Impact of leachate on groundwater pollution due to non-engineered municipal solid waste landfill sites of erode city, Tamil Nadu, India

PubMed Central

2012-01-01

Leachate and groundwater samples were collected from Vendipalayam, Semur and Vairapalayam landfill sites in Erode city, Tamil Nadu, India, to study the possible impact of leachate percolation on groundwater quality. Concentrations of various physicochemical parameters including heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Fe and Zn) were determined in leachate samples and are reported. The concentrations of Cl-, NO3-, SO42-, NH4+ were found to be in considerable levels in the groundwater samples particularly near to the landfill sites, likely indicating that groundwater quality is being significantly affected by leachate percolation. Further they were proved to be the tracers for groundwater contamination near Semur and Vendipalayam dumpyards. The presence of contaminants in groundwater particularly near the landfill sites warns its quality and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures are suggested to reduce further groundwater contamination via leachate percolation, the present study demands for the proper management of waste in Erode city. PMID:23369323

Ground-water hydrology of James City County, Virginia

USGS Publications Warehouse

Harsh, John F.

1980-01-01

Urbanization and increase in water demand prompted a 2-year study of groundwater availability and quality in the county of James City. The coastal-plain sediments, parts of which underlie the county, are the largest source of groundwater in Virginia. Four aquifers form the complex aquifer system. Hydraulic characteristics vary from aquifer to aquifer and from place to place. The Cretaceous aquifer furnishes nearly all the water for industrial and municipal needs. Movement of water in the Cretaceous aquifer is toward cones of depression formed by pumping centers at Williamsburg and Dow Badische Co. All aquifers contain water that generally meets State standards for drinking water. Water in the Cretaceous aquifer is of the sodium chloride bicarbonate type. As depth of aquifer increases, the concentrations of dissolved solids and chloride also increase. Saline water (more than 250 milligrams per liter) occupies the deeper parts of the confined aquifers. The amount of water stored in the coastal sediments is estimated to be 650-1300 billion gallons. An increase in pumpage to accomodate the expected daily demand of 9.8 million gallons per day in year 2000 is feasible provided pumpage is distributed over the county. (USGS)

Large Scale Groundwater Flow Model for Ho Chi Minh City and its Catchment Area, Southern Vietnam

NASA Astrophysics Data System (ADS)

Sigrist, M.; Tokunaga, T.; Takizawa, S.

2005-12-01

Ho Chi Minh City (HCMC) has become a fast growing city in recent decades and is still growing at a high pace. The water demand for more than 7 million people has increased tremendously, too. Beside surface water, groundwater is used in big amounts to satisfy the need of water. By now, more than 200,000 wells have been developed with very little control. To investigate the sustainability of the water abstraction, a model had been built for the HCMC area and its surrounding. On the catchment scale (around 24,000km2); however, many questions have remained unsolved. In this study, we first gathered and complied geological and hydrogeological information as well as data on groundwater quality to get an idea on regional groundwater flow pattern and problems related to the temporal change of the groundwater situation. Two problems have been depicted by this study. One is the construction of a water reservoir upstream of the Saigon River. This construction has probably changed the water table of the unconfined aquifer, and hence, has significantly changed the properties of soils in some areas. The other problem is the distribution of salty groundwater. Despite the distance of more than 40km from the seashore, groundwater from some wells in and around HCMC shows high concentrations of chloride. Several wells started to produce non-potable water. The chloride concentrations show a complicated and patchy distribution below HCMC, suggesting the possibility of the remnant saltwater at the time of sediment deposition. On the other hand, seawater invades along the streams far beyond HCMC during the dry season and this might be one of the possible sources of salty groundwater by vertical infiltration. A large-scale geological model was constructed and transformed into a hydrogeological model to better understand and quantify the groundwater flow system and the origin of saltwater. Based on the constructed model and numerical calculation, we discuss the influence of reservoir

Impact assessment of on-site sanitation system on groundwater quality in alluvial settings: A case study from Lucknow city in North India.

PubMed

Jangam, Chandrakant; Ramya Sanam, S; Chaturvedi, M K; Padmakar, C; Pujari, Paras R; Labhasetwar, Pawan K

2015-10-01

The present case study has been undertaken to investigate the impact of on-site sanitation on groundwater quality in alluvial settings in Lucknow City in India. The groundwater samples have been collected in the areas of Lucknow City where the on-site sanitation systems have been implemented. The groundwater samples have been analyzed for the major physicochemical parameters and fecal coliform. The results of analysis reveal that none of the groundwater samples exceeded the Bureau of Indian Standards (BIS) limits for all the parameters. Fecal coliform was not found in majority of the samples including those samples which were very close to the septic tank. The study area has a thick alluvium cover as a top layer which acts as a natural barrier for groundwater contamination from the on-site sanitation system. The t test has been performed to assess the seasonal effect on groundwater quality. The statistical t test implies that there is a significant effect of season on groundwater quality in the study area.

Modelling of lindane transport in groundwater of metropolitan city Vadodara, Gujarat, India.

PubMed

Sharma, M K; Jain, C K; Rao, G Tamma; Rao, V V S Gurunadha

2015-05-01

Migration pattern of organochloro pesticide lindane has been studied in groundwater of metropolitan city Vadodara. Groundwater flow was simulated using the groundwater flow model constructed up to a depth of 60 m considering a three-layer structure with grid size of 40 × 40 × 40 m(3). The general groundwater flow direction is from northeast to south and southwest. The river Vishwamitri and river Jambua form natural hydrologic boundary. The constant head in the north and south end of the study area is taken as another boundary condition in the model. The hydraulic head distribution in the multilayer aquifer has been computed from the visual MODFLOW groundwater flow model. TDS has been computed though MT3D mass transport model starting with a background concentration of 500 mg/l and using a porosity value of 0.3. Simulated TDS values from the model matches well with the observed data. Model MT3D was run for lindane pesticide with a background concentration of 0.5 μg/l. The predictions of the mass transport model for next 50 years indicate that advancement of containment of plume size in the aquifer system both spatially and depth wise as a result of increasing level of pesticide in river Vishwamitri. The restoration of the aquifer system may take a very long time as seen from slow improvement in the groundwater quality from the predicted scenarios, thereby, indicating alarming situation of groundwater quality deterioration in different layers. It is recommended that all the industries operating in the region should install efficient effluent treatment plants to abate the pollution problem.

Assessment of groundwater vulnerability by applying the modified DRASTIC model in Beihai City, China.

PubMed

Wu, Xiaoyu; Li, Bin; Ma, Chuanming

2018-05-01

This study assesses vulnerability of groundwater to pollution in Beihai City, China, as a support of groundwater resource protection. The assessment result not only objectively reflects potential possibility of groundwater to contamination but also provides scientific basis for the planning and utilization of groundwater resources. This study optimizes the parameters consisting of natural factors and human factors upon the DRASTIC model and modifies the ratings of these parameters, based on the local environmental conditions for the study area. And a weight of each parameter is assigned by the analytic hierarchy process (AHP) to reduce the subjectivity of humans to vulnerability assessment. The resulting scientific ratings and weights of modified DRASTIC model (AHP-DRASTLE model) contribute to obtain the more realistic assessment of vulnerability of groundwater to contaminant. The comparison analysis validates the accuracy and rationality of the AHP-DRASTLE model and shows it suits the particularity of the study area. The new assessment method (AHP-DRASTLE model) can provide a guide for other scholars to assess the vulnerability of groundwater to contamination. The final vulnerability map for the AHP-DRASTLE model shows four classes: highest (2%), high (29%), low (55%), and lowest (14%). The vulnerability map serves as a guide for decision makers on groundwater resource protection and land use planning at the regional scale and that it is adapted to a specific area.

Physico-chemical characteristics of groundwater in and around Surat City (India).

PubMed

Raval, Viral H; Malik, G M

2010-10-01

Groundwater samples were collected from different locations of Surat city, Gujarat (India). These samples from 32 locations of Surat city were analysed for their physico-chemical characteristics involving pH, colour, odour, hardness, chloride, alkalinity, COD, sulfate, TDS, SS, iron, Cu, boron, chromium, temperature and Langelier Saturation Index. On comparing the results against drinking water quality standards laid by Indian Council of Medical Research (ICMR) and World Health Organization (WHO), it is found that most of the water samples are non-potable. Most of the samples indicated Total Alkalinity, Hardness, Chloride and TDS values much higher than the permissible level stipulated by ICMR and WHO. Even at some places Langelier Saturation Index values found higher too. The high values of these parameters may have health implications and therefore these need attention.

Evaluation of groundwater quality and its suitability for drinking and agricultural use in Thanjavur city, Tamil Nadu, India.

PubMed

Nagarajan, R; Rajmohan, N; Mahendran, U; Senthamilkumar, S

2010-12-01

As groundwater is a vital source of water for domestic and agricultural activities in Thanjavur city due to lack of surface water resources, groundwater quality and its suitability for drinking and agricultural usage were evaluated. In this study, 102 groundwater samples were collected from dug wells and bore wells during March 2008 and analyzed for pH, electrical conductivity, temperature, major ions, and nitrate. Results suggest that, in 90% of groundwater samples, sodium and chloride are predominant cation and anion, respectively, and NaCl and CaMgCl are major water types in the study area. The groundwater quality in the study site is impaired by surface contamination sources, mineral dissolution, ion exchange, and evaporation. Nitrate, chloride, and sulfate concentrations strongly express the impact of surface contamination sources such as agricultural and domestic activities, on groundwater quality, and 13% of samples have elevated nitrate content (>45 mg/l as NO(3)). PHREEQC code and Gibbs plots were employed to evaluate the contribution of mineral dissolution and suggest that mineral dissolution, especially carbonate minerals, regulates water chemistry. Groundwater suitability for drinking usage was evaluated by the World Health Organization and Indian standards and suggests that 34% of samples are not suitable for drinking. Integrated groundwater suitability map for drinking purposes was created using drinking water standards based on a concept that if the groundwater sample exceeds any one of the standards, it is not suitable for drinking. This map illustrates that wells in zones 1, 2, 3, and 4 are not fit for drinking purpose. Likewise, irrigational suitability of groundwater in the study region was evaluated, and results suggest that 20% samples are not fit for irrigation. Groundwater suitability map for irrigation was also produced based on salinity and sodium hazards and denotes that wells mostly situated in zones 2 and 3 are not suitable for

A city scale study on the effects of intensive groundwater heat pump systems on heavy metal contents in groundwater.

PubMed

García-Gil, Alejandro; Epting, Jannis; Garrido, Eduardo; Vázquez-Suñé, Enric; Lázaro, Jesús Mateo; Sánchez Navarro, José Ángel; Huggenberger, P; Calvo, Miguel Ángel Marazuela

2016-12-01

As a result of the increasing use of shallow geothermal resources, hydraulic, thermal and chemical impacts affecting groundwater quality can be observed with ever increasing frequency (Possemiers et al., 2014). To overcome the uncertainty associated with chemical impacts, a city scale study on the effects of intensive geothermal resource use by groundwater heat pump systems on groundwater quality, with special emphasis on heavy metal contents was performed. Statistical analysis of geochemical data obtained from several field campaigns has allowed studying the spatiotemporal relationship between temperature anomalies in the aquifer and trace element composition of groundwater. The relationship between temperature and the concentrations of trace elements resulted in weak correlations, indicating that temperature changes are not the driving factor in enhancing heavy metal contaminations. Regression models established for these correlations showed a very low reactivity or response of heavy metal contents to temperature changes. The change rates of heavy metal contents with respect to temperature changes obtained indicate a low risk of exceeding quality threshold values by means of the exploitation regimes used, neither producing nor enhancing contamination significantly. However, modification of pH, redox potential, electrical conductivity, dissolved oxygen and alkalinity correlated with the concentrations of heavy metals. In this case, the change rates of heavy metal contents are higher, with a greater risk of exceeding threshold values. Copyright © 2016 Elsevier B.V. All rights reserved.

Data Validation Package: April 2016 Groundwater Sampling at the Falls City, Texas, Disposal Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jasso, Tashina; Widdop, Michael

Nine groundwater samples were collected at the Falls City, Texas, Disposal Site as specified in the March 2008 Long-Term Surveillance Plan for the US Department of Energy Falls City Uranium Mill Tailings Disposal Site, Falls City, Texas (DOE-LM/1602-2008). Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for US Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). The wells sampled included the cell performance monitoring wells (0709, 0858, 0880, 0906, and 0921) and the groundwater monitoring wells (0862, 0886, 0891, 0924, and 0963). A duplicate sample was collected from location 0891. Water levelsmore » were measured at each sampled well. Historically, cell performance monitoring wells 0908 and 0916 have not produced water and were confirmed as dry during this sampling event. These wells are completed above the saturated interval in the formation. Notable observations for time-concentration graphs in this report include: (1) uranium concentrations in well 0891 continue to increase; (2) the uranium concentration in well 0880 is higher than the 2015 value and lower than the 2014 value, and it remains within the range of historical values; and (3) uranium concentrations in the other sampled wells are below 2 mg/L and consistent with previous results.« less

Simulation of proposed increases in ground-water withdrawals on the Atlantic City 800-foot sand, New Jersey coastal plain

USGS Publications Warehouse

Pope, Daryll A.

2006-01-01

The confined Atlantic City 800-foot sand and the unconfined Kirkwood-Cohansey aquifer system (surficial aquifer) are major sources of water for southeastern New Jersey. Because of recent concerns about streamflow depletion resulting from ground-water withdrawals and the potential ecological effects on stream habitat in the area, the focus on future withdrawals has been shifted away from the surficial aquifer to the confined Atlantic City 800-foot sand until the effects of increased withdrawals from the surficial aquifer can be investigated. A study was conducted to evaluate the effects of seven proposed increases in ground-water withdrawals from the Atlantic City 800-foot sand and the Kirkwood-Cohansey aquifer system on the Atlantic City 800-foot sand. The proposed withdrawals are increases above the 2004 allocated rates (full allocation). The effects of full-allocation ground-water withdrawals and the cumulative effect of withdrawals for each of seven proposed increases in withdrawals were simulated using three previously published ground-water flow models: the New Jersey Coastal Plain Regional Aquifer System Analysis model, the Coastal Plain Optimization model, and a model of the Atlantic City 800-foot sand in Atlantic County, New Jersey. These models were used to simulate changes in water levels, the source supplying the increased ground-water flow, and the effects on saltwater movement towards production wells in Cape May County as a result of the proposed increased withdrawals at proposed or existing wells. The results of the simulations represent the effects of the proposed increase from full-allocation withdrawals to an additional 1,825 Mgal/yr (million gallons per year) from the Atlantic City 800-foot sand and an additional 1,045 Mgal/yr from the deep part of the Kirkwood-Cohansey aquifer system near the updip limit of the Atlantic City 800-foot sand. Most of the simulated decline in water levels in Atlantic County occurred as the result of the proposed

REMOVAL OF ORGANIC CONTAMINANTS FROM GROUNDWATER.

EPA Science Inventory

More are than lOO million Americans depend on groundwater as a source of drinking water. hree quarters of U.S. cities get their water supplies totally or in part from groundwater and one-third of the largest cities rely on groundwater for at least part of their potable water supp...

Green Infrastructure, Groundwater and the Sustainable City

NASA Astrophysics Data System (ADS)

Band, L. E.

2014-12-01

The management of water is among the most important attributes of urbanization. Provision of sufficient quantities and quality of freshwater, treatment and disposal of wastewater and flood protection are critical for urban sustainability. Over the last century, two major shifts in water management paradigms have occurred, the first to improve public health with the provision of infrastructure for centralized sanitary effluent collection and treatment, and the rapid drainage and routing of stormwater. A current shift in paradigm is now occurring in response to the unintended consequences of sanitary and stormwater management, which have degraded downstream water bodies and shifted flood hazard downstream. Current infrastructure is being designed and implemented to retain, rather than rapidly drain, stormwater, with a focus on infiltration based methods. In urban areas, this amounts to a shift in hydrologic behavior to depression focused recharge. While stormwater is defined as surface flow resulting from developed areas, an integrated hydrologic systems approach to urban water management requires treatment of the full critical zone. In urban areas this extends from the top of the vegetation and building canopy, to a subsurface depth including natural soils, fill, saprolite and bedrock. In addition to matric and network flow in fracture systems, an urban "karst" includes multiple generations of current and past infrastructure, which has developed extensive subsurface pipe networks for supply and drainage, enhancing surface/groundwater flows and exchange. In this presentation, Band will discuss the need to focus on the urban critical zone, and the development and adaptation of new modeling and analytical approaches to understand and plan green infrastructure based on surface/groundwater/ecosystem interactions, and implications for the restoration and new design of cities.

Heavy metals contamination in surface and groundwater supply of an urban city.

PubMed

Dixit, R C; Verma, S R; Nitnaware, V; Thacker, N P

2003-04-01

There is a continuous increase in the demand of water supply in cities due to the industrialization and growing population. This extra supply is generally met by groundwaters or nearby available surface waters. It may lead into incomplete treatment and substandard supply of drinking water. To ensure that the intake water derived from surface and groundwater is clear, palatable, neither corrosive nor scale forming, free from undesirable taste, odor and acceptable from aesthetic and health point of view, the final water quality at Delhi have been evaluated. The final water supply of four treatment plants and 80 tubewells at Delhi were surveyed in 2000-2001 for cadmium, chromium, copper, iron, lead, manganese, nickel, selenium and zinc. The levels of manganese, copper, selenium and cadmium were found marginally above the Indian Standards (IS) specification regulated for drinking water. The data was used to assess the final water quality supplied at Delhi.

Geophysical investigation to reveal the groundwater condition at new Borg El-Arab industrial city, Egypt

NASA Astrophysics Data System (ADS)

Basheer, Alhussein A.; Mansour, Khamis Q.; Abdalla, Mohammed A.

2014-12-01

New Borg El-Arab City, 60 km to the southwest of Alexandria City, is one of new industrial cities planned by the Egyptian Government through its program to transfer the population from the condensed Nile Delta to other places in Egypt. Because such a city includes airport, huge buildings, factories, and worker settlements, a careful geophysical study is planned to reveal the groundwater condition. This will help in defining the places of wells that are supposed to be drilled. Therefore more industrial and agricultural activities will be flourished. The present study embraces Vertical Electrical Soundings (VES'es) and Time Domain Electromagnetic sounding (TEM) to investigate the study area. The study aims to delineate the main subsurface conditions from the viewpoint of groundwater location, depth and water quality. Analysis and interpretation of the obtained results reveal that the subsurface consists of five geoelectrical layers with a gentle general slope toward the Mediterranean Sea. The third and the fourth layers in the succession are suggested to be the two water bearing formations of which the third layer is saturated with fresh water overlying saline water at the bottom of the fourth one. It is worth mentioning that the fresh water depth varies between 50 and 354 m under the ground surface. The thickness of the fresh water aquifer varies from 9.5 to 66 m; and the saline water depth varies between 116 and 384 m below the ground surface, the thickness of saline water aquifer differs from 34 to 90.5 m.

Temporal-Spatial Evolution of Groundwater Nitrogen Pollution Over Seven Years in a Highly Urbanized City in the Southern China.

PubMed

He, Xiaorui; Qian, Jiazhong; Liu, Zufa; Lu, Yuehan; Ma, Lei; Zhao, Weidong; Kang, Bo

2017-12-01

Understanding the temporospatial variation in nitrogen pollution in groundwater and the associated controlling factors is important to establish management practices that ensure sustainable use of groundwater. In this study, we analyzed inorganic nitrogen content (nitrate, nitrite, and ammonium) in 1164 groundwater samples from shallow, middle-deep, and deep aquifers in Zhanjiang, a highly urbanized city in the southern China. Our data span a range of 7 years from 2005 to 2011. Results show that shallow aquifers had been heavily contaminated by nitrate and ammonium. Temporal patterns show that N contamination levels remained high and relatively stable over time in urban areas. This stability and high concentration is hypothesized as a result of uncontrolled, illicit sewer discharges from nearby business facilities. Groundwater in urban land and farmland displays systematic differences in geochemical characteristics. Collectively, our findings demonstrate the importance of continuously monitoring groundwater quality and strictly regulating sewage discharges in Zhanjiang.

Groundwater vulnerability assessment for organic compounds: fuzzy multi-criteria approach for Mexico city.

PubMed

Mazari-Hiriart, Marisa; Cruz-Bello, Gustavo; Bojórquez-Tapia, Luis A; Juárez-Marusich, Lourdes; Alcantar-López, Georgina; Marín, Luis E; Soto-Galera, Ernesto

2006-03-01

This study was based on a groundwater vulnerability assessment approach implemented for the Mexico City Metropolitan Area (MCMA). The approach is based on a fuzzy multi-criteria procedure integrated in a geographic information system. The approach combined the potential contaminant sources with the permeability of geological materials. Initially, contaminant sources were ranked by experts through the Analytic Hierarchy Process. An aggregated contaminant sources map layer was obtained through the simple additive weighting method, using a scalar multiplication of criteria weights and binary maps showing the location of each source. A permeability map layer was obtained through the reclassification of a geology map using the respective hydraulic conductivity values, followed by a linear normalization of these values against a compatible scale. A fuzzy logic procedure was then applied to transform and combine the two map layers, resulting in a groundwater vulnerability map layer of five classes: very low, low, moderate, high, and very high. Results provided a more coherent assessment of the policy-making priorities considered when discussing the vulnerability of groundwater to organic compounds. The very high and high vulnerability areas covered a relatively small area (71 km(2) or 1.5% of the total study area), allowing the identification of the more critical locations. The advantage of a fuzzy logic procedure is that it enables the best possible use to be made of the information available regarding groundwater vulnerability in the MCMA.

Vertical groundwater flow in Permo-Triassic sediments underlying two cities in the Trent River Basin (UK)

NASA Astrophysics Data System (ADS)

Taylor, R. G.; Cronin, A. A.; Trowsdale, S. A.; Baines, O. P.; Barrett, M. H.; Lerner, D. N.

2003-12-01

The vertical component of groundwater flow that is responsible for advective penetration of contaminants in sandstone aquifers is poorly understood. This lack of knowledge is of particular concern in urban areas where abstraction disrupts natural groundwater flow regimes and there exists an increased density of contaminant sources. Vertical hydraulic gradients that control vertical groundwater flow were investigated using bundled multilevel piezometers and a double-packer assembly in dedicated boreholes constructed to depths of between 50 and 92 m below ground level in Permo-Triassic sediments underlying two cities within the Trent River Basin of central England (Birmingham, Nottingham). The hydrostratigraphy of the Permo-Triassic sediments, indicated by geophysical logging and hydraulic (packer) testing, demonstrates considerable control over observed vertical hydraulic gradients and, hence, vertical groundwater flow. The direction and magnitude of vertical hydraulic gradients recorded in multilevel piezometers and packers are broadly complementary and range, within error, from +0.1 to -0.7. Groundwater is generally found to flow vertically toward transmissive zones within the hydrostratigraphical profile though urban abstraction from the Sherwood Sandstone aquifer also influences observed vertical hydraulic gradients. Bulk, downward Darcy velocities at two locations affected by abstraction are estimated to be in the order of several metres per year. Consistency in the distribution of hydraulic head with depth in Permo-Triassic sediments is observed over a one-year period and adds support the deduction of hydrostratigraphic control over vertical groundwater flow.

Fluoride enrichment in groundwater of semi-arid urban area: Khan Younis City, southern Gaza Strip (Palestine)

NASA Astrophysics Data System (ADS)

Abu Jabal, Mohamed Shaban; Abustan, Ismail; Rozaimy, Mohd Remy; Al-Najar, Hussam

2014-12-01

The aim of this study is to determine fluoride enhancement in the groundwater of semi-arid urban area of Khan Younis City, southern Gaza Strip. Physicochemical data for a total of 200 groundwater samples were analyzed. The fluoride concentrations were varied from 0.3 to 6.45 mg/L with average value of 2.87 mg/L. Correlations between fluorides with other measured ions were relatively observed, negative correlation with calcium and the positive correlation with pH, bicarbonate and sodium increase the dissolution/solubility of fluoride bearing minerals, leading to fluoride leaching into the groundwater. Fluoride enrichment in the groundwater of the area is due to water hydrochemistry, mineral-water interaction (mainly calcite and fluorite), fluorite resulted from fluorapatite dissolution. The saturation indexes evaluation indicated that 42% of the samples are over saturated with respect to calcite and 35.5% under saturated with respect to fluorite, while 40.5% approached equilibrium with respect to both calcite and fluorite. At fluoride concentrations of less than 2.2 mg/L fluorite saturation indexes show under-saturation condition for fluorite and at higher fluoride concentrations show near saturation condition.

Evapotranspiration Dynamics and Effects on Groundwater Recharge and Discharge at the Tuba City, Arizona, Disposal Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

The U.S. Department of Energy Office of Legacy Management is evaluating groundwater flow and contaminant transport at a former uranium mill site near Tuba City, Arizona. We estimated effects of temporal and spatial variability in evapotranspiration (ET) on recharge and discharge within a groundwater model domain (GMD) as part of this evaluation. We used remote sensing algorithms and precipitation (PPT) data to estimate ET and the ET/PPT ratios within the 3531 hectare GMD. For the period from 2000 to 2012, ET and PPT were nearly balanced (129 millimeters per year [mm yr -1] and 130 mm yr -1, respectively; ET/PPTmore » = 0.99). However, seasonal and annual variability in ET and PPT were out of phase, and spatial variability in vegetation differentiated discharge and recharge areas within the GMD. Half of ET occurred during spring and early summer when PPT was low, and about 70% of PPT arriving in fall and winter was discharged as plant transpiration in the spring and summer period. Vegetation type and health had a significant effect on the site water balance. Plant cover and ET were significantly higher (1) during years of lighter compared to years of heavier grazing pressure, and (2) on rangeland protected from grazing compared to rangeland grazed by livestock. Heavy grazing increased groundwater recharge (PPT > ET over the 13-year period). Groundwater discharge (ET > PPT over the 13-year period) was highest in riparian phreatophyte communities but insignificant in desert phreatophyte communities impacted by heavy grazing. Grazing management in desert upland and phreatophyte communities may result in reduced groundwater recharge, increased groundwater discharge, and could be used to influence local groundwater flow.« less

Statistical analysis of lake levels and field study of groundwater and surface-water exchanges in the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015: Chapter A of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

USGS Publications Warehouse

Jones, Perry M.; Trost, Jared J.; Diekoff, Aliesha L.; Rosenberry, Donald O.; White, Eric A.; Erickson, Melinda L.; Morel, Daniel L.; Heck, Jessica M.

2016-10-19

Water levels declined from 2003 to 2011 in many lakes in Ramsey and Washington Counties in the northeast Twin Cities Metropolitan Area, Minnesota; however, water levels in other northeast Twin Cities Metropolitan Area lakes increased during the same period. Groundwater and surface-water exchanges can be important in determining lake levels where these exchanges are an important component of the water budget of a lake. An understanding of groundwater and surface-water exchanges in the northeast Twin Cities Metropolitan Area has been limited by the lack of hydrologic data. The U.S. Geological Survey, in cooperation with the Metropolitan Council and Minnesota Department of Health, completed a field and statistical study assessing lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes. This report documents the analysis of collected hydrologic, water-quality, and geophysical data; and existing hydrologic and geologic data to (1) assess the effect of physical setting and climate on lake-level fluctuations of selected lakes, (2) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (3) estimate general ages for waters extracted from the wells, and (4) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake. Statistical analyses of lake levels during short-term (2002–10) and long-term (1925–2014) periods were completed to help understand lake-level changes across the northeast Twin Cities Metropolitan Area. Comparison of 2002–10 lake levels to several landscape and geologic characteristics explained variability in lake-level changes for 96 northeast Twin Cities Metropolitan Area lakes. Application of several statistical methods determined that (1) closed-basin lakes (without an active outlet) had larger lake-level declines than flow-through lakes with an outlet; (2

Factors controlling groundwater quality in the Yeonjegu District of Busan City, Korea, using the hydrogeochemical processes and fuzzy GIS.

PubMed

Venkatramanan, Senapathi; Chung, Sang Yong; Selvam, Sekar; Lee, Seung Yeop; Elzain, Hussam Eldin

2017-10-01

The hydrogeochemical processes and fuzzy GIS techniques were used to evaluate the groundwater quality in the Yeonjegu district of Busan Metropolitan City, Korea. The highest concentrations of major ions were mainly related to the local geology. The seawater intrusion into the river water and municipal contaminants were secondary contamination sources of groundwater in the study area. Factor analysis represented the contamination sources of the mineral dissolution of the host rocks and domestic influences. The Gibbs plot exhibited that the major ions were derived from the rock weathering condition. Piper's trilinear diagram showed that the groundwater quality was classified into five types of CaHCO 3 , NaHCO 3 , NaCl, CaCl 2 , and CaSO 4 types in that order. The ionic relationship and the saturation mineral index of the ions indicated that the evaporation, dissolution, and precipitation processes controlled the groundwater chemistry. The fuzzy GIS map showed that highly contaminated groundwater occurred in the northeastern and the central parts and that the groundwater of medium quality appeared in most parts of the study area. It suggested that the groundwater quality of the study area was influenced by local geology, seawater intrusion, and municipal contaminants. This research clearly demonstrated that the geochemical analyses and fuzzy GIS method were very useful to identify the contaminant sources and the location of good groundwater quality.

Ground-water flow and quality in the Atlantic City 800-foot sand, New Jersey

USGS Publications Warehouse

McAuley, Steven D.; Barringer, Julia L.; Paulachok, Gary N.; Clark, Jeffrey S.; Zapecza, Otto S.

2001-01-01

reported for water in a former supply well in southern Cape May County. These data indicate that salty water has moved inland in Cape May County. Analysis of the chloride-concentration data indicates that ground water with a chloride concentration of 250 mg/L is within 4 miles of supply wells in Stone Harbor, Cape May County, and is about 10 miles offshore of supply wells near Atlantic City. Results of numerical simulations of ground-water flow were analyzed to determine the effects of four water-supply alternatives on water levels, the flow budget, and potential saltwater movement toward pumping centers during 1986-2040. In the supply alternatives, pumpage is (1) held constant at 1986 rates of pumpage; (2) increased by 35 percent at 1986 locations; (3) increased by 35 percent, but with relocation of some supply wells further inland; and (4) increased by 35 percent but with some of the increase derived from inland wells tapping the Kirkwood-Cohansey aquifer system rather than the Atlantic City 800-foot sand. Inland relocation of supply wells closer to the updip limit of the overlying confining unit results in the smallest decline in water levels and the smallest rate of ground-water flow between the offshore location of salty water and coastal supply wells. Increased pumpage from coastal supply wells results in the greatest water-level declines and the greatest increase in the rate of ground-water flow from offshore to coastal wells. Flow of undesirable salty ground water from offshore locations remains nearly the same as for current (1986) conditions when pumping rates do not change, and the flow-rate increase is smallest for the relocated pumpage (fourth) alternative. In comparing the two conditions of a 35-percent increase in pumpage, the flow from undesirable salty water positions is lessened and flow from the unconfined aquifer is increased when some of the pumping centers are relocated farther inland. Ground water from the 250-mg/L isochlor position does not reach

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

NASA Astrophysics Data System (ADS)

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.

Map showing ground-water conditions in the Kaibito and Tuba City areas, Coconino and Navajo counties, Arizona, 1978

USGS Publications Warehouse

Farrar, C.D.

1978-01-01

The Kaibito and Tuba City areas include about 2,500 square miles in north-central Arizona. Ground water is obtained from the N aquifer and from alluvium. The N aquifer consists of Navajo Sandstone, Kayenta Formation, Moenave Formation, and the Lukachukai Member of the Wingate Sandstone. The main source of ground water is the Navajo Sandstone. Ground-water development has been slight in the areas. In 1977 the estimated ground-water withdrawals were about 350 acre-feet in the Kaibito area and 650 acre-feet in the Tuba City area. Water levels ranged from flowing at the land surface to 1,360 feet below the land surface. The chemical quality of the water in the N aquifer does not vary greatly in the areas. Dissolved-solids concentrations in the water range from 101 to 669 milligrams per liter but generally are less than 300 milligrams per liter. Along some of the valleys in the Kaibito and Tuba City areas, the alluvium yields water to many shallow dug wells. The water levels generally are from 5 to 15 feet below the land surface. Dissolved-solids concentrations in water from the alluvium usually are less than 600 milligrams per liter. Information shown on the map (scale 1:125,000) includes depth to water, altitude of the water level, and specific conductance and fluoride concentrations. (Woodard-USGS)

Hydro-chemical Survey and Quantifying Spatial Variations of Groundwater Quality in Dwarka, Sub-city of Delhi, India

NASA Astrophysics Data System (ADS)

Rawat, Kishan Singh; Tripathi, Vinod Kumar

2015-06-01

Hydrological and geological aspect of the region play vital role for water resources utilization and development. Protection and management of groundwater resources are possible with the study of spatio-temporal water quality parameters. The study was undertaken to assess the deterioration in groundwater quality, through systematic sampling during post monsoon seasons of the year 2008 by collecting water samples from thirty bore wells located in Dwarka, sub-city of Delhi, India. The average concentrations of groundwater quality parameters namely Calcium (Ca2+), Magnesium (Mg2+), Nitrate (NO3 -), Chloride (Cl-), sulphate (SO4 2-), total hardness (TH), total dissolved solids (TDS), and electrical conductivity were 300, 178, 26.5, 301, 103, 483, 1042 mg/l and 1909 μS/cm respectively. Estimated physico-chemical parameters revealed that 7 % of the groundwater samples shown nitrate concentrations higher than safe limit prescribed by World Health Organization (WHO). Groundwater quality the in study region was poor due to come out result that NO3 - concentration exceeding the threshold value of 50 mg/l, and main cause is disposal of sewage and animal wastes to Najafgarh drain. Dominant cations are Mg2+, Ca2+ and anions are SO4 2- and Cl-. The abundance of the major ions in groundwater is in the order: Ca2+ > Mg2+ and Cl- > SO4 2- > NO3. TH have strong correlation with Ca2+ (r = 0.81), Mg2+ (r = 0.82), Cl- (r = 0.86) but poor correlation with TDS (r = 0.52). Knowledge of correlation values between water quality parameters is helpful to take decision of appropriate management strategy for controlling groundwater pollution.

The Subsidence Signature Due To Groundwater Extraction as Inferred from Remote Sensing Data in Mexico City

NASA Astrophysics Data System (ADS)

Patel, V.; Chen, J.

2015-12-01

Mexico City is facing a severe water shortage; current drought conditions in the city have led to an increase in the demand for groundwater, the pumping of which can cause significant land subsidence. In this study we explored what new information interferometric synthetic aperture radar (InSAR) data collected by the TerraSAR-X satellite could bring to water resource managers in the city so that they can efficiently and sustainably allocate water resources. Previous work done over Mexico City indicates that InSAR can be used to detect deformation due to groundwater pumping. Cabral-Cano et al. (2008) processed InSAR data acquired from ERS between 1996-2000 and from ENVISAT between 2003-2005. They compared the deformation map to geology maps of the region with information obtained by seismic methods. They found that a spatial correlation between the land deformation and the presence of young lacustrine clay beds, which indicate that the subsidence was caused by fluid pressure loss in the aquitard. They also concluded that the subsidence, for the most part, had no seasonal variation and continues to occur at near-constant, high rates. TerraSAR-­X satellite data is known to be more sensitive to small deformations than the data from satellites used in previous studies in the region because of its frequent revisit cycle, short wavelength, and accurate orbital information. For this project, we derived long sequences of crustal deformation time series from TerraSAR-­X data between May 2011 and December 2012 using the Small Baseline Subset (SBAS) method. The resulting time series was then compared to GPS data for calibration and validation. We observed a long-term deformation that was similar to those found in previous studies. The next step in our work is to determine whether the increased sensitivity of the TerraSAR-­X data allows us to detect a seasonal deformation pattern over the study area.

Impacts of at-site wastewater disposal systems on the groundwater aquifer in arid regions: case of Sfax City, Southern Tunisia

NASA Astrophysics Data System (ADS)

Chamtouri, Ibticem; Abida, Habib; Khanfir, Hafedh; Bouri, Salem

2008-09-01

Groundwater in Sfax City (Tunisia) has been known since the beginning of the century for its deterioration in quality, as a result of wastewater recharge into the aquifer. An average value of 12 × 106 m3 of untreated wastewater reaches the groundwater aquifer each year. This would result not only in a chemical and biological contamination of the groundwater, but also in an increase of the aquifer piezometric level. Quantitative impacts were evaluated by examining the groundwater piezometric level at 57 surface wells and piezometers. The survey showed that, during the last two decades, the groundwater level was ever increasing in the urban area with values reaching 7 m in part; and decreasing in Sidi Abid (agricultural area) with values exceeding -3 m. Groundwater samples for chemical and microbial analysis were collected from 41 wells spread throughout the study area. Results showed significantly elevated levels of sodium, chlorides, nitrates and coliform bacteria all over the urban area. High levels (NO3: 56-254 mg/l; Na >1,500 mg/l; Coliforms >30/100 ml) can be related to more densely populated areas with a higher density of pit latrine and recharge wells. Alternatively results showed a very variable chemical composition of groundwater, e.g. electrical conductivity ranges from 4,040 to19,620 μs/cm and the dry residual varies between 1.4 and 14 g/l with concentrations increasing downstream. Furthermore a softening of groundwater in Set Ezzit (highly populated sector) was observed.

Risk screening for exposure to groundwater pollution in a wastewater irrigation district of the Mexico City region.

PubMed

Downs, T J; Cifuentes-García, E; Suffet, I M

1999-07-01

Untreated wastewater from the Mexico City basin has been used for decades to irrigate cropland in the Mezquital Valley, State of Hidalgo, Mexico. Excess irrigation water recharges the near-surface aquifer that is used as a domestic water supply source. We assessed the groundwater quality of three key groundwater sources of domestic water by analyzing for 24 trace metals, 67 target base/neutral/acid (BNA) organic compounds, nontarget BNA organics, 23 chlorinated pesticides, 20 polychlorinated biphenyls, and nitrate, as well as microbiological contaminants--coliforms, Vibrio cholerae, and Salmonella. Study participants answered a questionnaire that estimated ingestion and dermal exposure to groundwater; 10% of the sample reported frequent diarrhea and 9% reported persistent skin irritations. Detection of V. cholerae non-01 in surface waters at all sites suggested a potential risk (surrogate indicator present) of diarrheal disease for canal and river bathers by accidental ingestion, as well as potential Vibrio contamination of near-surface groundwater and potential cholera risk, magnified by lapses in disinfection. High total coliform levels in surface water and lower levels in groundwater at all sites indicated fecal contamination and a potential risk of gastrointestinal disease in populations exposed to inadequately disinfected groundwater. Using chemical criteria, no significant risk from ingestion or dermal contact was identified at the method detection limits at any site, except from nitrate exposure: infants and young children are at risk from methemoglobinemia at all sites. Results suggest that pathogen risk interventions are a priority, whereas nitrate risk needs further characterization to determine if formal treatment is needed. The risks exist inside and outside the irrigation district. The method was highly cost-effective.

Risk screening for exposure to groundwater pollution in a wastewater irrigation district of the Mexico City region.

PubMed Central

Downs, T J; Cifuentes-García, E; Suffet, I M

1999-01-01

Untreated wastewater from the Mexico City basin has been used for decades to irrigate cropland in the Mezquital Valley, State of Hidalgo, Mexico. Excess irrigation water recharges the near-surface aquifer that is used as a domestic water supply source. We assessed the groundwater quality of three key groundwater sources of domestic water by analyzing for 24 trace metals, 67 target base/neutral/acid (BNA) organic compounds, nontarget BNA organics, 23 chlorinated pesticides, 20 polychlorinated biphenyls, and nitrate, as well as microbiological contaminants--coliforms, Vibrio cholerae, and Salmonella. Study participants answered a questionnaire that estimated ingestion and dermal exposure to groundwater; 10% of the sample reported frequent diarrhea and 9% reported persistent skin irritations. Detection of V. cholerae non-01 in surface waters at all sites suggested a potential risk (surrogate indicator present) of diarrheal disease for canal and river bathers by accidental ingestion, as well as potential Vibrio contamination of near-surface groundwater and potential cholera risk, magnified by lapses in disinfection. High total coliform levels in surface water and lower levels in groundwater at all sites indicated fecal contamination and a potential risk of gastrointestinal disease in populations exposed to inadequately disinfected groundwater. Using chemical criteria, no significant risk from ingestion or dermal contact was identified at the method detection limits at any site, except from nitrate exposure: infants and young children are at risk from methemoglobinemia at all sites. Results suggest that pathogen risk interventions are a priority, whereas nitrate risk needs further characterization to determine if formal treatment is needed. The risks exist inside and outside the irrigation district. The method was highly cost-effective. Images Figure 1 PMID:10398590

Potentiometric Surfaces and Changes in Groundwater Levels in Selected Bedrock Aquifers in the Twin Cities Metropolitan Area, March-August 2008 and 1988-2008

USGS Publications Warehouse

Sanocki, Christopher A.; Langer, Susan K.; Menard, Jason C.

