy of the region, such as the supply to the uranium industry and, above all serving the needs of the local population. The objective of the present investigation is the determination of the signatures of Pb in groundwater and sediments as well as the identification of environments under influences of geogenic and/or anthropogenic sources. It was determined that the Pb in the majority of sediments was geogenic in origin. Although data from the literature, related to the environmental studies, consider {sup 206}Pb/{sup 207}Pb isotopic ratio values below or close to 1.2 as an indicative of anthropogenic Pb, the {sup 206}Pb/{sup 207}Pb determined for the majority of groundwater samples ranged from 1.14 to 1.19, and are similar to the data reported for rocks samples (1.09 to 1.96) from area with U mineralization. It was also determined that the anthropogenic influence of the uranium was restricted to a single sampling point within the mining area. (author)

Investigations into Pb isotope signatures in groundwater and sediments in a uranium-mineralized area

Directory of Open Access Journals (Sweden)

Adriana Mônica Dalla Vecchia

Full Text Available ABSTRACT: This work presents the investigation in an environment that contains uranium deposits by using Pb isotope signatures. The study area, southeast of Brazil, is characterized by the lack of surface water and, as a consequence, the groundwater plays an important role in the economy of the region, such as the supply to the uranium industry and, above all serving the needs of the local population. The objective of the present investigation is the determination of the signatures of Pb in groundwater and sediments as well as the identification of environments under influences of geogenic and/or anthropogenic sources. It was determined that the Pb in the majority of sediments was geogenic in origin. Although data from the literature, related to the environmental studies, consider 206Pb/207Pb isotopic ratio values below or close to 1.2 as an indicative of anthropogenic Pb, the 206Pb/ 207Pb determined for the majority of groundwater samples ranged from 1.14 to 1.19, and are similar to the data reported for rocks samples (1.09 to 1.96 from area with U mineralization. It was also determined that the anthropogenic influence of the uranium was restricted to a single sampling point within the mining area.

Prospectivity Modeling of Karstic Groundwater Using a Sequential Exploration Approach in Tepal Area, Iran

Science.gov (United States)

Sharifi, Fereydoun; Arab-Amiri, Ali Reza; Kamkar-Rouhani, Abolghasem; Yousefi, Mahyar; Davoodabadi-Farahani, Meysam

2017-09-01

The purpose of this study is water prospectivity modeling (WPM) for recognizing karstic water-bearing zones by using analyses of geo-exploration data in Kal-Qorno valley, located in Tepal area, north of Iran. For this, a sequential exploration method applied on geo-evidential data to delineate target areas for further exploration. In this regard, two major exploration phases including regional and local scales were performed. In the first phase, indicator geological features, structures and lithological units, were used to model groundwater prospectivity as a regional scale. In this phase, for karstic WPM, fuzzy lithological and structural evidence layers were generated and combined using fuzzy operators. After generating target areas using WPM, in the second phase geophysical surveys including gravimetry and geoelectrical resistivity were carried out on the recognized high potential zones as a local scale exploration. Finally the results of geophysical analyses in the second phase were used to select suitable drilling locations to access and extract karstic groundwater in the study area.

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

Use of stable isotopes in the investigation of the effects of wastewater reuse on groundwater in Mexico

International Nuclear Information System (INIS)

Chilton, P.J.; Stuart, M.E.; Darling, W.G.

1998-01-01

Agricultural irrigation with wastewater is widely practised in Mexico, often in areas where the underlying aquifers are used for potable water supply. Studies in two areas of the country have examined the fate and behaviour of contaminants from untreated wastewater. The use of δ 18 O and δ 2 H isotopes was integrated with hydrogeological techniques such as core drilling, geophysics, major ion and trace element analysis of water samples, soil sampling and simple modelling. In both study areas, the isotope data helped to confirm the hydrochemical results. Conventional plots of δ 2 H and δ 18 O provide indications of altitude differences and evaporation processes in looking at sources of recharge. Plotting δ 18 O against chloride provides a convenient way of distinguishing groundwater types. In Leon, isotopic data confirmed that recharge to the deep volcanic-rock aquifer underlying the area of wastewater irrigation came partly from the surrounding mountains where this formation outcrops. In the Mezquital Valley, recharge to groundwaters beneath the valley floor originates from infiltration of wastewater. Comparison with data from 25 years ago indicated that isotopic compositions at some locations have become significantly less depleted in δ 18 O, suggesting that the contribution from irrigation water had increased. The study has demonstrated the importance of establishing good conceptual models at an early stage of such investigations, particularly where multiple and changing sources of groundwater recharge are anticipated. (author)

Geochemical studies of groundwater systems of semiarid Yola area ...

African Journals Online (AJOL)

This was to determine the process controlling the water chemistry and to assess the ... for the deep groundwater and Na+-Cl- for the surface water bodies. ... Groundwater samples from the shallow groundwater indicate pH values (6.10 to 7.08) ...

The Effect Of Land Cover/Land Use On Groundwater Resources In Southern Egypt (Luxor Area): Remote Sensing And Field Studies

International Nuclear Information System (INIS)

Faid, A.M.; Hinz, E.A.; Montgomery, H.

2003-01-01

The impact of land cover/land use on groundwater can be critical. Land cover / land use maps give an early warning for planners and developers to protect groundwater resources from depletion and preserve its sustain ability. These land cover / land use maps can be used for the planning of groundwater development to prevent the deterioration of the aquifer. The Research Institute for Groundwater of Egypt (RIGW) has carried out hydrogeological studies in 1990 to evaluate the potentiality of groundwater in Luxor area in southern Egypt close to the Nile valley. The region is characterized by a rapid and continuous increase in land reclamation and development on the fringes which surround the already heavily cultivated land within the Nile valley. This presented a need for continuous monitoring and information updating over a vast region in a short time and at a reasonable cost. This study illustrates how remote sensing techniques can be effectively used for monitoring changes in land cover / land use in an effort to aid groundwater management. Landsat Thematic Mapper (TM) data collected in 1984 and 2000 were processed and analyzed over the study area to produce land cover/land use maps. The Normalized Difference Vegetation Index (NDVI) technique is used for Landsat TM images of to quantify areas which are covered by vegetation. Results indicated significant increase in cultivated areas. Remote sensing results are compared with iso-piezo metric maps and iso-salinity maps that were produced in 1984 and 2000. Comparison of these maps indicates groundwater depletion and salinity increase from 1984 to 2000. We relate this to the increase of the area being cultivated

Groundwater Flow Model of the General Separations Area Using PORFLOW

International Nuclear Information System (INIS)