2008-01-01

This report depicts potentiometric surfaces and groundwater- level changes in three aquifers that underlie the seven-county Twin Cities Metropolitan Area. Approximately 350 groundwater levels were measured in wells from the three aquifers-the Prairie du Chien-Jordan, the Franconia-Ironton-Galesville, and the Mount Simon-Hinckley aquifers-in March and August of 2008. The report presents maps, associated data tables, and 22 geographic information system datasets. The maps presented in this report show the potentiometric surfaces in March and August of 2008 for all three aquifers, groundwater-level changes from March to August 2008 for each aquifer, and revised potentiometric-surface contours for the winter of 1988-89 for the Prairie du Chien-Jordan and the Mount Simon-Hinckley aquifers, and the estimated long-term (winter of 1988-89 to March 2008) groundwater-level changes for the Prairie du Chien-Jordan and Mount Simon-Hinckley aquifers. This report documents the methods used to construct the maps and provides a context for the period of the measurements. Although withdrawal demand is increasing in the Twin Cities Metropolitan area, particularly in the Prairie du Chien-Jordan aquifer, year-to-year changes in withdrawals can be substantial, and the relation between potentiometric surfaces in the major aquifers and year-to-year withdrawals is not well established. The estimated long-term (19-year) groundwater-level changes for the Prairie du Chien-Jordan and Mount Simon-Hinckley aquifers have not been large based on data and maps produced during this study, despite the large seasonal fluctuations shown by the March and August 2008 synoptic measurements.

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

USGS Publications Warehouse

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

2013-01-01

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

Impacts of urbanization and climate on groundwater in a growing Africa city: the case of Ouagadougou (Burkina Faso)

NASA Astrophysics Data System (ADS)

Mouhouddine, Alihoumadi; Yameogo, Suzanne; Genthon, Pierre; Travi, Yves

2016-04-01

African cities are presently facing the combined impacts of growing urbanization and climate change. In several instances; providing safe drinking water for all is still a challenge, especially for cities located on basement aquifers, were groundwater is scarce. Here we assess the effects of climate change and land use change on groundwater amount and quality in the main city of Ouagadougou (Burkina Faso) taking advantage of the CIEH borehole, where a mostly continuous record lasts since 1978. This record spans most of the Great African Drought (1970-1990) and recovery from the Drought since the 2000s. A piezometric network of 14 wells and boreholes was setup around the CIEH borehole and monitored during the 2013-2014 hydrologic year. The piezometric network spans an old settlement, the Ouagadougou University, a vegetable gardening area and a natural forested area. Water balance estimates are provided by a 1D box model. The study area, although it lies partly on an old settlement in Ouagadougou and on the University area, presents a rather uniform runoff coefficient of 22% and ET amounting to 80-90 % of rainfall, which usually characterizes natural areas. It is suspected that the almost absence of asphalted surfaces, the presence of trees and flow of rainwater from roofs toward bare soils or sumps could be responsible of this budget. However, the two wells located in the forested Bangr Weogo recreational area are characterized by almost no runoff and a nearly 100 % ET. While drinking water can be pumped in several places in the city of Ouagadougou, chemical major analyses show that two mechanisms impact groundwater quality during the rainy season: (i) rise of the water table at pit latrine level, mainly in old settlements, and entrainment of harmful substances from soil to the aquifer in gardening area near some artisan activities. The CIEH borehole is not fully representative of its neighboring area since (i) it lies in a piezometric low, (ii) it presents the

Temporal and spatial variation of groundwater in quantity and quality in sand dune at coastal region, Kamisu city, central Japan.

NASA Astrophysics Data System (ADS)

Umei, Yohei; Tsujimura, Maki; Sakakibara, Koichi; Watanabe, Yasuto; Minema, Motomitsu

2016-04-01

The role of groundwater in integrated water management has become important in recent 10 years, though the surface water is the major source of drinking water in Japan. Especially, it is remarked that groundwater recharge changed due to land cover change under the anthropogenic and climatic condition factors. Therefore, we need to investigate temporal and spatial variation of groundwater in quantity and quality focusing on the change during recent 10-20 years in specific region. We performed research on groundwater level and quality in sand dune at coastal region facing Pacific Ocean, Kamisu city, Ibaraki Prefecture, which have been facing environmental issues, such as land cover change due to soil mining for construction and urbanization. We compared the present situation of groundwater with that in 2000 using existed data to clarify the change of groundwater from 2000 to 2015. The quality of water is dominantly characterized by Ca2+-HCO3- in both 2000 and 2015, and nitrate was not observed in 2015, though it was detected in some locations in 2000. This may be caused by improvement of the domestic wastewater treatment. The topography of groundwater table was in parallel with that of ground surface in 2015, same as that in 2000. However, a depletion of groundwater table was observed in higher elevation area in 2015 as compared with that in 2000, and this area corresponds to the locations where the land cover has changed due to soil mining and urbanization between 2015 and 2000. In the region of soil mining, the original soil is generally replaced by impermeable soil after mining, and this may cause a decrease of percolation and net groundwater recharge, thus the depletion of groundwater table occurred after the soil mining.

Assessment of groundwater vulnerability using DRASTIC Model and GIS : A case study of two sub-districts in Banda Aceh city, Indonesia

NASA Astrophysics Data System (ADS)

Machdar, I.; Zulfikar, T.; Rinaldi, W.; Alfiansyah, Y.

2018-03-01

This present study assessed the groundwater vulnerability to protect aquifer in part of Banda Aceh City (the sub-district of Banda Raya and Lueng Bata), Indonesia. The study provides an additional tool for local planner and manager as for managing and protecting groundwater resources. The study area covers 1,164 ha and total population was estimated around 50,000 inhabitants. DRASTIC model in a GIS (Geographic Information System) environment was used in this study to generate vulnerability maps. The maps were created by applied seven criteria as standard in DRASTIC approach, i.e. depth to groundwater, recharge, aquifer type, soil properties, topography, impact of the vadose zone, and hydraulic conductivity. The vulnerability maps provides five categories of vulnerability, i.e. less, low, medium, high, and very high. It was found that the village areas, labelled with the high groundwater pollution potential, are mainly in the area of Lamlagang and the part of Geuce Kaye Jatoe and Geuce Komplek (Banda Raya sub-district) and the part of Batoh and Suka Damai (Lueng Bata sub-distric) This study prompts that the DRASTIC approach is helpful and efficient instrument for assessing groundwater vulnerability. The generated map can be an effective tool for local administrators in groundwater management as well.

Urban heat islands in the subsurface of German cities

NASA Astrophysics Data System (ADS)

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

2012-04-01

In the subsurface of many cities there are widespread and persistent thermal anomalies (subsurface urban heat islands) that result in a warming of urban aquifers. The reasons for this heating are manifold. 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 German cities, such as Berlin, Munich, Cologne and Karlsruhe, 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 superposition of various heat sources results in an extensive temperature increase. In many cases, the maximum temperature elevation is found close to the city centre. Regional groundwater temperature differences between the city centre 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 Karlsruhe, for example, also indicates a

Development of a Conductivity Sensor for Monitoring Groundwater Resources to Optimize Water Management in Smart City Environments.

PubMed

Parra, Lorena; Sendra, Sandra; Lloret, Jaime; Bosch, Ignacio

2015-08-26

The main aim of smart cities is to achieve the sustainable use of resources. In order to make the correct use of resources, an accurate monitoring and management is needed. In some places, like underground aquifers, access for monitoring can be difficult, therefore the use of sensors can be a good solution. Groundwater is very important as a water resource. Just in the USA, aquifers represent the water source for 50% of the population. However, aquifers are endangered due to the contamination. One of the most important parameters to monitor in groundwater is the salinity, as high salinity levels indicate groundwater salinization. In this paper, we present a specific sensor for monitoring groundwater salinization. The sensor is able to measure the electric conductivity of water, which is directly related to the water salinization. The sensor, which is composed of two copper coils, measures the magnetic field alterations due to the presence of electric charges in the water. Different salinities of the water generate different alterations. Our sensor has undergone several tests in order to obtain a conductivity sensor with enough accuracy. First, several prototypes are tested and are compared with the purpose of choosing the best combination of coils. After the best prototype was selected, it was calibrated using up to 30 different samples. Our conductivity sensor presents an operational range from 0.585 mS/cm to 73.8 mS/cm, which is wide enough to cover the typical range of water salinities. With this work, we have demonstrated that it is feasible to measure water conductivity using solenoid coils and that this is a low cost application for groundwater monitoring.

Development of a Conductivity Sensor for Monitoring Groundwater Resources to Optimize Water Management in Smart City Environments

PubMed Central

Parra, Lorena; Sendra, Sandra; Lloret, Jaime; Bosch, Ignacio

2015-01-01

The main aim of smart cities is to achieve the sustainable use of resources. In order to make the correct use of resources, an accurate monitoring and management is needed. In some places, like underground aquifers, access for monitoring can be difficult, therefore the use of sensors can be a good solution. Groundwater is very important as a water resource. Just in the USA, aquifers represent the water source for 50% of the population. However, aquifers are endangered due to the contamination. One of the most important parameters to monitor in groundwater is the salinity, as high salinity levels indicate groundwater salinization. In this paper, we present a specific sensor for monitoring groundwater salinization. The sensor is able to measure the electric conductivity of water, which is directly related to the water salinization. The sensor, which is composed of two copper coils, measures the magnetic field alterations due to the presence of electric charges in the water. Different salinities of the water generate different alterations. Our sensor has undergone several tests in order to obtain a conductivity sensor with enough accuracy. First, several prototypes are tested and are compared with the purpose of choosing the best combination of coils. After the best prototype was selected, it was calibrated using up to 30 different samples. Our conductivity sensor presents an operational range from 0.585 mS/cm to 73.8 mS/cm, which is wide enough to cover the typical range of water salinities. With this work, we have demonstrated that it is feasible to measure water conductivity using solenoid coils and that this is a low cost application for groundwater monitoring. PMID:26343653

Ground-water data: Beaver, Escalante, Cedar City, and Parowan Valleys; parts of Washington, Iron, Beaver, and Millard Counties, Utah

USGS Publications Warehouse

Sandberg, George W.

1963-01-01

This report is intended to serve two purposes: (1) to make available to the public basic ground-water data useful in planning and studying development of water resources, and (2) to supplement an interpretive report that will be published later.Records were collected during the period 1935-62 by the U.S. Geological Survey in cooperation with the Utah State Engineer as part of the investigation of ground-water conditions in the Beaver, Escalante, Cedar City, and Parowan Walleys. This report will include records collected subsequent to data published in earlier reports listed in the bibliography. The interpretive material will be published in a companion report by George W. Sandberg.This report is most useful in predicting conditions likely to be found in areas that are being considered as well sites. The person considering the new well can spot the proposed site on plate 1 and examine the records of nearby wells as shown in the tables and figure 2. From table 1 he can note such things as diameter, depth, water level, yield, use of water, and depth to aquifers in wells in the vicinity, and from the well logs in table 3 he can note the type of material that yields water to the wells. Table 2 gives several years record of yields and pumping levels of irrigation wells, and in table 4 are the chemical analyses of water from wells and springs. Figure 2 shows the historic fluctuations and trends of water levels in the four valleys. If the reader decides from his examination that conditions are favorable, he can place an application to drill a well with the State Engineer. During the past several years, however, the State Engineer has rejected new applications to appropriate water in major portions of Beaver Valley, Milford and Beryl-Enterprise districts in Escalante Valley, and Cedar City Valley. Anyone seeking to initiate a new ground-water right in any of these areas should obtain information from the State Engineer's Office in either Salt Lake City or Cedar City to

Sinking Coastal Cities

NASA Astrophysics Data System (ADS)

Erkens, G.; Stuurman, R.; De Lange, G.; Bucx, T.; Lambert, J.

2014-12-01

In many coastal cities land subsidence now exceeds absolute sea level rise up to a factor of ten. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will continue to sink, even below sea level. The ever increasing industrial and domestic demand for water in these cities results in excessive groundwater extraction, causing severe subsidence. In addition, coastal cities are often faced with larger natural subsidence, as they are built on thick sequences of soft soil. The impacts of subsidence are further exacerbated by climate-induced sea level rise. Land subsidence results in two types damage: foremost it increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. Secondly, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs of roads and transportation networks, sewage systems, buildings and foundations. The total damage worldwide is estimated at billions of dollars annually. To survey the extent of groundwater associated subsidence, we conducted a quick-assessment of subsidence in a series of mega-cities (Jakarta, Ho Chi Minh City, Dhaka, New Orleans and Bangkok). For each city research questions included: what are the main causes, how much is the current subsidence rate and what are predictions, where are the vulnerable areas, what are the impacts and risks, how can adverse impacts can be mitigated or compensated for, and what governmental bodies are involved and responsible to act? Using the assessment, this paper discusses subsidence modelling and measurement results from the selected cities. The focus is on the importance of delayed settlement after increases in hydraulic heads, the role of the subsurface composition for subsidence rates and best practice solutions for subsiding cities. For the latter, urban (ground)water management, adaptive flood risk management

Contributing recharge areas, groundwater travel time, and groundwater water quality of the Missouri River alluvial aquifer near the City of Independence, Missouri, well field, 1997-2008

USGS Publications Warehouse

Kelly, Brian P.

2011-01-01

The City of Independence, Missouri, operates a well field in the Missouri River alluvial aquifer. Contributing recharge areas (CRA) were last determined for the well field in 1996. Since that time, eight supply wells have been installed in the area north of the Missouri River and well pumpage has changed for the older supply wells. The change in pumping has altered groundwater flow and substantially changed the character of the CRA and groundwater travel times to the supply wells. The U.S Geological Survey, in a cooperative study with the City of Independence, Missouri, simulated steady-state groundwater flow for 2007 well pumpage, average annual river stage, and average annual recharge. Particle-tracking analysis was used to determine the CRA for supply wells and monitoring wells, and the travel time from recharge areas to supply wells, recharge areas to monitoring wells, and monitoring wells to supply wells. The simulated CRA for the well field is elongated in the upstream direction and extends to both sides of the Missouri River. Groundwater flow paths and recharge areas estimated for monitoring wells indicate the origin of water to each monitoring well, the travel time of that water from the recharge area, the flow path from the vicinity of each monitoring well to a supply well, and the travel time from the monitoring well to the supply well. Monitoring wells 14a and 14b have the shortest groundwater travel time from their contributing recharge area of 0.30 years and monitoring well 29a has the longest maximum groundwater travel time from its contributing recharge area of 1,701 years. Monitoring well 22a has the shortest groundwater travel time of 0.5 day to supply well 44 and monitoring well 3b has the longest maximum travel time of 31.91 years to supply well 10. Water-quality samples from the Independence groundwater monitoring well network were collected from 1997 to 2008 by USGS personnel during ongoing annual sampling within the 10-year contributing

Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy

NASA Astrophysics Data System (ADS)

Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.

2015-04-01

The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping

Groundwater monitoring plan for the Missouri River alluvial aquifer in the vicinity of the City of Independence, Missouri, well field

USGS Publications Warehouse

Wilkison, Donald H.

2012-01-01

Source contributions to monitoring and supply wells, contributing recharge areas, groundwater travel times, and current (2012) understanding of alluvial water quality were used to develop a groundwater monitoring plan for the Missouri River alluvial aquifer in the vicinity of the City of Independence, Missouri well field. The plan was designed to evaluate long-term alluvial water quality and assess potential changes in, and threats to, well-field water quality. Source contributions were determined from an existing groundwater flow model in conjunction with particle-tracking analysis and verified with water-quality data collected from 1997 through 2010 from a network of 68 monitoring wells. Three conjunctive factors - well-field pumpage, Missouri River discharge, and aquifer recharge - largely determined groundwater flow and, therefore, source contributions. The predominant source of groundwater to most monitoring wells and supply wells is the Missouri River, and this was reflected, to some extent, in alluvial water quality. To provide an estimate of the maximum potential lead time available for remedial action, monitoring wells where groundwater travel times from the contributing recharge areas are less than 2 years and predominately singular sources (such as the Missouri River or the land surface) were selected for annual sampling. The sample interval of the remaining wells, which have varying travel times and intermediate mixtures of river and land-surface contributions, were staggered on a 2-, 3-, or 4-year rotation. This was done to provide data from similar contributing areas and account for inherent aquifer variability yet minimize sample redundancy.

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

NASA Astrophysics Data System (ADS)

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

Albuquerque, New Mexico, USA: A sunbelt city rapidly outgrowing its aquifer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turin, H.J.; Gaume, A.N.; Bitner, M.J.

1997-02-01

Albuquerque, New Mexico, is located along the Rio Grande in central New Mexico, at an elevation of 5280 feet. Albuquerque`s climate reflects its high desert setting; average annual precipitation in the basin is only 8 to 10 inches. The Albuquerque metropolitan area is part of the rapidly growing {open_quotes}sunbelt{close_quotes} region of the southwestern United States and is undergoing rapid development. The municipal, industrial, and residential water needs of the entire population are currently met by groundwater, while agricultural needs within the basin are met by surface water diverted from the Rio Grande. While the city is blessed with an extremelymore » productive aquifer, current metropolitan area annual groundwater extractions of 170,000 acre-feet far exceed the sustainable yield of the aquifer. Continued drawdown will lead to greater pumping costs, ground surface subsidence problems, and eventual aquifer depletion. At the same time, industrial and non-point-source contamination and naturally occurring arsenic levels are raising concerns about groundwater quality. New Mexico water law has required the City to acquire surface water rights and allocations on the Rio Grande sufficient to offset estimated losses from the river induced by the City`s groundwater extraction. It has become increasingly clear that the induced recharge had been greatly overestimated, and that the City is thus not actually consuming its surface water as intended. The City, in cooperation with local, state, and federal agencies, has explored a variety of conjunctive use proposals, all designed to permit the City to use its surface water more directly. The City Council is presently considering a strategy calling for full use of the city`s surface water resources and creation of a groundwater drought reserve. Implementation of this strategy will require regulatory approval and major capital investment, both of which require political support.« less

Groundwater quality assessment for drinking and agriculture purposes in Abhar city, Iran.

PubMed

Jafari, Khadijeh; Asghari, Farzaneh Baghal; Hoseinzadeh, Edris; Heidari, Zahra; Radfard, Majid; Saleh, Hossein Najafi; Faraji, Hossein

2018-08-01

The main objective of this study is to assess the quality of groundwater for drinking consume and agriculture purposes in abhar city. The analytical results shows higher concentration of electrical conductivity (100%), total hardness (66.7%), total dissolved solids (40%), magnesium (23%), Sulfate (13.3%) which indicates signs of deterioration as per WHO and Iranian standards for drinking consume. Agricultural index, in terms of the hardness index, 73.3% of the samples in hard water category and 73.3% in sodium content were classified as good. Therefore, the main problem in the agricultural sector was the total hardness Water was estimated. For the RSC index, all 100% of the samples were desirable. In the physicochemical parameters of drinking water, 100% of the samples were undesirable in terms of electrical conductivity and 100% of the samples were desirable for sodium and chlorine parameters. Therefore, the main water problem in Abhar is related to electrical conductivity and water total hardness.

Numerical groundwater-flow model of the Minnelusa and Madison hydrogeologic units in the Rapid City area, South Dakota

USGS Publications Warehouse

Putnam, Larry D.; Long, Andrew J.

2009-01-01

The city of Rapid City and other water users in the Rapid City area obtain water supplies from the Minnelusa and Madison aquifers, which are contained in the Minnelusa and Madison hydrogeologic units. A numerical groundwater-flow model of the Minnelusa and Madison hydrogeologic units in the Rapid City area was developed to synthesize estimates of water-budget components and hydraulic properties, and to provide a tool to analyze the effect of additional stress on water-level altitudes within the aquifers and on discharge to springs. This report, prepared in cooperation with the city of Rapid City, documents a numerical groundwater-flow model of the Minnelusa and Madison hydrogeologic units for the 1,000-square-mile study area that includes Rapid City and the surrounding area. Water-table conditions generally exist in outcrop areas of the Minnelusa and Madison hydrogeologic units, which form generally concentric rings that surround the Precambrian core of the uplifted Black Hills. Confined conditions exist east of the water-table areas in the study area. The Minnelusa hydrogeologic unit is 375 to 800 feet (ft) thick in the study area with the more permeable upper part containing predominantly sandstone and the less permeable lower part containing more shale and limestone than the upper part. Shale units in the lower part generally impede flow between the Minnelusa hydrogeologic unit and the underlying Madison hydrogeologic unit; however, fracturing and weathering may result in hydraulic connections in some areas. The Madison hydrogeologic unit is composed of limestone and dolomite that is about 250 to 610 ft thick in the study area, and the upper part contains substantial secondary permeability from solution openings and fractures. Recharge to the Minnelusa and Madison hydrogeologic units is from streamflow loss where streams cross the outcrop and from infiltration of precipitation on the outcrops (areal recharge). MODFLOW-2000, a finite-difference groundwater

Characterization of the groundwater aquifers at El Sadat City by joint inversion of VES and TEM data

NASA Astrophysics Data System (ADS)

Massoud, Usama; Kenawy, Abeer A.; Ragab, El-Said A.; Abbas, Abbas M.; El-Kosery, Heba M.

2014-12-01

Vertical Electrical Sounding (VES) and Transient ElectroMagnetic (TEM) survey have been applied for characterizing the groundwater aquifers at El Sadat industrial area. El-Sadat city is one of the most important industrial cities in Egypt. It has been constructed more than three decades ago at about 80 km northwest of Cairo along the Cairo-Alexandria desert road. Groundwater is the main source of water supplies required for domestic, municipal and industrial activities in this area due to the lack of surface water sources. So, it is important to maintain this vital resource in order to sustain the development plans of this city. In this study, VES and TEM data were identically measured at 24 stations along 3 profiles trending NE-SW with the elongation of the study area. The measuring points were arranged in a grid-like pattern with both inter-station spacing and line-line distance of about 2 km. After performing the necessary processing steps, the VES and TEM data sets were inverted individually to multi-layer models, followed by a joint inversion of both data sets. Joint inversion process has succeeded to overcome the model-equivalence problem encountered in the inversion of individual data set. Then, the joint models were used for the construction of a number of cross sections and contour maps showing the lateral and vertical distribution of the geoelectrical parameters in the subsurface medium. Interpretation of the obtained results and correlation with the available geological and hydrogeological information revealed TWO aquifer systems in the area. The shallow Pleistocene aquifer consists of sand and gravel saturated with fresh water and exhibits large thickness exceeding 200 m. The deep Pliocene aquifer is composed of clay and sand and shows low resistivity values. The water-bearing layer of the Pleistocene aquifer and the upper surface of Pliocene aquifer are continuous and no structural features have cut this continuity through the investigated area.

Evolving Groundwater Rights and Management in Metropolitan Los Angeles: Implications for Water Supply and Stormwater

NASA Astrophysics Data System (ADS)

Porse, E.; Pincetl, S.; Glickfeld, M.

2015-12-01

Groundwater supports many aspects of human life. In cities, groundwater can provide a cost-effective source of water for drinking and industrial uses, while groundwater basins provide storage. The role of groundwater in a city's water supply tends to change over time. In the Los Angeles metropolitan area, groundwater is critical. Over decades, users in the region's many basins allocated annual pumping rights to groundwater among users through adjudications. These rights were determined through collective processes over decades, which contributed to the complex array of public and private organizations involved in water management. The rights also continue to evolve. We analyzed changes in the distribution of groundwater rights over time for adjudicated basins in Southern Los Angeles County. Results indicate that groundwater rights are increasingly: 1) controlled or regulated by public institutions and municipalities, and 2) consolidated among larger users. Yet, both the percentage of total supplies provided by groundwater, as well as the distribution of groundwater rights, varies widely among cities and communities throughout Los Angeles. As metropolitan Los Angeles faces reduced water imports and emphasizes local water reliance, access to pumping rights and storage capacity in groundwater basins will become even more vital. We discuss implications of our results for future urban water management.

Identification and temporal decrease of 137Cs and 134Cs in groundwater in Minami-Soma City following the accident at the Fukushima Dai-ichi nuclear power plant.

PubMed

Shizuma, Kiyoshi; Fujikawa, Yoko; Kurihara, Momo; Sakurai, Yushi

2018-03-01

The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on March 11, 2011, caused severe radioactive contamination in Fukushima Prefecture. In order to clarify the safety of drinking water, we have conducted radiocesium monitoring of public tap water and groundwater in Minami-Soma City, which is 10-40 km north of the nuclear power plant. The source of tap water for Minami-Soma City is groundwater, which is treated by rapid filtration before distribution in two of the three treatment plants. The tap water was collected from six stations during 2012-2016 and groundwater was collected from 11 stations with wells between 5 and 100 m deep during 2014-2016. Radiocesium contamination of groundwater has been considered unlikely in Japan because of the small vertical migration velocity of radiocesium in Japanese soil. However, radiocesium was detected in public tap water after 2012, and the maximum 137 Cs concentration of 292 mBq L -1 was observed in 2013. In all the well water, radiocesium was detected between 2014 and 2015, at concentrations similar to those observed in tap water in the same period. In tap water and groundwater, radiocesium was decreased to below the detection limit in 2016 except for four stations. Radiocesium concentration in shallow water reached a maximum between 2013 and 2015, 2-4 years after the FDNPP accident, and then decreased. The results are interpreted that dissolved 137 Cs migrated in the soil and reached aquifers of various depth. Copyright © 2017 Elsevier Ltd. All rights reserved.

The contribution of geology and groundwater studies to city-scale ground heat network strategies: A case study from Cardiff, UK

NASA Astrophysics Data System (ADS)

Boon, David; Farr, Gareth; Patton, Ashley; Kendall, Rhian; James, Laura; Abesser, Corinna; Busby, Jonathan; Schofield, David; White, Debbie; Gooddy, Daren; James, David; Williams, Bernie; Tucker, David; Knowles, Steve; Harcombe, Gareth

2016-04-01

The development of integrated heat network strategies involving exploitation of the shallow subsurface requires knowledge of ground conditions at the feasibility stage, and throughout the life of the system. We describe an approach to the assessment of ground constraints and energy opportunities in data-rich urban areas. Geological and hydrogeological investigations have formed a core component of the strategy development for sustainable thermal use of the subsurface in Cardiff, UK. We present findings from a 12 month project titled 'Ground Heat Network at a City Scale', which was co-funded by NERC/BGS and the UK Government through the InnovateUK Energy Catalyst grant in 2015-16. The project examined the technical feasibility of extracting low grade waste heat from a shallow gravel aquifer using a cluster of open loop ground source heat pumps. Heat demand mapping was carried out separately. The ground condition assessment approach involved the following steps: (1) city-wide baseline groundwater temperature mapping in 2014 with seasonal monitoring for at least 12 months prior to heat pump installation (Patton et al 2015); (2) desk top and field-based investigation of the aquifer system to determine groundwater levels, likely flow directions, sustainable pumping yields, water chemistry, and boundary conditions; (3) creation of a 3D geological framework model with physical property testing and model attribution; (4) use steps 1-3 to develop conceptual ground models and production of maps and GIS data layers to support scenario planning, and initial heat network concept designs; (5) heat flow modelling in FEFLOW software to analyse sustainability and predict potential thermal breakthrough in higher risk areas; (6) installation of a shallow open loop GSHP research observatory with real-time monitoring of groundwater bodies to provide data for heat flow model validation and feedback for system control. In conclusion, early ground condition modelling and subsurface

Ratio of Major Ions in Groundwater to Determine Saltwater Intrusion in Coastal Areas

NASA Astrophysics Data System (ADS)

Sudaryanto; Naily, Wilda

2018-02-01

Saltwater or seawater intrusion into groundwater aquifers occurs mostly in big cities and developing coastal cities. Coastal hydrology is associated with complex and highly dynamic environmental characteristics of interactions between groundwater, surface water, and water from the estuary. The rise of sea levels and excessive use of groundwater for clean water source trigger saltwater intrusion. Identification of saltwater intrusion into groundwater can be done by groundwater sampling and major ion analysis. The major ions dissolved in water are Ca, Mg, Na, K, Cl, HCO3, and SO4; the major ion ratios are Cl/Br, Ca/Mg, Ca/ (HCO3 and SO4), and Na/Cl. By knowing whether groundwater quality has been or has not been influenced by saltwater, groundwater zones can be determined in every coastal area. In addition, by analyzing and reviewing some concepts about the intrusion or contamination of saltwater into groundwater, there will be sufficient results for the identification of saltwater intrusion.

Geohydrology and simulation of ground-water flow in the aquifer system near Calvert City, Kentucky

USGS Publications Warehouse

Starn, J.J.; Arihood, L.D.; Rose, M.F.

1995-01-01

The U.S. Geological Survey, in cooperation with the Kentucky Natural Resources and Environmental Protection Cabinet, constructed a two-dimensional, steady-state ground-water-flow model to estimate hydraulic properties, contributing areas to discharge boundaries, and the average linear velocity at selected locations in an aquifer system near Calvert City, Ky. Nonlinear regression was used to estimate values of model parameters and the reliability of the parameter estimates. The regression minimizes the weighted difference between observed and calculated hydraulic heads and rates of flow. The calibrated model generally was better than alternative models considered, and although adding transmissive faults in the bedrock produced a slightly better model, fault transmissivity was not estimated reliably. The average transmissivity of the aquifer was 20,000 feet squared per day. Recharge to two outcrop areas, the McNairy Formation of Cretaceous age and the alluvium of Quaternary age, were 0.00269 feet per day (11.8 inches per year) and 0.000484 feet per day (2.1 inches per year), respectively. Contributing areas to wells at the Calvert City Water Company in 1992 did not include the Calvert City Industrial Complex. Since completing the fieldwork for this study in 1992, the Calvert City Water Company discontinued use of their wells and began withdrawing water from new wells that were located 4.5 miles east-southeast of the previous location; the contributing area moved farther from the industrial complex. The extent of the alluvium contributing water to wells was limited by the overlying lacustrine deposits. The average linear ground-water velocity at the industrial complex ranged from 0.90 feet per day to 4.47 feet per day with a mean of 1.98 feet per day.

Groundwater flow system under a rapidly urbanizing coastal city as determined by hydrogeochemistry

NASA Astrophysics Data System (ADS)

Kagabu, Makoto; Shimada, Jun; Delinom, Robert; Tsujimura, Maki; Taniguchi, Makoto

2011-01-01

In the Jakarta area (Indonesia), excessive groundwater pumping due to the rapidly increasing population has caused groundwater-related problems such as brackish water contamination in coastal areas and land subsidence. In this study, we adopted multiple hydrogeochemical techniques to demonstrate the groundwater flow system in the Jakarta area. Although almost all groundwater existing in the Jakarta basin is recharged at similar elevations, the water quality and residence time demonstrates a clear difference between the shallow and deep aquifers. Due to the rapid decrease in the groundwater potential in urban areas, we found that the seawater intrusion and the shallow and deep groundwaters are mixing, a conclusion confirmed by major ions, Br -:Cl - ratios, and chlorofluorocarbon (CFC)-12 analysis. Spring water and groundwater samples collected from the southern mountainside area show younger age characteristics with high concentrations of 14C and Ca-HCO 3 type water chemistry. We estimated the residence times of these groundwaters within 45 years under piston flow conditions by tritium analysis. Also, these groundwater ages can be limited to 20-30 years with piston flow evaluated by CFCs. Moreover, due to the magnitude of the CFC-12 concentration, we can use a pseudo age indicator in this field study, because we found a positive correlation between the major type of water chemistry and the CFC-12 concentration.

Thermal management of an urban groundwater body

NASA Astrophysics Data System (ADS)

Epting, J.; Huggenberger, P.

2012-06-01

This study presents a management concept for the sustainable thermal use of an urban groundwater body. The concept is designed to be applied for shallow thermal groundwater use and is based on (1) a characterization of the present thermal state of the investigated urban groundwater body; (2) the definition of development goals for specific aquifer regions, including future aquifer use and urbanization; and (3) an evaluation of the thermal use potential for these regions. The investigations conducted in the city of Basel (Switzerland) focus on thermal processes down-gradient of thermal groundwater use, effects of heated buildings in the aquifer as well as the thermal influence of river-groundwater interaction. Investigation methods include: (1) short- and long-term data analysis; (2) high-resolution multilevel groundwater temperature monitoring; as well as (3) 3-D numerical groundwater flow and heat-transport modeling and scenario development. The combination of these methods allows quantifying the thermal influence on the investigated urban groundwater body, including the influences of thermal groundwater use and additional heat from urbanization. Subsequently, management strategies for minimizing further groundwater temperature increase, targeting "potential natural" groundwater temperatures for specific aquifer regions and exploiting the thermal use potential are discussed.

Megacity pumping and preferential flow threaten groundwater quality

PubMed Central

Khan, Mahfuzur R.; Koneshloo, Mohammad; Knappett, Peter S. K.; Ahmed, Kazi M.; Bostick, Benjamin C.; Mailloux, Brian J.; Mozumder, Rajib H.; Zahid, Anwar; Harvey, Charles F.; van Geen, Alexander; Michael, Holly A.

2016-01-01

Many of the world's megacities depend on groundwater from geologically complex aquifers that are over-exploited and threatened by contamination. Here, using the example of Dhaka, Bangladesh, we illustrate how interactions between aquifer heterogeneity and groundwater exploitation jeopardize groundwater resources regionally. Groundwater pumping in Dhaka has caused large-scale drawdown that extends into outlying areas where arsenic-contaminated shallow groundwater is pervasive and has potential to migrate downward. We evaluate the vulnerability of deep, low-arsenic groundwater with groundwater models that incorporate geostatistical simulations of aquifer heterogeneity. Simulations show that preferential flow through stratigraphy typical of fluvio-deltaic aquifers could contaminate deep (>150 m) groundwater within a decade, nearly a century faster than predicted through homogeneous models calibrated to the same data. The most critical fast flowpaths cannot be predicted by simplified models or identified by standard measurements. Such complex vulnerability beyond city limits could become a limiting factor for megacity groundwater supplies in aquifers worldwide. PMID:27673729

Investigation of the potential source area, contamination pathway, and probable release history of chlorinated-solvent-contaminated groundwater at the Capital City Plume Site, Montgomery, Alabama, 2008-2010

USGS Publications Warehouse

Landmeyer, James E.; Miller, Scott; Campbell, Bruce G.; Vroblesky, Don A.; Gill, Amy C.; Clark, Athena P.

2011-01-01

Detection of the organic solvent perchloroethylene (PCE) in a shallow public-supply well in 1991 and exposure of workers in 1993 to solvent vapors during excavation activities to depths near the water table provided evidence that the shallow aquifer beneath the capital city of Montgomery, Alabama, was contaminated. Investigations conducted from 1993 to 1999 by State and Federal agencies confirmed the detection of PCE in the shallow aquifer, as well as the detection of the organic solvent trichloroethylene (TCE) and various inorganic compounds, but the source of the groundwater contamination was not determined. In May 2000 the U.S. Environmental Protection Agency proposed that the site, called the Capital City Plume (CCP) Site, be a candidate for the National Priorities List. Between 2000 and 2007, numerous site-investigation activities also did not determine the source of the groundwater contamination. In 2008, additional assessments were conducted at the CCP Site to investigate the potential source area, contamination pathway, and the probable release history of the chlorinated-solvent-contaminated groundwater. The assessments included the collection of (1) pore water in 2008 from the hyporheic zone of a creek using passive-diffusion bag samplers; (2) tissue samples in 2008 and 2009 from trees growing in areas of downtown Montgomery characterized by groundwater contamination and from trees growing in riparian zones along the Alabama River and Cypress Creek; and (3) groundwater samples in 2009 and 2010. The data collected were used to investigate the potential source area of contaminants detected in groundwater, the pathway of groundwater contamination, and constraints on the probable contaminant-release history. The data collected between 2008 and 2010 indicate that the PCE and TCE contamination of the shallow aquifer beneath the CCP Site most likely resulted from the past use and disposal of industrial wastewater from printing operations containing chlorinated

Urban and rural groundwater use in Zhengzhou, China: challenges in joint management

NASA Astrophysics Data System (ADS)

Sun, Ronglin; Jin, Menggui; Giordano, Mark; Villholth, Karen G.

2009-09-01

Groundwater plays an important role in the total water supply of much of China, particularly in the north. It has contributed substantially to both agricultural growth and urban and industrial expansion. However, overexploitation and poor management have contributed to infamous groundwater depletion problems and less publicized groundwater quality deterioration. One of the key challenges for China will be how to make groundwater use sustainable while still meeting increased food needs as well as the industrial and domestic demands of a rapidly urbanizing society. Zhengzhou City, one of China’s test cities for building a “water saving society” highlights both the difficulties and potential solutions to northern China’s joint rural and urban groundwater challenges. Based on secondary data and a primary survey of groundwater management in the region, this report provides an overview of Zhengzhou’s groundwater development and use as well as the ongoing institutional and policy reform processes within the water sector. The results highlight how a deepening of ongoing reforms, which simultaneously consider groundwater as an integral rural and urban issue and a fundamental economic and social asset, may improve groundwater outcomes, not only in Zhengzhou but in China, as the country’s economy and demography continue to change.

Ground-water levels in Wyoming, 1975

USGS Publications Warehouse

Ballance, Wilbur C.; Freudenthal, Pamela B.

1976-01-01

Ground-water levels are measured periodically in a network of about 260 observation wells in Wyoming to record changes in ground-water storage. The areas of water-level observation are mostly where ground water is used in large quantities for irrigation or municipal purposes. This report contains maps showing location of observation wells and water-level changes from 1975 to 1976. Well history, highest and lowest water levels , and hydrographs for most wells also are included in this report.The program of ground-water observation is conducted by the U.S. Geological Survey in cooperation with the Wyoming State Engineer and the city of Cheyenne.

Analysis of the influence of Nanchang Metro Line 4 on groundwater

NASA Astrophysics Data System (ADS)

Lan, Yingying

2017-04-01

Nanchang city subway excavation depth and the Quaternary aquifer layers are located at approximately the same depth. After the completion of the subway, that is equivalent to adding a retaining wall in the phreatic aquifer. The metro line 4 influence on groundwater flow field was analyzed based on the groundwater flow field and the dynamic relationship between groundwater and surface water. The result was that the groundwater level would rise in the area of facing groundwater movement, while others decrease. The influence of metro was apparent at the place where hydraulic contact of Gan River with groundwater was good, and vice versa.

Hydrogeological evaluation of an over-exploited aquifer in Dhaka, Bangladesh towards the implementation of groundwater artificial recharge

NASA Astrophysics Data System (ADS)

Azizur Rahman, M.; Rusteberg, Bernd; Sauter, Martin

2010-05-01

The population of Dhaka City is presently about 12 million and according to present trends in population growth, that number will most likely increase to 17.2 million by the year 2025. A serious water crisis is expected due to the extremely limited quality and quantity of water resources in the region. Previous studies have shown that the current trend in groundwater resource development is non-sustainable due to over-exploitation of the regional aquifer system, resulting in rapidly decreasing groundwater levels of about 2 to 3 meters per year. Today, annual groundwater extraction clearly exceeds natural groundwater recharge. New water management strategies are needed to guarantee future generations of Dhaka City a secured and sustained water supply as well as sustainable development of the city. The implementation of groundwater artificial recharge (AR) is one potential measure. As the first step towards a new water management strategy for Dhaka City, the authors report on the hydrogeological conditions of the greater Dhaka region and from this are able to present the location of potential recharge sites and identify appropriate recharge technologies for AR implementation. The aquifers of greater Dhaka can be grouped in three major categories: Holocene Deposit, Pleistocene Deposit and Plio-Pleistocene Deposit. The aquifers are generally thick and multilayered with relatively high transmissivity and storage coefficients. AR is considered feasible due to the fact these aquifers are alluvium deposit aquifers which characteristically have moderate to high hydraulic conductivity. Low costs for recovery of recharged water and large recharge volume capacity are generally associated with aquifers of unconsolidated sediments. Spatial analysis of the region has shown that Karaniganj, Kotoali, Savar, Dhamrai, Singair upazila, which are situated in greater Dhaka region and close to Dhaka City, could serve as recharge sites to the subsurface by pond infiltration technique. A

A 3D analysis of spatial relationship between geological structure and groundwater profile around Kobe City, Japan: based on ARCGIS 3D Analyst.