FLACH, GREGORY

2004-01-01

The E Area PA (McDowell-Boyer et al. 2000) includes a steady-state simulation of groundwater flow in the General Separations Area as a prerequisite for saturated zone contaminant transport analyses. The groundwater flow simulations are based on the FACT code (Hamm and Aleman2000). The FACT-based GSA model was selected during preparation of the original PA to take advantage of an existing model developed for environmental restoration applications at the SRS (Flach and Harris 1997, 1999; Flach 1999). The existing GSA/FACT model was then slightly modified for PA use, as described in the PA document. FACT is a finite-element code utilizing deformed brick elements. Material properties are defined at element centers, and state variables such as hydraulic head are located at element vertices. The PORFLOW code (Analytic and Computational Research, Inc. 2000) was selected for performing saturated zone transport simulations of source zone radionuclides and their progeny. PORFLOW utilizes control volume discretization and the nodal point integration method, with all properties and state variables being defined at the center of an interior grid cell. The groundwater flow calculation includes translating the Darcy velocity field computed by FACT into a form compatible for input to PORFLOW. The FACT velocity field is defined at element vertices, whereas PORFLOW requires flux across cell faces. For the present PA, PORFLOW cell face flux is computed in a two-step process. An initial face flux is computed from FACT as an average of the normal components of Darcy velocity at the four corners. The derived flux field approximately conserves mass, but not rigorously. Thus, the flux field is subsequently perturbed to force rigorous mass conservation on a cell-by-cell basis. The undocumented process used is non-unique and can introduce significant artifacts into the final flux field

Groundwater Monitoring and Tritium-Tracking Plan for the 200 Area State-Approved Land Disposal Site

Energy Technology Data Exchange (ETDEWEB)

DB Barnett

2000-08-31

The 200 Area State-Approved Land Disposal Site (SALDS) is a drainfield which receives treated wastewater, occasionally containing tritium from treatment of Hanford Site liquid wastes at the 200 Area Effluent Treatment Facility (ETF). Since operation of the SALDS began in December 1995, discharges of tritium have totaled {approx}304 Ci, only half of what was originally predicted for tritium quantity through 1999. Total discharge volumes ({approx}2.7E+8 L) have been commensurate with predicted volumes to date. This document reports the results of all tritium analyses in groundwater as determined from the SALDS tritium-tracking network since the first SALDS wells were installed in 1992 through July 1999, and provides interpretation of these results as they relate to SALDS operation and its effect on groundwater. Hydrologic and geochemical information are synthesized to derive a conceptual model, which is in turn used to arrive at an appropriate approach to continued groundwater monitoring at the facility.

Investigation of tritium in groundwater at Pickering NGS

International Nuclear Information System (INIS)

DeWilde, J.; Yu, L.; Belanger, D.; Wootton, R.; Hansen, K.; McGurk, E.; Teare, A.

2001-01-01

Ontario Power Generation Inc. (OPG) investigated tritium in groundwater at the Pickering Nuclear Generating Station (PNGS). The objectives of the study were to evaluate and define the extent of radio-nuclides, primarily tritium, in groundwater, investigate the causes or sources of contamination, determine impacts on the natural environment, and provide recommendations to prevent future discharges. This paper provides an overview of the investigations conducted in 1999 and 2000 to identify the extent of the tritium beneath the site and the potential sources of tritium released to the groundwater. The investigation and findings are summarized with a focus on unique aspects of the investigation, on lessons learned and benefits. Some of the investigative techniques discussed include process assessments, video inspections, hydrostatic and tracer tests, Helium 3 analysis for tritium age dating, deuterium and tritium in soil analysis. The investigative techniques have widespread applications to other nuclear generating stations. (author)

A multiple-tracer approach to understanding regional groundwater flow in the Snake Valley area of the eastern Great Basin, USA

International Nuclear Information System (INIS)

Gardner, Philip M.; Heilweil, Victor M.

2014-01-01

Highlights: • Age tracers and noble gases constrain intra- and inter-basin groundwater flow. • Tritium indicates modern (<60 yr) recharge occurring in all mountain areas. • Noble-gas data identify an important interbasin hydraulic discontinuity. • Further groundwater development may significantly impact Snake Valley springs. - Abstract: Groundwater in Snake Valley and surrounding basins in the eastern Great Basin province of the western United States is being targeted for large-scale groundwater extraction and export. Concern about declining groundwater levels and spring flows in western Utah as a result of the proposed groundwater withdrawals has led to efforts that have improved the understanding of this regional groundwater flow system. In this study, environmental tracers (δ 2 H, δ 18 O, 3 H, 14 C, 3 He, 4 He, 20 Ne, 40 Ar, 84 Kr, and 129 Xe) and major ions from 142 sites were evaluated to investigate groundwater recharge and flow-path characteristics. With few exceptions, δ 2 H and δ 18 O show that most valley groundwater has similar ratios to mountain springs, indicating recharge is dominated by relatively high-altitude precipitation. The spatial distribution of 3 H, terrigenic helium ( 4 He terr ), and 3 H/ 3 He ages shows that modern groundwater (<60 yr) in valley aquifers is found only in the western third of the study area. Pleistocene and late-Holocene groundwater is found in the eastern parts of the study area. The age of Pleistocene groundwater is supported by minimum adjusted radiocarbon ages of up to 32 ka. Noble gas recharge temperatures (NGTs) are generally 1–11 °C in Snake and southern Spring Valleys and >11 °C to the east of Snake Valley and indicate a hydraulic discontinuity between Snake and Tule Valleys across the northern Confusion Range. The combination of NGTs and 4 He terr shows that the majority of Snake Valley groundwater discharges as springs, evapotranspiration, and well withdrawals within Snake Valley rather than

Large-Scale Groundwater Flow with Free Water Surface Based on Data from SKB's Site Investigation in the Forsmark Area

International Nuclear Information System (INIS)

Woerman, Anders; Sjoegren, Bjoern; Marklund, Lars

2004-12-01

This report describes a data-base that covers entire Sweden with regard to various geographical parameters with implications to simulation of groundwater circulation on a regional and continental scale. The data-base include topography, stream network properties, and-use and water chemistry for limited areas. Furthermore, the report describes a computational (finite difference) code that solves the continuum equation for laminar, stationary and isotropic groundwater flow. The formulation accounts for a free groundwater surface except where the groundwater recharge into the stream network and lake bottoms. The theoretical background of the model is provided and the codes are described. The report also contain a simple user manual in a Matlab environment and provides and example calculation for the Forsmark area, Uppland, Sweden.

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

Subsurface thermal regime to delineate the paleo-groundwater flow system in an arid area, Al Kufra, Libya

Directory of Open Access Journals (Sweden)

Zenhom El-Said Salem

2016-12-01

Full Text Available The purpose of this study was to understand the groundwater flow system in Al Kufra basin, Libya, as a case study of arid areas using subsurface temperature. The temperature-depth profiles and water levels were measured in eight boreholes in the area. Well 6 is considered a recharge type profile with low geothermal gradient (0.0068 °C/m and an estimated paleo-temperature around 19.5 °C. The other profiles are of discharge type with higher geothermal gradient (0.0133 to 0.0166 °C/m. The constructed horizontal 2D distribution maps of the hydraulic heads and the subsurface temperature measurements reveal that the main recharge area is located to the south with low temperature while the main discharge area is located to the north with higher temperature. Vertical 2D distribution maps show that location of well 4 has low hydraulic heads and higher temperature indicating that the fault defined in the area may have affected the groundwater flow system. The estimated groundwater flux ranges from 0.001 to 0.1 mm/day for the recharge area and from −0.3 to −0.7 mm/day in average in the discharge area.