NASA Astrophysics Data System (ADS)

Shibahara, A.; Tsukamoto, H.; Kazahaya, K.; Morikawa, N.; Takahashi, M.; Takahashi, H.; Yasuhara, M.; Ohwada, M.; Oyama, Y.; Inamura, A.; Handa, H.; Nakama, J.

2008-12-01

Kobe city is located on the northern side of Osaka sedimentary basin, Japan, containing 1,000-2,000 m thick Quaternary sediments. After the Hanshin-Awaji Earthquake (January 17, 1995), a number of geological and geophysical surveys were conducted in this region. Then high-temperature anomaly of groundwater accompanied with high Cl concentration was detected along fault systems in this area. In addition, dissolved He in groundwater showed nearly upper mantle-like 3He/4He ratio, although there were no Quaternary volcanic activities in this region. Some recent studies have assumed that these groundwater profiles are related with geological structure because some faults and joints can function as pathways for groundwater flow, and mantle-derived water can upwell through the fault system to the ground surface. To verify these hypotheses, we established 3D geological and hydrological model around Osaka sedimentary basin. Our primary goal is to analyze spatial relationship between geological structure and groundwater profile. In the study region, a number of geological and hydrological datasets, such as boring log data, seismic profiling data, groundwater chemical profile, were reported. We converted these datasets to meshed data on the GIS, and plotted in the three dimensional space to visualize spatial distribution. Furthermore, we projected seismic profiling data into three dimensional space and calculated distance between faults and sampling points, using Visual Basic for Applications (VBA) scripts. All 3D models are converted into VRML format, and can be used as a versatile dataset on personal computer. This research project has been conducted under the research contract with the Japan Nuclear Energy Safety Organization (JNES).

U.S. Geological Survey ground-water studies in Missouri

USGS Publications Warehouse

Smith, B.J.

1993-01-01

The activities of the USGS Water Resources Division in Missouri are conducted by scientists, technicians, and support staff in offices in Rolla, Olivette, and Independence. During 1992, the USGS had cooperative or cost-sharing agreements with about 30 Federal, State, and local agencies involving 20 hydrologic investigations in Missouri; 12 of these investigations included studies of groundwater quantity and quality. Several examples of groundwater studies by the USGS that address specific groundwater issues in Missouri include the occurrence of pesticides, groundwater flow and quality in the Missouri River alluvium near Kansas City, groundwater flow in claypan soils, radioactive- and nitroaromatic-compound contami- nation at Weldon Spring, and hydrologic monitoring of a wetland complex. (USGS)

Geohydrology, water quality, and estimation of ground-water recharge in San Francisco, California, 1987-92

USGS Publications Warehouse

Phillips, S.P.; Hamlin, S.N.; Yates, E.B.

1993-01-01

The city of San Francisco is considering further development of local groundwater resources as a supplemental source of water for potable or nonpotable use. By the year 2010, further water demand is projected to exceed the delivery capacity of the existing supply system, which is fed by surface-water sources; thus supplies are susceptible to drought conditions and damage to conveyance lines by earthquakes. The primary purpose of this study is to describe local geohydrology and water quality and to estimate groundwater recharge in the area of the city of San Francisco. Seven groundwater basins were identified in San Francisco on the basis of geologic and geophysical data. Basins on the east side of the city are relatively thin and contain a greater percentage of fine-grained sediments than those on the west side. The relatively small capacity of the basins and greater potential for contamination from sewer sources may limit the potential for groundwater development on the east side. Basins on the west side of the city have a relatively large capacity and low density sewer network. Water-level data indicate that the southern part of the largest basin on the west side of the city (Westside basin) probably cannot accommodate additional groundwater development without adversely affecting water levels and water quality in Lake Merced; however, the remainder of the basin, which is largely undeveloped, could be developed further. A hydrologic routing model was developed for estimating groundwater recharge throughout San Francisco. The model takes into account climatic factors, land and water use, irrigation, leakage from underground pipes, rainfall runoff, evapotranspiration, and other factors associated with an urban environment. Results indicate that area recharge rates for water years 1987-88 for the 7 groundwater basins ranged from 0.32 to 0.78 feet per year. Recharge for the Westside basin was estimated at 0.51 feet per year. Average annual groundwater recharge

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

PubMed

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

2018-03-06

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

Complex Controls on Groundwater Quality in Growing Mid-sized Cities: A Case Study Focused on Nitrate and Emerging Contaminants

NASA Astrophysics Data System (ADS)

Ohr, C. A.; Godsey, S.; Welhan, J. A.; Larson, D. M.; Lohse, K. A.; Finney, B.; Derryberry, D.

2015-12-01

Many regions rely on quality groundwater to support urban growth. Groundwater quality often responds in a complex manner to stressors such as land use change, climate change, or policy decisions. Urban growth patterns in mid-sized cities, especially ones that are growing urban centers in water-limited regions in the western US, control and are controlled by water availability and its quality. We present a case study from southeastern Idaho where urban growth over the past 20 years has included significant ex-urban expansion of houses that rely on septic systems rather than city sewer lines for their wastewater treatment. Septic systems are designed to mitigate some contaminants, but not others. In particular, nitrates and emerging contaminants, such as pharmaceuticals, are not removed by most septic systems. Thus, even well-maintained septic systems at sufficiently high densities can impact down gradient water quality. Here we present patterns of nitrate concentrations over the period from 1985-2015 from the Lower Portneuf River Valley in southeastern Idaho. Concentrations vary from 0.03 to 27.09 nitrate-nitrogen mg/L, with average values increasing significantly over the 30 year time period from 3.15 +/- 0.065 to 3.57 +/- 0.43 mg/L. We examine temporal changes in locations of nitrate hotspots, and present pilot data on emerging contaminants of concern. Initial results suggest that high nitrate levels are generally associated with higher septic densities, but that this pattern is influenced by legacy agricultural uses and strongly controlled by underlying aquifer properties. Future work will include more detailed hydrological modeling to predict changes in hotspot locations under potential climate change scenarios.

Ground-water flow and ground- and surface-water interaction at McBaine Bottoms, Columbia, Missouri--2000-02

USGS Publications Warehouse

Smith, Brenda J.

2003-01-01

McBaine Bottoms southwest of Columbia, Missouri, is the site of 4,269 acres of the Eagle Bluffs Conservation Area operated by the Missouri Department of Conservation, about 130 acres of the city of Columbia wastewater-treat-ment wetlands, and the city of Columbia munici-pal-supply well field. The city of Columbia wastewater-treatment wetlands supply treated effluent to the Eagle Bluffs Conservation Area. The presence of a sustained ground-water high underlying the Eagle Bluffs Conservation Area has indicated that ground-water flow is toward the municipal well field that supplies drinking water to the city of Columbia. The U.S. Geological Survey, in cooperation with the Missouri Department of Conservation and the city of Columbia, measured the ground-water levels in about 88 monitoring wells and the surface-water elevation at 4 sites monthly during a 27-month period to determine the ground-water flow and the ground- and surface-water interaction at McBaine Bottoms. Lateral ground-water flow was dominated by the presence of a ground-water high that was beneath the Eagle Bluffs Conservation Area and the presence of a cone of depression in the northern part of the study area. The ground-water high was present during all months of the study. 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 toward the north toward the city of Columbia well field. The cone of depression was centered 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 beneath the Eagle Bluffs Conservation Area was present throughout the study period, the configuration of the high changed depending on hydrologic conditions. Generally in the spring, the height of the ground-water high began to decrease and hydraulic

Groundwater vulnerability in the District of Abidjan (Côte d'Ivoire)

NASA Astrophysics Data System (ADS)

Kouame, Agnes; Jaboyedoff, Michel; Derron, Marc-Henri; Tacher, Laurent

2014-05-01

The District of Abidjan, located on the coastal sedimentary basin south of Côte d'Ivoire (West Africa) covers an area of 2,1 km2. This sedimentary basin is composed of continuous groundwater aquifers in Quaternary, Tertiary and Upper Cretaceous rocks. Our study focuses on the unconfined Quaternary groundwater called the Continental Terminal which formations are composed mainly of lenticular stratification of coarse sands, clays, ferruginous sandstone and iron ore. This Continental Terminal aquifer is the main source of drinking water for the city of Abidjan. Indeed, the city of Abidjan is facing various pollution problems such as illegal dumping of household waste, waste oils garages, domestic and industrial wastewater, gas stations, public discharge Akouédo and the spill of approximately 500 tons of toxic waste from the ship "Probo Koala" the night of 19 August 2006. These toxic wastes have killed more than 10 people and several infections. The infiltration of these contaminants under the influence of rainwater in the basement is a serious threat to groundwater from the District of Abidjan especially as the rains are very strong in this part of the country. What would be the fate of pollutants such as organochlorines, hydrogen sulfide, sulfides and hydrocarbons contained in toxic waste, knowing that this aquifer is the main source of supply of drinking water to the city of Abidjan? It therefore seems necessary to study the vulnerability of groundwater of Abidjan District. The overall objective of this study is to assess the risk of groundwater contamination by organochlorines, sulfides, hydrogen sulfide and hydrocarbons. This project is to develop groundwater flow and contaminant transport models such as organochlorines models, hydrogen sulfide and sulfides with two digital codes, Visual Modflow and Feflow. Then several scenarios with different pollutants are finally made to realize maps of groundwater vulnerability from Abidjan to these contaminants.

Adsorptive properties of alluvial soil for arsenic(V) and its potential for protection of the shallow groundwater among Changsha, Zhuzhou, and Xiangtan cities, China.

PubMed

Chen, Hongwei; Mei, Jinhua; Luo, Yueping; Qiu, Anni; Wang, Huan

2017-02-01

The study area is among Changsha, Zhuzhou, and Xiangtan cities, which was under agricultural use and natural conditions about 10 years ago and now is becoming part of the metropolis because of the urban expansion. This study aims to investigate the mechanisms and capabilities of the local alluvial soil layer for protecting the local shallow groundwater from arsenic pollution by field surveys and batch experiments. The field surveys showed that there was an acidic tendency of the groundwater, and phosphate, nitrate, and arsenic in the groundwater significantly increased comparing to their reference values. It indicates that the disturbance of the former agricultural land due to the change of land use may be responsible for these changes. From the experimental results, the maximum adsorption capacity of the soil for As(V) was as low as 0.334 mg/g, and lower As(V) adsorption capacities were obtained at higher As(V) concentration, higher pH, and lower temperature. The presence of H 2 PO 4 - and SiO 3 2- posed negative, while HCO 3 - slight positive, and SO 4 2- , NO 3 - and Cl - negligible influences on the As(V) adsorption. The surface-derived organic matter played a negative role in the adsorption process, and low specific surface area influenced adsorption capacity of the soil. The study reveals that the local soil layer shows poor potential for protection of the local shallow groundwater from As(V) pollution, and the change trends of the groundwater environments due to more intensive anthropogenic activities will further weaken this potential and increase the risk of the groundwater contamination.

Quantification of groundwater recharge in urban environments.

PubMed

Tubau, Isabel; Vázquez-Suñé, Enric; Carrera, Jesús; Valhondo, Cristina; Criollo, Rotman

2017-08-15

Groundwater management in urban areas requires a detailed knowledge of the hydrogeological system as well as the adequate tools for predicting the amount of groundwater and water quality evolution. In that context, a key difference between urban and natural areas lies in recharge evaluation. A large number of studies have been published since the 1990s that evaluate recharge in urban areas, with no specific methodology. Most of these methods show that there are generally higher rates of recharge in urban settings than in natural settings. Methods such as mixing ratios or groundwater modeling can be used to better estimate the relative importance of different sources of recharge and may prove to be a good tool for total recharge evaluation. However, accurate evaluation of this input is difficult. The objective is to present a methodology to help overcome those difficulties, and which will allow us to quantify the variability in space and time of the recharge into aquifers in urban areas. Recharge calculations have been initially performed by defining and applying some analytical equations, and validation has been assessed based on groundwater flow and solute transport modeling. This methodology is applicable to complex systems by considering temporal variability of all water sources. This allows managers of urban groundwater to evaluate the relative contribution of different recharge sources at a city scale by considering quantity and quality factors. The methodology is applied to the assessment of recharge sources in the Barcelona city aquifers. Copyright © 2017 Elsevier B.V. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2015-05-01

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

Thermal management of an unconsolidated shallow urban groundwater body

NASA Astrophysics Data System (ADS)

Epting, J.; Händel, F.; Huggenberger, P.

2013-05-01

This study presents the development of tools for the sustainable thermal management of a shallow unconsolidated urban groundwater body in the city of Basel (Switzerland). The concept of the investigations is based on (1) a characterization of the present thermal state of the urban groundwater body, and (2) the evaluation of potential mitigation measures for the future thermal management of specific regions within the groundwater body. The investigations focus on thermal processes down-gradient of thermal groundwater use, effects of heated buildings in the subsurface as well as the thermal influence of river-groundwater interaction. Investigation methods include (1) short- and long-term data analysis, (2) high-resolution multilevel groundwater temperature monitoring, as well as (3) 3-D numerical groundwater flow and heat transport modeling and scenario development. The combination of these methods allows for the quantifying of the thermal influences on the investigated urban groundwater body, including the influences of thermal groundwater use and heated subsurface constructions. Subsequently, first implications for management strategies are discussed, including minimizing further groundwater temperature increase, targeting "potential natural" groundwater temperatures for specific aquifer regions and exploiting the thermal potential.

Groundwater-pumping optimization for land-subsidence control in Beijing plain, China

NASA Astrophysics Data System (ADS)

Qin, Huanhuan; Andrews, Charles B.; Tian, Fang; Cao, Guoliang; Luo, Yong; Liu, Jiurong; Zheng, Chunmiao

2018-01-01

Beijing, in the North China plain, is one of the few megacities that uses groundwater as its main source of water supply. Groundwater accounts for about two-thirds of the city's water supply, and during the past 50 years the storage depletion from the unconsolidated aquifers underlying the city has been >10.4 billion m3. By 2010, groundwater pumping in the city had resulted in a cumulative subsidence of greater than 100 mm in an area of about 3,900 km2, with a maximum cumulative subsidence of >1,200 mm. This subsidence has caused significant social and economic losses in Beijing, including significant damage to underground utilities. This study was undertaken to evaluate various future pumping scenarios to assist in selecting an optimal pumping scenario to minimize overall subsidence, meet the requirements of the Beijing Land Subsidence Prevention Plan (BLSPP 2013-2020), and be consistent with continued sustainable economic development. A numerical groundwater and land-subsidence model was developed for the aquifer system of the Beijing plain to evaluate land subsidence rates under the possible future pumping scenarios. The optimal pumping scenario consistent with the evaluation constraints is a reduction in groundwater pumping from three major pumping centers by 100, 50 and 20%, respectively, while maintaining an annual pumping rate of 1.9 billion m3. This scenario's land-subsidence rates satisfy the BLSPP 2013-2020 and the pumping scenario is consistent with continued economic development. It is recommended that this pumping scenario be adopted for future land-subsidence management in Beijing.

Groundwater-pumping optimization for land-subsidence control in Beijing plain, China

NASA Astrophysics Data System (ADS)

Qin, Huanhuan; Andrews, Charles B.; Tian, Fang; Cao, Guoliang; Luo, Yong; Liu, Jiurong; Zheng, Chunmiao

2018-06-01

Beijing, in the North China plain, is one of the few megacities that uses groundwater as its main source of water supply. Groundwater accounts for about two-thirds of the city's water supply, and during the past 50 years the storage depletion from the unconsolidated aquifers underlying the city has been >10.4 billion m3. By 2010, groundwater pumping in the city had resulted in a cumulative subsidence of greater than 100 mm in an area of about 3,900 km2, with a maximum cumulative subsidence of >1,200 mm. This subsidence has caused significant social and economic losses in Beijing, including significant damage to underground utilities. This study was undertaken to evaluate various future pumping scenarios to assist in selecting an optimal pumping scenario to minimize overall subsidence, meet the requirements of the Beijing Land Subsidence Prevention Plan (BLSPP 2013-2020), and be consistent with continued sustainable economic development. A numerical groundwater and land-subsidence model was developed for the aquifer system of the Beijing plain to evaluate land subsidence rates under the possible future pumping scenarios. The optimal pumping scenario consistent with the evaluation constraints is a reduction in groundwater pumping from three major pumping centers by 100, 50 and 20%, respectively, while maintaining an annual pumping rate of 1.9 billion m3. This scenario's land-subsidence rates satisfy the BLSPP 2013-2020 and the pumping scenario is consistent with continued economic development. It is recommended that this pumping scenario be adopted for future land-subsidence management in Beijing.

Investigation on the Sources of Recharge and Salinity in Deep Groundwater System Underlying a Coastal City of Bangladesh by Combined Geochemical and Isotopic Approaches

NASA Astrophysics Data System (ADS)

Rahman, M.; Tokunaga, T.

2017-12-01

The Khulna city, situated in the southwestern coastal Bangladesh, has been abstracting deep groundwater (DGW, >150 m below ground level, bgl) since 1970s due to the prevalence of salinity, iron, and arsenic in shallow groundwater (SGW, <150 m bgl). In this study, we obtained environmental isotopes (δ18O, δ2H, δ13C, 3H, and 14C) and geochemical data to constrain the sources of recharge and the possible reasons for salinization of DGW. Samples were collected from DGW, SGW, pond water (PndW), and river water (RW). δ18O and δ2H of DGW, SGW, and RW fall on the local meteoric water line (LMWL) whereas PndW shows evaporation effect as plotted below the LMWL. All these water features form distinct clusters among one another. DGW was not recharged from modern precipitation as 3H values were below detection limit (0.3 TU). 14C activities of 7.9 to 17.5 pMC and apparent radiocarbon age of around 14-21 ka most probably indicate the recharge with paleo-meteoric water. However, elevated 3H and 14C in SGW, reported in recent studies, suggest their recharge with modern precipitation. Neither modern seawater nor SGW influences the salinization of DGW as perceived from a cross plot between Cl- and δ18O. Salinity in DGW might have evolved through mineral dissolution, rock weathering, or mixing with paleo-brackish water. Although DGW level and SGW level fluctuate similarly with monsoon rainfall and river stages, we found no direct connection between SGW and DGW with respect to geochemical and isotopic signatures. Further efforts are necessary for improved understanding of the system for sustainable groundwater management and ensuring long-term freshwater supply for the Khulna city, Bangladesh.

[Prokaryote diversity in water environment of land-ocean ecotone of Zhuhai City].

PubMed

Huang, Xiao-Lan; Chen, Jian-Yao; Zhou, Shi-Ning; Xie, Li-Chun; Fu, Cong-Sheng

2010-02-01

By constructing 16S rDNA clone library with PCR-RFLP, the prokaryote diversity in the seawater and groundwater of land-ocean ecotone of Zhuhai City was investigated, and the similarity and cluster analyses were implemented with the database of the sequences in Genbank. In the seawater, Proteobacteria was dominant, followed by Archaeon, Gemmatimonadetes, Candidate division OP3 and OP8, and Planctomycetes, etc.; while in the groundwater, Archaeon was dominant, followed by Proteobacteria, Sphingobacteria, Candidate division OP3, Actinobacterium, and Pseudomonas. The dominant taxa in the groundwater had high similarity to the unculturable groups of marine microorganisms. Large amount of bacteria capable of degrading organic matter and purifying water body existed in the groundwater, suggesting that after long-term evolution, the land-ocean ecotone of Zhuhai City had the characteristics of both land and ocean.

Redox potential of shallow groundwater by 1-month continuous in situ potentiometric measurements

NASA Astrophysics Data System (ADS)

Ioka, Seiichiro; Muraoka, Hirofumi; Suzuki, Yota

2017-10-01

One-month continuous in situ potentiometric measurements of redox potential (Eh) were used to investigate the dominant redox processes in the shallow groundwater (i.e., <10 m) of a Holocene aquifer, Aomori City, northern Japan. The Eh values, which were determined using a platinum electrode, were -163, -169 and -173 mV, respectively, for three monitoring campaigns. The temperatures and pH values of shallow groundwater during all three periods were approximately 12 °C and 6.6, respectively. Dissolved oxygen and sulfide ion concentrations were not detected. Chemical analyses showed that the shallow groundwater is Na-Fe-HCO3 type, and contains over 40 mg/L of Fe (the dominant cation) and over 200 mg/L of HCO3 - (the dominant anion). A good fit was found between measured Eh values and Eh values calculated using thermodynamic data of fine-grained goethite. This suggests that Fe redox system is related to the Eh values of shallow groundwater in the Aomori City aquifer.

Land subsidence caused by groundwater exploitation in Suzhou City, China

NASA Astrophysics Data System (ADS)

Chen, Chongxi; Pei, Shunping; Jiao, Jiu Jimmy

2002-09-01

Suzhou City, located at the lower reaches of the Yangtze River in southeastern Jiangsu Province, is one of the few cities in China which suffer from severe ground settlement. A research project was carried out to investigate this problem. Geological and hydrogeological studies show that there is a multi-layered aquifer system with three distinct, soft mud layers of marine and lagoonal origins. An examination of historical records of groundwater extraction, water levels, and ground settlement shows that the ground subsidence is associated with the continuously increasing groundwater extraction in the deep, confined aquifer. It is believed that the consolidation of the soft mud layers, especially the third layer which is thick and close to the main pumped aquifer, contributes to the ground settlement. A three-dimensional finite difference numerical model representing the multi-layered aquifer system was developed to study the ground settlement in response to groundwater extraction. By calibrating the model with both the measured groundwater level and ground settlement, the aquifer parameters were estimated. The model outputs fit reasonably well with the observed results, which indicates that the numerical model can reproduce the dynamic processes of both groundwater flow and soil consolidation. The hydraulic conductivity of the third mud layer near the center of the ground settlement has been reduced by over 30% in the last 14 years. The gradual deterioration in the hydraulic conductivity of the mud may have significant adverse effect on the sustainable groundwater resource of the deep confined aquifer, since the recharge from the shallow aquifers through the mud layer is the only source of water to the deep aquifer. An analysis of the spatial distributions of groundwater drawdown and ground settlement shows that the area with maximum drawdown is not necessarily the area with maximum ground settlement due to the occurrence of the soft mud layer. A simple reallocation

Roles of surface water areas for water and solute cycle in Hanoi city, Viet Nam

NASA Astrophysics Data System (ADS)

Hayashi, Takeshi; Kuroda, Keisuke; Do Thuan, An; Tran Thi Viet, Nga; Takizawa, Satoshi

2013-04-01

Hanoi city, the capital of Viet Nam, has developed beside the Red river. Recent rapid urbanization of this city has reduced a large number of natural water areas such as lakes, ponds and canals not only in the central area but the suburban area. Contrary, the urbanization has increased artificial water areas such as pond for fish cultivation and landscaping. On the other hand, the urbanization has induced the inflow of waste water from households and various kinds of factories to these water areas because of delay of sewerage system development. Inflow of the waste water has induced eutrophication and pollution of these water areas. Also, there is a possibility of groundwater pollution by infiltration of polluted surface water. However, the role of these water areas for water cycle and solute transport is not clarified. Therefore, this study focuses on the interaction between surface water areas and groundwater in Hanoi city to evaluate appropriate land development and groundwater resource management. We are carrying out three approaches: a) understanding of geochemical characteristics of surface water and groundwater, b) monitoring of water levels of pond and groundwater, c) sampling of soil and pond sediment. Correlation between d18O and dD of precipitation (after GNIP), the Red River (after GNIR) and the water samples of this study showed that the groundwater is composed of precipitation, the Red River and surface water that has evaporation process. Contribution of the surface water with evaporation process was widely found in the study area. As for groundwater monitoring, the Holocene aquifers at two sites were in unconfined condition in dry season and the groundwater levels in the aquifer continued to increase through rainy season. The results of isotopic analysis and groundwater level monitoring showed that the surface water areas are one of the major groundwater sources. On the other hand, concentrations of dissolved Arsenic (filtered by 0.45um) in the pore

Ground-water-use trends in the Twin Cities metropolitan area, Minnesota, 1880-1980

USGS Publications Warehouse

Horn, M.A.

1983-01-01

Ground-water use was analyzed by use category and aquifer and several trends were observed. Eighty percent of ground water currently withdrawn is from wells in the Prairie du Chien-Jordan aquifer. Ground-water use increased from 1880 until the early 1970's, and then declined slightly in the late 1970's. Industrial use in particular declined during the 1970's as a result of conservation that was prompted by increased sewagetreatment and energy costs. The intensity of pumping has decreased within the St. Paul and Minneapolis city limits and increased outside the city limits. The seasonal variability of ground-water use became more pronounced as the percentage of water used for irrigation and air conditioning increased.

Construction of a groundwater-flow model for the Big Sioux Aquifer using airborne electromagnetic methods, Sioux Falls, South Dakota

USGS Publications Warehouse

Valder, Joshua F.; Delzer, Gregory C.; Carter, Janet M.; Smith, Bruce D.; Smith, David V.

2016-09-28

The city of Sioux Falls is the fastest growing community in South Dakota. In response to this continued growth and planning for future development, Sioux Falls requires a sustainable supply of municipal water. Planning and managing sustainable groundwater supplies requires a thorough understanding of local groundwater resources. The Big Sioux aquifer consists of glacial outwash sands and gravels and is hydraulically connected to the Big Sioux River, which provided about 90 percent of the city’s source-water production in 2015. Managing sustainable groundwater supplies also requires an understanding of groundwater availability. An effective mechanism to inform water management decisions is the development and utilization of a groundwater-flow model. A groundwater-flow model provides a quantitative framework for synthesizing field information and conceptualizing hydrogeologic processes. These groundwater-flow models can support decision making processes by mapping and characterizing the aquifer. Accordingly, the city of Sioux Falls partnered with the U.S. Geological Survey to construct a groundwater-flow model. Model inputs will include data from advanced geophysical techniques, specifically airborne electromagnetic methods.

Modelling Urban diffuse pollution in groundwater

NASA Astrophysics Data System (ADS)

Jato, Musa; Smith, Martin; Cundy, Andrew

2017-04-01

Diffuse urban pollution of surface and ground waters is a growing concern in many cities and towns. Traffic-derived pollutants such as salts, heavy metals and polycyclic aromatic hydrocarbons (PAHs) may wash off road surfaces in soluble or particulate forms which later drain through soils and drainage systems into surface waters and groundwater. In Brighton, about 90% of drinking water supply comes from groundwater (derived from the Brighton Chalk block). In common with many groundwater sources the Chalk aquifer has been relatively extensively monitored and assessed for diffuse rural contaminants such as nitrate, but knowledge on the extent of contamination from road run-off is currently lacking. This project examines the transfer of traffic-derived contaminants from the road surface to the Chalk aquifer, via urban drainage systems. A transect of five boreholes have been sampled on a monthly basis and groundwater samples analysed to examine the concentrations of key, mainly road run-off derived, hydrocarbon and heavy metal contaminants in groundwater across the Brighton area. Trace concentrations of heavy metals and phenols have been observed in groundwater. Electrical conductivity changes in groundwater have also been used to assess local changes in ionic strength which may be associated with road-derived contaminants. This has been supplemented by systematic water and sediment sampling from urban gully pots, with further sampling planned from drainage and settlement ponds adjacent to major roads, to examine initial road to drainage system transport of major contaminants.

Groundwater quality in the Owens Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

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

Assessment of groundwater/surface-water interaction and simulation of potential streamflow depletion induced by groundwater withdrawal, Uinta River near Roosevelt, Utah

USGS Publications Warehouse

Lambert, P.M.; Marston, T.; Kimball, B.A.; Stolp, B.J.

2011-01-01

Roosevelt City, Utah, asserts a need for an additional supply of water to meet municipal demands and has identified a potential location for additional groundwater development at the Sprouse well field near the West Channel of the Uinta River. Groundwater is commonly hydraulically linked to surface water and, under some conditions, the pumpage of groundwater can deplete water in streams and other water bodies. In 2008, the U.S. Geological Survey, in cooperation with Roosevelt City, the Utah Department of Natural Resources, and the Ute Indian Tribe, began a study to improve understanding of the local interconnection between groundwater and surface water and to assess the potential for streamflow depletion from future groundwater withdrawals at a potential Roosevelt City development location—the Sprouse well field near the West Channel of the Uinta River.In the study, streamflow gains and losses at the river/aquifer boundary near the well field and changes in those conditions over time were assessed through (1) synoptic measurement of discharge in the stream at multiple sites using tracer-dilution methods, (2) periodic measurement of the vertical hydraulic gradient across the streambed, and (3) continuous measurement of stream and streambed water temperature using heat as a tracer of flow across the streambed. Although some contradictions among the results of the three assessment methods were observed, results of the approaches generally indicated (1) losing streamflow conditions on the West Channel of the Uinta River north of and upstream from the Sprouse well field within the study area, (2) gaining streamflow conditions south of and downstream from the well field, and (3) some seasonal changes in those conditions that correspond with seasonal changes in stream stage and local water-table altitudes.A numerical groundwater flow model was developed on the basis of previously reported observations and observations made during this study, and was used to estimate

Groundwater potential zoning of a peri-urban wetland of south Bengal Basin, India.

PubMed

Sahu, Paulami; Sikdar, Pradip K

2011-03-01

Demand for groundwater for drinking, agricultural, and industrial purposes has increased due to rapid increase in population. Therefore, it is imperative to assess the groundwater potential of different areas, especially in a fragile wetland ecosystem to select appropriate sites for developing well fields to minimize adverse environmental impacts of groundwater development. This study considers East Calcutta Wetlands (ECW)--a freshwater peri-urban inland wetland ecosystem located at the lower part of the deltaic alluvial plain of South Bengal Basin and east of Kolkata city. This wetland is well known over the world for its resource recovery systems developed by local people through ages, using wastewater of the city. The subsurface geology is completely blanketed by the Quaternary sediments comprising a succession of silty clay, sand of various grades, and sand mixed with occasional gravels and thin intercalations of silty clay. Groundwater occurs mostly under confined condition except in those places where the top aquitard has been obliterated due to scouring action of past channels. The groundwater in the study area is being over-extracted at the rate of 65 × 10(3) m(3)/day. Overlay analysis in Geographic Information System platform using multiple criteria such as water quality index, hydraulic conductivity, groundwater velocity, and depth to piezometric surface reveals that in and around ECW, there are five groundwater potential zones. About 74% of the aquifer of this area shows very poor to medium groundwater potential. Management options such as minimization of groundwater abstraction by introducing the treated surface water supply system and the implementation of rainwater harvesting and artificial recharge in high-rise buildings and industries are suggested for different potential zones.

Optimization of ground-water withdrawal in the lower Fox River communities, Wisconsin

USGS Publications Warehouse

Walker, J.F.; Saad, D.A.; Krohelski, J.T.

1998-01-01

Pumping from closely spaced wells in the Central Brown County area and the Fox Cities area near the north shore of Lake Winnebago has resulted in the formation of deep cones of depression in the vicinity of the two pumping centers. Water-level measurements indicate there has been a steady decline in water levels in the vicinity of these two pumping centers for the past 50 years. This report describes the use of ground-water optimization modeling to efficiently allocate the ground-water resources in the Lower Fox River Valley. A 3-dimensional ground-water flow model was used along with optimization techniques to determine the optimal withdrawal rates for a variety of management alternatives. The simulations were conducted separately for the Central Brown County area and the Fox Cities area. For all simulations, the objective of the optimization was to maximize total ground-water withdrawals. The results indicate that ground water can supply nearly all of the projected 2030 demand for Central Brown County municipalities if all of the wells are managed (including the city of Green Bay), 8 new wells are installed, and the water-levels are allowed to decline to 100 ft below the bottom of the confining unit. Ground water can supply nearly all of the projected 2030 demand for the Fox Cities if the municipalities in Central Brown County convert to surface water; if Central Brown County municipalities follow the optimized strategy described above, there will be a considerable shortfall of available ground water for the Fox Cities communities. Relaxing the water-level constraint in a few wells, however, would likely result in increased availability of water. In all cases examined, optimization alternatives result in a rebound of the steady-state water levels due to projected 2030 withdrawal rates to levels at or near the bottom of the confining unit, resulting in increased well capacity. Because the simulations are steady-state, if all of the conditions of the model remain

Understanding shallow groundwater contamination in Bwaise slum, Kampala, Uganda

NASA Astrophysics Data System (ADS)

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

2012-04-01

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

Simulation of Groundwater Contaminant Transport at a Decommissioned Landfill Site—A Case Study, Tainan City, Taiwan

PubMed Central

Chen, Chao-Shi; Tu, Chia-Huei; Chen, Shih-Jen; Chen, Cheng-Chung

2016-01-01

Contaminant transport in subsurface water is the major pathway for contamination spread from contaminated sites to groundwater supplies, to remediate a contaminated site. The aim of this paper was to set up the groundwater contaminant transport model for the Wang-Tien landfill site, in southwestern Taiwan, which exhibits high contamination of soil and groundwater and therefore represents a potential threat for the adjacent Hsu-Hsian Creek. Groundwater Modeling System software, which is the most sophisticated groundwater modeling tool available today, was used to numerically model groundwater flow and contaminant transport. In the simulation, the total mass of pollutants in the aquifer increased by an average of 72% (65% for ammonium nitrogen and 79% for chloride) after 10 years. The simulation produced a plume of contaminated groundwater that extends 80 m in length and 20 m in depth northeastward from the landfill site. Although the results show that the concentrations of ammonium nitrogen and chlorides in most parts are low, they are 3.84 and 467 mg/L, respectively, in the adjacent Hsu-Hsian Creek. PMID:27153078

Evapotranspiration And Geochemical Controls On Groundwater Plumes At Arid Sites: Toward Innovative Alternate End-States For Uranium Processing And Tailings Facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Looney, Brian B.; Denham, Miles E.; Eddy-Dilek, Carol A.

2014-01-08

Management of legacy tailings/waste and groundwater contamination are ongoing at the former uranium milling site in Tuba City AZ. The tailings have been consolidated and effectively isolated using an engineered cover system. For the existing groundwater plume, a system of recovery wells extracts contaminated groundwater for treatment using an advanced distillation process. The ten years of pump and treat (P&T) operations have had minimal impact on the contaminant plume – primarily due to geochemical and hydrological limits. A flow net analysis demonstrates that groundwater contamination beneath the former processing site flows in the uppermost portion of the aquifer and exitsmore » the groundwater as the plume transits into and beneath a lower terrace in the landscape. The evaluation indicates that contaminated water will not reach Moenkopi Wash, a locally important stream. Instead, shallow groundwater in arid settings such as Tuba City is transferred into the vadose zone and atmosphere via evaporation, transpiration and diffuse seepage. The dissolved constituents are projected to precipitate and accumulate as minerals such as calcite and gypsum in the deep vadose zone (near the capillary fringe), around the roots of phreatophyte plants, and near seeps. The natural hydrologic and geochemical controls common in arid environments such as Tuba City work together to limit the size of the groundwater plume, to naturally attenuate and detoxify groundwater contaminants, and to reduce risks to humans, livestock and the environment. The technical evaluation supports an alternative beneficial reuse (“brownfield”) scenario for Tuba City. This alternative approach would have low risks, similar to the current P&T scenario, but would eliminate the energy and expense associated with the active treatment and convert the former uranium processing site into a resource for future employment of local citizens and ongoing benefit to the Native American Nations.« less

Rapid decadal evolution in the groundwater arsenic content of Kolkata, India and its correlation with the practices of her dwellers.

PubMed

Malakar, Arindam; Islam, Samirul; Ali, Md Ashif; Ray, Sugata

2016-10-01

Increasing arsenic contamination in the groundwater is one of the biggest environmental challenges that the Bengal delta is facing today. Groundwater is still the main source of water for a large number of population in this region and therefore, significant presence of toxic arsenic has a direct consequence on human lives here. Moreover, arsenic also enters into the food chain through the consumed agricultural products grown in this area. Therefore, acquiring knowledge about the ever-changing map of arsenic contamination and employing adequate protective measures are of utmost importance. Here, we present a comprehensive municipal ward-wise map of the arsenic content of the shallow groundwater table of Kolkata-the most important and highly population dense city of the delta. Comparison with previously available data reveals a rapid change and the grim situation for the city. Our study suggests that it should be an immediate task of the administration to extend treated water service to the whole population of the city for direct consumption, and artificial recharge and maximum rainwater replenishment need to be taken up with utmost urgency to avoid intrusion of toxicity in biological food chains via agricultural products. We hope our study would drive the city planners to reconsider the existing urbanization and development plans of all the cities, placed over arsenic-contaminated groundwater aquifers.

Use of hydrologic budgets and hydrochemistry to determine ground-water and surface-water interactions for Rapid Creek, Western South Dakota

USGS Publications Warehouse

Anderson, Mark T.

1995-01-01

The study of ground-water and surface-water interactions often employs streamflow-gaging records and hydrologic budgets to determine ground-water seepage. Because ground-water seepage usually is computed as a residual in the hydrologic budget approach, all uncertainty of measurement and estimation of budget components is associated with the ground-water seepage. This uncertainty can exceed the estimate, especially when streamflow and its associated error of measurement, is large relative to other budget components. In a study of Rapid Creek in western South Dakota, the hydrologic budget approach with hydrochemistry was combined to determine ground-water seepage. The City of Rapid City obtains most of its municipal water from three infiltration galleries (Jackson Springs, Meadowbrook, and Girl Scout) constructed in the near-stream alluvium along Rapid Creek. The reach of Rapid Creek between Pactola Reservoir and Rapid City and, in particular the two subreaches containing the galleries, were studied intensively to identify the sources of water to each gallery. Jackson Springs Gallery was found to pump predominantly ground water with a minor component of surface water. Meadowbrook and Girl Scout Galleries induce infiltration of surface water from Rapid Creek but also have a significant component of ground water.

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

NASA Astrophysics Data System (ADS)

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

2009-12-01

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

Analysis of Spring Flow Change in the Jinan City under Influences of Recent Human Activities

NASA Astrophysics Data System (ADS)

Liu, Xiaomeng; Hu, Litang; Sun, Kangning

2018-06-01

Jinan city, the capital of Shandong Province in China, is famous for its beautiful springs. With the rapid development of the economy in recent years, water demand in Jinan city has been increasing rapidly. The over-exploitation of groundwater has caused a decline in groundwater level and, notably, dried up springs under extreme climate conditions. To keep the springs gushing perennially and sustainably use groundwater resources, the local government has implemented many measures to restore the water table, such as the Sponge City Construction Project in Jinan. Focusing on changes in spring flow and its impact factors in Jinan, this paper analyzes the changes in observed spring flow in the most recent 50 years and then discusses the causes of decreases in the spring flow with the consideration of climate and human activities. Spring flow in the study area was changed from the natural state to a period of multiwater source management. The artificial neural network (ANN) model was developed to demonstrate the relationship among spring flow, precipitation, and groundwater abstraction to predict the variations of spring flow under the conditions of climate change and human activities. The good agreement between the simulated and observed results indicates that both precipitation and exploitation are important influence factors. However the effective infiltration of precipitation into groundwater is the most influential factor. The results can provide guidance for groundwater resource protection in the Jinan spring catchment.

Building groundwater modeling capacity in Mongolia

USGS Publications Warehouse

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

2016-06-16

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

The use of tritium content as an indicator of the groundwater contamination by sanitary landfills leachates in the region of Belo Horizonte City, Brazil.

PubMed

Bandeira, J V; Mingote, R M; Baptista, M B; Oliveira, D M; Lima, F P

2008-01-01

Tritium content in the leachate of sanitary landfills, in concentrations well above those observed in global precipitation, can be used as a tracer for the evaluation of the contamination of groundwater in piezometers of the landfills and in neighbouring tubular wells. This possibility was first investigated in Brazil for sanitary landfills in the region of Belo Horizonte City. Tritium levels together with the content of metals present in water and the measurement of soil electrical conductivity, proved to be valuable for these studies and also as a tracer for hydrodynamic studies of the surface water in the Ressaca creek. IWA Publishing 2008.

Management decision of optimal recharge water in groundwater artificial recharge conditions- A case study in an artificial recharge test site

NASA Astrophysics Data System (ADS)

He, H. Y.; Shi, X. F.; Zhu, W.; Wang, C. Q.; Ma, H. W.; Zhang, W. J.

2017-11-01

The city conducted groundwater artificial recharge test which was taken a typical site as an example, and the purpose is to prevent and control land subsidence, increase the amount of groundwater resources. To protect groundwater environmental quality and safety, the city chose tap water as recharge water, however, the high cost makes it not conducive to the optimal allocation of water resources and not suitable to popularize widely. To solve this, the city selects two major surface water of River A and B as the proposed recharge water, to explore its feasibility. According to a comprehensive analysis of the cost of recharge, the distance of the water transport, the quality of recharge water and others. Entropy weight Fuzzy Comprehensive Evaluation Method is used to prefer tap water and water of River A and B. Evaluation results show that water of River B is the optimal recharge water, if used; recharge cost will be from 0.4724/m3 to 0.3696/m3. Using Entropy weight Fuzzy Comprehensive Evaluation Method to confirm water of River B as optimal water is scientific and reasonable. The optimal water management decisions can provide technical support for the city to carry out overall groundwater artificial recharge engineering in deep aquifer.

Groundwater quality & sustainability in Ulaanbaatar, the fast growing Capital of Mongolia

NASA Astrophysics Data System (ADS)

Batsaikhan, N.; Woo, N. C.; Nemer, B.

2011-12-01

About 40% (1.1 million out of 2.7 million total) of Mongolian population lives in the capital city, Ulaanbaatar. The city's drinking water totally depends on groundwater pumped from the alluvial aquifer along the Tuul River and some private wells for domestic usage. As a measure to evaluate groundwater conditions, a total 55 samples from groundwater and surface waters were collected in the public central well-field and its adjacent area from August 2010 to Feb. 2011, for characteristics of water chemistry and environmental isotopic signatures. The water types were classified with Ca-Mg-HCO3, Ca-Na-HCO3 and Ca-HCO3 in summer, but predominantly Ca-HCO3 in winter. Statistical analysis of water compositions shows two groups of water: group-A waters from the Public central supply well-field with Tuul river waters, and group-B from other area including Ger dwelling areas. In terms of water quality, nitrate concentrations exceeded the WHO Guidelines for drinking-water quality (50 mg/l) in 55% (15 out of 27 samples) of the group-B; it implies that the potential sources of groundwater contamination be domestic waste-disposal practices and underdeveloped sewage systems. Environmental isotopes and water-level monitoring data indicated that shallow wells, showing the depth to water less than 3 m bgs, appear to be directly recharged from rainfalls and river water. In contrast, wells with the depth to water in between 5 and 7 m and located some distance from Tuul River take approximately 2 to 3 months to be recharged in rainy season. Since Ulaanbaatar has been growing fast as the Capital of Mongolia, various types of potential sources of groundwater contamination have also been located inside the city boundary including tanning industries, coal-based thermal power plants, gas stations, etc. Thus, for the sustainable development of the Capitol, it is warranted to develop better management measures with long-term and systematic monitoring to protect water-supply sources.

Simulation of the impact of managed aquifer recharge on the groundwater system in Hanoi, Vietnam

NASA Astrophysics Data System (ADS)

Glass, Jana; Via Rico, Daniela A.; Stefan, Catalin; Nga, Tran Thi Viet

2018-05-01

A transient numerical groundwater flow model using MODFLOW-NWT was set up and calibrated for Hanoi city, Vietnam, to understand the local groundwater flow system and to suggest solutions for sustainable water resource management. Urban development in Hanoi has caused a severe decline of groundwater levels. The present study evaluates the actual situation and investigates the suitability of managed aquifer recharge (MAR) to stop further depletion of groundwater resources. The results suggest that groundwater is being overexploited, as vast cones of depression exist in parts of the study area. Suitable locations to implement two MAR techniques—riverbank filtration and injection wells—were identified using multi-criteria decision analysis based on geographic information system (GIS). Three predictive scenarios were simulated. The relocation of pumping wells towards the Red River to induce riverbank filtration (first scenario) demonstrates that groundwater levels can be increased, especially in the depression cones. Groundwater levels can also be improved locally by the infiltration of surplus water into the upper aquifer (Holocene) via injection wells during the rainy season (second scenario), but this is not effective to raise the water table in the depression cones. Compared to the first scenario, the combination of riverbank filtration and injection wells (third scenario) shows a slightly raised overall water table. Groundwater flow modeling suggests that local overexploitation can be stopped by a smart relocation of wells from the main depression cones and the expansion of riverbank filtration. This could also avoid further land subsidence while the city's water demand is met.

Geomatics for Mapping of Groundwater Potential Zones in Northern Part of the United Arab Emiratis - Sharjah City

NASA Astrophysics Data System (ADS)

Al-Ruzouq, R.; Shanableh, A.; Merabtene, T.

2015-04-01

In United Arab Emirates (UAE) domestic water consumption has increased rapidly over the last decade. The increased demand for high-quality water, create an urgent need to evaluate the groundwater production of aquifers. The development of a reasonable model for groundwater potential is therefore crucial for future systematic developments, efficient management, and sustainable use of groundwater resources. The objective of this study is to map the groundwater potential zones in northern part of UAE and assess the contributing factors for exploration of potential groundwater resources. Remote sensing data and geographic information system will be used to locate potential zones for groundwater. Various maps (i.e., base, soil, geological, Hydro-geological, Geomorphologic Map, structural, drainage, slope, land use/land cover and average annual rainfall map) will be prepared based on geospatial techniques. The groundwater availability of the basin will qualitatively classified into different classes based on its hydro-geo-morphological conditions. The land use/land cover map will be also prepared for the different seasons using a digital classification technique with a ground truth based on field investigation.

Hydrogeology and simulation of groundwater flow in the Arbuckle-Simpson aquifer, south-central Oklahoma

USGS Publications Warehouse

Christenson, Scott; Osborn, Noel I.; Neel, Christopher R.; Faith, Jason R.; Blome, Charles D.; Puckette, James; Pantea, Michael P.

2011-01-01

Groundwater in the aquifer moves from areas of high head (altitude) to areas of low head along streams and springs. The potentiometric surface in the eastern Arbuckle-Simpson aquifer generally slopes from a topographic high from northwest to the southeast, indicating that regional groundwater flow is predominantly toward the southeast. Freshwater is known to extend beyond the aquifer outcrop near the City of Sulphur, Oklahoma, and Chickasaw National Recreation Area, where groundwater flows west from the outcrop of the eastern Arbuckle-Simpson aquifer and becomes confin

CAD-DRASTIC: chloride application density combined with DRASTIC for assessing groundwater vulnerability to road salt application

NASA Astrophysics Data System (ADS)

Salek, Mansour; Levison, Jana; Parker, Beth; Gharabaghi, Bahram

2018-06-01

Road salt is pervasively used throughout Canada and in other cold regions during winter. For cities relying exclusively on groundwater, it is important to plan and minimize the application of salt accordingly to mitigate the adverse effects of high chloride concentrations in water supply aquifers. The use of geospatial data (road network, land use, Quaternary and bedrock geology, average annual recharge, water-table depth, soil distribution, topography) in the DRASTIC methodology provides an efficient way of distinguishing salt-vulnerable areas associated with groundwater supply wells, to aid in the implementation of appropriate management practices for road salt application in urban areas. This research presents a GIS-based methodology to accomplish a vulnerability analysis for 12 municipal water supply wells within the City of Guelph, Ontario, Canada. The chloride application density (CAD) value at each supply well is calculated and related to the measured groundwater chloride concentrations and further combined with soil media and aquifer vadose- and saturated-zone properties used in DRASTIC. This combined approach, CAD-DRASTIC, is more accurate than existing groundwater vulnerability mapping methods and can be used by municipalities and other water managers to further improve groundwater protection related to road salt application.

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

PubMed

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

2014-07-01

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

Sinking coastal cities

NASA Astrophysics Data System (ADS)

Erkens, Gilles; Bucx, Tom; Dam, Rien; De Lange, Ger; Lambert, John

2014-05-01

In many coastal and delta cities land subsidence now exceeds absolute sea level rise up to a factor of ten. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Land subsidence increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. In addition, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs. This effects roads and transportation networks, hydraulic infrastructure - such as river embankments, sluice gates, flood barriers and pumping stations -, sewage systems, buildings and foundations. The total damage worldwide is estimated at billions of dollars annually. Excessive groundwater extraction after rapid urbanization and population growth is the main cause of severe land subsidence. In addition, coastal cities are often faced with larger natural subsidence, as they are built on thick sequences of soft soil. Because of ongoing urbanization and population growth in delta areas, in particular in coastal megacities, there is, and will be, more economic development in subsidence-prone areas. The impacts of subsidence are further exacerbated by extreme weather events (short term) and rising sea levels (long term).Consequently, detrimental impacts will increase in the near future, making it necessary to address subsidence related problems now. Subsidence is an issue that involves many policy fields, complex technical aspects and governance embedment. There is a need for an integrated approach in order to manage subsidence and to develop appropriate strategies and measures that are effective and efficient on both the short and long term. Urban (ground)water management, adaptive flood risk management and related spatial planning strategies are just examples of the options available. A major rethink is needed to deal with the 'hidden' but urgent

Sinking coastal cities

NASA Astrophysics Data System (ADS)

Erkens, G.; Bucx, T.; Dam, R.; de Lange, G.; Lambert, J.

2015-11-01

In many coastal and delta cities land subsidence now exceeds absolute sea level rise up to a factor of ten. A major cause for severe land subsidence is excessive groundwater extraction related to rapid urbanization and population growth. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Land subsidence increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. In addition, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs for (infra)structure. The total damage worldwide is estimated at billions of dollars annually. As subsidence is often spatially variable and can be caused by multiple processes, an assessment of subsidence in delta cities needs to answer questions such as: what are the main causes? What is the current subsidence rate and what are future scenarios (and interaction with other major environmental issues)? Where are the vulnerable areas? What are the impacts and risks? How can adverse impacts be mitigated or compensated for? Who is involved and responsible to act? In this study a quick-assessment of subsidence is performed on the following mega-cities: Jakarta, Ho Chi Minh City, Dhaka, New Orleans and Bangkok. Results of these case studies will be presented and compared, and a (generic) approach how to deal with subsidence in current and future subsidence-prone areas is provided.

Assessing the Impact of Chlorinated-Solvent Sites on Metropolitan Groundwater Resources

PubMed Central

Brusseau, Mark L.; Narter, Matthew

2014-01-01

Chlorinated-solvent compounds are among the most common groundwater contaminants in the U.S.A. The majority of the many sites contaminated by chlorinated-solvent compounds are located in metropolitan areas, and most such areas have one or more chlorinated-solvent contaminated sites. Thus, contamination of groundwater by chlorinated-solvent compounds may pose a potential risk to the sustainability of potable water supplies for many metropolitan areas. The impact of chlorinated-solvent sites on metropolitan water resources was assessed for Tucson, AZ, by comparing the aggregate volume of extracted groundwater for all pump-and-treat systems associated with contaminated sites in the region to the total regional groundwater withdrawal. The analysis revealed that the aggregate volume of groundwater withdrawn for the pump-and-treat systems operating in Tucson, all of which are located at chlorinated-solvent contaminated sites, was 20% of the total groundwater withdrawal in the city for the study period. The treated groundwater was used primarily for direct delivery to local water supply systems or for reinjection as part of the pump-and-treat system. The volume of the treated groundwater used for potable water represented approximately 13% of the total potable water supply sourced from groundwater, and approximately 6% of the total potable water supply. This case study illustrates the significant impact chlorinated-solvent contaminated sites can have on groundwater resources and regional potable-water supplies. PMID:24116872

Drugs of abuse in urban groundwater. A case study: Barcelona.

NASA Astrophysics Data System (ADS)

Jurado, A.; Mastroianni, N.; Vazquez-Suñe, E.; Carrera, J.; Tubau, I.; Pujades, E.; Postigo, C.; Lopez de Alda, M.; Barceló, D.

2012-04-01

This study is concerned with drugs of abuse (DAs) and their metabolites in urban groundwater at field scale in relation to (1) the spatial distribution of the groundwater samples, (2) the depth of the groundwater sample, (3) the presence of DAs in recharge sources, and (4) the identification of processes affecting the fate of DAs in groundwater. To this end, urban groundwater samples were collected in the city of Barcelona and a total of 21 drugs were analyzed including cocainics, amphetamine-like compounds, opioids, lysergics and cannabinoids and the prescribed drugs benzodiazepines. Overall, the highest groundwater concentrations and the largest number of detected DAs were found in zones basically recharged by a river that receives large amounts of effluents from waste water treatment plants (WWTPs). In contrast, the urbanized areas yielded not only lower concentrations but also a much smaller number of drugs, which suggests a local origin. In fact, cocaine and its metabolite were dominant in more prosperous neighbourhoods, whereas the cheaper (MDMA) was the dominant DA in poorer districts. Concentrations of DAs estimated mainly from the waste water fraction in groundwater samples were consistently higher than the measured ones, suggesting that DAs undergo removal processes in both reducing and oxidizing conditions.

[Study on the risk assessment method of regional groundwater pollution].

PubMed

Yang, Yan; Yu, Yun-Jiang; Wang, Zong-Qing; Li, Ding-Long; Sun, Hong-Wei

2013-02-01

Based on the boundary elements of system risk assessment, the regional groundwater pollution risk assessment index system was preliminarily established, which included: regional groundwater specific vulnerability assessment, the regional pollution sources characteristics assessment and the health risk assessment of regional featured pollutants. The three sub-evaluation systems were coupled with the multi-index comprehensive method, the risk was characterized with the Spatial Analysis of ArcMap, and a new method to evaluate regional groundwater pollution risk that suitable for different parts of natural conditions, different types of pollution was established. Take Changzhou as an example, the risk of shallow groundwater pollution was studied with the new method, and found that the vulnerability index of groundwater in Changzhou is high and distributes unevenly; The distribution of pollution sources is concentrated and has a great impact on groundwater pollution risks; Influenced by the pollutants and pollution sources, the values of health risks are high in the urban area of Changzhou. The pollution risk of shallow groundwater is high and distributes unevenly, and distributes in the north of the line of Anjia-Xuejia-Zhenglu, the center of the city and the southeast, where the human activities are more intense and the pollution sources are intensive.

Local capacity for groundwater protection in Ontario.

PubMed

De Loë, Rob C; Di Giantomasso, Sandra E; Kreutzwiser, Reid D

2002-02-01

Preventing groundwater contamination is vastly cheaper than remediation. Recognizing this, attention in water and land management agencies in North America increasingly turn to groundwater protection. Local agencies, such as municipalities and watershed management districts, are vital to successful groundwater protection, but they face daunting challenges. In the United States, senior governments have recognized these challenges and provide considerable support for local agencies. In Ontario, Canada, local agencies are, to a much greater extent, on their own. The aims in this paper are to analyze factors that shape local capacity for groundwater protection, focusing on Ontario, and to recommend avenues for capacity building. Interrelationships among five dimensions of capacity (technical, financial, institutional, social, and political) are explored through an analysis of three smaller Ontario communities: City of Guelph (population 93,400), Town of Orangeville (population 22,188), and Town of Erin (population 11,000). Size clearly influences capacity for groundwater protection. However, other considerations unrelated to size appear to be as important. These other factors include the ability to form horizontal and vertical linkages with external agencies, political leadership and commitment, and citizen involvement. Thus, smaller communities in Ontario (and other jurisdictions with limited senior government support) would do well to focus on these areas at the same time as they develop their technical, financial, and institutional capacity.

Eolian transport, saline lake basins, and groundwater solutes

USGS Publications Warehouse

Wood, Warren W.; Sanford, Ward E.

1995-01-01

Eolian processes associated with saline lakes are shown to be important in determining solute concentration in groundwater in arid and semiarid areas. Steady state mass balance analyses of chloride in the groundwater at Double Lakes, a saline lake basin in the southern High Plains of Texas, United States, suggest that approximately 4.5 × 105 kg of chloride is removed from the relatively small (4.7 km2) basin floor each year by deflation. This mass enters the groundwater down the wind gradient from the lake, degrading the water quality. The estimates of mass transport were independently determined by evaluation of solutes in the unsaturated zone and by solute mass balance calculations of groundwater flux. Transport of salts from the lake was confirmed over a short term (2 years) by strategically placed dust collectors. Results consistent with those at Double Lake were obtained from dune surfaces collected upwind and downwind from a sabkha near the city of Abu Dhabi in the United Arab Emirates. The eolian transport process provides an explanation of the degraded groundwater quality associated with the 30–40 saline lake basins on the southern half of the southern High Plains of Texas and New Mexico and in many other arid and semiarid areas.

Urbanization effect on groundwater quality (Paleohydrogeological study)

NASA Astrophysics Data System (ADS)

Sabri, Raghid; Merkel, Broder; Tichomirowa, Marion

2015-04-01

Speleothem growing in caves usually contain hydrological information. Carbonates precipitation growing in tunnels under cities contain information about anthropological influence on water system. Carbonate samples were taken from Roman tunnels in rural and urban area in Nablus district- Palestine. These laminated samples were analyzed for rare earth elements (REE), 13C and 18O. For REE, five samples were examined, each lamination was extracted and diluted with 0.1 ml 65% HNO3 and measured using ICP-MS. Yet, limited number of lamination was used for isotope analysis using Isotope ratio mass spectrometry. Total concentration of rare earth elements were calculated for each of the five samples. In all examined samples, the newer laminations show higher peaks than the older one of each sample. On the other hand, one sample (8 measurements) of 13C show values between -31.6° and -36°. These values mean that the carbonate is from organic origin. In an urban area, wastewater infiltration into groundwater system can be the source of organic matter. 18O measurements show continues enrichments within the growth of the carbonate. This increase of the 18O values reflects drier weather. Our results can be explained by the increase of water consumption in the household in the recent 100 years, rather than the increase of using detergents and cleaning products which have influenced groundwater quality as appeared in the carbonate samples. On the other hand, 18O results could be linked with the expansion of the building up area in the city and subsequently reduction of groundwater recharge

Hydrogeology, ground-water use, and ground-water levels in the Mill Creek Valley near Evendale, Ohio

USGS Publications Warehouse

Schalk, Charles; Schumann, Thomas

2002-01-01

Withdrawals of ground water in the central Mill Creek Valley near Evendale, Ohio, caused water-level declines of more than 100 feet by the 1950s. Since the 1950s, management practices have changed to reduce the withdrawals of ground water, and recovery of water levels in long-term monitoring wells in the valley has been documented. Changing conditions such as these prompted a survey of water use, streamflow conditions, and water levels in several aquifers in the central Mill Creek Valley, Hamilton and Butler Counties, Ohio. Geohydrologic information, water use, and water levels were compiled from historical records and collected during the regional survey. Data collected during the survey are presented in terms of updated geohydrologic information, water use in the study area, water levels in the aquifers, and interactions between ground water and surface water. Some of the data are concentrated at former Air Force Plant 36 (AFP36), which is collocated with the General Electric Aircraft Engines (GEAE) plant, and these data are used to describe geohydrology and water levels on a more local scale at and near the plant. A comparison of past and current ground-water use and levels indicates that the demand for ground water is decreasing and water levels are rising. Before 1955, most of the major industrial ground-water users had their own wells, ground water was mined from a confined surficial (lower) aquifer, and water levels were more than 100 feet below their predevelopment level. Since 1955, however, these users have been purchasing their water from the city of Cincinnati or a private water purveyor. The cities of Reading and Lockland, both producers of municipal ground-water supplies in the area, shut down their well fields within their city limits. Because the demand for ground-water supplies in the valley has lessened greatly since the 1950s, withdrawals have decreased, and, consequently, water levels in the lower aquifer are 65 to 105 feet higher than they were

Groundwater vulnerability mapping in Guadalajara aquifers system (Western Mexico)

NASA Astrophysics Data System (ADS)

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

2016-04-01

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

Groundwater quality assessment of urban Bengaluru using multivariate statistical techniques

NASA Astrophysics Data System (ADS)

Gulgundi, Mohammad Shahid; Shetty, Amba

2018-03-01

Groundwater quality deterioration due to anthropogenic activities has become a subject of prime concern. The objective of the study was to assess the spatial and temporal variations in groundwater quality and to identify the sources in the western half of the Bengaluru city using multivariate statistical techniques. Water quality index rating was calculated for pre and post monsoon seasons to quantify overall water quality for human consumption. The post-monsoon samples show signs of poor quality in drinking purpose compared to pre-monsoon. Cluster analysis (CA), principal component analysis (PCA) and discriminant analysis (DA) were applied to the groundwater quality data measured on 14 parameters from 67 sites distributed across the city. Hierarchical cluster analysis (CA) grouped the 67 sampling stations into two groups, cluster 1 having high pollution and cluster 2 having lesser pollution. Discriminant analysis (DA) was applied to delineate the most meaningful parameters accounting for temporal and spatial variations in groundwater quality of the study area. Temporal DA identified pH as the most important parameter, which discriminates between water quality in the pre-monsoon and post-monsoon seasons and accounts for 72% seasonal assignation of cases. Spatial DA identified Mg, Cl and NO3 as the three most important parameters discriminating between two clusters and accounting for 89% spatial assignation of cases. Principal component analysis was applied to the dataset obtained from the two clusters, which evolved three factors in each cluster, explaining 85.4 and 84% of the total variance, respectively. Varifactors obtained from principal component analysis showed that groundwater quality variation is mainly explained by dissolution of minerals from rock water interactions in the aquifer, effect of anthropogenic activities and ion exchange processes in water.

Risk of Giardia intestinalis infection in children from an artificially recharged groundwater area in Mexico City.

PubMed

Cifuentes, Enrique; Suárez, Leticia; Espinosa, Martha; Juárez-Figueroa, Luis; Martínez-Palomo, Adolfo

2004-07-01

The objective of this study was to assess the risk of infection with Giardia intestinalis in children living in an area with artificial groundwater recharge and potable water reuse in Mexico City. Eligible wells and surrounding homesteads were defined by using a geographic information system. Five wells were tested for G. intestinalis cysts per 400 liters of water. A total of 750 eligible households were visited during two cross-sectional surveys. Stool samples were provided by 986 children in the rainy season study and 928 children during the dry season survey for parasitologic tests. Their guardians provided information on water, sanitation, hygiene, and socioeconomic variables. The prevalence rates of G. intestinalis infection were 9.4% in the rainy season and 4.4% in the dry season. Higher rates of infection were observed in older individuals (9.5% and 10.6%) and girls had a lower risk of infection than boys (odds ratio [OR] =0.55, 95% confidence interval [CI] = 0.34, 0.88 in the rainy season and OR = 0.47, 95% CI = 0.25, 0.90 in the dry season). During the wet season survey, a health risk was detected among those storing water in unprotected receptacles (OR = 4.00, 4.69, and 5.34 for those using uncovered jars, cisterns or tanks, and buckets, respectively), and bathing outside the dwelling, i.e., using a tap (OR = 1.93, 95% CI = 1.10, 3.39). A health risk was also detected among children from households with unsafe food hygiene practices (OR =2.41, 95% CI =1.10, 5.30) and those with no hand-washing habits (OR = 2.27, 95% CI = 1.00, 5.20). Groundwater reserves are at risk of fecal pollution, as indicated by the presence of G. intestinalis cysts. However, the endemic pattern of intestinal infection reflects low standards of personal hygiene and unsafe drinking water storage and food-related practices at household level. Prevention activities must address health education and environmental protection policies.

Application of RBFN network and GM (1, 1) for groundwater level simulation

NASA Astrophysics Data System (ADS)

Li, Zijun; Yang, Qingchun; Wang, Luchen; Martín, Jordi Delgado

2017-10-01

Groundwater is a prominent resource of drinking and domestic water in the world. In this context, a feasible water resources management plan necessitates acceptable predictions of groundwater table depth fluctuations, which can help ensure the sustainable use of a watershed's aquifers for urban and rural water supply. Due to the difficulties of identifying non-linear model structure and estimating the associated parameters, in this study radial basis function neural network (RBFNN) and GM (1, 1) models are used for the prediction of monthly groundwater level fluctuations in the city of Longyan, Fujian Province (South China). The monthly groundwater level data monitored from January 2003 to December 2011 are used in both models. The error criteria are estimated using the coefficient of determination ( R 2), mean absolute error (E) and root mean squared error (RMSE). The results show that both the models can forecast the groundwater level with fairly high accuracy, but the RBFN network model can be a promising tool to simulate and forecast groundwater level since it has a relatively smaller RMSE and MAE.

Identification of surface water-groundwater interaction by hydrogeochemical indicators and assessing its suitability for drinking and irrigational purposes in Chennai, Southern India

NASA Astrophysics Data System (ADS)

Brindha, K.; Neena Vaman, K. V.; Srinivasan, K.; Sathis Babu, M.; Elango, L.

2014-06-01

Large cities face water quality and quantity problems due to increasing population and improper disposal of solid and liquid wastes. It is essential to monitor the water quality to take corrective measures. This study was carried out in one of the densely populated metropolitan cities in India to ascertain the suitability of groundwater for drinking and irrigation activity, identify the processes controlling the geochemistry of groundwater and the impact of Adyar River on the groundwater quality. Magnesium and pH concentration in groundwater of this area were within the maximum permissible limits of WHO standards. Sodium and potassium concentration of groundwater were greater than the permissible limit in 30.8 % and in 50 % of the samples, respectively. About 35 % of the groundwater samples were not permissible for drinking based on the electrical conductivity (EC). The EC of groundwater was increasing towards the coast. In general, the quality of groundwater for irrigation purpose vary from moderate to good based on Na%, magnesium hazard, residual sodium carbonate, sodium absorption ratio, permeability index, and USDA classification. Na-Cl and Ca-Mg-Cl were the dominant groundwater and surface water type. Increased ionic concentration of groundwater towards the eastern part of the study area is due to the discharge of industrial effluents and domestic sewage into the Adyar River. Seawater intrusion is also one of the reasons for Na-Cl dominant groundwater near the coast. Evaporation and ion exchange were the major processes controlling groundwater chemistry in this area. The groundwater quality of this region is affected by the contaminated surface water.

Groundwater quality in the Mojave area, California

USGS Publications Warehouse

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

Development of monitoring and modelling tools as basis for sustainable thermal management concepts of urban groundwater bodies

NASA Astrophysics Data System (ADS)

Mueller, Matthias H.; Epting, Jannis; Köhler, Mandy; Händel, Falk; Huggenberger, Peter

2015-04-01

Increasing groundwater temperatures observed in many urban areas strongly interfere with the demand of thermal groundwater use. The groundwater temperatures in these urban areas are affected by numerous interacting factors: open and closed-loop geothermal systems for heating and cooling, sealed surfaces, constructions in the subsurface (infrastructure and buildings), artificial groundwater recharge, and interaction with rivers. On the one hand, these increasing groundwater temperatures will negatively affect the potential for its use in the future e.g. for cooling purposes. On the other hand, elevated subsurface temperatures can be considered as an energy source for shallow geothermal heating systems. Integrated thermal management concepts are therefore needed to coordinate the thermal use of groundwater in urban areas. These concepts should be based on knowledge of the driving processes which influence the thermal regime of the aquifer. We are currently investigating the processes influencing the groundwater temperature throughout the urban area of Basel City, Switzerland. This involves a three-dimensional numerical groundwater heat-transport model including geothermal use and interactions with the unsaturated zone such as subsurface constructions reaching into the aquifer. The cantonal groundwater monitoring system is an important part of the data base in our model, which will help to develop sustainable management strategies. However, single temperature measurements in conventional groundwater wells can be biased by vertical thermal convection. Therefore, multilevel observation wells are used in the urban areas of the city to monitor subsurface temperatures reaching from the unsaturated zone to the base of the aquifer. These multilevel wells are distributed in a pilot area in order to monitor the subsurface temperatures in the vicinity of deep buildings and to quantify the influence of the geothermal use of groundwater. Based on time series of the conventional

Groundwater-level data from an earthen dam site in southern Westchester County, New York

USGS Publications Warehouse

Noll, Michael L.; Chu, Anthony

2018-05-01

In 2005, the U.S. Geological Survey began a cooperative study with New York City Department of Environmental Protection to characterize the local groundwater-flow system and identify potential sources of seeps on the southern embankment of the Hillview Reservoir in Westchester County, New York. Groundwater levels were collected at 49 wells at Hillview Reservoir, and 1 well in northern Bronx County, from April 2005 through November 2016. Groundwater levels were measured discretely with a chalked steel or electric tape, or continuously with a digital pressure transducer, or both, in accordance with U.S. Geological Survey groundwatermeasurement standards. These groundwater-level data were plotted as time series and are presented in this report as hydrographs. Twenty-eight of the 50 hydrographs have continuous record and discrete field groundwater-level measurements, 22 of the hydrographs contain only discrete measurements.

Digital data sets that describe aquifer characteristics of the Elk City Aquifer in western Oklahoma

USGS Publications Warehouse

Becker, C.J.; Runkle, D.L.; Rea, Alan

1997-01-01

ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000 acres and supplies ground water for irrigation, domestic, and industrial purposes in Beckham, Custer, Roger Mills, and Washita Counties along the divide between the Washita and Red River basins. The Elk City aquifer consists of the Elk City Sandstone and overlying terrace deposits, made up of clay, silt, sand and gravel, and dune sands in the eastern part and sand and gravel of the Ogallala Formation (or High Plains aquifer) in the western part of the aquifer. The Elk City aquifer is unconfined and composed of very friable sandstone, lightly cemented with clay, calcite, gypsum, or iron oxide. Most of the grains are fine-sized quartz but the grain size ranges from clay to cobble in the aquifer. The Doxey Shale underlies the Elk City aquifer and acts as a confining unit, restricting the downward movement of ground water. All of the data sets were digitized and created from information and maps in a ground-water modeling thesis and report of the Elk City aquifer. The maps digitized were published at a scale of 1:63,360. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Groundwater quality in the Monterey Bay and Salinas Valley groundwater basins, California

USGS Publications Warehouse

Kulongoski, Justin T.; Belitz, Kenneth

2011-01-01

. Land use in the study unit is about 44 percent (%) natural (mostly grassland and forests), 43% agricultural, and 13% urban. The primary agricultural uses are row crops, pasture, hay, and vineyards. The largest urban areas are the cities of Santa Cruz, Watsonville, Monterey, Salinas, King City, and Paso Robles. Recharge to the groundwater system is primarily from stream-channel infiltration from the major rivers and their tributaries, and from infiltration of water from precipitation and irrigation. The primary sources of discharge are water pumped for irrigation and municipal supply, evaporation, and discharge to streams.

Identifying anthropogenic anomalies in air, surface and groundwater temperatures in Germany.

PubMed

Benz, Susanne A; Bayer, Peter; Blum, Philipp

2017-04-15

Human activity directly influences ambient air, surface and groundwater temperatures. The most prominent phenomenon is the urban heat island effect, which has been investigated particularly in large and densely populated cities. This study explores the anthropogenic impact on the thermal regime not only in selected urban areas, but on a countrywide scale for mean annual temperature datasets in Germany in three different compartments: measured surface air temperature, measured groundwater temperature, and satellite-derived land surface temperature. Taking nighttime lights as an indicator of rural areas, the anthropogenic heat intensity is introduced. It is applicable to each data set and provides the difference between measured local temperature and median rural background temperature. This concept is analogous to the well-established urban heat island intensity, but applicable to each measurement point or pixel of a large, even global, study area. For all three analyzed temperature datasets, anthropogenic heat intensity grows with increasing nighttime lights and declines with increasing vegetation, whereas population density has only minor effects. While surface anthropogenic heat intensity cannot be linked to specific land cover types in the studied resolution (1km×1km) and classification system, both air and groundwater show increased heat intensities for artificial surfaces. Overall, groundwater temperature appears most vulnerable to human activity, albeit the different compartments are partially influenced through unrelated processes; unlike land surface temperature and surface air temperature, groundwater temperatures are elevated in cultivated areas as well. At the surface of Germany, the highest anthropogenic heat intensity with 4.5K is found at an open-pit lignite mine near Jülich, followed by three large cities (Munich, Düsseldorf and Nuremberg) with annual mean anthropogenic heat intensities >4K. Overall, surface anthropogenic heat intensities >0K and

Groundwater quality in Coachella Valley, California

USGS Publications Warehouse

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. Coachella Valley is one of the study areas being evaluated. The Coachella study area is approximately 820 square miles (2,124 square kilometers) and includes the Coachella Valley groundwater basin (California Department of Water Resources, 2003). Coachella Valley has an arid climate, with average annual rainfall of about 6 inches (15 centimeters). The runoff from the surrounding mountains drains to rivers that flow east and south out of the study area to the Salton Sea. Land use in the study area is approximately 67 percent (%) natural, 21% agricultural, and 12% urban. The primary natural land cover is shrubland. The largest urban areas are the cities of Indio and Palm Springs (2010 populations of 76,000 and 44,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Coachella Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Coachella Valley are completed to depths between 490 and 900 feet (149 to 274 meters), consist of solid casing from the land surface to a depth of 260 to 510 feet (79 to 155 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to

Ground-water resources of Kansas

USGS Publications Warehouse

Moore, R.C.; Lohman, S.W.; Frye, J.C.; Waite, H.A.; McLaughlin, Thad G.; Latta, Bruce

1940-01-01

Importance of ground-water resources.—The importance of Kansas' ground-water resources may be emphasized from various viewpoints and in different ways. More than three-fourths of the public water supplies of Kansas are obtained from wells. In 1939, only 60 out of 375 municipal water supplies in Kansas, which is 16 percent, utilized surface waters. If the water wells of the cities and those located on all privately owned land in the state were suddenly destroyed, making it necessary to go to streams, springs, lakes (which are almost all artificial), and ponds for water supply domestic, stock, and industrial use, there would be almost incalculable difficulty and expense. If one could not go to springs, or dig new wells, or use any surface water derived from underground flow, much of Kansas would become uninhabitable.  These suggested conditions seem absurd, but they emphasize our dependence on ground-water resources. Fromm a quantitative standpoint, ground-water supplies existent in Kansas far outweigh surface waters that are present in the state at any one time. No exact figures for such comparison can be given, but, taking 384 square miles as the total surface water area of the state and estimating an average water depth of five feet, the computed volume of surface waters is found to be 1/100th of that of the conservatively estimated ground-water storage in Kansas. The latter takes account only of potable fresh water and is based on an assumed mean thickness of ten feet of reservoir having an effective porosity of twenty percent. It is to be remembered, however, that most of the surface water is run-off, which soon leaves the state, stream valleys being replenished from rainfall and flow from ground-water reservoirs. Most of the ground-water supplies, on the other hand, have existed for many years with almost no appreciable movement--in fact, it is reasonably certain that some well water drawn from beneath the surface of Kansas in 1940 represents rainfall in

Supplementary report on the ground-water supplies of the Atlantic City region

USGS Publications Warehouse

Barksdale, Henry C.; Sundstrom, Raymond W.; Brunstein, Maurice S.

1936-01-01

At present more potable water is taken from the Atlantic City 800-foot sand than from any other source of supply for the region. This sand is the sole source for some of the smaller communities on the barrier beaches. The original static head of the water in it at Atlantic City was between 20 and 25 feet above sea level. The head has been lowered more than 50 feet over much of the region,  and in parts of Atlantic City it has been lowered considerably more than 100 feet. A consideration of the principles governing the relation between salt water and fresh water in water-bearing sands indicates that the 800-foot sand probably contained salt water at a distance of 5 or 10 miles out from Atlantic City before any water was pumped from it. The evidence collected in this investigation indicates that the cone of depression created by the pumping from this sand in the Atlantic City region has probably extended inland to the intake area of the sand, the nearest part of which is probably about 40 miles from Atlantic City. If this is so, the conclusion is almost inescapable that it has also extended oceanward for a distance considerably greater than the 5 or 10 miles to the original zone of contact between the fresh and salt waters, and that salt water is probably being drawn toward the Atlantic City region through this sand. The time of its arrival will depend primarily upon the rate of pumping in the region and upon how much of the fresh water that originally lay between the region and the zone of contact must be removed before the salt water can reach the region. It may arrive in the near future if it advances in the form of a narrow tongue. On the other hand, if it advances along a broader front; so that more of the intervening fresh water must be pumped out of the formation, its arrival may be delayed for some time.

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

NASA Astrophysics Data System (ADS)

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

Geology and ground-water resources of the Lawrenceville area, Georgia

USGS Publications Warehouse

Chapman, Melinda J.; Crawford, Thomas J.; Tharpe, W. Todd

1999-01-01

The population of the Atlanta Metropolitan area continues to grow at a rapid pace and the demand for water supplies steadily increases. Exploration for ground-water resources, as a supplement to surface-water supplies, is being undertaken by many city and county governments. The application of effective investigative methods to characterization of the complex igneous and metamorphic fractured bedrock aquifers of the Piedmont physiographic province is essential to the success of these ground-water exploration programs. The U.S. Geological Survey, in cooperation with the City of Lawrenceville, Ga., began a study in December 1994 to apply various investigative techniques for field characterization of fractured crystalline-bedrock aquifers near Lawrenceville. Five major lithologic units were mapped in the Lawrenceville, Ga., area as part of an ongoing study of ground-water resources-amphibolite, biotite gneiss, button schist, granite gneiss, and quartzite/aluminous schist. These units generally are thin in outcrop width, have low angles of dip (nearly 0 to 20 degrees, dip reversals occur over short distances), and exhibit some shearing characteristics. The most productive unit for ground-water resources, on the basis of subsurface data collected through 1997, is the amphibolite. Historically, two wells drilled into this unit are recognized as having possibly the highest yields in the Piedmont region of northern Georgia. The City of Lawrenceville refurbished one well at the Rhodes Jordan Wellfield in 1990, and has pumped this well at an average rate of about 230 gallons per minute since 1995. In general, the composition of water collected from the bedrock wells, regolith wells, and City Lake is similar; calcium and bicarbonate are the dominant cation and anion, respectively. Water from the regolith wells and the lake have lower concentrations of major ions than does water from the bedrock wells. Many of the ground-water samples collected from the Rhodes Jordan Wellfield

Groundwater Change in Storage Estimation by Using Monitoring Wells Data

NASA Astrophysics Data System (ADS)

Flores, C. I.

2016-12-01

In present times, remarkable attention is being given to models and data in hydrology, regarding their role in meeting water management requirements to enable well-informed decisions. Water management under the Sustainable Groundwater Management Act (SGMA) is currently challenging, due to it requires that groundwater sustainability agencies (GSAs) formulate groundwater sustainability plans (GSPs) to comply with new regulations and perform a responsible management to secure California's groundwater resources, particularly when droughts and climate change conditions are present. In this scenario, water budgets and change in groundwater storage estimations are key components for decision makers, but their computation is often difficult, lengthy and uncertain. Therefore, this work presents an innovative approach to integrate hydrologic modeling and available groundwater data into a single simplified tool, a proxy function, that estimate in real time the change in storage based on monitoring wells data. A hydrologic model was developed and calibrated for water years 1970 to 2015, the Yolo County IWFM, which was applied to generate the proxy as a study case, by regressing simulated change in storage versus change in head for the cities of Davis and Woodland area, and obtain a linear function dependent on heads variations over time. Later, the proxy was applied to actual groundwater data in this region to predict the change in storage. Results from this work provide proxy functions to approximate change in storage based on monitoring data for daily, monthly and yearly frameworks, being as well easily transferable to any spreadsheet or database to perform simply yet crucial computations in real time for sustainable groundwater management.

Science to Help Understand and Manage Important Ground-Water Resources

USGS Publications Warehouse

Nickles, James

2008-01-01

Throughout California, as pressure on water resources continues to grow, water-supply agencies are looking to the state?s biggest ?reservoir? ? its ground-water basins ? for supply and storage. To better utilize that resource, the Sweetwater Authority and other local partners, including the city of San Diego and Otay Water Districts, are working with the U.S. Geological Survey (USGS) to develop the first comprehensive study of the coastal ground-water resources of southern San Diego County. USGS research is providing the integrated geologic and hydrologic knowledge necessary to help effectively utilize this resource on a coordinated, regional basis. USGS scientists are building a real-time well-monitoring network and gathering information about how the aquifers respond to different pumping and recharge-management strategies. Real-time ground-water levels are recorded every hour and are viewable on a project web site (http://ca.water.usgs.gov/sandiego/index.html). Data from the wells are helping to define the geology and hydrogeology of the area, define ground-water quality, and assess ground-water levels. The wells also are strategi-cally placed and designed to be usable by the local agencies for decades to come to help manage surface-water and ground-water operations. Additionally, the knowledge gained from the USGS study will help local, state, and federal agencies; water purveyors; and USGS scientists to understand the effects of urbanization on the local surface-water, ground-water, and biological resources, and to better critique ideas and opportuni-ties for additional ground-water development in the San Diego area.

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

USGS Publications Warehouse

Smith, Brenda Joyce; Richards, Joseph M.