100-D Area In Situ Redox Treatability Test for Chromate-Contaminated Groundwater

Energy Technology Data Exchange (ETDEWEB)

Williams, Mark D.; Vermeul, Vincent R.; Szecsody, James E.; Fruchter, Jonathan S.

2000-10-12

A treatability test was conducted for the In Situ Redox Manipulation (ISRM) technology at the 100 D Area of the U. S. Department of Energy's Hanford Site. The target contaminant was dissolved chromate in groundwater. The ISRM technology creates a permeable subsurface treatment zone to reduce mobile chromate in groundwater to an insoluble form. The ISRM permeable treatment zone is created by reducing ferric iron to ferrous iron within the aquifer sediments, which is accomplished by injecting aqueous sodium dithionite into the aquifer and then withdrawing the reaction products. The goal of the treatability test was to create a linear ISRM barrier by injecting sodium dithionite into five wells. Well installation and site characterization activities began in spring 1997; the first dithionite injection took place in September 1997. The results of this first injection were monitored through the spring of 1998. The remaining four dithionite injections were carried out in May through July of 1998.These five injections created a reduced zone in the Hanford unconfined aquifer approximately 150 feet in length (perpendicular to groundwater flow) and 50 feet wide. The reduced zone extended over the thickness of the unconfined zone. Analysis of post-emplacement groundwater samples showed concentrations of chromate, in the reduced zone decreased from approximately 1.0 mg/L before the tests to below analytical detection limits (<0.007 mg/L). Chromate concentrations also declined in downgradient monitoring wells to as low as 0.020 mg/L. These data, in addition to results from pre-test reducible iron characterization, indicate the barrier should be effective for 20 to 25 years. The 100-D Area ISRM barrier is being expanded to a length of up to 2,300 ft to capture a larger portion of the chromate plume.

Results of the groundwater quality assessment program at the 216-A-29 ditch RCRA facility

International Nuclear Information System (INIS)

Votava, J.M.

1995-01-01

This report presents the findings of the groundwater quality assessment program for the 216-A-29 Ditch. The information presented in this report Ditch have affected the quality of the groundwater in the unconfined aquifer beneath the facility. The results indicate that the 216-A-29 Ditch is the source of elevated specific conductance in well 299-E25-35 and that the source is nonhazardous. This report describes the current monitoring status of the 216-A-29 Ditch, groundwater chemical data interpretation, and recommends the reinstatement of an indicator-evaluation monitoring program in accordance with 40 CFR 265.93(d)(6)

Seasonal and spatial variation of arsenic in groundwater in a rhyolithic volcanic area of Lesvos Island, Greece.

Science.gov (United States)

Zkeri, Eirini; Aloupi, Maria; Gaganis, Petros

2017-12-23

A survey conducted in water wells located in the rhyolithic volcanic area of Mandamados, Lesvos Island, Greece, indicated that significant seasonal variation of arsenic concentration in groundwater exists mainly in wells near the coastal zone. However, there were differences among those coastal wells with regard to the processes and factors responsible for the observed seasonal variability of the element, although they are all located in a small homogeneous area. These processes and factors include (a) a higher rate of silicate weathering and ion exchange during the dry period followed by the dilution by the recharge water during the wet period, (b) enhanced desorption promoted by higher pH in summer and subsequent dilution of As by rainwater infiltration during the wet period, and (c) reductive dissolution of Mn during the wet period and by desorption under high pH values during the dry period. On the other hand, in wells located in higher-relief regions, the concentration of As in groundwater followed a fairly constant pattern throughout the year, which is probably related to the faster flow of groundwater in this part of the area due to a higher hydraulic gradient. In general, seasonal variation of As in groundwater in the study area was found to be related to geology, recharge rate, topography-distance from coast, and well depth.

Groundwater flow in a relatively old oceanic volcanic island: The Betancuria area, Fuerteventura Island, Canary Islands, Spain

Energy Technology Data Exchange (ETDEWEB)

Herrera, Christian, E-mail: cherrera@ucn.cl [Universidad Católica del Norte, Av. Angamos 0610, Antofagasta (Chile); Custodio, Emilio [Department of Geo-Engineering, Technical University of Catalonia (UPC), Barcelona (Spain)

2014-10-15

The island of Fuerteventura is the oldest of the Canary Islands' volcanic archipelago. It is constituted by volcanic submarine and subaerial activity and intrusive Miocene events, with some residual later volcanism and Quaternary volcanic deposits that have favored groundwater recharge. The climate is arid, with an average rainfall that barely attains 60 mm/year in the coast and up to 200 mm/year in the highlands. The aquifer recharge is small but significant; it is brackish due to large airborne atmospheric salinity, between 7 and 15 g m{sup −2} year{sup −1} of chloride deposition, and high evapo-concentration in the soil. The average recharge is estimated to be less than about 5 mm/year at low altitude and up to 10 mm/year in the highlands, and up to 20 mm/year associated to recent lava fields. Hydrochemical and water isotopic studies, supported by water table data and well and borehole descriptions, contribute a preliminary conceptual model of groundwater flow and water origin in the Betancuria area, the central area of the island. In general, water from springs and shallow wells tends to be naturally brackish and of recent origin. Deep saline groundwater is found and is explained as remnants of very old marine water trapped in isolated features in the very low permeability intrusive rocks. Preliminary radiocarbon dating indicates that this deep groundwater has an apparent age of less than 5000 years BP but it is the result of mixing recent water recharge with very old deep groundwater. Most of the groundwater flow occurs through the old raised volcanic shield of submarine and subaerial formations and later Miocene subaerial basalts. Groundwater transit time through the unsaturated zone is of a few decades, which allows the consideration of long-term quasi-steady state recharge. Transit times are up to a few centuries through the saturated old volcanics and up to several millennia in the intrusive formations, where isolated pockets of very old water may

A high resolution 3D velocity model beneath the Tokyo Metropolitan area by MeSO-net

Science.gov (United States)

Nakagawa, S.; Sakai, S.; Honda, R.; Kimura, H.; Hirata, N.