2008-01-01

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

Simulated effects of alternative withdrawal strategies on groundwater flow in the unconfined Kirkwood-Cohansey aquifer system, the Rio Grande water-bearing zone, and the Atlantic City 800-foot sand in the Great Egg Harbor and Mullica River Basins, New Jersey

USGS Publications Warehouse

Pope, Daryll A.; Carleton, Glen B.; Buxton, Debra E.; Walker, Richard L.; Shourds, Jennifer L.; Reilly, Pamela A.

2012-01-01

Groundwater is essential for water supply and plays a critical role in maintaining the environmental health of freshwater and estuarine ecosystems in the Atlantic Coastal basins of New Jersey. The unconfined Kirkwood-Cohansey aquifer system and the confined Atlantic City 800-foot sand are major sources of groundwater in the area, and each faces different water-supply concerns. The U.S. Geological Survey (USGS), in cooperation with the New Jersey Department of Environmental Protection (NJDEP), conducted a study to simulate the effects of withdrawals in the Kirkwood-Cohansey aquifer system, the Atlantic City 800-foot sand, and the Rio Grande water-bearing zone and to evaluate potential scenarios. The study area encompasses Atlantic County and parts of Burlington, Camden, Gloucester, Ocean, Cape May, and Cumberland Counties. The major hydrogeologic units affecting water supply in the study area are the surficial Kirkwood-Cohansey aquifer system, a thick diatomaceous clay confining unit in the upper part of Kirkwood Formation; the Rio Grande water-bearing zone; and the Atlantic City 800-foot sand of the Kirkwood Formation. Hydrogeologic data from 18 aquifer tests and specific capacity data from 230 wells were analyzed to provide horizontal hydraulic conductivity of the aquifers. Groundwater withdrawals are greatest from the Kirkwood-Cohansey aquifer system, and 65 percent of the water is used for public supply. Groundwater withdrawals from the Atlantic City 800-foot sand are about half those from the Kirkwood-Cohansey aquifer system. Ninety-five percent of the withdrawals from the Atlantic City 800-foot sand is used for public supply. Data from six streamgaging stations and 51 low-flow partial record sites were used to estimate base flow in the area. Base flow ranges from 60 to 92 percent of streamflow. A groundwater flow model of the Kirkwood-Cohansey aquifer system, the Rio Grande water-bearing zone, and the Atlantic City 800-foot sand was developed and calibrated

Uranium isotopes in groundwater occurring at Amazonas State, Brazil.

PubMed

da Silva, Márcio Luiz; Bonotto, Daniel Marcos

2015-03-01

This paper reports the behavior of the dissolved U-isotopes (238)U and (234)U in groundwater providing from 15 cities in Amazonas State, Brazil. The isotope dilution technique accompanied by alpha spectrometry were utilized for acquiring the U content and (234)U/(238)U activity ratio (AR) data, 0.01-1.4µgL(-1) and 1.0-3.5, respectively. These results suggest that the water is circulating in a reducing environment and leaching strata containing minerals with low uranium concentration. A tendency to increasing ARs values following the groundwater flow direction is identified in Manaus city. The AR also increases according to the SW-NE directions: Uarini→Tefé; Manacapuru→Manaus; Presidente Figueiredo→São Sebastião do Uatumã; and Boa Vista do Ramos→Parintins. Such trends are possibly related to several factors, among them the increasing acid character of the waters. The waters analyzed are used for human consumption and the highest dissolved U content is much lower than the maximum established by the World Health Organization. Therefore, in view of this radiological parameter they can be used for drinking purposes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hydrogeologic investigation and simulation of ground-water flow in the Upper Floridan Aquifer of north-central Florida and southwestern Georgia and delineation of contributing areas for selected city of Tallahassee, Florida, water-supply wells

USGS Publications Warehouse

Davis, J. Hal

1996-01-01

A 4-year investigation of the Upper Floridan aquifer and ground-water flow system in Leon County, Florida, and surrounding counties of north-central Florida and southwestern Georgia began in 1990. The purpose of the investigation was to describe the ground-water flow system and to delineate the contributing areas to selected City of Tallahassee, Florida, water-supply wells. The investigation was prompted by the detection of low levels of tetrachloroethylene in ground-water samples collected from several of the city's water-supply wells. Hydrologic data and previous studies indicate that; ground-water flow within the Upper Floridan aquifer can be considered steady-state; the Upper Floridan aquifer is a single water-bearing unit; recharge is from precipitation; and that discharge occurs as spring flow, leakage to rivers, leakage to the Gulf of Mexico, and pumpage. Measured transmissivities of the aquifer ranged from 1,300 ft2/d (feet squared per day) to 1,300,000 ft2/d. Steady-state ground-water flow in the Upper Floridan aquifer was simulated using a three-dimensional ground- water flow model. Transmissivities ranging from less than 5,000 ft2/d to greater than 11,000,000 ft2/d were required to calibrate to observed conditions. Recharge rates used in the model ranged from 18.0 inches per year in areas where the aquifer was unconfined to less than 2 inches per year in broad areas where the aquifer was confined. Contributing areas to five Tallahassee water-supply wells were simulated by particle- tracking techniques. Particles were seeded in model cells containing pumping wells then tracked backwards in time toward recharge areas. The contributing area for each well was simulated twice, once assuming a porosity of 25 percent and once assuming a porosity of 5 percent. A porosity of 25 percent is considered a reasonable average value for the Upper Floridan aquifer; the 5 percent porosity simulated the movement of ground-water through only solution-enhanced bedding plains

Radon (222Rn) in groundwater studies in two volcanic zones of central Mexico

NASA Astrophysics Data System (ADS)

Cortés, A.; Cardona, A.; Pérez-Quezadas, J.; Inguaggiato, S.; Vázquez-López, C.; Golzarri, J. I.; Espinosa, G.

2013-07-01

The distribution of radon (222Rn) concentrations in groundwater from two basins of volcanic origin is presented. Regions have different physiographic characteristics with fractured mafic/intermediate and felsic rocks. Samples were taken from deep wells and springs. Concentrations were field measured by two methods: i) scintillator, coupled to a photomultiplier, and ii) passive method, using Nuclear Track Detectors. Qualitatively, results of 222Rn measured with both techniques are comparable only when concentrations have values less than 1 Bq/l. For the Basin of Mexico City the data shows an average difference of 0.13 Bq/l. Results of 222Rn concentrations in 46 groundwater samples indicate that the data are below 11.1 Bq/l, with both methodologies. Low concentrations of 222Rn in the Basin of Mexico City are related to the mafic intermediate composition rocks such as basalt. The anomalies with high values are correlated with the transition zone between volcanic units and clays from ancient lakes. In San Luis Potosí 10 samples show an average of 4.2 Bq/l. These concentrations compared with those of the Basin of Mexico City are related to the composition of the felsic (rhyolite) volcanic rocks.

The Virginia Beach shallow ground-water study

USGS Publications Warehouse

Johnson, Henry M.

1999-01-01

IntroductionVirginia Beach is a rapidly growing city of more than 425,000 people. Sources of fresh water within the city, however, are limited. Prior to 1998, the Virginia Beach Public Utilities Department met the city's water needs by purchasing treated drinking water from the City of Norfolk. Because Norfolk had to meet its own requirements, the amount of water available to Virginia Beach was limited to about 30 million gallons per day (mgd) and even less during droughts. This water supply was supplemented with ground water from city-owned, community, and private wells. In many parts of the city, however, ground water cannot be used because of high concentrations of chloride, iron, and (or) sulfur, which give the water an unpleasant taste.In early 1998, a pipeline came on-line that can carry up to 45 mgd of water from Lake Gaston to Virginia Beach. The Gaston pipeline has alleviated concerns about water supply and quality for most residents living north of the "Green Line." These residents primarily use ground water only for small-scale domestic activities such as watering lawns, filling ponds and pools, and washing cars. City water and sewer services have been extended beyond the Green Line into the "Transition Area." Residents and businesses south of the Transition Area, however, continue to rely on ground water to meet most of their needs for potable and non-potable water. To help assure a continued, reliable supply of ground water, the U.S. Geological Survey (USGS), in cooperation with the City of Virginia Beach Public Utilities Department, has begun an assessment of the shallow ground-water resources underlying the City of Virginia Beach.

Hydrogeology and simulation of groundwater flow in the Central Oklahoma (Garber-Wellington) Aquifer, Oklahoma, 1987 to 2009, and simulation of available water in storage, 2010–2059

USGS Publications Warehouse

Mashburn, Shana L.; Ryter, Derek W.; Neel, Christopher R.; Smith, S. Jerrod; Magers, Jessica S.

2014-02-10

The Central Oklahoma (Garber-Wellington) aquifer underlies about 3,000 square miles of central Oklahoma. The study area for this investigation was the extent of the Central Oklahoma aquifer. Water from the Central Oklahoma aquifer is used for public, industrial, commercial, agricultural, and domestic supply. With the exception of Oklahoma City, all of the major communities in central Oklahoma rely either solely or partly on groundwater from this aquifer. The Oklahoma City metropolitan area, incorporating parts of Canadian, Cleveland, Grady, Lincoln, Logan, McClain, and Oklahoma Counties, has a population of approximately 1.2 million people. As areas are developed for groundwater supply, increased groundwater withdrawals may result in decreases in long-term aquifer storage. The U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, investigated the hydrogeology and simulated groundwater flow in the aquifer using a numerical groundwater-flow model. The purpose of this report is to describe an investigation of the Central Oklahoma aquifer that included analyses of the hydrogeology, hydrogeologic framework of the aquifer, and construction of a numerical groundwater-flow model. The groundwater-flow model was used to simulate groundwater levels and for water-budget analysis. A calibrated transient model was used to evaluate changes in groundwater storage associated with increased future water demands.

Numerical simulation of groundwater flow in Dar es Salaam Coastal Plain (Tanzania)

NASA Astrophysics Data System (ADS)

Luciani, Giulia; Sappa, Giuseppe; Cella, Antonella

2016-04-01

They are presented the results of a groundwater modeling study on the Coastal Aquifer of Dar es Salaam (Tanzania). Dar es Salaam is one of the fastest-growing coastal cities in Sub-Saharan Africa, with with more than 4 million of inhabitants and a population growth rate of about 8 per cent per year. The city faces periodic water shortages, due to the lack of an adequate water supply network. These two factors have determined, in the last ten years, an increasing demand of groundwater exploitation, carried on by quite a number of private wells, which have been drilled to satisfy human demand. A steady-state three dimensional groundwater model has been set up by the MODFLOW code, and calibrated with the UCODE code for inverse modeling. The aim of the model was to carry out a characterization of groundwater flow system in the Dar es Salaam Coastal Plain. The inputs applied to the model included net recharge rate, calculated from time series of precipitation data (1961-2012), estimations of average groundwater extraction, and estimations of groundwater recharge, coming from zones, outside the area under study. Parametrization of the hydraulic conductivities was realized referring to the main geological features of the study area, based on available literature data and information. Boundary conditions were assigned based on hydrogeological boundaries. The conceptual model was defined in subsequent steps, which added some hydrogeological features and excluded other ones. Calibration was performed with UCODE 2014, using 76 measures of hydraulic head, taken in 2012 referred to the same season. Data were weighted on the basis of the expected errors. Sensitivity analysis of data was performed during calibration, and permitted to identify which parameters were possible to be estimated, and which data could support parameters estimation. Calibration was evaluated based on statistical index, maps of error distribution and test of independence of residuals. Further model

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

NASA Astrophysics Data System (ADS)

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

2015-03-01

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

Anthropogenic effects on the subsurface thermal and groundwater environments in Osaka, Japan and Bangkok, Thailand.

PubMed

Taniguchi, Makoto; Shimada, Jun; Fukuda, Yoichi; Yamano, Makoto; Onodera, Shin-ichi; Kaneko, Shinji; Yoshikoshi, Akihisa

2009-04-15

Anthropogenic effects in both Osaka and Bangkok were evaluated to compare the relationships between subsurface environment and the development stage of both cities. Subsurface thermal anomalies due to heat island effects were found in both cities. The Surface Warming Index (SWI), the departure depth from the steady geothermal gradient, was used as an indicator of the heat island effect. SWI increases (deeper) with the magnitude of heat island effect and the elapsed time starting from the surface warming. Distributions of subsurface thermal anomalies due to the heat island effect agreed well with the distribution of changes in air temperature due to the same process, which is described by the distribution of population density in both Osaka and Bangkok. Different time lags between groundwater depression and subsidence in the two cities was found. This is attributed to differences in hydrogeologic characters, such as porosity and hydraulic conductivity. We find that differences in subsurface degradations in Osaka and Bangkok, including subsurface thermal anomalies, groundwater depression, and land subsidence, depends on the difference of the development stage of urbanization and hydrogeological characters.

Numerical simulation of groundwater artificial recharge in a semiarid-climate basin of northwest Mexico, case study the Guadalupe Valley Aquifer, Baja California

NASA Astrophysics Data System (ADS)

Campos-Gaytan, J. R.; Herrera-Oliva, C. S.

2013-05-01

In this study was analyzed through a regional groundwater flow model the effects on groundwater levels caused by the application of different future groundwater management scenarios (2007-2025) at the Guadalupe Valley, in Baja California, Mexico. Among these studied alternatives are those scenarios designed in order to evaluate the possible effects generated for the groundwater artificial recharge in order to satisfy a future water demand with an extraction volume considered as sustainable. The State of Baja California has been subject to an increment of the agricultural, urban and industrials activities, implicating a growing water-demand. However, the State is characterized by its semiarid-climate with low surface water availability; therefore, has resulted in an extensive use of groundwater in local aquifer. Water level measurements indicate there has been a decline in water levels in the Guadalupe Valley for the past 30 years. The Guadalupe Valley aquifer represents one the major sources of water supply in Ensenada region. It supplies about 25% of the water distributed by the public water supplier at the city of Ensenada and in addition constitutes the main water resource for the local wine industries. Artificially recharging the groundwater system is one water resource option available to the study zone, in response to increasing water demand. The existing water supply system for the Guadalupe Valley and the city of Ensenada is limited since water use demand periods in 5 to 10 years or less will require the construction of additional facilities. To prepare for this short-term demand, one option available to water managers is to bring up to approximately 3.0 Mm3/year of treated water of the city of Ensenada into the valley during the low-demand winter months, artificially recharge the groundwater system, and withdraw the water to meet the summer demands. A 2- Dimensional groundwater flow was used to evaluate the effects of the groundwater artificial recharge

CHROMIUM REMOVAL PROCESSES DURING GROUNDWATER REMEDIATION BY A ZEROVALENT IRON PERMEABLE REACTIVE BARRIER

EPA Science Inventory

Solid-phase associations of chromium were examined in core materials collected from a full-scale, zerovalent iron, permeable reactive barrier (PRB) at the U.S. Coast Guard Support Center located near Elizabeth City (NC). The PRB was installed in 1996 to treat groundwater contami...

IN-SITU REDUCTION OF CHROMIUM-CONTAMINATED GROUNDWATER, SOILS, AND SEDIMENTS BY SODIUM DITHIONITE

EPA Science Inventory

Laboratory studies were conducted to characterize the extent of chromium contamination in the groundwater and underlying soils and sediments of a chrome-plating shop at the USCG Support Center near Elizabeth City, NC. Most of the mobile Cr(VI) is present in the capillary zone ...

Internet Portal For A Distributed Management of Groundwater

NASA Astrophysics Data System (ADS)

Meissner, U. F.; Rueppel, U.; Gutzke, T.; Seewald, G.; Petersen, M.

The management of groundwater resources for the supply of German cities and sub- urban areas has become a matter of public interest during the last years. Negative headlines in the Rhein-Main-Area dealt with cracks in buildings as well as damaged woodlands and inundated agriculture areas as an effect of varying groundwater levels. Usually a holistic management of groundwater resources is not existent because of the complexity of the geological system, the large number of involved groups and their divergent interests and a lack of essential information. The development of a network- based information system for an efficient groundwater management was the target of the project: ?Grundwasser-Online?[1]. The management of groundwater resources has to take into account various hydro- geological, climatic, water-economical, chemical and biological interrelations [2]. Thus, the traditional approaches in information retrieval, which are characterised by a high personnel and time expenditure, are not sufficient. Furthermore, the efficient control of the groundwater cultivation requires a direct communication between the different water supply companies, the consultant engineers, the scientists, the govern- mental agencies and the public, by using computer networks. The presented groundwater information system consists of different components, especially for the collection, storage, evaluation and visualisation of groundwater- relevant information. Network-based technologies are used [3]. For the collection of time-dependant groundwater-relevant information, modern technologies of Mobile Computing have been analysed in order to provide an integrated approach in the man- agement of large groundwater systems. The aggregated information is stored within a distributed geo-scientific database system which enables a direct integration of simu- lation programs for the evaluation of interactions in groundwater systems. Thus, even a prognosis for the evolution of groundwater states

Groundwater

USGS Publications Warehouse

Stonestrom, David A.; Wohl, Ellen E.

2016-01-01

Groundwater represents the terrestrial subsurface component of the hydrologic cycle. As such, groundwater is generally in motion, moving from elevated areas of recharge to lower areas of discharge. Groundwater usually moves in accordance with Darcy’s law (Dalmont, Paris: Les Fontaines Publiques de la Ville de Dijon, 1856). Groundwater residence times can be under a day in small upland catchments to over a million years in subcontinental-sized desert basins. The broadest definition of groundwater includes water in the unsaturated zone, considered briefly here. Water chemically bound to minerals, as in gypsum (CaSO4 • 2H2O) or hydrated clays, cannot flow in response to gradients in total hydraulic head (pressure head plus elevation head); such water is thus usually excluded from consideration as groundwater. In 1940, M. King Hubbert showed Darcy’s law to be a special case of thermodynamically based potential field equations governing fluid motion, thereby establishing groundwater hydraulics as a rigorous engineering science (Journal of Geology 48, pp. 785–944). The development of computer-enabled numerical methods for solving the field equations with real-world approximating geometries and boundary conditions in the mid-1960s ushered in the era of digital groundwater modeling. An estimated 30 percent of global fresh water is groundwater, compared to 0.3 percent that is surface water, 0.04 percent atmospheric water, and 70 percent that exists as ice, including permafrost (Shiklomanov and Rodda 2004, cited under Groundwater Occurrence). Groundwater thus constitutes the vast majority—over 98 percent—of the unfrozen fresh-water resources of the planet, excluding surface-water reservoirs. Environmental dimensions of groundwater are equally large, receiving attention on multiple disciplinary fronts. Riparian, streambed, and spring-pool habitats can be sensitively dependent on the amount and quality of groundwater inputs that modulate temperature and solutes

Groundwater quality in the Colorado River basins, California

USGS Publications Warehouse

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 Colorado River make up one of the study areas being evaluated. The Colorado River study area is approximately 884 square miles (2,290 square kilometers) and includes the Needles, Palo Verde Mesa, Palo Verde Valley, and Yuma groundwater basins (California Department of Water Resources, 2003). The Colorado River study area has an arid climate and is part of the Sonoran Desert. Average annual rainfall is about 3 inches (8 centimeters). Land use in the study area is approximately 47 percent (%) natural (mostly shrubland), 47% agricultural, and 6% urban. The primary crops are pasture and hay. The largest urban area is the city of Blythe (2010 population of 21,000). 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 deposited by the Colorado River or derived from surrounding mountains. The primary aquifers in the Colorado River 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 Colorado River basins are completed to depths between 230 and 460 feet (70 to 140 meters), consist of solid casing from the land surface to a depth of 130 of 390 feet (39 to 119 meters), and are screened or perforated below the solid casing. The main source of recharge to the groundwater systems in the Needles, Palo Verde Mesa, and Palo Verde Valley basins is the Colorado River; in the Yuma basin, the main source of recharge is from

Evaluation of measures to meet future supply demand gap in Chennai city, India

NASA Astrophysics Data System (ADS)

Lakshmanan, E.; Paul, N.

2016-12-01

Availability of water forever has daunted all the major cities of the world and the cities of India are no exception. Even with high annual average rainfall of 1200 mm the Chennai city has an availability of just 108 lpcd of water, which is much lower than 150 lpcd prescribed by the World Health Organisation. The water requirement presently is met mainly from five reservoirs and partly from groundwater pumping which has given rise to seawater intrusion. The objective of this study is to find effective measures for overcoming the chronic demand supply gap and to predict the results of such measures quantitatively by modelling with the Water Evaluation and Planning System(WEAP). The modelling of city's water demand and supply system was carried out using WEAP and calibration was done using PEST. The data required for this study was obtained from various sources as well as by field investigations. There has been a continuous decrease in the actual water supply even with high availability as predicted by the model. About 60 percent of the city's supplied water ends in sewage and after treatment is presently supplied to industries, on its reuse it is found to meet completely the city's demand alone. The modelled heavy rainfall scenario demonstrates an increase in the water availability up to 20 percent during the years of heavy rainfall. The rejuvenation of existing water bodies in the outskirts of Chennai will increase the water availability for agriculture by 60 percent and hence more groundwater can be pumped for city's water supply. With addition of a new desalination plant over the existing two, the city's water supply-demand gap can be reduced by about 80%. If all the measures are implemented the water availability will exceed the demand. Thus, the WEAP model was successfully used to suggest means for sustainable water management plans for the Chennai city.

Groundwater quality in the Antelope Valley, California

USGS Publications Warehouse

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. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic

Surface-Water and Groundwater Interactions along the Withlacoochee River, West-Central Florida

USGS Publications Warehouse

Trommer, J.T.; Yobbi, D.K.; McBride, W.S.

2009-01-01

flow in the aquifer did not vary greatly from season to season during the study. Potentiometric contours indicate groundwater discharge to the river in the vicinity of Dade City and Lake Panasoffkee. During dry periods, groundwater from the underlying Upper Floridan aquifer contributed to the flow in the river. During wet periods, streamflow had additional contributions from runoff and input from tributaries. Groundwater has a greater effect on streamflow downstream from the Dade City station than upstream from the Dade City station because confinement between surficial deposits and the Upper Floridan aquifer is greater in the Green Swamp area than in downstream areas. Estimates of streamflow gains and losses were made along the Withlacoochee River during base-flow conditions in May 2004, April 2005, and April 2006. Base flow was higher in April 2005 than in May 2004 and April 2006. Consistent net seepage gains were identified in 16 of 20 subreaches analyzed during all seepage runs. The direction of exchange was variable in the remaining four subreaches. Low specific conductance, pH, and calcium concentrations in water from the Withlacoochee River near the headwater area indicated a surface-water system not directly connected to the Upper Floridan aquifer. Downstream from the Dade City station, higher specific conductance, pH, and calcium concentrations in the river water indicated an increasing influence of groundwater, and were similar to groundwater during low-flow conditions. Strontium isotope ratios indicate groundwater originates from shallow parts of the Upper Floridan aquifer in the upper reaches of the river, and from increasingly deeper parts of the aquifer in the downstream direction. Mean annual base-flow estimates also indicate increasing groundwater discharge to the river in the downstream direction. Mean annual base flow estimated using standard hydrograph separation method assumptions ranged from about 4.7 to 5.1 inches per year

Numerical simulation of ground-water flow in La Crosse County, Wisconsin, and into nearby pools of the Mississippi River

USGS Publications Warehouse

Hunt, Randall J.; Saad, David A.; Chapel, Dawn M.

2003-01-01

The models provide estimates of the locations and amount of ground-water flow into Pool 8 and the southern portion of Pool 7 of the Mississippi River. Ground-water discharges into all areas of the pools, except along the eastern shore in the vicinity of the city of La Crosse and immediately downgradient from lock and dam 7 and 8. Ground-water flow into the pools is generally greatest around the perimeter with decreasing amounts away from the perimeter. An area of relatively high ground-water discharge extends out towards the center of Pool 7 from the upper reaches of the pool and may

Anthropization of groundwater resources in the Mediterranean region: processes and challenges

NASA Astrophysics Data System (ADS)

Leduc, Christian; Pulido-Bosch, Antonio; Remini, Boualem

2017-09-01

A comprehensive overview is provided of processes and challenges related to Mediterranean groundwater resources and associated changes in recent decades. While most studies are focused thematically and/or geographically, this paper addresses different stages of groundwater exploitation in the region and their consequences. Examples emphasize the complex interactions between the physical and social dimensions of uses and evolution of groundwater. In natural conditions, Mediterranean groundwater resources represent a wide range of hydrogeological contexts, recharge conditions and rates of exploitation. They have been actively exploited for millennia but their pseudo-natural regimes have been considerably modified in the last 50 years, especially to satisfy agricultural demand (80% of total water consumption in North Africa), as well as for tourism and coastal cities. Climate variability affects groundwater dynamics but the various forms of anthropization are more important drivers of hydrological change, including changes in land use and vegetation, hydraulic works, and intense pumpings. These changes affect both the quantity and quality of groundwater at different scales, and modify the nature of hydrogeological processes, their location, timing, and intensity. The frequent cases of drastic overexploitation illustrate the fragility of Mediterranean groundwater resources and the limits of present forms of management. There is no easy way to maintain or recover sustainability, which is often threatened by short-term interests. To achieve this goal, a significant improvement in hydrogeological knowledge and closer collaboration between the various disciplines of water sciences are indispensable.

Groundwater quality characterization around Jawaharnagar open dumpsite, Telangana State

NASA Astrophysics Data System (ADS)

Unnisa, Syeda Azeem; Zainab Bi, Shaik

2017-11-01

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

[Design of sponge city and its inspiration to landscape ecology: A case of Liaodong Bay area of Panjin City, Northeast China].

PubMed

Sui, Jin Ling; Liu, Miao; Li, Chun Lin; Hu, Yuan Man; Wu, Yi Lin; Liu, Chong

2017-03-18

With the expansion of urban area, many cities are facing urban water environment issues, i.e., water resources shortage, lack of groundwater reserves, water pollution, urban waterlogging. For resolving these urban issues, 'sponge city' was proposed in 2015 in China. Liaodong Bay area of Panjin City in Liaoning Province of China was chosen as case study. Based on 'Sponge City Construction Technology Guide: Low Impact Development Rainwater System Building (Trial)', the underlying surface and types of land use in the typical area were analyzed. Sponge city plan of the study area was designed through combining topography, hydrology, rainfall intensity and other factors, and selecting LID measures. The results showed that when the study area reached the ove-rall target control rate (the control rate of the total annual runoff was ＞75%), the subsidence greenbelt rate was 1%-31%, with a total area of 13.73 km 2 ; the pervious pavement rate was 1%-13%, with a total area of 2.29 km 2 . This study could provide a case study for planning and designing of 'sponge city', proposing new ideas and methods for the research on landscape pattern and process.

Historical Evaluation of Groundwater Responses to Underground Injection Controls in an Urban Watershed

NASA Astrophysics Data System (ADS)

Harrison, M.; Haggerty, R.; Santelmann, M. V.

2017-12-01

Underground injection controls (UICs) are drywells designed to recharge stormwater to alleviate flooding events. The development of UICs affect the dynamics of the urban hydrologic setting in which more than half of precipitation can be recharged directly into UICs systems. This study seeks to better understand how the development of UICs affect groundwater levels and streamflows. The Portland, OR metropolitan area consist of well over 10,000 of UICs to mitigate flooding during storm events. This study evaluates historical precipitation, streamflow, and groundwater levels from over 20 monitoring wells within a watershed in the city Portland, OR along with well log data of UICs. UICs within the study area are approximately 30 feet in depth and have noted to contribute to about 12% of recharge. This study evaluates the dynamics of groundwater levels in relation towards the development of UICs. The results of obtained from this analysis is applied to model seasonal groundwater, precipitation, and streamflow relationships within a neighborhood subcatchment.

Quantitative evaluation of specific vulnerability to nitrate for groundwater resource protection based on process-based simulation model.

PubMed

Huan, Huan; Wang, Jinsheng; Zhai, Yuanzheng; Xi, Beidou; Li, Juan; Li, Mingxiao

2016-04-15

It has been proved that groundwater vulnerability assessment is an effective tool for groundwater protection. Nowadays, quantitative assessment methods for specific vulnerability are scarce due to limited cognition of complicated contaminant fate and transport processes in the groundwater system. In this paper, process-based simulation model for specific vulnerability to nitrate using 1D flow and solute transport model in the unsaturated vadose zone is presented for groundwater resource protection. For this case study in Jilin City of northeast China, rate constants of denitrification and nitrification as well as adsorption constants of ammonium and nitrate in the vadose zone were acquired by laboratory experiments. The transfer time at the groundwater table t50 was taken as the specific vulnerability indicator. Finally, overall vulnerability was assessed by establishing the relationship between groundwater net recharge, layer thickness and t50. The results suggested that the most vulnerable regions of Jilin City were mainly distributed in the floodplain of Songhua River and Mangniu River. The least vulnerable areas mostly appear in the second terrace and back of the first terrace. The overall area of low, relatively low and moderate vulnerability accounted for 76% of the study area, suggesting the relatively low possibility of suffering nitrate contamination. In addition, the sensitivity analysis showed that the most sensitive factors of specific vulnerability in the vadose zone included the groundwater net recharge rate, physical properties of soil medium and rate constants of nitrate denitrification. By validating the suitability of the process-based simulation model for specific vulnerability and comparing with index-based method by a group of integrated indicators, more realistic and accurate specific vulnerability mapping could be acquired by the process-based simulation model acquiring. In addition, the advantages, disadvantages, constraint conditions and

Simulated effects of ground-water management scenarios on the Santa Fe group aquifer system, Middle Rio Grande Basin, New Mexico, 2001-40

USGS Publications Warehouse

Bexfield, Laura M.; McAda, Douglas P.

2003-01-01

Future conditions in the Santa Fe Group aquifer system through 2040 were simulated using the most recent revision of the U.S. Geological Survey groundwater- flow model for the Middle Rio Grande Basin. Three simulations were performed to investigate the likely effects of different scenarios of future groundwater pumping by the City of Albuquerque on the ground-water system. For simulation I, pumping was held constant at known year-2000 rates. For simulation II, pumping was increased to simulate the use of pumping to meet all projected city water demand through 2040. For simulation III, pumpingwas reduced in accordance with a plan by the City of Albuquerque to use surfacewater to meet most of the projectedwater demand. The simulations indicate that for each of the three pumping scenarios, substantial additional watertable declines would occur in some areas of the basin through 2040. However, the reduced pumping scenario of simulation III also results in water-table rise over a broad area of the city. All three scenarios indicate that the contributions of aquifer storage and river leakage to the ground-water system would change between 2000 and 2040. Comparisons among the results for simulations I, II, and III indicate that the various pumping scenarios have substantially different effects on water-level declines in the Albuquerque area and on the contribution of each water-budget component to the total budget for the ground-water system. Between 2000 and 2040, water-level declines for continued pumping at year-2000 rates are as much as 120 feet greater than for reduced pumping; water-level declines for increased pumping to meet all projected city demand are as much as 160 feet greater. Over the same time period, reduced pumping results in retention in aquifer storage of about 1,536,000 acre-feet of ground water as compared with continued pumping at year- 2000 rates and of about 2,257,000 acre-feet as compared with increased pumping. The quantity of water retained in

Levels and distributions of organochlorine pesticides in the soil-groundwater system of vegetable planting area in Tianjin City, Northern China.

PubMed

Pan, Hong-Wei; Lei, Hong-Jun; He, Xiao-Song; Xi, Bei-Dou; Han, Yu-Ping; Xu, Qi-Gong

2017-04-01

To study the influence of long-term pesticide application on the distribution of organochlorine pesticides (OCPs) in the soil-groundwater system, 19 soil samples and 19 groundwater samples were collected from agricultural area with long-term pesticide application history in Northern China. Results showed that the composition of OCPs changed significantly from soil to groundwater. For example, ∑DDT, ∑HCH, and ∑heptachlor had high levels in the soil and low levels in the groundwater; in contrast, endrin had low level in the soil and high level in the groundwater. Further study showed that OCP distribution in the soil was significantly influenced by its residue time, soil organic carbon level, and small soil particle contents (i.d. <0.0002 mm). Correlation analysis also indicates that the distribution of OCPs in the groundwater was closely related to the levels of OCPs in the soil layer, which may act as a pollution source.

Groundwater Quality beneath an Asian Megacity on a Delta: Kolkata's (Calcutta's) Disappearing Arsenic and Present Manganese.

PubMed

McArthur, J M; Sikdar, P K; Leng, M J; Ghosal, U; Sen, I

2018-05-01

Kolkata, the capital city of West Bengal, exploits groundwater for public water-supply. The groundwater has been reported to be widely polluted by arsenic (As). Analysis for As in 280 groundwaters from across Kolkata, failed to detect As concentrations >10 μg/L from natural processes. Arsenic concentrations between 10 and 79 μg/L found in 14 of the 280 groundwaters are remnant from a pollution-plume emanating from a single factory site where Paris Green, an arsenical pesticide, was manufactured between 1965 and 1985. In 45% of groundwaters sampled, concentrations of Mn exceed 0.4 mg/L, a putative health guideline value for drinking water. Sporadic minor hazards are posed by Pb > 10 μg/L introduced into groundwater from well-fittings, from 4% of groundwaters with F concentrations between 0.75 and 1 mg/L, and the 14% of groundwaters containing more than 500 mg/L Na, concentrations that might contribute to excessive daily intake of Na. Compounding hazards from As, F, Mn, Na, and Pb, shows that 64% of public wells and 40% of municipal wells supply groundwater of suspect quality. Groundwaters comply with WHO Guideline Values for drinking water in terms of Cr, Cu, Co, NO 2 , NO 3 , Sb, Se, and U. Aesthetic guideline values for Fe, Mn, SO 4 , and Cl are exceeded for many groundwaters.

Unraveling the heat island effect observed in urban groundwater bodies - Definition of a potential natural state

NASA Astrophysics Data System (ADS)

Epting, Jannis; Huggenberger, Peter

2013-09-01

A superposition of several thermal processes leads to an elevation of groundwater temperatures of up to 9 °C above the natural state in the city of Basel, Switzerland. The urban thermal groundwater regime is influenced by: (1) urbanization and annual heating periods; (2) thermal groundwater use; (3) seasonal trends; (4) river-groundwater interaction; and (5) climate change and consequences thereof. The combination of short- and long-term data analysis, including conventional and high-resolution multilevel groundwater temperature monitoring, as well as 3D numerical groundwater flow and heat-transport modeling allowed quantifying the thermal influences on the investigated urban groundwater body. Results facilitate to describe the “present state” of the urban thermal groundwater regime and to derive a “potential natural state” of the investigated groundwater body. The study originated from a request of the executive council to provide a basis for cost estimates of infrastructure adaptation measures necessary to mitigate the impact of climate change. It is shown that the principal trigger for the observed thermal development is not climate change but that local and regional anthropogenic factors are dominating. Although in urban areas, groundwater is increasingly used for cooling purposes; the geothermal potential, resulting from elevated groundwater temperatures, is generally not exploited. The presented approach provides a basis for the setup of combined and thermally balanced heating and cooling systems.

Scientists Focus on Land Subsidence Impacts on Coastal and Delta Cities

NASA Astrophysics Data System (ADS)

Showstack, Randy

2014-05-01

Some coastal and delta cities around the world are sinking but not necessarily due only to sea level rise and impacts from extreme weather events. Land subsidence that is caused by anthropogenic processes—including the extraction of groundwater, oil, and gas and the drainage of soils—is a significant concern for Jakarta, Indonesia; Manila, Philippines; New Orleans, La.; and many other coastal and delta cities, according to scientists at a 28 April briefing held at the European Geosciences Union's General Assembly in Vienna, Austria.

Simulation of ground-water flow and land subsidence in the Antelope Valley ground-water basin, California

USGS Publications Warehouse

Leighton, David A.; Phillips, Steven P.

2003-01-01

Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley ground-water basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, ground water provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most ground-water pumping in the valley occurs in the Antelope Valley ground-water basin, which includes the rapidly growing cities of Lancaster and Palmdale. Ground-water-level declines of more than 200 feet in some parts of the ground-water basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may continue to increase reliance on ground water. To better understand the ground-water flow system and to develop a tool to aid in effectively managing the water resources, a numerical model of ground-water flow and land subsidence in the Antelope Valley ground-water basin was developed using old and new geohydrologic information. The ground-water flow system consists of three aquifers: the upper, middle, and lower aquifers. The aquifers, which were identified on the basis of the hydrologic properties, age, and depth of the unconsolidated deposits, consist of gravel, sand, silt, and clay alluvial deposits and clay and silty clay lacustrine deposits. Prior to ground-water development in the valley, recharge was primarily the infiltration of runoff from the surrounding mountains. Ground water flowed from the recharge areas to discharge areas around the playas where it discharged either from the aquifer system as evapotranspiration or from springs. Partial barriers to horizontal ground-water flow, such as faults, have been identified in the ground-water basin. Water-level declines owing to

Application of groundwater residence time tracers and broad screening for micro-organic contaminants in the Indo-Gangetic aquifer system

NASA Astrophysics Data System (ADS)

Lapworth, Dan; Das, Prerona; Mukherjee, Abhijit; Petersen, Jade; Gooddy, Daren; Krishan, Gopal

2017-04-01

Groundwater abstracted from aquifers underlying urban centres across India provide a vital source of domestic water. Abstraction from municipal and private supplies is considerable and growing rapidly with ever increasing demand for water from expanding urban populations. This trend is set to continue. The vulnerability of deeper aquifers (typically >100 m below ground) used for domestic water to contamination migration from often heavily contaminated shallow aquifer systems has not been studies in detail in India. This paper focusses on the occurrence of micro-organic contaminants within sedimentary aquifers beneath urban centres which are intensively pumped for drinking water and domestic use. New preliminary results from a detailed case study undertaken across Varanasi, a city with an estimated population of ca. 1.5 million in Uttar Pradesh. Micro -organic groundwater quality status and evolution with depth is investigated through selection of paired shallow and deep sites across the city. These results are considered within the context of paired groundwater residence time tracers within the top 150m within the sedimentary aquifer system. Groundwater emerging contaminant results are compared with surface water quality from the Ganges which is also used for drinking water supply. Broad screening for >800 micro-organic compounds was undertaken. Age dating tools were employed to constrain and inform a conceptual model of groundwater recharge and contaminant evolution within the sedimentary aquifer system.

Ground-water resources of the Bengasi area, Cyrenaica, United Kingdom of Libya

USGS Publications Warehouse

Doyel, William Watson; Maguire, Frank J.

1964-01-01

The Benpsi area of Libya, in the northwestern part of the Province of Cyrenaica (Wilayat Barqah), is semiarid, and available ground-water supplies in the area are relatively small. Potable ground water from known sources is reserved for the present and future needs of the city, and no surface-water supplies are available in the area. This investigation to evaluate known, as well as potential, water supplies in the area was undertaken as part of a larger program of ground-water investigations in Libya under the auspices of the U. S. Operations Mission to Libya and the Government of Libya. A ground-water reservoir underlies the Bengasi area, in which the water occurs in solution channels, cavities, and other openings in Miocene limestone. The reservoir is recharged directly by rainfall on the area and by infiltration from ephemeral streams (wadis) rising in Al Jabal al Akhar to the east. In the Baninah and Al Fuwayhit areas the ground-water reservoir yields water of fair quality and in sufficient quantity for the current (1959) needs. of the Bengasi city supply. The test-drilling program in the area south and southeast of Bengasi indicates that water in sufficient quantity for additional public supply probably can be obtained in some localities from wells. The water, however, is moderately to highly mineralized and would require treatment or demineralization before it could be used for additional public supply. Much of the water could be used directly for irrigation, but careful attention would have to be given to cultivation, drainage, and cropping practices. The hazard of saltwater encroachment also exists if large-scale withdrawals are undertaken in the coastal zones.