2015-12-01

Beneath the Tokyo metropolitan area, the Philippine Sea Plate (PSP) subducts and causes devastating mega-thrust earthquakes, such as the 1703 Genroku earthquake (M8.0) and the 1923 Kanto earthquake (M7.9). An M7 or greater (M7+) earthquake in this area at present has high potential to produce devastating serious loss of life and property with even greater global economic repercussions. The Central Disaster Management Council of Japan estimates that an M7+ earthquake will cause 23,000 fatalities and 95 trillion yen (about 1 trillion US$) economic loss. We have launched the Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters in collaboration with scientists, engineers, and social-scientists in nationwide institutions since 2012. We analyze data from the dense seismic array called Metropolitan Seismic Observation network (MeSO-net), which has 296 seismic stations with spacing of 5 km (Sakai and Hirata, 2009; Kasahara et al., 2009). We applied the double-difference tomography method (Zhang and Thurber, 2003) and estimated the velocity structure and the upper boundary of PSP (Nakagawa et al., 2010). The 2011 Tohoku-oki earthquake (M9.0) has activated seismicity also in Kanto region, providing better coverage of ray paths for tomographic analysis. We obtain much higher resolution velocity models from whole dataset observed by MeSO-net between 2008 and 2015. A detailed image of tomograms shows that PSP contacts Pacific plate at a depth of 50 km beneath northern Tokyo bay. A variation of velocity along the oceanic crust suggests dehydration reaction to produce seismicity in a slab, which may related to the M7+ earthquake. Acknowledgement: This study was supported by the Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters of MEXT, Japan and the Earthquake Research Institute cooperative research program.

Impact of rising groundwater on sustainable irrigated agriculture in the command area of gadeji minor, sindh, pakistan

International Nuclear Information System (INIS)

Solangi, G.S.

2017-01-01

A study has been conducted in the command area of Gadeji minor, Sindh, Pakistan to compute the amount of net groundwater recharge and its effect on sustainable irrigated agriculture. In this connection, Water budget equation was used and three groundwater recharging components along with one discharging component were computed for both Rabi and Kharif crop seasons for the period (2001-2013). Data shows that groundwater is rising at rapid rate during the Kharif season. The percolation rate through cropped fields is the major recharge component; accounting for 81% in the total mean recharge of 8.42 million m3, moreover the rice area is the major contributor to net groundwater recharge during Kharif season. The contributions of canal seepage and rainfall are estimated to be 16 and 04% respectively for the above period. However, during the Rabi season groundwater is rising at low rate where canal seepage is the major recharging component with an average contribution of 48% in the total mean recharge of 2.32 million m3, the contribution of deep percolation from cropped fields is estimated to be 47% as compared to the rainfall of only 05%. Survey shows non-functionality of most of the tubewells, groundwater withdrawal is not sufficient to fully offset groundwater recharge which has increased water table and caused waterlogging and soil salinity in more than 40% of agricultural land. To overcome this rising water table problem, it is recommended: to change existing cropping pattern (i.e. minimize or no cultivation of rice crop), lining of minor and all its watercourses, adopt salt tolerant crops and increase groundwater withdrawals by operating tube-wells on emergency basis. (author)

Synopsis of strontium isotope variations in groundwater at Aspo, southern Sweden

Science.gov (United States)

Peterman, Z.E.; Wallin, B.

1999-01-01

Strontium isotope ratios are used to identify end-member ground-water compositions at Aspo in southeastern Sweden where the Hard Rock Laboratory (HRL) has been constructed to evaluate the suitability of crystalline rock for the geologic disposal of nuclear waste. The Hard Rock Laboratory is a decline (tunnel) constructed in 1.8 Ga-old granitic rock that forms islands in an archipelago along the Swedish coast. Ground-water samples were obtained for isotopic analyses from boreholes drilled from the surface and from side boreholes drilled within the HRL. Infiltration at Aspo occurs primarily through fractures zones in the granitic bedrock beneath thin soils throughout the area. Because of extremely low Sr concentrations, rain and snow are not important contributors to the Sr isotope budget of the ground-water system. At shallow levels, water percolating downward along fractures and fracture zones acquires a ??87Sr between +9.5 and +10.0??? and maintains this value downward while Sr concentrations increase by two orders of magnitude. Ground-water samples from both boreholes and from in the HRL show the effects of mixing with saline waters containing as much as 59 mg/L Sr and ??87Sr values as large as +13.92%, Baltic Sea water is a potential component of the groundwater system with ??87Sr values only slightly larger than modern marine values (+0.3???) but with much lower concentrations (1.5 mg/L) than ocean water (8 mg/L). However, because of large Sr concentration differences between the saline groundwater (59 mg/L) and Baltic Sea water (1.5 rag/L), ??87Sr values are not particularly sensitive indicators of sea-water intrusion even though their ??87Sr values differ substantially.

Preliminary uncertainty analysis of pre-waste-emplacement groundwater travel times for a proposed repository in basalt

International Nuclear Information System (INIS)

Clifton, P.M.; Arnett, R.C.

1984-01-01

Preliminary uncertainty analyses of pre-waste-emplacement groundwater travel times are presented for a potential high-level nuclear waste repository in the deep basalts beneath the Hanford Site, Washington State. The uncertainty analyses are carried out by means of a Monte Carlo technique, which requires the uncertain inputs to be described as either random variables or spatial stochastic processes. Pre-waste-emplacement groundwater travel times are modeled in a continuous, flat-lying basalt flow top that is assumed to overlie the repository horizon. Two-dimensional, steady state groundwater flow is assumed, and transmissivity, effective thickness, and regional hydraulic gradient are considered as uncertain inputs. Groundwater travel time distributions corresponding to three groundwater models are presented and compared. Limitations of these preliminary simulation results are discussed in detail

Imaging Canary Island hotspot material beneath the lithosphere of Morocco and southern Spain

Science.gov (United States)

Miller, Meghan S.; O'Driscoll, Leland J.; Butcher, Amber J.; Thomas, Christine

2015-12-01

The westernmost Mediterranean has developed into its present day tectonic configuration as a result of complex interactions between late stage subduction of the Neo-Tethys Ocean, continental collision of Africa and Eurasia, and the Canary Island mantle plume. This study utilizes S receiver functions (SRFs) from over 360 broadband seismic stations to seismically image the lithosphere and uppermost mantle from southern Spain through Morocco and the Canary Islands. The lithospheric thickness ranges from ∼65 km beneath the Atlas Mountains and the active volcanic islands to over ∼210 km beneath the cratonic lithosphere in southern Morocco. The common conversion point (CCP) volume of the SRFs indicates that thinned lithosphere extends from beneath the Canary Islands offshore southwestern Morocco, to beneath the continental lithosphere of the Atlas Mountains, and then thickens abruptly at the West African craton. Beneath thin lithosphere between the Canary hot spot and southern Spain, including below the Atlas Mountains and the Alboran Sea, there are distinct pockets of low velocity material, as inferred from high amplitude positive, sub-lithospheric conversions in the SRFs. These regions of low seismic velocity at the base of the lithosphere extend beneath the areas of Pliocene-Quaternary magmatism, which has been linked to a Canary hotspot source via geochemical signatures. However, we find that this volume of low velocity material is discontinuous along strike and occurs only in areas of recent volcanism and where asthenospheric mantle flow is identified with shear wave splitting analyses. We propose that the low velocity structure beneath the lithosphere is material flowing sub-horizontally northeastwards beneath Morocco from the tilted Canary Island plume, and the small, localized volcanoes are the result of small-scale upwellings from this material.

The origin of groundwater composition in the Pampeano Aquifer underlying the Del Azul Creek basin, Argentina.

Science.gov (United States)

Zabala, M E; Manzano, M; Vives, L

2015-06-15

The Pampean plain is the most productive region in Argentina. The Pampeano Aquifer beneath the Pampean plain is used mostly for drinking water. The study area is the sector of the Pampeano Aquifer underlying the Del Azul Creek basin, in Buenos Aires province. The main objective is to characterize the chemical and isotopic compositions of groundwater and their origin on a regional scale. The methodology used involved the identification and characterization of potential sources of solutes, the study of rain water and groundwater chemical and isotopic characteristics to deduce processes, the development of a hydrogeochemical conceptual model, and its validation by hydrogeochemical modelling with PHREEQC. Groundwater samples come mostly from a two-depth monitoring network of the "Dr. Eduardo J. Usunoff" Large Plains Hydrology Institute (IHLLA). Groundwater salinity increases from SW to NE, where groundwater is saline. In the upper basin groundwater is of the HCO3-Ca type, in the middle basin it is HCO3-Na, and in the lower basin it is ClSO4-NaCa and Cl-Na. The main processes incorporating solutes to groundwater during recharge in the upper basin are rain water evaporation, dissolution of CO2, calcite, dolomite, silica, and anorthite; cationic exchange with Na release and Ca and Mg uptake, and clay precipitation. The main processes modifying groundwater chemistry along horizontal flow at 30 m depth from the upper to the lower basin are cationic exchange, dissolution of silica and anorthite, and clay precipitation. The origin of salinity in the middle and lower basin is secular evaporation in a naturally endorheic area. In the upper and middle basins there is agricultural pollution. In the lower basin the main pollution source is human liquid and solid wastes. Vertical infiltration through the boreholes annular space during the yearly flooding stages is probably the pollution mechanism of the samples at 30 m depth. Copyright © 2015 Elsevier B.V. All rights reserved.

Regional groundwater flow in the Atikokan Research Area : simulation of 18O and 3H distributions

International Nuclear Information System (INIS)

Ophori, D.U.; Chan, Tin.

1994-09-01

AECL is investigating a concept for disposing of nuclear fuel waste deep in plutonic rock of the Canadian Shield. As part of this investigation, we have performed a model simulation of regional groundwater flow in the Atikokan Research Area, a fractured plutonic rock environment of the Canadian Shield, and used the distribution of oxygen-18 ( 18 O) and tritium ( 3 H) in groundwater to test the model. At the first stage of model calibration, groundwater flow was simulated using a three-dimensional finite-element code, MOTIF, in conjunction with a conceptual framework model derived from field geological, geophysical and hydrogeological data. Hydraulic parameters (permeability and porosity) were systematically varied until simulated recharge rates to the water table compared favourably with estimated recharge rates based on stream flow analysis. At the second stage, vertical average linear groundwater velocities from the first stage of the calibration process were combined with conceptualized one-dimensional models of the system to generate depth concentration profiles of 18 O and 3 H. Recharge-, midline-and discharge area models of both the fracture zones and the rock mass were employed. The simulated profiles formed 'envelopes' around all field 18 O and 3 H data, indicating that the calibrated velocities used in the model are reasonable. The models demonstrate that the scatter of δ 18 O and 3 H field data from the Atikokan Research Area is consistent with the groundwater flow model predictions and can be explained by the complexity arising from different hydraulic regimes (recharge, midline, discharge) and hydrogeologic environments (fracture zones, rock mass) of the regional flow system. 50 refs., 14 figs., 3 tabs

Electrical Conductivity in the Vadose Zone beneath a Tamarisk Grove along the Virgin River in Nevada

Science.gov (United States)

Shillito, R.; Sueki, S.; Berli, M.; Healey, J. M.; Acharya, K.

2013-12-01

Thick tamarisk groves along river corridors of the Southwest can transpire vast quantities of water and, as an invasive species, compete with native plants for space and resources. It is hypothesized that tamarisk can outcompete other species by not only tolerating high soil salinity, but by increasing soil salinity due to transpiration of salt-rich near-surface groundwater. The goal of this study was to garner experimental evidence for salt accumulation around tamarisk trees in comparison with other species (mesquite) along the Virgin River near Riverside, NV. At the experimental site, electrical conductivity (EC), temperature (T), and volumetric water content (VWC) within the vadose zone were monitored using sensors at 20, 40, 60, 80 and 100 cm depth on 30-minute intervals within the tamarisk thicket where several mesquite trees are found. Nearby groundwater levels were monitored every 40 days. The 2012 - 2013 data reveal an unexpected EC profile between the surface and the groundwater table (average depth 100 cm). A crust was found within depressions on the surface with EC values as high as 18.8 mS/cm. In the vadose zone (0 to 80 cm depth), average EC values of 4.4 mS/cm were recorded. Most interestingly, in the capillary fringe immediately above the water table (80 to 100 cm depth) average EC values of only 1.25 mS/cm were found whereas the groundwater (>100 cm depth) showed considerably higher EC values averaging 8.8 mS/cm. Additionally, the surface beneath the tamarisk had double the EC as that beneath the mesquite. The contrast in the EC indicates an increase in the aquifer salinity, which may be due to leachate infiltration through the vadose zone concentrated by plant transpiration and direct deposition of saline tamarisk leaf litter and secretions onto the understory. Evapotranspiration and shedding of litter by the tamarisk accelerated the salinity concentrations in the uppermost part of the vadose zone. Ultimately, understanding the salinity regime as

On elevated fluoride and boron concentrations in groundwaters associated with the Lake Saint-Martin impact structure, Manitoba

International Nuclear Information System (INIS)

Desbarats, Alexandre J.

2009-01-01

Hydrogeological investigations conducted by the Geological Survey of Canada in the Lake Saint-Martin region of Manitoba have confirmed earlier reports of naturally elevated F - and B concentrations in local groundwaters. Fluoride and B concentrations are highly correlated (r 2 = 0.905) and reach 15.1 mg/L and 8.5 mg/L, respectively. Virtually all groundwaters with F - concentrations greater than the drinking water limit of 1.5 mg/L are from wells within the Lake Saint-Martin impact structure, a 208 Ma complex crater 23 km in diameter underlying a large part of the study area. The high-F - groundwaters can be classified into two groups according to their anionic and isotopic compositions. Group I samples consist of Na-mixed anion groundwaters, with Cl greater than 100 mg/L and highly depleted 18 O compositions indicative of recharge under much cooler climatic conditions than at present. Samples belonging to this group exhibit a striking relationship to crater morphology, and are found in an arcuate belt within the southern rim of the impact structure. Group II high-F - samples consist of Na-HCO 3 -SO 4 groundwaters, with little Cl, and less depleted 18 O compositions. Samples belonging to this group are associated with groundwaters recharged locally, on a low ridge within the impact structure. This paper traces the probable source of high-F - groundwaters to phosphatic pellets in shales of the Winnipeg Formation, a regional basal clastic unit which sub-crops at shallow depth beneath the crater rim as a result of more than 200 m of structural uplift associated with the impact event. This extensive aquifer is known elsewhere in southern Manitoba for its naturally-softened groundwaters and locally elevated F - concentrations. Group I groundwaters are interpreted as discharge from the Winnipeg Formation where it abuts against crater-fill deposits. Group II high-F - groundwaters are interpreted as modern recharge from within the impact structure, displacing Group I