The spatial geochemical characteristics of groundwater and surface in the Tuul River basin, Ulaanbatar, Mongolia

NASA Astrophysics Data System (ADS)

Batdelger, Odsuren; Tsujimura, Maki; Zorigt, Byambasuren; Togtokh, Enkhjargal

2017-04-01

The capital city, Ulaanbaatar, is located along the Tuul River and its water supply totally dependent on the groundwater, which comes from the aquifer of the Tuul River. Due to the rapid growth of the population and the increasing human pressures in this basin, water quality has been deteriorating and has become a crucial issue for sustainable environmental and socio-economic development. Hydro-chemical and stable isotope tracing approaches were applied into the groundwater and surface water in order to study geochemical characteristics and groundwater and surface water interaction. The Tuul River water was mostly characterized by the Ca-HCO3 type, spatially variable and it changed into Ca-Na-HCO3 type in the downstream of the city after wastewater (WW) meets the river. Also, electrical conductivity (EC) values of Tuul River are increasing gradually with distance and it increased more than 2 times after WW meets the stream, therefore anthropogenic activities influence to the downstream of the river. The dominant hydro-chemical facies of groundwater were the Ca-HCO3 type, which represents 83% of the total analyzed samples, while Ca- HCO3-Cl-NO3, Na-HCO3, Ca-HCO3-SO4 each represent 4%, and Ca-mixed and Ca-Mg-HCO3 each represent 2% of the total samples. This suggests that groundwater chemistry is controlled by rock-water interaction and anthropogenic pollution. The floodplain groundwater chemical characteristics were similar to Tuul River water and showing lowest EC values. Groundwater far from floodplain showed higher EC (mean value of 498 μs/cm) values than river waters and floodplain groundwater. Also, different kinds of hydro-chemical facies were observed. The stable isotopic compositions revealed less evaporation effect on the groundwater and surface water, as well as an altitude effect in the river water. The similarity of stable isotopes and chemical characteristics of floodplain groundwater and river water suggests that alluvial groundwater is recharged by

Seismic Landslide Hazard for the Cities of Oakland and Piedmont, California

USGS Publications Warehouse

Miles, Scott B.; Keefer, David K.

2001-01-01

This map describes the possible hazard from earthquake-induced landslides for the cities of Oakland and Piedmont, CA. The hazard depicted by this map was modeled for a scenario corresponding to an M=7.1 earthquake on the Hayward, CA fault. This scenario magnitude is associated with complete rupture of the northern and southern segments of the Hayward fault, an event that has an estimated return period of about 500 years. The modeled hazard also corresponds to completely saturated ground-water conditions resulting from an extreme storm event or series of storm events. This combination of earthquake and ground-water scenarios represents a particularly severe state of hazard for earthquake-induced landslides. For dry ground-water conditions, overall hazard will be less, while relative patterns of hazard are likely to change.

Simulation and Prediction of Groundwater Pollution from Planned Feed Additive Project in Nanning City Based on GMS Model

NASA Astrophysics Data System (ADS)

Liang, Yimin; Lan, Junkang; Wen, Zhixiong

2018-01-01

In order to predict the pollution of underground aquifers and rivers by the proposed project, Specialized hydrogeological investigation was carried out. After hydrogeological surveying and mapping, drilling, and groundwater level monitoring, the scope of the hydrogeological unit and the regional hydrogeological condition were found out. The permeability coefficients of the aquifers were also obtained by borehole water injection tests. In order to predict the impact on groundwater environment by the project, a GMS software was used in numerical simulation. The simulation results show that when unexpected sewage leakage accident happened, the pollutants will be gradually diluted by groundwater, and the diluted contaminants will slowly spread to southeast with groundwater flow, eventually they are discharged into Gantang River. However, the process of the pollutants discharging into the river is very long, the long-term dilution of the river water will keep Gantang River from being polluted.

Weekly variations of discharge and groundwater quality caused by intermittent water supply in an urbanized karst catchment

NASA Astrophysics Data System (ADS)

Grimmeisen, Felix; Zemann, Moritz; Goeppert, Nadine; Goldscheider, Nico

2016-06-01

Leaky sewerage and water distribution networks are an enormous problem throughout the world, specifically in developing countries and regions with water scarcity. Especially in many arid and semi-arid regions, intermittent water supply (IWS) is common practice to cope with water shortage. This study investigates the combined influence of urban activities, IWS and water losses on groundwater quality and discusses the implications for water management. In the city of As-Salt (Jordan), local water supply is mostly based on groundwater from the karst aquifer that underlies the city. Water is delivered to different supply zones for 24, 48 or 60 h each week with drinking water losses of around 50-60%. Fecal contamination in groundwater, mostly originating from the likewise leaky sewer system is a severe challenge for the local water supplier. In order to improve understanding of the local water cycle and contamination dynamics in the aquifer beneath the city, a down gradient spring and an observation well were chosen to identify contaminant occurrence and loads. Nitrate, Escherichia coli, spring discharge and the well water level were monitored for 2 years. Autocorrelation analyses of time series recorded during the dry season revealed weekly periodicity of spring discharge (45 ± 3.9 L s-1) and NO3-N concentrations (11.4 ± 0.8 mg L-1) along with weekly varying E. coli levels partly exceeding 2.420 MPN 100 mL-1. Cross-correlation analyses demonstrate a significant and inverse correlation of nitrate and discharge variations which points to a periodic dilution of contaminated groundwater by freshwater from the leaking IWS being the principal cause of the observed fluctuations. Contaminant inputs from leaking sewers appear to be rather constant. The results reveal the distinct impact of leaking clean IWS on the local groundwater and subsequently on the local water supply and therefore demonstrate the need for action regarding the mitigation of groundwater contamination and

The changing pattern of ground-water development on Long Island, New York

USGS Publications Warehouse

Heath, Ralph C.; Foxworthy, B.L.; Cohen, Philip M.

1966-01-01

Ground-water development on Long Island has followed a pattern that has reflected changing population trends, attendant changes in the use and disposal of water, and the response of the hydrologic system to these changes. The historic pattern of development has ranged from individually owned shallow wells tapping glacial deposits to large-capacity public-supply wells tapping deep artesian aquifers. Sewage disposal has ranged from privately owned cesspools to modern large-capacity sewage-treatment plants discharging more than 70 mgd of water to the sea. At present (1965), different parts of long Island are characterized by different stages of ground-water development. In parts of Suffolk County in eastern long Island, development is similar to the earliest historical stages. Westward toward New York City, ground-water development becomes more intensive and complex, and the attendant problems become more acute. The alleviation of present problems and those that arise in the future will require management decisions based on the soundest possible knowledge of the hydrologic system, including an understanding of the factors involved in the changing pattern of ground-water development on the island.

Groundwater.

ERIC Educational Resources Information Center

Braids, Olin C.; Gillies, Nola P.

1978-01-01

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

Bibliography of ground-water references for all 254 counties in Texas, 1886-2001

USGS Publications Warehouse

Baker, E.T.

2005-01-01

PrefaceThis bibliography comprises more than 10,000 citations of ground-water references involving all 254 counties in Texas. The reference citations date from 1886 and extend into 2001. Publications and reports from more than 30 agencies, universities, water districts, geological societies, cities, consultants, and private publication outlets are included in the bibliography. The bibliographic listing is, first, alphabetical by county and, second, chronological by date of the report, from oldest to most recent. The passing years have seen a proliferation in both published and unpublished reports, and such proliferation continues to expand at an accelerating pace. All 254 counties have had groundwater studies, either cursory or detailed. Investigation and development of the ground-water resources of the State of Texas resulted in reports that appear in a variety of formats, including Federal, State, and local agency reports; scholarly, professional, and trade journals; conference proceedings; guidebooks; maps; and theses and dissertations. The end result for the person seeking ground-water information about specific Texas counties is the increasing difficulty in locating pertinent data among the many and diverse ground-water reports in which the information is recorded. This bibliography, covering a span of 115 years, should have considerable utility in guiding those individuals seeking ground-water information.

Groundwater potential prediction by using geoelectricity method a case study in Simpang Lima and around it

NASA Astrophysics Data System (ADS)

Rahmawati, D. R.; Supriyadi; Aryani, N. P.; Naufal, M. A.

2018-03-01

Water is an important natural resource, which is available both on surface as well as in recharge zone of weathered layer and in various other suitable water reservoir formations/structures below the surface. The study was conducted in Semarang City, Indonesian. Simpang Lima area were chosen since they have geology record of thick alluvium. The condition of Simpang Lima and around it which currently has developed into the main business area in Semarang City. This is marked by the presence like hotels, super market, that is more than one. This condition certainly requires a supply of water for various purposes that support economic efforts in the region. During this time the water needs are met by drilling wells and used as much as possible without taking into account the impact of water utilization. This study aims to determine the zones that have the potential existence of groundwater. The method used is Geoelectric method with Shlumberger configuration in 7 distributed spatial point. The results showed that there is a potential groundwater in eastern Pekunden, Erlanga, behind The Hotel Horizon, and Simpang Lima. Groundwater is found successively at an average depth of 15 meters under earth’s surface.

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

USGS Publications Warehouse

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

1998-01-01

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

A groundwater management plan for Stuttgart.

PubMed

Vasin, Sandra; Carle, Achim; Lang, Ulrich; Kirchholtes, Hermann Josef

2016-09-01

In general, groundwater in urban areas is exposed to anthropogenic influence and suffers from concentrations of contaminants. Stuttgart, as a highly industrialized city, has more than 5000 contaminated sites which might influence the Stuttgart's mineral water quality. Despite tremendous efforts and intensive single site orientated remediation since 1984 in downtown, the mineral springs were still affected with chlorinated hydrocarbons at low concentrations. Therefore, the applied practices of environmental management and measures for mitigation of pollution sources were not sufficient and had to be adjusted. The main goal of this study is to define an integral remediation plan (a groundwater management plan), focusing on the key sources of chlorinated solvents which are relevant for the mineral springs. For the large-scale investigated area of 26.6km(2) and eight aquifers, an extensive investigation and characterization methods were used in order to delineate the contamination plumes. By means of a 3D numerical model, the prioritization of the contaminated sites could be performed. Five contaminated sites with high remediation priority and need for optimized or additional remediation efforts were determined. For those five contaminated sites feasibility studies were performed which resulted in recommendation of remediation measures with total costs of more than 12.5 million euros. The proposed strategy and approach are suitable for multiple sources of contamination. Only in this way, the contributions of single contaminated sites to the total groundwater contamination can be identified and local remediation measures with their spatial impact simulated. Due to very complex geological conditions, technically there is no alternative to this strategy in order to achieve the contamination reduction in groundwater. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessing the effects of urbanization and climate change on groundwater management in China

NASA Astrophysics Data System (ADS)

Hua, S.; Zheng, C.

2017-12-01

Groundwater is expected to be more vulnerable in the future due to climate change coupled with rapid urbanization. Thus, protecting future groundwater resources under the impact of urbanization and climate change is necessary towards more sustainable groundwater resource development. This study is intended to shed lights on how water managers may plan for the adverse effects of urbanization and climate change on groundwater quality. A new approach is presented in which the groundwater vulnerability under future climate change scenarios is employed as a constraint to urban expansion. An original form of the Land Transformation Model (LTM) and a revised LTM simulation are applied to model the urbanization. The results indicated that there would be a notable and uneven urban growth between 2010 and 2050. Future groundwater vulnerability is expected to shift significantly under future climate change scenarios. The results of the revised LTM project more urban expansion in the central regions of China, while those of the original LTM project urban expansion in throughout China, although the two projections have the same areas of expansion. The urban expansion simulated by the original LTM follows the historical trend under the drivers of socioeconomic, political and geographic factors. However, the revised LTM drives the urban expansion to the regions with relatively lower groundwater vulnerability, in contrast to the historical trend. This study demonstrates that the integration of LTM and future groundwater vulnerability in the urban planning can better protect the groundwater resource and promote more sustainable socioeconomic development. The methodology developed in this study provides water managers and city planners a useful groundwater management tool for mitigating the risks associated with rapid urbanization and climate change.

Modeling the Effects of Sea-Level Rise on Groundwater Levels in Coastal New Hampshire

NASA Astrophysics Data System (ADS)

Jacobs, J. M.; Knott, J. F.; Daniel, J.; Kirshen, P. H.

2017-12-01

Coastal communities with high population density and low topography are vulnerable from sea-level rise (SLR) caused by climate change. Groundwater in coastal communities will rise with sea level impacting water quality, the structural integrity of infrastructure, and natural ecosystem health. SLR-induced groundwater rise has been studied in areas of high aquifer transmissivity and in low-lying areas immediately along the coast. In this regional study, we investigate SLR-induced groundwater rise in a coastal area characterized by shallow unconsolidated deposits overlying fractured bedrock, typical of the glaciated northeast United States. MODFLOW, a numerical groundwater-flow model, is used with groundwater observations, lidar topography, surface-water hydrology, and groundwater withdrawals to investigate SLR-induced changes in groundwater levels and vadose-zone thickness in New Hampshire's Seacoast. The SLR groundwater signal is detected up to 5 km from the coast, more than 3 times farther inland than projected surface-water flooding associated with SLR. Relative groundwater rise ranges from 38 to 98% of SLR within 1 km of the shoreline and drops below 4% between 4 and 5 km from the coast. The largest magnitude of SLR-induced groundwater rise occurs in the marine and estuarine deposits and land areas with tidal water bodies on three sides. In contrast, groundwater rise is dampened near streams. Groundwater inundation caused by 2 m of SLR is projected to contribute 48% of the total land inundation area in the City of Portsmouth with consequences for built and natural resources. Freshwater wetlands are projected to expand 3% by year 2030 increasing to 25% by year 2100 coupled with water-depth increases. These results imply that underground infrastructure and natural resources in coastal communities will be impacted by rising groundwater much farther inland than previously thought when considering only surface-water flooding from SLR.

Combining geochemical tracers with geophysical tools to study groundwater quality in Mesilla Bolson of the semi-arid Rio Grande watershed

NASA Astrophysics Data System (ADS)

Ma, L.; Hiebing, M.; Garcia, S.; Szynkiewicz, A.; Doser, D. I.

2017-12-01

Mesilla Bolson is an important alluvial aquifer system of the semi-arid Rio Grande watershed in southern New Mexico and West Texas. It is one of the two major groundwater sources for the City of El Paso in Texas and provides about 30% of the region's domestic groundwater needs. Groundwater from Mesilla Bolson is also extensively used for agriculture irrigation in this region. However, high concentrations of total dissolved solids in some areas of this region significantly impact groundwater quality for the Rio Grande alluvial aquifer. For example, an increase in groundwater salinity is generally observed from north to south within the aquifer. Some previous researchers have suggested this salinity change is due to 1) runoff and recharge from agricultural activity; 2) natural upwelling of deeper brackish groundwater; and 3) water-rock interactions in the aquifer. To better study how agricultural and municipal practices contribute to increasing salinity, we sampled 50 wells of the Mesilla Bolson in 2015-2016 for uranium (234U/238U), strontium (87Sr/86Sr), boron (d11B), and sulfur (d34S) isotope compositions to characterize major salinity sources of groundwater. In addition, we applied a geophysical gravity survey to determine the possible influences of faults and other subsurface structures on groundwater quality in this region. Our multi-isotope results suggest that the groundwater resources of this alluvial aquifer have been already impacted by human activities and groundwater recharge to the alluvial aquifer is affected by surface processes such as i) the return flows from the Rio Grande surface water used for irrigation, ii) municipal discharges, and iii) irrigation with the reclaimed city water. However, natural upwelling is also probably responsible for the salinity increase near some fault areas, primarily due to water-rock interactions such as dissolution of evaporites within the deeper basin. In some areas of the Mesilla Bolson, fault systems act as conduits

Methanogenic biodegradation of charcoal production wastes in groundwater at Kingsford, Michigan, USA

USGS Publications Warehouse

Michael, Godsy E.; Warren, E.; Westjohn, D.B.

2001-01-01

A house exploded in the City of Kingsford, Michigan USA. The explosion was caused by CH4 that leaked into the basement from the surrounding soil. Evidence suggests that biodegradation of products from the distillation and spillage at or near a former wood carbonization plant site was the major source of CH4 and CO2 in the groundwater system. The plant area is directly upgradient from deep groundwater, samples of which are green-yellow in colour, have a very strong odour of burnt wood, contain high concentrations of mononuclear aromatic and phenolic compounds, and extremely high concentrations of volatile fatty acids. The majority of the dissolved compounds in these groundwater samples have been shown, using laboratory microcosms, to be anaerobically biodegradable to CH4 and CO2. The biodegradable compounds, and the amounts of CH4 and CO2 produced in the microcosms, are consistent with observations from field samples.

Simulation of groundwater flow, effects of artificial recharge, and storage volume changes in the Equus Beds aquifer near the city of Wichita, Kansas well field, 1935–2008

USGS Publications Warehouse

Kelly, Brian P.; Pickett, Linda L.; Hansen, Cristi V.; Ziegler, Andrew C.

2013-01-01

The Equus Beds aquifer is a primary water-supply source for Wichita, Kansas and the surrounding area because of shallow depth to water, large saturated thickness, and generally good water quality. Substantial water-level declines in the Equus Beds aquifer have resulted from pumping groundwater for agricultural and municipal needs, as well as periodic drought conditions. In March 2006, the city of Wichita began construction of the Equus Beds Aquifer Storage and Recovery project to store and later recover groundwater, and to form a hydraulic barrier to the known chloride-brine plume near Burrton, Kansas. In October 2009, the U.S. Geological Survey, in cooperation with the city of Wichita, began a study to determine groundwater flow in the area of the Wichita well field, and chloride transport from the Arkansas River and Burrton oilfield to the Wichita well field. Groundwater flow was simulated for the Equus Beds aquifer using the three-dimensional finite-difference groundwater-flow model MODFLOW-2000. The model simulates steady-state and transient conditions. The groundwater-flow model was calibrated by adjusting model input data and model geometry until model results matched field observations within an acceptable level of accuracy. The root mean square (RMS) error for water-level observations for the steady-state calibration simulation is 9.82 feet. The ratio of the RMS error to the total head loss in the model area is 0.049 and the mean error for water-level observations is 3.86 feet. The difference between flow into the model and flow out of the model across all model boundaries is -0.08 percent of total flow for the steady-state calibration. The RMS error for water-level observations for the transient calibration simulation is 2.48 feet, the ratio of the RMS error to the total head loss in the model area is 0.0124, and the mean error for water-level observations is 0.03 feet. The RMS error calculated for observed and simulated base flow gains or losses for the

Groundwater-flow model and effects of projected groundwater use in the Ozark Plateaus Aquifer System in the vicinity of Greene County, Missouri - 1907-2030

USGS Publications Warehouse

Richards, Joseph M.

2010-01-01

Recent and historical periods of rapid growth have increased the stress on the groundwater resources in the Ozark aquifer in the Greene County, Missouri area. Historical pumpage from the Ozark aquifer has caused a cone of depression beneath Springfield, Missouri. In an effort to ease its dependence on groundwater for supply, the city of Springfield built a pipeline in 1996 to bring water from Stockton Lake to the city. Rapid population growth in the area coupled with the expanding cone of depression raised concern about the sustainability of groundwater as a resource for future use. A groundwater-flow model was developed by the U.S. Geological Survey in cooperation with Greene County, Missouri, the U. S. Army Corps of Engineers, and the Missouri Department of Natural Resources to assess the effect that increased groundwater demand is having on the long-term availability of groundwater in and around Greene County, Missouri. Three hydrogeologic units were represented in the groundwater-flow model: the Springfield Plateau aquifer, the Ozark confining unit, and the Ozark aquifer. The Springfield Plateau aquifer is less than 350 feet thick in the model area and generally is a low yield aquifer suitable only for domestic use. The Ozark aquifer is composed of a more than 900-foot thick sequence of dolomite and sandstone in the model area and is the primary aquifer throughout most of southern Missouri. Wells open to the entire thickness of the Ozark aquifer typically yield 1,000 gallons per minute or more. Between the two aquifers is the Ozark confining unit composed of as much as 98 feet of shale and limestone. Karst features such as sinkholes, springs, caves, and losing streams are present in both aquifers, but the majority of these features occur in the Springfield Plateau aquifer. The solution-enlarged fracture and bedding plane conduits in the karst system, particularly in the Springfield Plateau aquifer, are capable of moving large quantities of groundwater through

Groundwater quality in the Indian Wells Valley, California

USGS Publications Warehouse

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. Indian Wells Valley is one of the study areas being evaluated. The Indian Wells study area is approximately 600 square miles (1,554 square kilometers) and includes the Indian Wells Valley groundwater basin (California Department of Water Resources, 2003). Indian Wells Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lake beds in the lower parts of the valley. Land use in the study area is approximately 97.0 percent (%) natural, 0.4% agricultural, and 2.6% urban. The primary natural land cover is shrubland. The largest urban area is the city of Ridgecrest (2010 population of 28,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from the Sierra Nevada to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and direct infiltration from irrigation and septic systems. The primary sources of discharge are pumping wells and evapotranspiration near the dry lakebeds. The primary aquifers in the Indian Wells 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

Geospatial Data Management Platform for Urban Groundwater

NASA Astrophysics Data System (ADS)

Gaitanaru, D.; Priceputu, A.; Gogu, C. R.

2012-04-01

Due to the large amount of civil work projects and research studies, large quantities of geo-data are produced for the urban environments. These data are usually redundant as well as they are spread in different institutions or private companies. Time consuming operations like data processing and information harmonisation represents the main reason to systematically avoid the re-use of data. The urban groundwater data shows the same complex situation. The underground structures (subway lines, deep foundations, underground parkings, and others), the urban facility networks (sewer systems, water supply networks, heating conduits, etc), the drainage systems, the surface water works and many others modify continuously. As consequence, their influence on groundwater changes systematically. However, these activities provide a large quantity of data, aquifers modelling and then behaviour prediction can be done using monitored quantitative and qualitative parameters. Due to the rapid evolution of technology in the past few years, transferring large amounts of information through internet has now become a feasible solution for sharing geoscience data. Furthermore, standard platform-independent means to do this have been developed (specific mark-up languages like: GML, GeoSciML, WaterML, GWML, CityML). They allow easily large geospatial databases updating and sharing through internet, even between different companies or between research centres that do not necessarily use the same database structures. For Bucharest City (Romania) an integrated platform for groundwater geospatial data management is developed under the framework of a national research project - "Sedimentary media modeling platform for groundwater management in urban areas" (SIMPA) financed by the National Authority for Scientific Research of Romania. The platform architecture is based on three components: a geospatial database, a desktop application (a complex set of hydrogeological and geological analysis

Evaluation of aquifer environment under Hazaribagh leather processing zone of Dhaka city

NASA Astrophysics Data System (ADS)

Zahid, Anwar; Balke, K.-D.; Hassan, M. Qumrul; Flegr, Matthias

2006-07-01

Hazaribagh is a densely populated area of Dhaka city where about 185 leather processing industries have been operating and discharging solid and liquid wastes directly to the low-lying areas, river and natural canals without proper treatment. The area is covered by alluvial deposits of Holocene age and is underlain by Pleistocene Madhupur clay. The Dupi Tila Formation of Mio-Pliocene age underlain by this yellowish gray to brick red clay bed serves as the main water-bearing aquifer of Dhaka city. To assess the environmental degradation as well as the groundwater environment, major anions, cations and heavy metals of water samples, heavy metals and organic carbon content of sediment samples were analyzed in this study. Analyses of tannery effluent detect high concentration of Na+, Mg2+, Cl- and SO{4/2-} followed by Ca2+, NH{4/+} and K+ with remarkable contents of some trace elements, mainly Cr, Fe, Mn, S, Ni and Pb. Higher accumulations of Cr, Al and Fe are observed in topsoil samples with significant amounts of Mn, Zn, Ni and Cu. Concentrations of ions and all the investigated trace elements of sampled groundwater were within the maximum allowable limit for drinking water of the Department of Environment, Bangladesh (DoE), and World Health Organization (WHO). However, excessive concentrations of Cr, Pb, etc., have already been reported in the shallow groundwater (10-20 m) of the area. Due to excessive withdrawal the vulnerability of groundwater contamination in deeper parts cannot be avoided for the future.

Iron Isotope Variations in Reduced Groundwater and in Drinking Water Supplies: A Case Study of Hanoi, Vietnam

NASA Astrophysics Data System (ADS)

Teutsch, N.; Berg, M.; von Gunten, U.; Halliday, A.

2004-12-01

In reduced groundwater iron is involved in biotic and abiotic transformation processes, both of which could lead to iron isotope fractionation. The reduced groundwater aquifers in the area of the Vietnamese capital of Hanoi are the main drinking water sources for the city. These groundwaters contain arsenic, which imposes a serious health threat to millions of people. Dissolved arsenic is related to the reducing conditions prevalent in the groundwater, and iron and arsenic contents are correlated in the sediments. We are employing iron isotope composition as a tool to better understand the processes leading to the transformation of iron in the groundwater and its role in various biogeochemical processes in reduced environments. Drinking water is supplied to the city of Hanoi from several water treatment plants (WTP) which pump the raw groundwater from a lower aquifer, while the rural surroundings pump untreated groundwater from an upper aquifer by private tubewells. Surface water from the Red River delta is the main source of recharge to these two aquifers. Due to high content of particulate natural organic matter (NOM) in the sediment leading to extensive microbial activity, the groundwaters are anoxic and rich in dissolved iron(II). The iron(II) removal in the WTPs is carried by a multi-step treatment including aeration, settling, filtration, and chlorination. We have collected natural groundwater samples for isotopic analysis from two aquifers at several locations, a groundwater depth profile and its corresponding sediment phases from the upper aquifer and the underlying aquitard, raw and treated water from several WTPs, as well as the corresponding iron(III) precipitates. The iron concentrations of groundwaters analysed in this study range from 3 to 28 mg/L and δ 57Fe (57/54 deviation from IRMM 014) values vary between -1.2 and +1.5 ‰ . The sediment depth profile has a δ 57Fe around +0.3 ‰ , which implies that the high values obtained in the groundwater

Geochemical evolution of groundwater in southern Bengal Basin: The example of Rajarhat and adjoining areas, West Bengal, India

NASA Astrophysics Data System (ADS)

Sahu, Paulami; Sikdar, P. K.; Chakraborty, Surajit

2016-02-01

Detailed geochemical analysis of groundwater beneath 1223 km2 area in southern Bengal Basin along with statistical analysis on the chemical data was attempted, to develop a better understanding of the geochemical processes that control the groundwater evolution in the deltaic aquifer of the region. Groundwater is categorized into three types: `excellent', `good' and `poor' and seven hydrochemical facies are assigned to three broad types: `fresh', `mixed' and `brackish' waters. The `fresh' water type dominated with sodium indicates active flushing of the aquifer, whereas chloride-rich `brackish' groundwater represents freshening of modified connate water. The `mixed' type groundwater has possibly evolved due to hydraulic mixing of `fresh' and `brackish' waters. Enrichment of major ions in groundwater is due to weathering of feldspathic and ferro-magnesian minerals by percolating water. The groundwater of Rajarhat New Town (RNT) and adjacent areas in the north and southeast is contaminated with arsenic. Current-pumping may induce more arsenic to flow into the aquifers of RNT and Kolkata cities. Future large-scale pumping of groundwater beneath RNT can modify the hydrological system, which may transport arsenic and low quality water from adjacent aquifers to presently unpolluted aquifer.

Simulation of groundwater flow in the Edwards-Trinity and related aquifers in the Pecos County region, Texas

USGS Publications Warehouse

Thomas, Jonathan V.

2014-01-01

The Edwards-Trinity aquifer, a major aquifer in the Pecos County region of western Texas, is a vital groundwater resource for agricultural, industrial, and public supply uses. Resource managers would like to better understand the future availability of water in the Edwards-Trinity aquifer in the Pecos County region and the effects of the possible increase or temporal redistribution of groundwater withdrawals. To that end, the U.S. Geological Survey (USGS), in cooperation with the Middle Pecos Groundwater Conservation District, Pecos County, City of Fort Stockton, Brewster County, and Pecos County Water Control and Improvement District No. 1, completed a comprehensive, integrated analysis of available hydrogeologic data to develop a groundwater-flow model of the Edwards-Trinity and related aquifers in parts of Brewster, Jeff Davis, Pecos, and Reeves Counties. Following calibration, the model was used to evaluate the sustainability of recent (2008) and projected water-use demands on groundwater resources in the study area.

Health assessment for Shaw Avenue Dump Site, Charles City, Iowa, Region 7 (amended). CERCLIS No. IAD980630560. Preliminary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1988-12-07

The Shaw Avenue Dump Site is listed by the U.S. Environmental Protection Agency (USEPA) on the National Priorities List (NPL). The 8-acre city dump site, consisting of three waste disposal areas, is located in the southeast edge of Charles City approximately 500 feet east of the Cedar River. The three disposal areas are no longer in use and have been covered with soil and are vegetated. Arsenic is the contaminant of concern at the Shaw Avenue Dump Site. On-site soil samples collected in 1981 contained concentrations of arsenic that ranged from 4-820 mg/kg. On-site groundwater, surface water, and air analysesmore » were not conducted in previous investigations. From the available information, this site is considered to be of public health concern because of the potential risk to human health caused by possible exposure to hazardous substances via ingestion of groundwater, soil, and surface water; inhalation of fugitive dust; and dermal contact with soil, surface water, and groundwater.« less

Simulated effects of groundwater withdrawals from aquifers in Ocean County and vicinity, New Jersey

USGS Publications Warehouse

Cauller, Stephen J.; Voronin, Lois M.; Chepiga, Mary M.

2016-10-21

Rapid population growth since the 1930s in Ocean County and vicinity, New Jersey, has placed increasing demands upon the area’s freshwater resources. To examine effects of groundwater withdrawals, a three-dimensional groundwater-flow model was developed to simulate the groundwater-flow systems of five area aquifers: the unconfined Kirkwood-Cohansey aquifer system and Vincentown aquifer, and three confined aquifers— the Rio Grande water-bearing zone, the Atlantic City 800-foot sand, and the Piney Point aquifer. The influence of withdrawals is evaluated by using transient groundwater-flow model simulations that incorporate three withdrawal schemes. These are (1) no-withdrawal conditions; (2) 2000–03 withdrawal conditions, using reported monthly withdrawals at all production wells from January 2000 through December 2003; and (3) maximum-allocation withdrawal conditions using the maximum withdrawal allowed by New Jersey Department of Environmental Protection permits at each well. Particle tracking analysis, using results from model simulations, delineated particle flow paths from production wells to the point of recharge, and estimated particle travel times.Compared with no-withdrawal conditions, 2000–03 withdrawal conditions reduced the amount of groundwater flow out of the Kirkwood-Cohansey aquifer system into streams, increased the net flow of water into other layers, reduced net flow into or out of storage, and reduced flow from the Kirkwood-Cohansey aquifer system to constant head cells.Freshwater discharging to the Barnegat Bay-Little Egg Harbor estuary from streams and groundwater is essential to maintaining the ecology of the bay. Examination of selected stress periods indicates that simulated base flow in streams flowing into the Barnegat Bay-Little Egg Harbor estuary is reduced by as much as 49 cubic feet per second for 2000 to 2003 withdrawal conditions when compared with no-withdrawal conditions.In the three confined aquifers, water levels during

Ground-water conditions in Avra Valley, Pima and Pinal Counties, Arizona -1985

USGS Publications Warehouse

Cuff, Melinda K.; Anderson, S.R.

1987-01-01

Avra Valley is a north-trending alluvial basin about 15 mi west of Tucson in Pima and Pinal Counties in south-central Arizona. The valley includes about 520 sq mi of which about 100 sq mi is in the San Xavier Indian Reservation. The basin is bounded on the east by the Tortolita, Tucson, and Sierrita Mountains and on the west by the Picacho, Silverbell, and Roskruge Mountains. The climate of the valley is semiarid, the average annual precipitation ranges from 8 to 12 in., and the average annual lake evaporation ranges from 58 to 62 in. Two major ephemeral streams--Santa Cruz River and Brawley Wash--drain the area. Santa Cruz River and Brawley Wash and their tributaries provide a source of recharge to an extensive alluvial aquifer that underlies the valley floor. Since 1940, the amount of groundwater pumped from the aquifer has been greater than the amount of natural recharge from infiltration and underflow. Overdraft of the aquifer resulted in substantial water level declines throughout the valley. Until 1969, use of groundwater in Avra Valley was for irrigation. Since 1969, the city of Tucson has pumped and transported groundwater for municipal use in the adjacent Tucson basin from lands that were purchased and retired from agriculture. The purpose of this report is to describe groundwater conditions in Avra Valley as of 1985. A brief discussion of the geohydrologic setting and history of groundwater development are given to define aquifer characteristics, changes in groundwater levels, and groundwater pumpage since 1940. (Lantz-PTT)

U.S. Geological Survey ground-water studies in Utah

USGS Publications Warehouse

Gates, Joseph S.

1988-01-01

Ground water is an important natural resource in Utah. In the basins west of the Wasatch Front, and in many other parts of Utah, ground water is the primary source of water. In many of the basins of the western desert and in parts of the Colorado Plateau, ground water is the only reliable source of water. Along the Wasatch Front to the north and south of Salt Lake City, in the Uinta Basin, and in the Sevier River drainage, surface water is the primary source of water. Ground-water sources supply about 20 percent of all water used in Utah and about 63 percent of the water for public supply. Of the total amount of ground water used, 44 percent is for irrigation, 35 percent is for public supply, 11 percent is for industry, 5 percent is for rural domestic supplies, and 5 percent is for livestock. The major issues related to ground water in Utah are: -Development of additional ground-water supplies while protecting existing water rights and minimizing effects on water levels, water quality, and streamflow, and-Protection of ground-water resources from contamination by pollutants from various types of land-use and waste-disposal practices.

The effects of urbanization on groundwater quantity and quality in the Zahedan aquifer, southeast Iran

USGS Publications Warehouse

Khazaei, E.; Mackay, R.; Warner, J.W.

2004-01-01

This paper investigates the impacts of urban growth on groundwater quality and quantity in the Zahedan aquifer, which is the sole source of water supply for the city of Zahedan, Iran. The investigation is based on the collection of available historical data, supplemented by field and laboratory investigations. Groundwater levels in 40 wells were measured in December 2000. In addition, 102 water samples were taken in two periods during November and December 2000. Of these, 43 samples were analyzed for major ions, 32 samples were analyzed for nitrogen and phosphorus and the remainder for bacteriological contamination. The water level data show that there has been a general decline since 1977 due to over-abstraction. The magnitude of this decline has reached about 20 m in some places. However, in one area over the same period, a rise of about 3 m has been observed. This occurs as a result of the local hydrogeological conditions of shallow bedrock and relatively low permeability materials down stream of this area that limits the flow of groundwater towards the northeastern part of the aquifer. The general fall in groundwater levels has been accompanied by a change in the direction of the groundwater flow and an overall reduction of the areal extent of the saturated region of the aquifer. The city now has a serious problem such that even if the abstracted groundwater is rationed, water is not available for long periods because the demand far exceeds the supply. The heavy impact of urbanization on the groundwater quality is shown through the observed high nitrate (up to 295 mg/l as nitrate) and high phosphorus values (about 0.1 mg/l as P). Significant changes in the chloride concentration are also observed in two areas: increasing from 100 mg/l to 1,600 mg/l and from 2,000 mg/l to 4,000 mg/l, respectively. Furthermore, the bacteriological investigations show that 33 percent of the 27 collected groundwater samples are positive for total coliform and 11 percent of the

Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, January 2016

USGS Publications Warehouse

Klager, Brian J.

2016-12-29

The Equus Beds aquifer in south-central Kansas, which is part of the High Plains aquifer, serves as a source of water for municipal and agricultural users in the area. The city of Wichita has used the Equus Beds aquifer as one of its primary water sources since the 1940s. The aquifer in and around Wichita’s well field reached historically low water levels in 1993, prompting the city to adopt new water-use and conservation strategies to ensure future water supply needs were met. Part of the plan was to initiate a managed aquifer recharge program called the Equus Beds Aquifer Storage and Recovery project. The goal of the managed aquifer recharge program is to artificially recharge the Equus Beds aquifer with treated water from the Little Arkansas River. As part of the Equus Beds Aquifer Storage and Recovery project, the city of Wichita and the U.S. Geological Survey have partnered in a long-term cooperative study to monitor and describe the quantity and quality of the water in the Equus Beds aquifer and the Little Arkansas River.The city of Wichita, the Equus Beds Groundwater Management District No. 2, the Kansas Department of Agriculture–Division of Water Resources, and the U.S. Geological Survey collected groundwater levels in numerous wells screened in the Equus Beds aquifer in the area in and around Wichita’s well field in January 2016. The measurements were used to interpolate potentiometric surfaces for shallow and deep parts of the aquifer in the study area. These potentiometric surfaces were compared with potentiometric surfaces from previous years to estimate changes in water levels and storage volume in the study area.Groundwater levels were generally higher in January 2016 than they were in January 2015. On average, in January 2016, groundwater levels in the shallow part of the aquifer were about 3.4 feet higher and groundwater levels in the deep part of the aquifer were about 3.8 feet higher than in January 2015. The volume of water stored in the

Uranium concentrations in groundwater, northeastern Washington

USGS Publications Warehouse

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

2018-04-18

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

Groundwater productivity potential mapping using evidential belief function.

PubMed

Park, Inhye; Kim, Yongsung; Lee, Saro

2014-09-01

The evidential belief function (EBF) model was applied and validated for analysis of groundwater-productivity potential (GPP) in Boryeong and Pohang cities, agriculture region in Korea using geographic information systems (GIS). Data about related factors, including topography, lineament, geology, forest, soil, and groundwater data were collected and input into a spatial database. Additionally, in the Boryeong area, specific capacity (SPC) data not lower than 4.55 m3 /d/m were collected, corresponding to 300 m3 /d yield from 72 well locations. In the Pohang area, SPC data of ≥ 6.25 m3 /d/m were collected, corresponding to a yield of 500 m3 /d from 44 well locations. By using the constructed spatial database, 19 factors related to groundwater productivity were extracted. The relationships between the well locations and the factors were identified and quantified by using the EBF model. Four relationships were calculated: belief (Bel), disbelief (Dis), uncertainty (Unc), and plausibility (Pls). The relationships were used as factor ratings in the overlay analysis to create GPP indices and maps. The resulting GPP maps showed 83.41% and 77.53% accuracy in Boryeong and Pohang areas, respectively. The EBF model was found to be more effective in terms of prediction accuracy. © 2014, National Ground Water Association.

Spatial variability and long-term analysis of groundwater quality of Faisalabad industrial zone

NASA Astrophysics Data System (ADS)

Nasir, Muhammad Salman; Nasir, Abdul; Rashid, Haroon; Shah, Syed Hamid Hussain

2017-10-01

Water is the basic necessity of life and is essential for healthy society. In this study, groundwater quality analysis was carried out for the industrial zone of Faisalabad city. Sixty samples of groundwater were collected from the study area. The quality maps of deliberately analyzed results were prepared in GIS. The collected samples were analyzed for chemical parameters and heavy metals, such as total hardness, alkalinity, cadmium, arsenic, nickel, lead, and fluoride, and then, the results were compared with the WHO guidelines. The values of these results were represented by a mapping of quality parameters using the ArcView GIS v9.3, and IDW was used for raster interpolation. The long-term analysis of these parameters has been carried out using the `R Statistical' software. It was concluded that water is partially not fit for drinking, and direct use of this groundwater may cause health issues.

Assessing Groundwater Resources Sustainability Using Groundwater Footprint Concept

NASA Astrophysics Data System (ADS)

Charchousi, Despoina; Spanoudaki, Katerina; Papadopoulou, Maria P.

2017-04-01

Over-pumping, water table depletion and climate change impacts require effective groundwater management. The Groundwater Footprint (GWF), introduced by Gleeson et al. in 2012 expresses the area required to sustain groundwater use and groundwater dependent ecosystem services. GWF represents a water balance between aquifer inflows and outflows, focusing on environmental flow requirements. Developing the water balance, precipitation recharge and additional recharge from irrigation are considered as inflows, whereas outflows are considered the groundwater abstraction from the aquifer of interest and the quantity of groundwater that is needed to sustain ecosystem services. The parameters required for GWF calculation can be estimated through in-situ measurements, observations and models outputs. The actual groundwater abstraction is often difficult to be estimated with a high accuracy. Environmental flow requirements can be calculated through different approaches; the most accurate of which are considered the ones that focus on hydro-ecological data analysis. As the GWF is a tool recently introduced in groundwater assessment and management, only a few studies have been reported in the literature to use it as groundwater monitoring and management tool. The present study emphasizes on a case study in Southern Europe, where awareness should be raised about rivers' environmental flow. GWF concept will be applied for the first time to a pilot area in Greece, where the flow of the perennial river that crosses the area of interest is dependent on baseflow. Recharge and abstraction of the pilot area are estimated based on historical data and previous reports and a groundwater flow model is developed using Visual Modflow so as to diminish the uncertainty of the input parameters through model calibration. The groundwater quantity that should be allocated on surface water body in order to sustain satisfactory biological conditions is estimated under the assumption that surface

Determination of micro-organic contaminants in groundwater (Maribor, Slovenia).