Nevada Test Site, 2006 Waste Management Monitoring Report, Area 3 and Area 5 Radioactive Waste Management Sites

International Nuclear Information System (INIS)

David B. Hudson

2007-01-01

Environmental monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site. These data are associated with radiation exposure, air, groundwater, meteorology, vadose zone, subsidence, and biota. This report summarizes the 2006 environmental data to provide an overall evaluation of RWMS performance and to support environmental compliance and performance assessment (PA) activities. Some of these data (e.g., radiation exposure, air, and groundwater) are presented in other reports (U.S. Department of Energy, 2006; Warren and Grossman, 2007; National Security Technologies, LLC, 2007). Direct radiation monitoring data indicate that exposure levels around the RWMSs are at or below background levels. Air monitoring data at the Area 3 and Area 5 RWMSs indicate that tritium concentrations are slightly above background levels. There is no detectable man-made radioactivity by gamma spectroscopy, and concentrations of americium and plutonium are only slightly above detection limits at the Area 3 RWMS. Measurements at the Area 5 RWMS show that radon flux from waste covers is no higher than natural radon flux from undisturbed soil in Area 5. Groundwater monitoring data indicate that the groundwater in the uppermost aquifer beneath the Area 5 RWMS is not impacted by facility operations. Precipitation during 2006 totaled 98.6 millimeters (mm) (3.9 inches [in.]) at the Area 3 RWMS and 80.7 mm (3.2 in.) at the Area 5 RWMS. Soil-gas tritium monitoring continues to show slow subsurface migration consistent with previous results. Moisture from precipitation at Area 5 remains at the bottom of the bare-soil weighing lysimeter, but this same moisture has been removed from the vegetated weighing lysimeter by evapotranspiration. Vadose zone data from the operational waste pit covers show that evaporation continues to slowly remove soil moisture that came from the heavy precipitation in the fall of 2004 and the spring of

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

Science.gov (United States)

Abdalla, Fathy; Khalil, Ramadan

2018-05-01

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

Health risk assessment of drinking arsenic-containing groundwater in Hasilpur, Pakistan: effect of sampling area, depth, and source.

Science.gov (United States)

Tabassum, Riaz Ahmad; Shahid, Muhammad; Dumat, Camille; Niazi, Nabeel Khan; Khalid, Sana; Shah, Noor Samad; Imran, Muhammad; Khalid, Samina

2018-02-10

Currently, several news channels and research publications have highlighted the dilemma of arsenic (As)-contaminated groundwater in Pakistan. However, there is lack of data regarding groundwater As content of various areas in Pakistan. The present study evaluated As contamination and associated health risks in previously unexplored groundwater of Hasilpur-Pakistan. Total of 61 groundwater samples were collected from different areas (rural and urban), sources (electric pump, hand pump, and tubewell) and depths (35-430 ft or 11-131 m). The water samples were analyzed for As level and other parameters such as pH, electrical conductivity, total dissolved solids, cations, and anions. It was found that 41% (25 out of 61) water samples contained As (≥ 5 μg/L). Out of 25 As-contaminated water samples, 13 water samples exceeded the permissible level of WHO (10 μg/L). High As contents have been found in tubewell samples and at high sampling depths (> 300 ft). The major As-contaminated groundwater in Hasilpur is found in urban areas. Furthermore, health risk and cancer risk due to As contamination were also assessed with respect to average daily dose (ADD), hazard quotient (HQ), and carcinogenic risk (CR). The values of HQ and CR of As in Hasilpur were up to 58 and 0.00231, respectively. Multivariate analysis revealed a positive correlation between groundwater As contents, pH, and depth in Hasilpur. The current study proposed the proper monitoring and management of well water in Hasilpur to minimize the As-associated health hazards.

Natural and anthropogenic factors affecting the shallow groundwater quality in a typical irrigation area with reclaimed water, North China Plain.

Science.gov (United States)

Gu, Xiaomin; Xiao, Yong; Yin, Shiyang; Pan, Xingyao; Niu, Yong; Shao, Jingli; Cui, Yali; Zhang, Qiulan; Hao, Qichen

2017-09-22

In this study, the hydrochemical characteristics of shallow groundwater were analyzed to get insight into the factors affecting groundwater quality in a typical agricultural dominated area of the North China Plain. Forty-four shallow groundwater samples were collected for chemical analysis. The water type changes from Ca·Na-HCO 3 type in grass land to Ca·Na-Cl (+NO 3 ) type and Na (Ca)-Cl (+NO 3 +SO 4 ) type in construction and facility agricultural land, indicating the influence of human activities. The factor analysis and geostatistical analysis revealed that the two major factors contributing to the groundwater hydrochemical compositions were the water-rock interaction and contamination from sewage discharge and agricultural fertilizers. The major ions (F, HCO 3 ) and trace element (As) in the shallow groundwater represented the natural origin, while the nitrate and sulfate concentrations were related to the application of fertilizer and sewage discharge in the facility agricultural area, which was mainly affected by the human activities. The values of pH, total dissolved solids, electric conductivity, and conventional component (K, Ca, Na, Mg, Cl) in shallow groundwater increased from grass land and cultivated land, to construction land and to facility agriculture which were originated from the combination sources of natural processes (e.g., water-rock interaction) and human activities (e.g., domestic effluents). The study indicated that both natural processes and human activities had influences on the groundwater hydrochemical compositions in shallow groundwater, while anthropogenic processes had more contribution, especially in the reclaimed water irrigation area.

Determination of polycyclic aromatic hydrocarbon levels of groundwater in Ife north local government area of Osun state, Nigeria

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Abolanle Saheed Adekunle

Full Text Available This study determined the presence and levels of Polycyclic Aromatic Hydrocarbons (PAHs of groundwater in Moro, Edun-Abon, Yakoyo and Ipetumodu communities in Ife-North Local Government Area of Osun State. This was with a view to create public awareness about the safety of groundwater as a source for domestic purposes (e.g., drinking, cooking etc. in non-industrial area. Water samples were collected on seasonal basis, comprising of three months (August–October in the wet season and three months (December–February in the dry season. The PAHs in the water samples were extracted with n-hexane using liquid–liquid extraction method, while their qualitative identifications and quantitative estimations were carried out with the use of gas chromatography. Levels of PAHs detected showed predominance of light PAHs (less than four fused rings for both wet and the dry seasons. Higher concentrations of PAHs were recorded during the wet season than the dry season. The study concluded that the groundwater in the communities was contaminated with light PAHs and the total PAHs in this area exceeded the maximum permissible limit of 10 μg L−1 recommended by World Health Organization (WHO for safety of groundwater. Keywords: Polycyclic aromatic hydrocarbons, Groundwater, Water quality, Seasonal variation, Health impact

Understanding the Groundwater Hydrology of a Geographically-Isolated Prairie Fen: Implications for Conservation.