PubMed

Koroša, A; Auersperger, P; Mali, N

2016-11-15

Micro-organic (MO) contaminants in groundwater can have adverse effects on both the environment and on human health. They enter the natural environment as a result of various processes, their presence in groundwater is the result of current anthropogenic activity and pollution loads from the past. A study on the occurrence and concentrations levels of selected contaminants in water was performed in the city of Maribor, Slovenia. A total of 56 groundwater and 4 surface water samples were collected in together four rounds in different hydrogeological periods (dry and wet seasons), and a total of 13 selected contaminants were analysed in this study. Carbamazepine, propyphenazone, caffeine, 2-methyl-2H-benzotriazole (2-MBT) and 2.4-dimethyl-2H-benzotriazole (2.4-DMBT) were determined as indicators of urban pollution, while pesticides and their metabolites (atrazine, desethylatrazine, deisopropylatrazine, terbuthylazine, desethylterbuthylazine, metolachlor, simazine, propazine) were mainly defined as indicators of crop production. All of the selected MO contaminants were detected both in the aquifer and Drava River. The most frequently detected MO compounds in groundwater were desethylatrazine (frequency of detection 98.2%; max. concentration 103.0ngL(-1)), atrazine (94.6%; 229ngL(-1)), 2.4-DMBT (92.9%; 273ngL(-1)), carbamazepine (80.4%; 88.00ngL(-1)), desethylterbuthylazine (76.8%; 7.0ngL(-1)) and simazine (76.8%; 29.6ngL(-1)), whereas propyphenazone (14.3%; 10.7ngL(-1)) was the least frequently detected. Detected MO concentrations in the study were compared with results published elsewhere around the world. Concentrations in groundwater indicate specific land use in their recharge areas. On the basis of correlations and the spatial distribution of selected MOs, groundwater origin for every sampling point was determined. Sampling sites were divided into three different groups for which indicative groundwater quality properties were defined. Copyright © 2016 Elsevier B

Applying Factor Analysis Combined with Kriging and Information Entropy Theory for Mapping and Evaluating the Stability of Groundwater Quality Variation in Taiwan

PubMed Central

Shyu, Guey-Shin; Cheng, Bai-You; Chiang, Chi-Ting; Yao, Pei-Hsuan; Chang, Tsun-Kuo

2011-01-01

In Taiwan many factors, whether geological parent materials, human activities, and climate change, can affect the groundwater quality and its stability. This work combines factor analysis and kriging with information entropy theory to interpret the stability of groundwater quality variation in Taiwan between 2005 and 2007. Groundwater quality demonstrated apparent differences between the northern and southern areas of Taiwan when divided by the Wu River. Approximately 52% of the monitoring wells in southern Taiwan suffered from progressing seawater intrusion, causing unstable groundwater quality. Industrial and livestock wastewaters also polluted 59.6% of the monitoring wells, resulting in elevated EC and TOC concentrations in the groundwater. In northern Taiwan, domestic wastewaters polluted city groundwater, resulting in higher NH3-N concentration and groundwater quality instability was apparent among 10.3% of the monitoring wells. The method proposed in this study for analyzing groundwater quality inspects common stability factors, identifies potential areas influenced by common factors, and assists in elevating and reinforcing information in support of an overall groundwater management strategy. PMID:21695030

Dye tracing techniques used to determine ground-water flow in a carbonate aquifer system near Elizabethtown, Kentucky

USGS Publications Warehouse

Mull, D.S.; Smoot, J.L.; Liebermann, T.D.

1988-01-01

Because of the vulnerability of karst aquifers to contamination and the need for water managers to know recharge areas and groundwater flow characteristics for springs and wells used for public water supply, qualitative and quantitative dye tracing techniques were used during a groundwater investigation in the Elizabethtown area, Hardin County, in north-central Kentucky. The principal aquifer in the Elizabethtown area is thick, nearly horizontal beds of limestone, and thin beds of shale of Mississippi age. As much as 65% of all water pumped for the city water supply is obtained from two springs and two wells that obtain water from these rocks. Sinkholes were classified according to their ability to funnel runoff directly into the groundwater flow system, based primarily on the nature of the swallet draining the sinkhole. The presence of bedrock in the sinkhole nearly always ensured a well defined swallet leading to the subsurface. Qualitative and quantitative dye tracing techniques and equipment are discussed in detail. Qualitative dye tracing with fluorescein dye and passive dye detectors, consisting of activated coconut charcoal identified point to point connection between representative sinkholes, sinking streams, and karst windows and the city springs and wells. Qualitative tracing confirmed the presence of infiltrated surface water from a perennial stream, Valley Creek, in water from city wells and generally confirmed the direction of groundwater flow as shown by a water level contour map. Quantitative dye tracing with rhodamin WT, automatic samplers, discharge measurements, and fluorometric analyses were used to determine flow characteristics such as traveltime for arrival of the leading edge, peak concentration, trailing edge, and persistence of the dye cloud at the spring resurgence. Analyses of the dye recovery curves for quantitative dye traces completed between the same sinkholes and a city spring, and during different flow conditions showed that the

Genesis analysis of karst water trichloroethylene pollution in the east of a city

NASA Astrophysics Data System (ADS)

Jiang, Peng; Ma, Zhenmin; Wen, Ming

2017-04-01

To understand the situation of Karst water Trichloroethylene (TCE) pollution in the east of city, Karst water samples sampled at 43 monitoring sites were analyzed. Result shows that relevance ratio of TCE is 100%, over the standard rate of 97.67% and the maximum value is 73.64μg/L, as 14.73 times as the standard value(5μg/L). Causes of groundwater TCE pollution were analyzed. Result shows that indiscriminate discharge of waste water and poor groundwater vulnerability are the main reasons. And based on the reasons, the pollution ways of TCE were found out.

Hydrology and simulation of ground-water flow in the Tooele Valley ground-water basin, Tooele County, Utah

USGS Publications Warehouse

Stolp, Bernard J.; Brooks, Lynette E.

2009-01-01

Ground water is the sole source of drinking water within Tooele Valley. Transition from agriculture to residential land and water use necessitates additional understanding of water resources. The ground-water basin is conceptualized as a single interconnected hydrologic system consisting of the consolidated-rock mountains and adjoining unconsolidated basin-fill valleys. Within the basin fill, unconfined conditions exist along the valley margins and confined conditions exist in the central areas of the valleys. Transmissivity of the unconsolidated basin-fill aquifer ranges from 1,000 to 270,000 square feet per day. Within the consolidated rock of the mountains, ground-water flow largely is unconfined, though variability in geologic structure, stratigraphy, and lithology has created some areas where ground-water flow is confined. Hydraulic conductivity of the consolidated rock ranges from 0.003 to 100 feet per day. Ground water within the basin generally moves from the mountains toward the central and northern areas of Tooele Valley. Steep hydraulic gradients exist at Tooele Army Depot and near Erda. The estimated average annual ground-water recharge within the basin is 82,000 acre-feet per year. The primary source of recharge is precipitation in the mountains; other sources of recharge are irrigation water and streams. Recharge from precipitation was determined using the Basin Characterization Model. Estimated average annual ground-water discharge within the basin is 84,000 acre-feet per year. Discharge is to wells, springs, and drains, and by evapotranspiration. Water levels at wells within the basin indicate periods of increased recharge during 1983-84 and 1996-2000. During these periods annual precipitation at Tooele City exceeded the 1971-2000 annual average for consecutive years. The water with the lowest dissolved-solids concentrations exists in the mountain areas where most of the ground-water recharge occurs. The principal dissolved constituents are calcium

California Groundwater Units

USGS Publications Warehouse

Johnson, Tyler D.; Belitz, Kenneth

2014-01-01

The California Groundwater Units dataset classifies and delineates areas within the State of California into one of three groundwater-based polygon units: (1) those areas previously defined as alluvial groundwater basins or subbasins, (2) highland areas that are adjacent to and topographically upgradient of groundwater basins, and (3) highland areas not associated with a groundwater basin, only a hydrogeologic province. In total, 938 Groundwater Units are represented. The Groundwater Units dataset relates existing groundwater basins with their newly delineated highland areas which can be used in subsequent hydrologic studies. The methods used to delineate groundwater-basin-associated highland areas are similar to those used to delineate a contributing area (such as for a lake or water body); the difference is that highland areas are constrained to the immediately surrounding upslope (upstream) area. Upslope basins have their own delineated highland. A geoprocessing tool was created to facilitate delineation of highland areas for groundwater basins and subbasins and is available for download.

Simulation of ground-water flow in the Vevay Township area, Ingham County, Michigan

USGS Publications Warehouse

Luukkonen, Carol L.; Simard, Andreanne

2004-01-01

Ground water is the primary source of water for domestic, public-supply, and industrial use within the Tri-County region that includes Clinton, Eaton, and Ingham Counties in Michigan. Because of the importance of this ground-water resource, numerous communities, including the city of Mason in Ingham County, have begun local Wellhead Protection Programs. In these programs, communities protect their groundwater resource by identifying the areas that contribute water to production wells and potential sources of contamination, and by developing methods to manage and minimize threats to the water supply. In addition, some communities in Michigan are concerned about water availability, particularly in areas experiencing water-level declines in the vicinity of quarry dewatering operations. In areas where Wellhead Protection Programs are implemented and there are potential threats to the water supply, residents and communities need adequate information to protect the water supply.In 1996, a regional ground-water-flow model was developed by the U.S. Geological Survey to simulate ground-water flow in Clinton, Eaton, and Ingham Counties. This model was developed primarily to simulate the bedrock ground-waterflow system; ground-water flow in the unconsolidated glacial sediments was simulated to support analysis of flow in the underlying bedrock Saginaw aquifer. Since its development in 1996, regional model simulations have been conducted to address protection concerns and water availability questions of local water-resources managers. As a result of these continuing model simulations, additional hydrogeologic data have been acquired in the Tri-County region that has improved the characterization of the simulated ground-water-flow system and improved the model calibration. A major benefit of these updates and refinements is that the regional Tri-County model continues to be a useful tool that improves the understanding of the ground-water-flow system in the Tri-County region

Seasonal changes in ground-water quality and ground-water levels and directions of ground-water movement in southern Elmore County, southwestern Idaho, including Mountain Home Air Force Base, 1990-1991

USGS Publications Warehouse

Young, H.W.; Parliman, D.J.; Jones, Michael L.

1992-01-01

The study area is located in southern Elmore County, southwestern Idaho, and includes the Mountain Home Air Force Base located approximately 10 mi southwest of the city of Mountain Home. Chemical analyzes have been made periodically since the late 1940's on water samples from supply wells on the Air Force Base. These analyses indicate increases in specific conductance and in concentrations of nitrogen compounds, chloride, and sulfate. The purposes of this report, which was prepared in cooperation with the Department of the Air Force, are to describe the seasonal changes in water quality and water levels and to depict the directions of ground-water movement in the regional aquifer system and perched-water zones. Although data presented in this report are from both the regional ground-water system and perched-water zones, the focus is on the regional system. A previous study by the U.S. Geological Survey (Parliman and Young, 1990) describes the areal changes in water quality and water levels during the fall of 1989. During March, July, and October 1990, 141 wells were inventoried and depth to water was measured. Continuous water-level recorders were installed on 5 of the wells and monthly measurements of depth to water were made in 17 of the wells during March 1990 through February 1991. Water samples from 33 wells and 1 spring were collected during the spring and fall of 1990 for chemical analyses. Samples also were collected monthly from 11 of those wells during April to September 1990 (table 1). Selected well-construction and water-use data and measurements of depth to water for 141 wells are given in table 2 (separated sheets in envelope). Directions of ground-water movement and selected hydrographs showing seasonal fluctuations of water levels in the regional ground-water system and perched-water zones are shown on sheet 2. Changes in water levels in the regional ground-water system during March to October 1990 are shown on sheet 2.

Evaluating the effects of urbanization and land-use planning using ground-water and surface-water models

USGS Publications Warehouse

Hunt, R.J.; Steuer, J.J.

2001-01-01

Why are the effects of urbanization a concern? As the city of Middleton, Wisconsin, and its surroundings continue to develop, the Pheasant Branch watershed (fig.l) is expected to undergo urbanization. For the downstream city of Middleton, urbanization in the watershed can mean increased flood peaks, water volume and pollutant loads. More subtly, it may also reduce water that sustains the ground-water system (called "recharge") and adversely affect downstream ecosystems that depend on ground water such as the Pheasant Branch Springs (hereafter referred to as the Springs). The relation of stormwater runoff and reduced ground-water recharge is complex because the surface-water system is coupled to the underlying ground-water system. In many cases there is movement of water from one system to the other that varies seasonally or daily depending on changing conditions. Therefore, it is difficult to reliably determine the effects of urbanization on stream baseflow and spring flows without rigorous investigation. Moreover, mitigating adverse effects after development has occurred can be expensive and administratively difficult. Overlying these concerns are issues such as stewardship of the resource, the rights of the public, and land owners' rights both of those developing their land and those whose land is affected by this development. With the often- contradictory goals, a scientific basis for assessing effects of urbanization and effectiveness of mitigation measures helps ensure fair and constructive decision-making. The U.S. Geological Survey, in cooperation with the City of Middleton and Wisconsin Department of Natural Resources, completed a study that helps address these issues through modeling of the hydrologic system. This Fact Sheet discusses the results of this work.

Presence of faecal indicator bacteria in groundwaters in Kathmandu Valley, Nepal

NASA Astrophysics Data System (ADS)

Nishida, K.; Shrestha, S.; Tanaka, Y.; Haramoto, E.; Nakamura, T.; Osaka, K.; Chapagain, S.

2010-12-01

Groundwater quality is a critical problem in Kathmandu Valley, Nepal. The population of the city increased 6 times in the last six decades and more than half of water demand depends on groundwater resource. Nevertheless, few data of microorganism presence have been reported qualitatively in the central area of the valley. We investigated distribution of faecal indicator bacteria (Total coliforms and Escherichia coli) detected in wells and analyzed the variations of the concentrations. Groundwater samples were collected from 12 deep tube wells (170-300m depths) and 36 shallow tube wells and dug wells (3-20m depths) in Aug 2008, Jan 2009, Aug 2009 and Aug 2010. River waters were also collected for analyzing effect on groundwater quality. E. coli was detected from most of all wells; the concentrations were within 1 log cfu/100mL in deep tube wells and shallow tube wells while those in dug wells ranged from 1 to 3 log cfu/100mL. E. coli was detected at extremely high level in river water, from 5 to 7 log cfu/100mL, however, no clear relation was observed between E. coli concentrations in any types of groundwaters and distance of wells from adjacent rivers. These results indicate that both types of tube wells were rather protected and dug wells were most vulnerable for faecal contamination at very local scale. Genetic analysis of bacterial communities for deep well samples showed the existence of Enterobacter, Acinetobacter as well as Methane-metabolizing groups which provide information of possible indicators other than total coliforms or E. coli for groundwater management in the valley.

Ground-water conditions and studies in Georgia, 2001

USGS Publications Warehouse

Leeth, David C.; Clarke, John S.; Craigg, Steven D.; Wipperfurth, Caryl J.

2003-01-01

The U.S. Geological Survey (USGS) collects ground-water data and conducts studies to monitor hydrologic conditions, to better define ground-water resources, and address problems related to water supply and water quality. Data collected as part of ground-water studies include geologic, geophysical, hydraulic property, water level, and water quality. A ground-water-level network has been established throughout most of the State of Georgia, and ground-water-quality networks have been established in the cities of Albany, Savannah, and Brunswick and in Camden County, Georgia. Ground-water levels are monitored continuously in a network of wells completed in major aquifers of the State. This network includes 17 wells in the surficial aquifer, 12 wells in the upper and lower Brunswick aquifers, 73 wells in the Upper Floridan aquifer, 10 wells in the Lower Floridan aquifer and underlying units, 12 wells in the Claiborne aquifer, 1 well in the Gordon aquifer, 11 wells in the Clayton aquifer, 11 wells in the Cretaceous aquifer system, 2 wells in Paleozoic-rock aquifers, and 7 wells in crystalline-rock aquifers. In this report, data from these 156 wells were evaluated to determine whether mean-annual ground-water levels were within, below, or above the normal range during 2001, based on summary statistics for the period of record. Information from these summaries indicates that water levels during 2001 were below normal in almost all aquifers monitored, largely reflecting climatic effects from drought and pumping. In addition, water-level hydrographs for selected wells indicate that water levels have declined during the past 5 years (since 1997) in almost all aquifers monitored, with water levels in some wells falling below historical lows. In addition to continuous water-level data, periodic measurements taken in 52 wells in the Camden County-Charlton County area, and 65 wells in the city of Albany-Dougherty County area were used to construct potentiometric-surface maps for

Groundwater geochemistry in the Seminole Well Field, Cedar Rapids, Iowa

USGS Publications Warehouse

Boyd, Robert A.

1999-01-01

The City of Cedar Rapids obtains its municipal water supply from four well fields in an alluvial aquifer along the Cedar River in east-central Iowa. Since 1992, the City and the U.S. Geological Survey have cooperatively studied the groundwater-flow system and water chemistry near the well fields. The geochemistry in the alluvial aquifer near the Seminole Well Field was assessed to identify potentially reactive minerals and possible chemical reactions that produce observed changes in water chemistry. Calcite, dolomite, ferrihydrite, quartz, rhodochrosite, and siderite were identified as potentially reactive minerals by calculating saturation indexes. Aluminosiicate minerals including albite, Ca-montmorillonite, gibbsite, illite, K-feldspar, and kaolinite were identified as potentially reactive minerals using hypothetical saturation indexes calculated with an assumed dissolved aluminum concentration of 1 microgram per liter. Balanced chemical equations derived from inverse-modeling techniques were used to assess chemical reactions as precipitation percolates to the water table. Calcite dissolution was predominate, but aluminosilicate weathering, cation exchange, and redox reactions also likely occurred. Microbial-catalyzed redox reactions altered the chemical composition of water infiltrating from the Cedar River into the alluvial aquifer by consuming dissolved oxygen, reducing nitrate, and increasing dissolved iron and manganese concentrations. Nitrate reduction only occurred in relatively shallow (3 to 7 meters below land surface) groundwater near the Cedar River and did not occur in water infiltrating to deeper zones of the alluvial aquifer.

Groundwater quality in the San Francisco Bay groundwater basins, California

USGS Publications Warehouse

Parsons, Mary C.; Kulongoski, Justin T.; Belitz, Kenneth

2013-01-01

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. Selected groundwater basins of the San Francisco Bay area constitute one of the study units being evaluated.

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

USGS Publications Warehouse

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.

Comparison of a Conceptual Groundwater Model and Physically Based Groundwater Mode

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Overview of groundwater sources and water-supply systems, and associated microbial pollution, in Finland, Norway and Iceland

NASA Astrophysics Data System (ADS)

Kløve, Bjørn; Kvitsand, Hanne Margrethe Lund; Pitkänen, Tarja; Gunnarsdottir, Maria J.; Gaut, Sylvi; Gardarsson, Sigurdur M.; Rossi, Pekka M.; Miettinen, Ilkka

2017-06-01

The characteristics of groundwater systems and groundwater contamination in Finland, Norway and Iceland are presented, as they relate to outbreaks of disease. Disparities among the Nordic countries in the approach to providing safe drinking water from groundwater are discussed, and recommendations are given for the future. Groundwater recharge is typically high in autumn or winter months or after snowmelt in the coldest regions. Most inland aquifers are unconfined and therefore vulnerable to pollution, but they are often without much anthropogenic influence and the water quality is good. In coastal zones, previously emplaced marine sediments may confine and protect aquifers to some extent. However, the water quality in these aquifers is highly variable, as the coastal regions are also most influenced by agriculture, sea-water intrusion and urban settlements resulting in challenging conditions for water abstraction and supply. Groundwater is typically extracted from Quaternary deposits for small and medium municipalities, from bedrock for single households, and from surface water for the largest cities, except for Iceland, which relies almost entirely on groundwater for public supply. Managed aquifer recharge, with or without prior water treatment, is widely used in Finland to extend present groundwater resources. Especially at small utilities, groundwater is often supplied without treatment. Despite generally good water quality, microbial contamination has occurred, principally by norovirus and Campylobacter, with larger outbreaks resulting from sewage contamination, cross-connections into drinking water supplies, heavy rainfall events, and ingress of polluted surface water to groundwater.

Efficient management of municipal water: water scarcity in Taiz City, Yemen - issues and options

NASA Astrophysics Data System (ADS)

Noaman, A.; Al-Sharjabe, A. W.

2015-04-01

The city of Taiz is the third largest city in Yemen, located about 250 km south of Sana'a and about 90 km inland from the Red Sea. Taiz is situated on the foothills and slopes of the Jabal Saber Mountain at elevations between 1100 and 1600 m a.s.l. Its population is rapidly increasing and is expected to grow from about 580 000 in 2012 to over 1 000 000 in 2020. Water supply is the most pressing problem in the city of Taiz today due to the significant shortages of supply (the average consumption is 23 L/d) caused by the depletion of existing water resources and the lack of a clear direction in dealing with the problem. This forces frequent service interruptions (30-40 days) and the service is rarely extended to new users (only 57% of the population are covered). Sanitation is another daunting problem. The (poorly maintained) sewerage network covers only 44% of the population. In several unsewered areas to the north, east and west of the city, raw sewage is disposed of directly into wadis, which causes a health hazard and threatens to contaminate groundwater resources. The proper computation of demand and supply is based on the various fields. It was performed under this study with a particular model: the Water Evaluation and Planning System (WEAP) developed by the Stockholm Environment Institute (SEI). WEAP is supported by a geographical information system (GIS). The available and relevant data on poverty and social indicators, water use and sources, surface runoff, surface and groundwater availability, groundwater depletion and management, crop production areas, soil cover, maps, and meteorological information were gathered from a number of sources. There are only two ways to decrease the water deficit: by increasing water supply or decreasing the water demand. Any adaptation project aims at one of the two. Six projects are proposed, with three in each category (1, 2 and 3 to decrease demand, and 4, 5 and 6 to increase supply): - Project 1: Improvement of

Impacts on groundwater recharge areas of megacity pumping: analysis of potential contamination of Kolkata, India, water supply

USGS Publications Warehouse

Sahu, Paulami; Michael, Holly A.; Voss, Clifford I.; Sikdar, Pradip K.

2013-01-01

Water supply to the world's megacities is a problem of quantity and quality that will be a priority in the coming decades. Heavy pumping of groundwater beneath these urban centres, particularly in regions with low natural topographic gradients, such as deltas and floodplains, can fundamentally alter the hydrological system. These changes affect recharge area locations, which may shift closer to the city centre than before development, thereby increasing the potential for contamination. Hydrogeological simulation analysis allows evaluation of the impact on past, present and future pumping for the region of Kolkata, India, on recharge area locations in an aquifer that supplies water to over 13 million people. Relocated recharge areas are compared with known surface contamination sources, with a focus on sustainable management of this urban groundwater resource. The study highlights the impacts of pumping on water sources for long-term development of stressed city aquifers and for future water supply in deltaic and floodplain regions of the world.

Nitrate-nitrogen contamination in groundwater: Spatiotemporal variation and driving factors under cropland in Shandong Province, China

NASA Astrophysics Data System (ADS)

Liu, J.; Jiang, L. H.; Zhang, C. J.; Li, P.; Zhao, T. K.

2017-08-01

High groundwater nitrate-N is a serious problem especially in highly active agricultural areas. In study, the concentration and spatialtemporal distribution of groundwater nitrate-N under cropland in Shandong province were assessed by statistical and geostatistical techniques. Nitrate-N concentration reached a maximum of 184.60 mg L-1 and 29.5% of samples had levels in excess of safety threshold concentration (20 mg L-1). The median nitrate-N contents after rainy season were significantly higher than those before rainy season, and decreased with increasing groundwater depth. Nitrate-N under vegetable and orchard area are significantly higher than ones under grain. The kriging map shows that groundwater nitrate-N has a strong spatial variability. Many districts, such as Weifang, Linyi in Shandong province are heavily contaminated with nitrate-N. However, there are no significant trends of NO3 --N for most cities. Stepwise regression analysis showed influencing factors are different for the groundwater in different depth. But overall, vegetable yield per unit area, percentages of orchard area, per capita agricultural production, unit-area nitrogen fertilizer, livestock per unit area, percentages of irrigation areas, population per unit area and annual mean temperature are significant variables for groundwater nitrate-N variation.

Estimating Groundwater Development area in Jianan Plain using Standardized Groundwater Index

NASA Astrophysics Data System (ADS)

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.

Preliminary development of a GIS-tool to assess threats to shallow groundwater quality from soil pollutants in Glasgow, UK (GRASP).

NASA Astrophysics Data System (ADS)

Dochartaigh, B. É. Ó.; Fordyce, F. M.; Ander, E. L.; Bonsor, H. C.

2009-04-01

The protection of groundwater and related surface water quality is a key aspect of the European Union Water Framework Directive and environmental legislation in many countries worldwide. Globally, the protection of urban groundwater resources and related ecosystem services is of growing concern as urbanisation increases. Although urban areas are often where groundwater resources are most in need of protection, there is frequently a lack of information about threats to groundwater quality. Most studies of soil and groundwater contamination, although detailed, are site-specific, and city-wide overviews are generally lacking. The British Geological Survey (BGS) is currently undertaking the Clyde Urban Super-Project (CUSP), delivering multi-disciplinary geoscience products for the Glasgow conurbation. Under this project, a GIS-based prioritisation tool known as GRASP (GRoundwater And Soil Pollutants) has been trialled to aid urban planning and sustainable development by providing a broad-scale assessment of threats to groundwater quality across the conurbation. GRASP identifies areas where shallow groundwater quality is at greatest threat from the leaching and downward movement of potentially harmful metals in the soil. Metal contamination is a known problem in many urban centres including Glasgow, which has a long industrial heritage and associated contamination legacy, notably with respect to Cr. GRASP is based primarily upon an existing British Standard - International Standards Organisation methodology to determine the leaching potential of metals from soils, which has been validated for 11 metals: Al, Fe, Cd, Co, Cr, Cu, Hg, Ni, Mn, Pb and Zn (BS-ISO 15175:2004). However, the GRASP tool is innovative as it combines assessments of soil leaching potential with soil metal content data to highlight threats to shallow groundwater quality. The input parameters required for GRASP (soil pH, clay, organic matter, sesquioxide and metal content) are based upon a systematic

Groundwater depth prediction in a shallow aquifer in north China by a quantile regression model

NASA Astrophysics Data System (ADS)

Li, Fawen; Wei, Wan; Zhao, Yong; Qiao, Jiale

2017-01-01

There is a close relationship between groundwater level in a shallow aquifer and the surface ecological environment; hence, it is important to accurately simulate and predict the groundwater level in eco-environmental construction projects. The multiple linear regression (MLR) model is one of the most useful methods to predict groundwater level (depth); however, the predicted values by this model only reflect the mean distribution of the observations and cannot effectively fit the extreme distribution data (outliers). The study reported here builds a prediction model of groundwater-depth dynamics in a shallow aquifer using the quantile regression (QR) method on the basis of the observed data of groundwater depth and related factors. The proposed approach was applied to five sites in Tianjin city, north China, and the groundwater depth was calculated in different quantiles, from which the optimal quantile was screened out according to the box plot method and compared to the values predicted by the MLR model. The results showed that the related factors in the five sites did not follow the standard normal distribution and that there were outliers in the precipitation and last-month (initial state) groundwater-depth factors because the basic assumptions of the MLR model could not be achieved, thereby causing errors. Nevertheless, these conditions had no effect on the QR model, as it could more effectively describe the distribution of original data and had a higher precision in fitting the outliers.

SITE CHARACTERIZATION OF A CHROMIUM SOURCE AREA AT THE USGS SUPPORT CENTER, ELIZABETH CITY, NC

EPA Science Inventory

Chromic and sulfuric acid wastes had discharged through a hole in the concrete floor of a chrome-plating shop located within a hangar at the U.S. Coast Guard Support Center near Elizabeth City, North Carolina and infiltrated the soils and groundwater beneath the shop. Following i...

Spatial and temporal variability of fluoride concentrations in groundwater resources of Larestan and Gerash regions in Iran from 2003 to 2010.

PubMed

Amini, Hassan; Haghighat, Gholam Ali; Yunesian, Masud; Nabizadeh, Ramin; Mahvi, Amir Hossein; Dehghani, Mohammad Hadi; Davani, Rahim; Aminian, Abd-Rasool; Shamsipour, Mansour; Hassanzadeh, Naser; Faramarzi, Hossein; Mesdaghinia, Alireza

2016-02-01

There is discrepancy about intervals of fluoride monitoring in groundwater resources by Iranian authorities. Spatial and temporal variability of fluoride in groundwater resources of Larestan and Gerash regions in Iran were analyzed from 2003 to 2010 using a geospatial information system and the Mann-Kendall trend test. The mean concentrations of fluoride for the 8-year period in the eight cities and 31 villages were 1.6 and 2.0 mg/l, respectively; the maximum values were 2.4 and 3.8 mg/l, respectively. Spatial, temporal, and spatiotemporal variability of fluoride in overall groundwater resources were relatively constant over the years. However, results of the Mann-Kendall trend test revealed a monotonic trend in the time series of one city and 11 villages for the 8-year period. Specifically, one city and three villages showed positive significant Kendall's Tau values, suggesting an upward trend in fluoride concentrations over the 8-year period. In contrast, seven villages displayed negative significant Kendall's Tau values, arguing for a downward trend in fluoride concentrations over the years. From 2003 to 2010, approximately 52 % of the Larestan and Gerash areas have had fluoride concentrations above the maximum permissible Iranian drinking water standard fluoride level (1.4 mg/l), and about 116,000 people were exposed to such excess amounts. Therefore, our study supports for a close monitoring of fluoride concentrations from health authorities in monthly intervals, especially in villages and cities that showed positive trend in fluoride concentrations. Moreover, we recommend simultaneous implementation of cost-effective protective measures or interventions until a standard fluoride level is achieved.

Groundwater depletion in Central Mexico: Use of GRACE and InSAR to support water resources management

NASA Astrophysics Data System (ADS)

Castellazzi, Pascal; Martel, Richard; Rivera, Alfonso; Huang, Jianliang; Pavlic, Goran; Calderhead, Angus I.; Chaussard, Estelle; Garfias, Jaime; Salas, Javier

2016-08-01

Groundwater deficits occur in several areas of Central Mexico, where water resource assessment is limited by the availability and reliability of field data. In this context, GRACE and InSAR are used to remotely assess groundwater storage loss in one of Mexico's most important watersheds in terms of size and economic activity: the Lerma-Santiago-Pacifico (LSP). In situ data and Land Surface Models are used to subtract soil moisture and surface water storage changes from the total water storage change measured by GRACE satellites. As a result, groundwater mass change time-series are obtained for a 12 years period. ALOS-PALSAR images acquired from 2007 to 2011 were processed using the SBAS-InSAR algorithm to reveal areas subject to ground motion related to groundwater over-exploitation. In the perspective of providing guidance for groundwater management, GRACE and InSAR observations are compared with official water budgets and field observations. InSAR-derived subsidence mapping generally agrees well with official water budgets, and shows that deficits occur mainly in cities and irrigated agricultural areas. GRACE does not entirely detect the significant groundwater losses largely reported by official water budgets, literature and InSAR observations. The difference is interpreted as returns of wastewater to the groundwater flow systems, which limits the watershed scale groundwater depletion but suggests major impacts on groundwater quality. This phenomenon is enhanced by ground fracturing as noticed in the field. Studying the fate of the extracted groundwater is essential when comparing GRACE data with higher resolution observations, and particularly in the perspective of further InSAR/GRACE combination in hydrogeology.

Groundwater conditions and studies in the Brunswick–Glynn County area, Georgia, 2008

USGS Publications Warehouse

Cherry, Gregory S.; Peck, Michael F.; Painter, Jaime A.; Stayton, Welby L.

2010-01-01

The Upper Floridan aquifer is contaminated with saltwater in a 2-square-mile area of downtown Brunswick, Georgia. This contamination has limited development of the groundwater supply in the Glynn County area. Hydrologic, geologic, and water-quality data are needed to effectively manage water resources. Since 1959, the U.S. Geological Survey has conducted a cooperative water program with the City of Brunswick to monitor and assess the effect of groundwater development on saltwater contamination of the Floridan aquifer system. During calendar year 2008, the cooperative water program included continuous water-level recording of 12 wells completed in the Floridan, Brunswick, and surficial aquifer systems; collecting water levels from 21 wells to map the potentiometric surface of the Upper Floridan aquifer during July 2008; and collecting and analyzing water samples from 26 wells to map chloride concentrations in the Upper Floridan aquifer during July 2008. Equipment was installed on 3 wells for real-time water level and specific conductance monitoring. In addition, work was continued to refine an existing groundwater-flow model for evaluation of water-management scenarios.

Arsenic contamination of groundwater and drinking water in Vietnam: a human health threat.

PubMed

Berg, M; Tran, H C; Nguyen, T C; Pham, H V; Schertenleib, R; Giger, W

2001-07-01

This is the first publication on arsenic contamination of the Red River alluvial tract in the city of Hanoi and in the surrounding rural districts. Due to naturally occurring organic matter in the sediments, the groundwaters are anoxic and rich in iron. With an average arsenic concentration of 159 micrograms/L, the contamination levels varied from 1 to 3050 micrograms/L in rural groundwater samples from private small-scale tubewells. In a highly affected rural area, the groundwater used directly as drinking water had an average concentration of 430 micrograms/L. Analysis of raw groundwater pumped from the lower aquifer for the Hanoi water supply yielded arsenic levels of 240-320 micrograms/L in three of eight treatment plants and 37-82 micrograms/L in another five plants. Aeration and sand filtration that are applied in the treatment plants for iron removal lowered the arsenic concentrations to levels of 25-91 micrograms/L, but 50% remained above the Vietnamese Standard of 50 micrograms/L. Extracts of sediment samples from five bore cores showed a correlation of arsenic and iron contents (r2 = 0.700, n = 64). The arsenic in the sediments may be associated with iron oxyhydroxides and released to the groundwater by reductive dissolution of iron. Oxidation of sulfide phases could also release arsenic to the groundwater, but sulfur concentrations in sediments were below 1 mg/g. The high arsenic concentrations found in the tubewells (48% above 50 micrograms/L and 20% above 150 micrograms/L) indicate that several million people consuming untreated groundwater might be at a considerable risk of chronic arsenic poisoning.

Occurrence and risk assessment of pharmaceuticals and personal care products and endocrine disrupting chemicals in reclaimed water and receiving groundwater in China.

PubMed

Li, Zhen; Xiang, Xi; Li, Miao; Ma, Yeping; Wang, Jihua; Liu, Xiang

2015-09-01

Groundwater recharge using reclaimed water is considered a promising method to alleviate groundwater depletion. However, pollutants in reclaimed water could be recharged into groundwater during this process, thereby posing a risk to groundwater and human health. In this study, 12 cities in northern China were selected for reclaimed water and groundwater sampling. Analysis of the samples revealed the presence of nine pharmaceutical and personal care products (PPCPs) and five endocrine disrupting compounds (EDCs). In reclaimed water, all the PPCPs and EDCs were found, with sulpiride (SP) and estriol (E3) being most frequently detected. In groundwater samples, only ketoprofen (KP), mefenamic acid (MA), nalidixic acid (NA) and SP were detected among PPCPs, while bisphenol-A (BPA) was dominant among the target EDCs. The risk quotients (RQs) of all target PPCPs and EDCs except 17α-ethinyl estradiol (EE2) and E3 were below 1 in groundwater samples, indicating that EE2 and E3 deserve priority preferential treatment before recharging. Copyright © 2015 Elsevier Inc. All rights reserved.

Analysis of the Control Factors of Groundwater Petroleum Hydrocarbons Contamination in a City’s West Part

NASA Astrophysics Data System (ADS)

Sun, L. H.; Ma, Z. M.; Liu, Z. W.

2018-05-01

Based on study of the hydrogeological condition and the characteristics of petroleum hydrocarbons pollution in karst groundwater, an oil refinery located in western part of a certain city is chosen as the study site to have an analysis on the control factors of groundwater petroleum hydrocarbons contamination. The study result shows that the control factors of groundwater petroleum hydrocarbons contamination are hydrogeological condition and biodegradation. The soil layer of Quaternary is very thin, the limestone is exposed in the surface, which makes the petroleum hydrocarbons easy to permeate into the water bearing layer. Karst-fractured zone in aquifer determines the migration way of petroleum hydrocarbons to be convection, but the magmatic rock in northern part has certain blocking effect on the migration of petroleum hydrocarbons. Biodegradation makes both the contamination plume area of petroleum hydrocarbons and the content of petroleum hydrocarbons decreased.

Study on the relationship between manganese concentrations in rural drinking water and incidence and mortality caused by cancer in Huai'an city.

PubMed

Zhang, Qin; Pan, Enchun; Liu, Linfei; Hu, Wei; He, Yuan; Xu, Qiujin; Liang, Cunzhen

2014-01-01

Cancer is a significant disease burden in the world. Many studies showed that heavy metals or their compounds had connection with cancer. But the data conflicting about the relationship of manganese (Mn) to cancer are not enough. In this paper, the relationship was discussed between Mn concentrations in drinking water for rural residents and incidence and mortality caused by malignant tumors in Huai'an city. A total of 158 water samples from 28 villages of 14 towns were, respectively, collected during periods of high flow and low flow in 3 counties of Huai'an city, along Chinese Huai'he River. The samples of deep groundwater, shallow groundwater, and surface water were simultaneously collected in all selected villages. Mn concentrations in all water samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS 7500a). The correlation analysis was used to study the relationship between the Mn concentration and cancer incidence and mortality. Mn concentrations detectable rate was 100% in all water samples. The mean concentration was 452.32 μg/L ± 507.76 μg/L. There was significant difference between the high flow period and low flow period (t = -5.23, P < 0.05) and also among deep groundwater, shallow groundwater, and surface water (F = 5.02, P < 0.05). The ratio of superscale of Mn was 75.32%. There was significant difference of Mn level between samples in the high flow period and low flow period (χ(2) = 45.62, P < 0.05) and also among deep groundwater, shallow groundwater, and surface water (χ(2) = 10.66, P < 0.05). And also we found that, during the low flow period, Mn concentration has positive correlation with cancer incidence and mortality; for a 1 μg/L increase in Mn concentration, there was a corresponding increase of 0.45/100000 new cancer cases and 0.35/100000 cancer deaths (P < 0.05). In Huai'an city, the mean concentration of Mn in drinking water was very high. Mn concentration correlated with cancer incidence and

Assessing groundwater policy with coupled economic-groundwater hydrologic modeling

NASA Astrophysics Data System (ADS)

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

2014-03-01

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

Spatial and temporal constraints on regional-scale groundwater flow in the Pampa del Tamarugal Basin, Atacama Desert, Chile

NASA Astrophysics Data System (ADS)

Jayne, Richard S.; Pollyea, Ryan M.; Dodd, Justin P.; Olson, Elizabeth J.; Swanson, Susan K.

2016-12-01

Aquifers within the Pampa del Tamarugal Basin (Atacama Desert, northern Chile) are the sole source of water for the coastal city of Iquique and the economically important mining industry. Despite this, the regional groundwater system remains poorly understood. Although it is widely accepted that aquifer recharge originates as precipitation in the Altiplano and Andean Cordillera to the east, there remains debate on whether recharge is driven primarily by near-surface groundwater flow in response to periodic flood events or by basal groundwater flux through deep-seated basin fractures. In addressing this debate, the present study quantifies spatial and temporal variability in regional-scale groundwater flow paths at 20.5°S latitude by combining a two-dimensional model of groundwater and heat flow with field observations and δ18O isotope values in surface water and groundwater. Results suggest that both previously proposed aquifer recharge mechanisms are likely influencing aquifers within the Pampa del Tamarugal Basin; however, each mechanism is operating on different spatial and temporal scales. Storm-driven flood events in the Altiplano readily transmit groundwater to the eastern Pampa del Tamarugal Basin through near-surface groundwater flow on short time scales, e.g., 100-101 years, but these effects are likely isolated to aquifers in the eastern third of the basin. In addition, this study illustrates a physical mechanism for groundwater originating in the eastern highlands to recharge aquifers and salars in the western Pampa del Tamarugal Basin over timescales of 104-105 years.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Residential exposure to chlorinated hydrocarbons from groundwater contamination and the impairment of renal function-An ecological study

NASA Astrophysics Data System (ADS)

Chen, Hui-Ming; Wu, Ming-Tsang

2017-01-01

Groundwater pollution from the petrochemical industry causes serious deterioration of soil and groundwater quality and impacts on human health worldwide. However, few studies have examined the effect of residential exposure to petrochemical chlorinated hydrocarbon-contaminated groundwater on renal function impairment in humans. We conducted an ecological study to investigate the two. A polyvinyl chloride (PVC) plant was located in one of the six villages, the study area, in Kaohsiung city of southwestern Taiwan. Based on the direction of groundwater flow and previous groundwater measurements of chlorinated hydrocarbons from Taiwan Environmental Protection Bureau, we divided the six villages into highly-polluted villages, moderately-polluted villages, and a non-polluted village. All inhabitants in those six villages were invited to receive free health examinations between May-June, 2010. In total, 4,432 study subjects ≥18 yrs old were analyzed. Compared to those in the non-polluted village, subjects in highly-polluted villages had 1.89- and 1.46-fold the risk of impaired estimated glomerular filtration rate (eGFR) and proteinuria (95% CI = 1.15-1.85 and 1.09-3.28, respectively) after adjusting for other covariates. Given this relative large sample size, we found that groundwater chlorinated hydrocarbon pollution can cause kidney damage in adults.