Science.gov (United States)

Sampath, Prasanna Venkatesh; Liao, Hua-Sheng; Curtis, Zachary Kristopher; Doran, Patrick J; Herbert, Matthew E; May, Christopher A; Li, Shu-Guang

2015-01-01

The sources of water and corresponding delivery mechanisms to groundwater-fed fens are not well understood due to the multi-scale geo-morphologic variability of the glacial landscape in which they occur. This lack of understanding limits the ability to effectively conserve these systems and the ecosystem services they provide, including biodiversity and water provisioning. While fens tend to occur in clusters around regional groundwater mounds, Ives Road Fen in southern Michigan is an example of a geographically-isolated fen. In this paper, we apply a multi-scale groundwater modeling approach to understand the groundwater sources for Ives Road fen. We apply Transition Probability geo-statistics on more than 3000 well logs from a state-wide water well database to characterize the complex geology using conditional simulations. We subsequently implement a 3-dimensional reverse particle tracking to delineate groundwater contribution areas to the fen. The fen receives water from multiple sources: local recharge, regional recharge from an extensive till plain, a regional groundwater mound, and a nearby pond. The regional sources deliver water through a tortuous, 3-dimensional "pipeline" consisting of a confined aquifer lying beneath an extensive clay layer. Water in this pipeline reaches the fen by upwelling through openings in the clay layer. The pipeline connects the geographically-isolated fen to the same regional mound that provides water to other fen clusters in southern Michigan. The major implication of these findings is that fen conservation efforts must be expanded from focusing on individual fens and their immediate surroundings, to studying the much larger and inter-connected hydrologic network that sustains multiple fens.

Groundwater screening evaluation/monitoring plan: 200 Area Treated Effluent Disposal Facility (Project W-049H). Revision 1

International Nuclear Information System (INIS)

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

1995-05-01

This report consists of the groundwater screening evaluation required by Section S.8 of the State Waste Discharge Permit for the 200 Area TEDF. Chapter 1.0 describes the purpose of the groundwater monitoring plan. The information in Chapter 2.0 establishes a water quality baseline for the facility and is the groundwater screening evaluation. The following information is included in Chapter 2.0: Facility description;Well locations, construction, and development data; Geologic and hydrologic description of the site and affected area; Ambient groundwater quality and current use; Water balance information; Hydrologic parameters; Potentiometric map, hydraulic gradients, and flow velocities; Results of infiltration and hydraulic tests; Groundwater and soils chemistry sampling and analysis data; Statistical evaluation of groundwater background data; and Projected effects of facility operation on groundwater flow and water quality. Chapter 3.0 defines, based on the information in Chapter 2.0, how effects of the TEDF on the environment will be evaluated and how compliance with groundwater quality standards will be documented in accordance with the terms and conditions of the permit. Chapter 3.0 contains the following information: Media to be monitored; Wells proposed as the point of compliance in the uppermost aquifer; Basis for monitoring well network and evidence of monitoring adequacy; Contingency planning approach for vadose zone monitoring wells; Which field parameters will be measured and how measurements will be made; Specification of constituents to be sampled and analyzed; and Specification of the sampling and analysis procedures that will be used. Chapter 4.0 provides information on how the monitoring results will be reported and the proposed frequency of monitoring and reporting. Chapter 5.0 lists all the references cited in this monitoring plan. These references should be consulted for additional or more detailed information

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.

Incorporating insights from Time Series Analysis in groundwater modelling for the urban area of the city of Amsterdam

NARCIS (Netherlands)

Graafstra, P.; Smits, F.J.C.; Janse, T.

2017-01-01

As the public water authority of the city of Amsterdam and surrounding areas, Waternet makes use of both steady-state and transient groundwater models for a variety of purposes involving urban groundwater management. For instance when determining the effect of planned measures on the occurrence of

Rice Field Geochemistry and Hydrology: An Explanation for Why Groundwater Irrigated Fields in Bangladesh are Net Sinks of Arsenic from Groundwater

Science.gov (United States)

Neumann, Rebecca B.; St. Vincent, Allison P.; Roberts, Linda C.; Badruzzaman, A. Borhan M.; Ali, M. Ashraf; Harvey, Charles F.

2011-01-01

Irrigation of rice fields in Bangladesh with arsenic-contaminated groundwater transfers tens of cubic kilometers of water and thousands of tons of arsenic from aquifers to rice fields each year. Here we combine observations of infiltration patterns with measurements of porewater chemical composition from our field site in Munshiganj Bangladesh to characterize the mobility of arsenic in soils beneath rice fields. We find that very little arsenic delivered by irrigation returns to the aquifer, and that recharging water mobilizes little, if any, arsenic from rice field subsoils. Arsenic from irrigation water is deposited on surface soils and sequestered along flow paths that pass through bunds, the raised soil boundaries around fields. Additionally, timing of flow into bunds limits the transport of biologically available organic carbon from rice fields into the subsurface where it could stimulate reduction processes that mobilize arsenic from soils and sediments. Together, these results explain why groundwater irrigated rice fields act as net sinks of arsenic from groundwater. PMID:21332196

2015 Groundwater Monitoring Report Project Shoal Area: Subsurface Correction Unit 447

Energy Technology Data Exchange (ETDEWEB)

Findlay, Rick [Navarro Research and Engineering, Oak Ridge, TN (United States)

2016-04-01

The Project Shoal Area in Nevada was the site of a 12-kiloton-yield underground nuclear test in 1963. Although the surface of the site has been remediated, investigation of groundwater contamination resulting from the test is still in the corrective action process. Annual sampling and hydraulic head monitoring are conducted at the site as part of the subsurface corrective action strategy. The corrective action strategy is currently focused on revising the site conceptual model (SCM) and evaluating the adequacy of the monitoring well network. Some aspects of the SCM are known; however, two major concerns are the uncertainty in the groundwater flow direction and the cause of rising water levels in site wells west of the shear zone. Water levels have been rising in the site wells west of the shear zone since the first hydrologic characterization wells were installed in 1996. Although water levels in wells west of the shear zone continue to rise, the rate of increase is less than in previous years. The SCM will be revised, and an evaluation of the groundwater monitoring network will be conducted when water levels at the site have stabilized to the agreement of both the U.S. Department of Energy Office of Legacy Management and the Nevada Division of Environmental Protection.

Modelling groundwater discharge areas using only digital elevation models as input data

International Nuclear Information System (INIS)

Brydsten, Lars

2006-10-01

Advanced geohydrological models require data on topography, soil distribution in three dimensions, vegetation, land use, bedrock fracture zones. To model present geohydrological conditions, these factors can be gathered with different techniques. If a future geohydrological condition is modelled in an area with positive shore displacement (say 5,000 or 10,000 years), some of these factors can be difficult to measure. This could include the development of wetlands and the filling of lakes. If the goal of the model is to predict distribution of groundwater recharge and discharge areas in the landscape, the most important factor is topography. The question is how much can topography alone explain the distribution of geohydrological objects in the landscape. A simplified description of the distribution of geohydrological objects in the landscape is that groundwater recharge areas occur at local elevation curvatures and discharge occurs in lakes, brooks, and low situated slopes. Areas in-between these make up discharge areas during wet periods and recharge areas during dry periods. A model that could predict this pattern only using topography data needs to be able to predict high ridges and future lakes and brooks. This study uses GIS software with four different functions using digital elevation models as input data, geomorphometrical parameters to predict landscape ridges, basin fill for predicting lakes, flow accumulations for predicting future waterways, and topographical wetness indexes for dividing in-between areas based on degree of wetness. An area between the village of and Forsmarks' Nuclear Power Plant has been used to calibrate the model. The area is within the SKB 10-metre Elevation Model (DEM) and has a high-resolution orienteering map for wetlands. Wetlands are assumed to be groundwater discharge areas. Five hundred points were randomly distributed across the wetlands. These are potential discharge points. Model parameters were chosen with the

[Distribution Characteristics and Source of Fluoride in Groundwater in Lower Plain Area of North China Plain: A Case Study in Nanpi County].

Science.gov (United States)

Kong, Xiao-le; Wang, Shi-qin; Zhao, Huan; Yuan, Rui-qiang

2015-11-01

There is an obvious regional contradiction between water resources and agricultural produce in lower plain area of North China, however, excessive fluorine in deep groundwater further limits the use of regional water resources. In order to understand the spatial distribution characteristics and source of F(-) in groundwater, study was carried out in Nanpi County by field survey and sampling, hydrogeochemical analysis and stable isotopes methods. The results showed that the center of low fluoride concentrations of shallow groundwater was located around reservoir of Dalang Lake, and centers of high fluoride concentrations were located in southeast and southwest of the study area. The region with high fluoride concentration was consistent with the over-exploitation region of deep groundwater. Point source pollution of subsurface drainage and non-point source of irrigation with deep groundwater in some regions were the main causes for the increasing F(-) concentrations of shallow groundwater in parts of the sampling sites. Rock deposition and hydrogeology conditions were the main causes for the high F(-) concentrations (1.00 mg x L(-1), threshold of drinking water quality standard in China) in deep groundwater. F(-) released from clay minerals into the water increased the F(-) concentrations in deep groundwater because of over-exploitation. With the increasing exploitation and utilization of brackish shallow groundwater and the compressing and restricting of deep groundwater exploitation, the water environment in the middle and east lower plain area of North China will undergo significant change, and it is important to identify the distribution and source of F(-) in surface water and groundwater for reasonable development and use of water resources in future.

Ground-water quality in agricultural areas, Anoka Sand Plain Aquifer, east-central Minnesota, 1984-90

Science.gov (United States)

Landon, M.K.; Delin, G.N.

1995-01-01

Ground-water quality in the Anoka Sand Plain aquifer was studied as part of the multiscale Management Systems Evaluation Area (MSEA) study by collecting water samples from shallow wells during August through November 1990. The sampling was conducted to: (1) aid in selection of the MSEA research area; (2) facilitate comparison of results at the MSEA research area to the regional scale; and (3) evaluate changes in ground-water quality in the Anoka Sand Plain aquifer since a previous study during 1984 through 1987. Samples were collected from 34 wells screened in the upper 6 meters of the surficial aquifer and located in cultivated agricultural areas. Water temperature, pH, specific conductance, and presence or absence of triazine herbicides were determined at all sites and samples from selected wells were analyzed for concentrations of dissolved oxygen, alkalinity, major cations and anions, nutrients, and selected herbicides and herbicide metabolites. The results of the study indicate that the water-quality of some shallow ground water in areas of predominantly agricultural land use has been affected by applications of nitrogen fertilizers and the herbicide atrazine.

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

Influence of lateral groundwater flow in a shallow aquifer on eco-hydrological process in a shrub-grass coexistence semiarid area

Science.gov (United States)

Wang, Siru; Sun, Jinhua; Lei, Huimin; Zhu, Qiande; Jiang, Sanyuan

2017-04-01

Topography has a considerable influence on eco-hydrological processes resulting from the patterns of solar radiation distribution and lateral water flow. However, not much quantitative information on the contribution of lateral groundwater flow on ecological processes such as vegetation growth and evapo-transpiration is available. To fill this gap, we used a simple eco-hydrological model based on water balance with a 3D groundwater module that uses Darcy's law. This model was applied to a non-contributing area of 50km2 dominated by grassland and shrubland with an underlying shallow aquifer. It was calibrated using manually and remotely sensed vegetation data and water flux data observed by eddy covariance system of two flux towers as well as water table data obtained from HOBO recorders of 40 wells. The results demonstrate that the maximum hydraulic gradient and the maximum flux of lateral groundwater flow reached to 0.156m m-1 and 0.093m3 s-1 respectively. The average annual maximum LAI in grassland, predominantly in low-lying areas, improved by about 5.9% while that in shrubland, predominantly in high-lying areas, remained the same when lateral groundwater flow is considered adequately compared to the case without considering lateral groundwater flow. They also show that LAI is positively and nonlinearly related to evapotranspiration, and that the greater the magnitude of evapotranspiration, the smaller the rate of increase of LAI. The results suggest that lateral groundwater flow should not be neglected when simulating eco-hydrological process in areas with a shallow aquifer.

Recharge sources and residence times of groundwater as determined by geochemical tracers in the Mayfield Area, southwestern Idaho, 2011–12

Science.gov (United States)

Hopkins, Candice B.

2013-01-01

Parties proposing residential development in the area of Mayfield, Idaho are seeking a sustainable groundwater supply. During 2011–12, the U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources, used geochemical tracers in the Mayfield area to evaluate sources of aquifer recharge and differences in groundwater residence time. Fourteen groundwater wells and one surface-water site were sampled for major ion chemistry, metals, stable isotopes, and age tracers; data collected from this study were used to evaluate the sources of groundwater recharge and groundwater residence times in the area. Major ion chemistry varied along a flow path between deeper wells, suggesting an upgradient source of dilute water, and a downgradient source of more concentrated water with the geochemical signature of the Idaho Batholith. Samples from shallow wells had elevated nutrient concentrations, a more positive oxygen-18 signature, and younger carbon-14 dates than deep wells, suggesting that recharge comes from young precipitation and surface-water infiltration. Samples from deep wells generally had higher concentrations of metals typical of geothermal waters, a more negative oxygen-18 signature, and older carbon-14 values than samples from shallow wells, suggesting that recharge comes from both infiltration of meteoric water and another source. The chemistry of groundwater sampled from deep wells is somewhat similar to the chemistry in geothermal waters, suggesting that geothermal water may be a source of recharge to this aquifer. Results of NETPATH mixing models suggest that geothermal water composes 1–23 percent of water in deep wells. Chlorofluorocarbons were detected in every sample, which indicates that all groundwater samples contain at least a component of young recharge, and that groundwater is derived from multiple recharge sources. Conclusions from this study can be used to further refine conceptual hydrological models of the area.