Surface displacement due to groundwater exploitation using spatial and terrestrial techniques.

NASA Astrophysics Data System (ADS)

Abajo Muñoz, T.; Fernandez, J.; Tiampo, K. F.; Luzon, F.

2016-12-01

Subsidence is a natural hazard that affects wide areas in the world causing important economic costs annually. It is estimated that there are over 150 cities in the world with serious problems of subsidence due to excessive groundwater withdrawal like the Po Valley (Italy), Mexico DC, San Joaquin Valley (USA) and Bangkok (Thailand). Globally, groundwater depletion rates have risen in recent decades and significant lowering of groundwater tables has been reported. Aquifer overdraft has been a concern for the management of water resources, due to the potential irreversible loss of aquifer storage caused by aquifer system compaction and associated land subsidence. From a mechanical point of view, groundwater extraction from a confined aquifer reduces groundwater pore pressure. Because the overburden remains unchanged, the effective stress on the grain matrix of the aquifer increases, and the volume of the confined aquifer decreases, resulting in compaction and triggering surface subsidence. The control of land subsidence could serve as a proxy for the management of pore pressure change and groundwater flows in underlying aquifers (Galloway & Hoffmann, 2007). Our main interest is to study the ground surface displacement and Coulomb stress transfer produced by an extended source located in a homogeneus, elastic and isotropic half-space, based on Geerstma's model (1973). This study implies the improvement, development and implementation of the tools necessary for modelling and interpretation of the observations, as well as to evaluate possible interactions with other phenomena, such as the potential to influence on nearby faults. REFERENCES Galloway, D.L., Hoffmann, J., 2007. The application of satellite differential SAR interferometry-derived ground displacements in hydrogeology. Hydrogeology J., 15, 133-154. Geertsma J., 1973. A basic theory of subsidence due to reservoir compaction: the homogeneus case. Verhandelingen Kon. Ned. Geol. Mijnbouwk. Gen., 28, 43-62.

Multiple Imputation of Groundwater Data to Evaluate Spatial and Temporal Anthropogenic Influences on Subsurface Water Fluxes in Los Angeles, CA

NASA Astrophysics Data System (ADS)

Manago, K. F.; Hogue, T. S.; Hering, A. S.

2014-12-01

In the City of Los Angeles, groundwater accounts for 11% of the total water supply on average, and 30% during drought years. Due to ongoing drought in California, increased reliance on local water supply highlights the need for better understanding of regional groundwater dynamics and estimating sustainable groundwater supply. However, in an urban setting, such as Los Angeles, understanding or modeling groundwater levels is extremely complicated due to various anthropogenic influences such as groundwater pumping, artificial recharge, landscape irrigation, leaking infrastructure, seawater intrusion, and extensive impervious surfaces. This study analyzes anthropogenic effects on groundwater levels using groundwater monitoring well data from the County of Los Angeles Department of Public Works. The groundwater data is irregularly sampled with large gaps between samples, resulting in a sparsely populated dataset. A multiple imputation method is used to fill the missing data, allowing for multiple ensembles and improved error estimates. The filled data is interpolated to create spatial groundwater maps utilizing information from all wells. The groundwater data is evaluated at a monthly time step over the last several decades to analyze the effect of land cover and identify other influencing factors on groundwater levels spatially and temporally. Preliminary results show irrigated parks have the largest influence on groundwater fluctuations, resulting in large seasonal changes, exceeding changes in spreading grounds. It is assumed that these fluctuations are caused by watering practices required to sustain non-native vegetation. Conversely, high intensity urbanized areas resulted in muted groundwater fluctuations and behavior decoupling from climate patterns. Results provides improved understanding of anthropogenic effects on groundwater levels in addition to providing high quality datasets for validation of regional groundwater models.

Ground-water use in the coastal plain of Maryland, 1900-1980

USGS Publications Warehouse

Wheeler, J.C.; Wilde, F.D.

1989-01-01

This report presents groundwater withdrawal data from 1900 through 1980 for Maryland counties lying with the Coastal Plain physiographic province, as well as a summary section for the total Maryland Coastal Plain. The types of water use included are domestic, military, water supplier, industrial/commercial, and irrigation. The data were obtained from state and county reports, biannual pumpage reports submitted to the Maryland Water Resources Administration, communication with individual owners, and estimates based on existing published data. The amount of groundwater withdrawn from aquifers in the Maryland Coastal Plain in 1900 was approximately 26 million gallons per day (Mgal/d) compared to nearly 134 Mgal/d in 1980. Jurisdictions withdrawing more than 10 Mgal/d for most of the 80-year period were Anne Arundel and Baltimore Counties and Baltimore City. The greatest withdrawals for most of the early part of the period were for domestic and industrial/commercial uses; however, water-supplier use dominated after 1965. Groundwater use for irrigation became important in the Coastal Plain around 1960 and increased steadily from approximately 2 Mgal/d in 1960 to nearly 12 Mgal/d in 1980. (USGS)

The combined use of MODFLOW and precipitation-runoff modeling to simulate groundwater flow in a diffuse-pollution prone watershed.

PubMed

Elçi, A; Karadaş, D; Fistikoğlu, O

2010-01-01

A numerical modeling case study of groundwater flow in a diffuse pollution prone area is presented. The study area is located within the metropolitan borders of the city of Izmir, Turkey. This groundwater flow model was unconventional in the application since the groundwater recharge parameter in the model was estimated using a lumped, transient water-budget based precipitation-runoff model that was executed independent of the groundwater flow model. The recharge rate obtained from the calibrated precipitation-runoff model was used as input to the groundwater flow model, which was eventually calibrated to measured water table elevations. Overall, the flow model results were consistent with field observations and model statistics were satisfactory. Water budget results of the model revealed that groundwater recharge comprised about 20% of the total water input for the entire study area. Recharge was the second largest component in the budget after leakage from streams into the subsurface. It was concluded that the modeling results can be further used as input for contaminant transport modeling studies in order to evaluate the vulnerability of water resources of the study area to diffuse pollution.

Kansas ground-water observation-well network, 1985

USGS Publications Warehouse

Dague, B.J.; Stullken, L.E.

1986-01-01

Water level measurements are made in 1,892 selected wells in 73 counties, which currently (1985) comprise the Kansas groundwater observation-well network. These measurements are made on a continuous, monthly, quarterly, or annual basis. Water level measurements have been made in observation wells since 1937 as part of a cooperative program among the Kansas Geological Survey , the Kansas State Board of Agriculture, the city of Wichita, and the U.S. Geological Survey. The objectives of the observation-well cooperative program are: (1) to provide long-term records of water level fluctuations in representative wells, (2) to facilitate the determination of possible water level trends that may indicate future availability of groundwater supplies, (3) to aid in the determination of possible changes in the base flow of streams, and (4) to provide information for use in water-resources research. This report lists for each well in the network the location, the first year of recorded water level measurement, the frequency and number of measurements, the land-surface altitude, hexagon-grid identifiers for wells in the High Plains aquifer, and the principal geologic unit(s) in which the well is completed. (USGS)

Groundwater sustainability strategies

USGS Publications Warehouse

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

2010-01-01

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

Regional ground-water evapotranspiration and ground-water budgets, Great Basin, Nevada

USGS Publications Warehouse

Nichols, William D.

2000-01-01

PART A: Ground-water evapotranspiration data from five sites in Nevada and seven sites in Owens Valley, California, were used to develop equations for estimating ground-water evapotranspiration as a function of phreatophyte plant cover or as a function of the depth to ground water. Equations are given for estimating mean daily seasonal and annual ground-water evapotranspiration. The equations that estimate ground-water evapotranspiration as a function of plant cover can be used to estimate regional-scale ground-water evapotranspiration using vegetation indices derived from satellite data for areas where the depth to ground water is poorly known. Equations that estimate ground-water evapotranspiration as a function of the depth to ground water can be used where the depth to ground water is known, but for which information on plant cover is lacking. PART B: Previous ground-water studies estimated groundwater evapotranspiration by phreatophytes and bare soil in Nevada on the basis of results of field studies published in 1912 and 1932. More recent studies of evapotranspiration by rangeland phreatophytes, using micrometeorological methods as discussed in Chapter A of this report, provide new data on which to base estimates of ground-water evapotranspiration. An approach correlating ground-water evapotranspiration with plant cover is used in conjunction with a modified soil-adjusted vegetation index derived from Landsat data to develop a method for estimating the magnitude and distribution of ground-water evapotranspiration at a regional scale. Large areas of phreatophytes near Duckwater and Lockes in Railroad Valley are believed to subsist on ground water discharged from nearby regional springs. Ground-water evapotranspiration by the Duckwater phreatophytes of about 11,500 acre-feet estimated by the method described in this report compares well with measured discharge of about 13,500 acre-feet from the springs near Duckwater. Measured discharge from springs near Lockes

The groundwater subsidy to vegetation: groundwater exchanges between landcover patches

NASA Astrophysics Data System (ADS)

Steven, L. I.; Gimenez, R.; Jobbagy, E. G.

2015-12-01

The Gran Chaco is a hot, dry plain, that spans over 60 million hectares across Bolivia, Paraguay, Brazil and Argentina. It supports high biodiversity in its dry forest and savannahs, but is rapidly being converted to agriculture in response to growing soy demand and technology including genetic modification and zero-till, that has made cultivation in drier landscapes more viable. Under natural conditions, the deep-rooted, native vegetation of the Chaco effectively captured all rainfall for evapotranspiration resulting in near zero groundwater recharge under the dry forest. Conversion to shallower rooted soy and corn, combined with the fallow period prior to the growing season, reduces evapotranspiration and allows some water to percolate through the root zone and recharge the groundwater system. When this groundwater recharge occurs, it creates groundwater mounding and a hydraulic gradient that drives flow to adjacent landcover patches where recharge does not occur. As the watertable rises, groundwater becomes available to the deep-rooted, dry forest vegetation. We develop a soil and groundwater flow model to simulate infiltration, percolation, evaporation, rootwater uptake, groundwater recharge and the lateral transfer of water between adjacent landcover patches to quantify this groundwater subsidy from converted agricultural lands to remnant patches of dry forest.

Reconnaissance of surface-water and ground-water quality at the Lincoln Boyhood National Memorial near Lincoln City, Indiana, 2001-02

USGS Publications Warehouse

Buszka, Paul M.; Fowler, Kathleen K.

2005-01-01

In cooperation with the National Park Service, the U.S. Geological Survey investigated water quality of key water bodies at the Lincoln Boyhood National Memorial near Lincoln City in southwestern Indiana. The key water bodies were a stock pond, representing possible nonpoint agricultural effects on water quality; an ephemeral stream, representing the water quality of drainage from forested areas of the park; parking-lot runoff, representing water quality related to roads and parking lots; an unnamed ditch below the parking lot, representing the water quality of drainage from the parking lot and from an adjacent railroad track; and Lincoln Spring, a historical ground-water source representing ground-water conditions near a former diesel-fuel-spill site along a rail line. Water samples were analyzed for pH, temperature, specific conductance, and dissolved oxygen and for concentrations of selected major ions and trace metals, nutrients, organic constituents, and Escherichia coli bacteria. Surface-water-quality data of water samples from the park represent baseline conditions for the area in relation to the data available from previous studies of area streams. Specific-conductance values and concentrations of most major ions and various nutrients in surface-water samples from the park were smaller than those reported for samples collected in other USGS studies in areas adjacent to the park. Water-quality-management issues identified by this investigation include potentially impaired water quality from parking-lot runoff, unknown effects on surface-water quality from adjacent railroads, and the potential impairment of water quality in Lincoln Spring from human influences. Parking-lot runoff is a source of calcium, alkalinity, iron, lead, and organic carbon in the water samples from the unnamed ditch. Detection of small concentrations of petroleum hydrocarbons in water from Lincoln Spring could indicate residual contamination from a 1995 diesel-fuel spill and cleanup

Spatial patterns and temporal variability in water quality from City of Albuquerque drinking-water supply wells and piezometer nests, with implications for the ground-water flow system

USGS Publications Warehouse

Bexfield, Laura M.; Anderholm, Scott K.

2002-01-01

Water-quality data for 93 City of Albuquerque drinking-water supply wells, 7 deep piezometer nests, and selected additional wells were examined to improve understanding of the regional ground-water system and its response to pumpage. Plots of median values of several major parameters showed discernible water-quality differences both areally and with depth in the aquifer. Areal differences were sufficiently large to enable delineation of five regions of generally distinct water quality, which are consistent with areas of separate recharge defined by previous investigators. Data for deep piezometer nests indicate that water quality generally degrades somewhat with depth, except in areas where local recharge influenced by evapotranspiration or contamination could be affecting shallow water. The orientations of the five water-quality regions indicate that the direction of ground-water flow has historically been primarily north to south. This is generally consistent with maps of predevelopment hydraulic heads, although some areas lack consistency, possibly because of differences in time scales or depths represented by water quality as opposed to hydraulic head. The primary sources of recharge to ground water in the study area appear to be mountain-front recharge along the Sandia Mountains to the east and the Jemez Mountains to the north, seepage from the Rio Grande, and infiltration through Tijeras Arroyo. Elevated concentrations of many chemical constituents in part of the study area appear to be associated with a source of water having large dissolved solids, possibly moving upward from depth. Hydraulic-head data for deep piezometer nests indicate that vertical head gradients differ in direction and magnitude across the study area. Hydraulic-head gradients are downward in the central and western parts of the study area and upward across much of the eastern part, except at the mountain front. Water-quality data for the piezometers indicate that the ground water is not

Using Data Assimilation in Real-Time Hydrological Modeling of Groundwater and Stream Flow in Silkeborg, Denmark

NASA Astrophysics Data System (ADS)

He, X.; Kidmose, J.; Madsen, H.; Zheng, C.; Refsgaard, J. C.

2017-12-01

Climate adaptation strategies have nowadays been used more and more frequently in European cities, such as low impact development to increase infiltration and thus reduce the risk of urban flooding. An alternative approach to cope with the increased precipitation under the future climate condition is by using real-time management techniques to operate the drainage system. In the present study, we developed a real-time hydrological modeling system which can forecast both surface water and groundwater in the city of Silkeborg, Denmark. The model is based on MIKE SHE code, and operates on 50 × 50 m grid cell with hourly time step. Real-time observation data, i.e. groundwater head data from 35 wells and 4 stream flow gauging stations, are used in a data assimilation (DA) framework in order to correct bias in each calculation cell. The DA framework is based on ensemble Kalman filter (EnKF) where uncertainties from forcing data, model parameters as well as observations are taken into consideration. A case study has been carried out where the DA enabled MIKE SHE model was executed in conjunction with the rainfall products from the Danish Meteorological Institute: short term weather forecast coming from HIRLAM model with temporal resolution of 10 minutes and 8 hours lead time, and longer term forecast coming from HARMONIE model with temporal resolution of 1 hour and 48 hour lead time. The results show that DA can visibly increase the model performance for both groundwater head and stream discharge simulations. Even for the short period when observation data are not available (June 2016), the DA based model can still outperform the model without DA. In the forecasting mode, the simulated stream discharge is much more responsive to the increase of rainfall than groundwater as expected. The predicted and observed groundwater head in some areas only varies in the magnitude of a few centimeters, which does not have so much practical meaning in reality, whereas in other areas

Origin of hexavalent chromium in groundwater: The example of Sarigkiol Basin, Northern Greece.

PubMed

Kazakis, N; Kantiranis, N; Kalaitzidou, K; Kaprara, E; Mitrakas, M; Frei, R; Vargemezis, G; Tsourlos, P; Zouboulis, A; Filippidis, A

2017-09-01

Hexavalent chromium constitutes a serious deterioration factor for the groundwater quality of several regions around the world. High concentrations of this contaminant have been also reported in the groundwater of the Sarigkiol hydrological basin (near Kozani city, NW Greece). Specific interest was paid to this particular study area due to the co-existence here of two important factors both expected to contribute to Cr(VI) presence and groundwater pollution; namely the area's exposed ophiolitic rocks and its substantial fly ash deposits originating from the local lignite burning power plant. Accordingly, detailed geochemical, mineralogical, hydro-chemical, geophysical and hydrogeological studies were performed on the rocks, soils, sediments and water resources of this basin. Cr(VI) concentrations varied in the different aquifers, with the highest concentration (up to 120μgL -1 ) recorded in the groundwater of the unconfined porous aquifer situated near the temporary fly ash disposal site. Recharge of the porous aquifer is related mainly to precipitation infiltration and occasional surface run-off. Nevertheless, a hydraulic connection between the porous and neighboring karst aquifers could not be delineated. Therefore, the presence of Cr(VI) in the groundwater of this area is thought to originate from both the ophiolitic rock weathering products in the soils, and the local leaching of Cr(VI) from the diffused fly ash located in the area surrounding the lignite power plant. This conclusion was corroborated by factor analysis, and the strongly positively fractionated Cr isotopes (δ 53 Cr up to 0.83‰) recorded in groundwater, an ash leachate, and the bulk fly ash. An anthropogenic source of Cr(VI) that possibly influences groundwater quality is especially apparent in the eastern part of the Sarigkiol basin. Copyright © 2017 Elsevier B.V. All rights reserved.

Chromium-removal processes during groundwater remediation by a zerovalent iron permeable reactive barrier.

PubMed

Wilkin, Richard T; Su, Chunming; Ford, Robert G; Paul, Cynthia J

2005-06-15

Solid-phase associations of chromium were examined in core materials collected from a full-scale, zerovalent iron permeable reactive barrier (PRB) at the U.S. Coast Guard Support Center located near Elizabeth City, NC. The PRB was installed in 1996 to treat groundwater contaminated with hexavalent chromium. After eight years of operation, the PRB remains effective at reducing concentrations of Cr from average values >1500 microg L(-1) in groundwater hydraulically upgradient of the PRB to values <1 microg L(-1) in groundwater within and hydraulically downgradient of the PRB. Chromium removal from groundwater occurs at the leading edge of the PRB and also within the aquifer immediately upgradient of the PRB. These regions also witness the greatest amount of secondary mineral formation due to steep geochemical gradients that result from the corrosion of zerovalent iron. X-ray absorption near-edge structure (XANES) spectroscopy indicated that chromium is predominantly in the trivalent oxidation state, confirming that reductive processes are responsible for Cr sequestration. XANES spectra and microscopy results suggest that Cr is, in part, associated with iron sulfide grains formed as a consequence of microbially mediated sulfate reduction in and around the PRB. Results of this study provide evidence that secondary iron-bearing mineral products may enhance the capacity of zerovalent iron systems to remediate Cr in groundwater, either through redox reactions at the mineral-water interface or by the release of Fe(II) to solution via mineral dissolution and/or metal corrosion.

Chemical, microbial and antibiotic susceptibility analyses of groundwater after a major flood event in Chennai

PubMed Central

Gowrisankar, Ganesan; Chelliah, Ramachandran; Ramakrishnan, Sudha Rani; Elumalai, Vetrimurugan; Dhanamadhavan, Saravanan; Brindha, Karthikeyan; Antony, Usha; Elango, Lakshmanan

2017-01-01

During floods, human exposure to pathogens through contaminated water leads to the outbreak of epidemic diseases. This research presents the first extensive assessment of surface and groundwater samples collected immediately after a flood (December 2015) and post-flood (April 2016) from the Adyar River of Chennai, a major city in India, for major ions, trace metals, bacterial population, and pathogens. Severe rains in a short period of time resulted in flooding which inundated the wells, allowing the entry of sewage contaminated river water into the groundwater zone. This has led to bacterial counts and chemical ions exceeding Bureau of Indian Standard’s recommended limits in most flood affected areas. Pathogens isolated from the groundwater showed resistance to antibiotics, namely ceftriaxone, doxycycline and nalidixic acid. However, they were sensitive to chloramphenicol, ciprofloxacin, norfloxacin, and tetracycline. Determining the antibiotic susceptibility of pathogens will help in the treatment of humans affected by contaminated water through an appropriate selection of prescribed medication. PMID:28994821

Complex interactions among climate change, sanitation, and groundwater quality: A case study from Ramotswa, Botswana

NASA Astrophysics Data System (ADS)

McGill, B. M.; Altchenko, Y.; Kenabatho, P. K.; Sylvester, S. R.; Villholth, K. G.

2017-12-01

With population growth, rapid urbanization, and climate change, groundwater is becoming an increasingly important source of drinking water around the world, including southern Africa. This is an investigation into the coupled human and natural system linking climate change, droughts, sanitation, and groundwater quality in Ramotswa, a town in the semi-arid southeastern Botswana. During the recent drought from 2013-2016, water shortages from reservoirs that supply the larger city of Gaborone resulted in curtailed water supply to Ramotswa, forcing people with flush toilets to use pit latrines. Pit latrines have been suspected as the cause of elevated nitrate in the Ramotswa groundwater, which also contributes to the town's drinking water supply. The groundwater pollution paradoxically makes Ramotswa dependent on Gaborone's water, supplied in large part by surface reservoirs, which are vulnerable to drought. Analysis of long-term rainfall records indicates that droughts like the one in 2013-2016 are increasing in likelihood due to climate change. Because of the drought, many more people used pit latrines than under normal conditions. Analysis of the groundwater for nitrate and using caffeine as an indicator, human waste leaching from pit latrines is implicated as the major culprit for the nitrate pollution. The results indicate a critical indirect linkage between climate change, sanitation, groundwater quality and water security in this area of rapid urbanization and population growth. Recommendations are offered for how Ramotswa's water security could be made less vulnerable to climate change.

Integrated site investigation and groundwater monitoring in an urban environment

NASA Astrophysics Data System (ADS)

Weatherl, R. K.

2017-12-01

Understanding groundwater dynamics around cities and other areas of human influence is of crucial importance for water resource management and protection, especially in a time of environmental and societal change. The human environment presents a unique challenge in terms of hydrological characterization, as the water cycle is generally artificialized and emissions of treated waste and chemical products into the surface- and groundwater system tend to disrupt the natural aqueous signature in significant ways. This project presents an integrated approach for robust characterization and monitoring of an urban aquifer which is actively exploited for municipal water supply. The study is carried out in the town of Fehraltorf, in the canton of Zürich, Switzerland. This particular town encompasses industrial and agricultural zones in addition to its standard urban setting. A minimal amount of data exist at this site, and the data that do exist are spatially and temporally sparse. Making use of traditional hydrogeological methods alongside evolving and emerging technologies, we aim to identify sources of contamination and to define groundwater flow and solute transport through space and time. Chemical and physical indicator parameters are identified for tracing contaminations including micropollutants and plant nutrients. Wireless sensors are installed for continuous on-line monitoring of essential parameters (electrical conductivity, temperature, water level). A wireless sensor network has previously been installed in the sewer system of the study site, facilitating investigation into interactions between sewer water and groundwater. Our approach illustrates the relations between land use, climate, rainfall dynamics, and the groundwater signature through time. At its conclusion, insights gained from this study will be used by municipal authorities to refine protective zones around pumping wells and to direct resources towards updating practices and replacing

Groundwater for urban water supplies in northern China - An overview

NASA Astrophysics Data System (ADS)

Zaisheng, Han

Groundwater plays an important role for urban and industrial water supply in northern China. More than 1000 groundwater wellfields have been explored and installed. Groundwater provides about half the total quantity of the urban water supply. Complete regulations and methods for the exploration of groundwater have been established in the P.R. China. Substantial over-exploitation of groundwater has created environmental problems in some cities. Some safeguarding measures for groundwater-resource protection have been undertaken. Résumé Les eaux souterraines jouent un rôle important dans l'approvisionnement en eau des agglomérations et des industries du nord de la Chine. Les explorations ont conduit à mettre en place plus de 1000 champs de puits captant des eaux souterraines. Les eaux souterraines satisfont environ la moitié des besoins en eau des villes. Une réglementation complète et des méthodes d'exploration des eaux souterraines ont étéétablies en République Populaire de Chine. Une surexploitation très nette est à l'origine de problèmes environnementaux dans certaines villes. Des mesures ont été prises pour protéger la ressource en eau souterraine. Resumen El agua subterránea desempeña un papel importante en el suministro de agua para uso doméstico e industrial en la China septentrional. Se han explorado y puesto en marcha más de 1000 campos de explotación de aguas subterráneas, que proporcionan cerca de la mitad del total del suministro urbano. En la República Popular de China se han definido totalmente la legislación y la metodología para realizar estas explotaciones. La gran sobreexplotación en algunas ciudades ha creado algunos problemas medioambientales. Como consecuencia, se han llevado a cabo algunas medidas de protección de los recursos de aguas subterráneas.

Groundwater availability of the Mississippi embayment

USGS Publications Warehouse

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

2011-01-01

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

Uncertainty in global groundwater storage estimates in a Total Groundwater Stress framework

PubMed Central

Richey, Alexandra S.; Thomas, Brian F.; Lo, Min‐Hui; Swenson, Sean; Rodell, Matthew

2015-01-01

Abstract Groundwater is a finite resource under continuous external pressures. Current unsustainable groundwater use threatens the resilience of aquifer systems and their ability to provide a long‐term water source. Groundwater storage is considered to be a factor of groundwater resilience, although the extent to which resilience can be maintained has yet to be explored in depth. In this study, we assess the limit of groundwater resilience in the world's largest groundwater systems with remote sensing observations. The Total Groundwater Stress (TGS) ratio, defined as the ratio of total storage to the groundwater depletion rate, is used to explore the timescales to depletion in the world's largest aquifer systems and associated groundwater buffer capacity. We find that the current state of knowledge of large‐scale groundwater storage has uncertainty ranges across orders of magnitude that severely limit the characterization of resilience in the study aquifers. Additionally, we show that groundwater availability, traditionally defined as recharge and redefined in this study as total storage, can alter the systems that are considered to be stressed versus unstressed. We find that remote sensing observations from NASA's Gravity Recovery and Climate Experiment can assist in providing such information at the scale of a whole aquifer. For example, we demonstrate that a groundwater depletion rate in the Northwest Sahara Aquifer System of 2.69 ± 0.8 km3/yr would result in the aquifer being depleted to 90% of its total storage in as few as 50 years given an initial storage estimate of 70 km3. PMID:26900184

Effects of surface-water and groundwater inflows and outflows on the hydrology of the Tsala Apopka Lake Basin in Citrus County, Florida

USGS Publications Warehouse

Sepúlveda, Nicasio; Fulkerson, Mark; Basso, Ron; Ryan, Patrick J.

2018-05-21

The U.S. Geological Survey, in cooperation with the Southwest Florida Water Management District, initiated a study to quantify the inflows and outflows in the Floral City, Inverness, and Hernando pools of the Tsala Apopka Lake Basin in Citrus County, Florida. This study assesses hydrologic changes in pool stages, groundwater levels, spring flows, and streamflows caused by the diversion of streamflow from the Withlacoochee River to the Tsala Apopka Lake Basin through water-control structures. A surface-water/groundwater flow model was developed using hydraulic parameters for lakes, streams, the unsaturated zone, and the underlying surficial and Upper Floridan aquifers estimated using an inverse modeling calibration technique. After calibration, the model was used to assess the relation between inflows and outflows in the Tsala Apopka Lake Basin and changes in pool stages.Simulation results using the calibrated surface-water/groundwater flow model showed that leakage rates from the pools to the Upper Floridan aquifer were largest at the deep lake cells and that these leakage rates to the Upper Floridan aquifer were the highest in the model area. Downward leakage to the Upper Floridan aquifer occurred beneath most of the extent of the Floral City, Inverness, and Hernando pools. These leakage rates depended on the lakebed leakance and the difference between lake stages and heads in the Upper Floridan aquifer. Leakage rates were higher for the Floral City pool than for the Inverness pool, and higher for the Inverness pool than for the Hernando pool. Lakebed leakance was higher for the Floral City pool than for the Hernando pool, and higher for the Hernando pool than for the Inverness pool.Simulation results showed that the average recharge rate to the surficial aquifer was 10.3 inches per year for the 2004 to 2012 simulation period. Areas that recharge the surficial aquifer covered about 86 percent of the model area. Simulations identified areas along segments of the

Beyond the Floodplain: Drivers of Flood Risk in Coastal Cities

NASA Astrophysics Data System (ADS)

Rosenzweig, B.; McPhearson, T.; Rosi, E. J.

2017-12-01

While the catastrophic impacts of Hurricane Katrina increased awareness of coastal flood risk, conventional approaches to flood risk assessment do not adequately represent the drivers of flood risk in the unique, highly engineered landscape of dense cities. We review the recent (1996-2016) history of flooding events and current regional climate change projection for 4 diverse coastal cities in the United States: San Juan, Miami, Baltimore and New York. Our review suggests that while all 4 of these cities face increased risk from direct coastal flooding with climate change, pluvial flooding will be an additional, important driver of risk that is currently poorly quantified. Unlike other types of flooding, pluvial flood risk is not limited to a contiguous riverine or coastal floodplain, but is instead driven by interactions between spatially variable geophysical drivers (intense rainfall, shallow groundwater, and influent tidal water), social drivers (patterns of land use) and technical drivers (urban stormwater and coastal infrastructure). We discuss approaches for quantitative assessment of pluvial flood risk, the challenges presented by the lack of data on geophysical flooding drivers in dense cities, and opportunities for integrated research to provide the scientific information needed by practitioners.

AN IN-SITU PERMEABLE REACTIVE BARRIER FOR THE TREATMENT OF HEXAVALENT CHROMIUM AND TRICHLOROETHYLENE IN GROUNDWATER: VOLUME 3 MULTICOMPONENT REACTIVE TRANSPORT MODELING

EPA Science Inventory

Reactive transport modeling has been conducted to describe the performance of the permeable reactive barrier at the Coast Guard Support Center near Elizabeth City, NC. The reactive barrier was installed to treat groundwater contaminated by hexavalent chromium and chlorinated org...

Assessment of trace metal contamination in groundwater in a highly urbanizing area of Shenfu New District, Northeast China

NASA Astrophysics Data System (ADS)

Lu, Yintao; Zang, Xinghua; Yao, Hong; Zhang, Shichao; Sun, Shaobin; Liu, Fang

2018-01-01

Shenfu New District, located between two old industrial cities, Shenyang and Fushun, is a typical area undergoing industrialization and urbanization in China. The sources and distributions of heavy metals were analyzed in groundwater by multivariate analysis and GIS, and the impact of urbanization on the aqueous distribution of these metals was investigated. The results indicated that the mean contents of zinc (Zn), arsenic (As), cadmium (Cd), and lead (Pb) in the wet periods were about two times of those in the dry period. Nickel (Ni) and chromium (Cr) were considered to be associated with the same anthropogenic origins (i.e., wastewater from agricultural processing). The concentration of Zn was high under natural conditions, but was also affected by human activities (e.g., wastewater from foundry and instrument manufacturers). As, Cd, and Pb are likely derived from both anthropogenic and natural sources (agricultural and water-rock interactions). The spatial distributions of heavy metals in groundwater were region-specific, with the highest concentrations mostly along the Hun River. The heavy metal pollution index (HPI) values from the dry and wet periods showed similar trends at different sampling sites. Only one site's HPI was above the critical value of 100. These results provide information that can be used to understand potential threats to the groundwater resources of other developing cities.

A catchment-scale groundwater model including sewer pipe leakage in an urban system

NASA Astrophysics Data System (ADS)

Peche, Aaron; Fuchs, Lothar; Spönemann, Peter; Graf, Thomas; Neuweiler, Insa

2016-04-01

Keywords: pipe leakage, urban hydrogeology, catchment scale, OpenGeoSys, HYSTEM-EXTRAN Wastewater leakage from subsurface sewer pipe defects leads to contamination of the surrounding soil and groundwater (Ellis, 2002; Wolf et al., 2004). Leakage rates at pipe defects have to be known in order to quantify contaminant input. Due to inaccessibility of subsurface pipe defects, direct (in-situ) measurements of leakage rates are tedious and associated with a high degree of uncertainty (Wolf, 2006). Proposed catchment-scale models simplify leakage rates by neglecting unsaturated zone flow or by reducing spatial dimensions (Karpf & Krebs, 2013, Boukhemacha et al., 2015). In the present study, we present a physically based 3-dimensional numerical model incorporating flow in the pipe network, in the saturated zone and in the unsaturated zone to quantify leakage rates on the catchment scale. The model consists of the pipe network flow model HYSTEM-EXTAN (itwh, 2002), which is coupled to the subsurface flow model OpenGeoSys (Kolditz et al., 2012). We also present the newly developed coupling scheme between the two flow models. Leakage functions specific to a pipe defect are derived from simulations of pipe leakage using spatially refined grids around pipe defects. In order to minimize computational effort, these leakage functions are built into the presented numerical model using unrefined grids around pipe defects. The resulting coupled model is capable of efficiently simulating spatially distributed pipe leakage coupled with subsurficial water flow in a 3-dimensional environment. References: Boukhemacha, M. A., Gogu, C. R., Serpescu, I., Gaitanaru, D., & Bica, I. (2015). A hydrogeological conceptual approach to study urban groundwater flow in Bucharest city, Romania. Hydrogeology Journal, 23(3), 437-450. doi:10.1007/s10040-014-1220-3. Ellis, J. B., & Revitt, D. M. (2002). Sewer losses and interactions with groundwater quality. Water Science and Technology, 45(3), 195

Western USA groundwater drilling

NASA Astrophysics Data System (ADS)

Jasechko, S.; Perrone, D.

2016-12-01

Groundwater in the western US supplies 40% of the water used for irrigated agriculture, and provides drinking water to individuals living in rural regions distal to perennial rivers. Unfortunately, current groundwater use is not sustainable in a number of key food producing regions. While substantial attention has been devoted to mapping groundwater depletion rates across the western US, the response of groundwater users via well drilling to changing land uses, water demands, pump and drilling technologies, pollution vulnerabilities, and economic conditions remains unknown. Here we analyze millions of recorded groundwater drilling events in the western US that span years 1850 to 2015. We show that groundwater wells are being drilled deeper in some, but not all, regions where groundwater levels are declining. Groundwater wells are generally deeper in arid and mountainous regions characterized by deep water tables (e.g., unconfined alluvial and fractured bedrock aquifers), and in regions that have productive aquifers with high water quality deep under the ground (e.g., confined sedimentary aquifers). Further, we relate water quality and groundwater drilling depths in 40 major aquifer systems across the western US. We show that there is substantial room for improvement to the existing 2-D continental-scale assessments of domestic well water vulnerability to pollution if one considers the depth that the domestic well is screened in addition to pollutant loading, surficial geology, and vertical groundwater flow rates. These new continental-scale maps can be used to (i) better assess economic, water quality, and water balance limitations to groundwater usage, (ii) steer domestic well drilling into productive strata bearing clean and protected groundwater resources, and (iii) assess groundwater management schemes across the western US.

Groundwater quality in the South Coast Range Coastal groundwater basins, California

USGS Publications Warehouse

Burton, Carmen A.; Belitz, Kenneth

2013-01-01

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 (PBP) of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. The coastal basins in the Southern Coast Ranges constitute one of the study units being evaluated.

Groundwater infiltration, surface water inflow and sewerage exfiltration considering hydrodynamic conditions in sewer systems.

PubMed

Karpf, Christian; Hoeft, Stefan; Scheffer, Claudia; Fuchs, Lothar; Krebs, Peter

2011-01-01

Sewer systems are closely interlinked with groundwater and surface water. Due to leaks and regular openings in the sewer system (e.g. combined sewer overflow structures with sometimes reverse pressure conditions), groundwater infiltration and surface water inflow as well as exfiltration of sewage take place and cannot be avoided. In the paper a new hydrodynamic sewer network modelling approach will be presented, which includes--besides precipitation--hydrographs of groundwater and surface water as essential boundary conditions. The concept of the modelling approach and the models to describe the infiltration, inflow and exfiltration fluxes are described. The model application to the sewerage system of the City of Dresden during a flood event with complex conditions shows that the processes of infiltration, exfiltration and surface water inflows can be described with a higher reliability and accuracy, showing that surface water inflow causes a pronounced system reaction. Further, according to the simulation results, a high sensitivity of exfiltration rates on the in-sewer water levels and a relatively low influence of the dynamic conditions on the infiltration rates were found.

Efficacy of electrical resistivity and induced polarization methods for revealing fluoride contaminated groundwater in granite terrain.

PubMed

Mondal, Nepal C; Rao, Ananda V; Singh, Vijay P

2010-09-01

The accumulation of fluoride (F) in groundwater is a common phenomenon in India and worldwide. Its location can be identified through a direct hydrochemical analysis, which was carried out in Kurmapalli watershed (located 60 km SE of Hyderabad city), Nalgonda district, Andhra Pradesh, India affected by F contamination. The results of the hydrochemical analysis showed that F varied from 0.71 to 19.01 mg/l and its concentration exceeded the permissible limit (i.e., 1.5 mg/l) in 78% of the total 32 samples analyzed. The highest F value (19.01 mg/l) was found near Madnapur village, which is located in the central part of the watershed. Resistivity and induced polarization (IP) surveys were also carried out to reveal the zones where elevated F-contaminated groundwater exists. The objective of this paper was to highlight the utility of resistivity and IP surveys, using hydrochemical constituents as constraint, for the successful delineation of such contaminated/polluted groundwater zones in the granite area.

Study on the Relationship between Manganese Concentrations in Rural Drinking Water and Incidence and Mortality Caused by Cancer in Huai'an City

PubMed Central

Zhang, Qin; Pan, Enchun; Liu, Linfei; Hu, Wei; He, Yuan; Xu, Qiujin; Liang, Cunzhen

2014-01-01

Background. Cancer is a significant disease burden in the world. Many studies showed that heavy metals or their compounds had connection with cancer. But the data conflicting about the relationship of manganese (Mn) to cancer are not enough. In this paper, the relationship was discussed between Mn concentrations in drinking water for rural residents and incidence and mortality caused by malignant tumors in Huai'an city. Methods. A total of 158 water samples from 28 villages of 14 towns were, respectively, collected during periods of high flow and low flow in 3 counties of Huai'an city, along Chinese Huai'he River. The samples of deep groundwater, shallow groundwater, and surface water were simultaneously collected in all selected villages. Mn concentrations in all water samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS 7500a). The correlation analysis was used to study the relationship between the Mn concentration and cancer incidence and mortality. Results. Mn concentrations detectable rate was 100% in all water samples. The mean concentration was 452.32 μg/L ± 507.76 μg/L. There was significant difference between the high flow period and low flow period (t = −5.23, P < 0.05) and also among deep groundwater, shallow groundwater, and surface water (F = 5.02, P < 0.05). The ratio of superscale of Mn was 75.32%. There was significant difference of Mn level between samples in the high flow period and low flow period (χ 2 = 45.62, P < 0.05) and also among deep groundwater, shallow groundwater, and surface water (χ 2 = 10.66, P < 0.05). And also we found that, during the low flow period, Mn concentration has positive correlation with cancer incidence and mortality; for a 1 μg/L increase in Mn concentration, there was a corresponding increase of 0.45/100000 new cancer cases and 0.35/100000 cancer deaths (P < 0.05). Conclusions. In Huai'an city, the mean concentration of Mn in drinking water was very high. Mn concentration

Future groundwater extraction scenarios for an aquifer in a semiarid environment: case study of Guadalupe Valley Aquifer, Baja California, Northwest Mexico.

PubMed

Campos-Gaytan, Jose Ruben; Kretzschmar, Thomas; Herrera-Oliva, Claudia Soledad

2014-11-01

Semiarid northwestern Mexico presents a growing water demand produced by agricultural and domestic requirements during the last two decades. The community of Guadalupe Valley and the city of Ensenada rely on groundwater pumping from the local aquifer as its sole source of water supply. This dependency has resulted in an imbalance between groundwater pumpage and natural recharge. A two-dimensional groundwater flow model was applied to the Guadalupe Valley Aquifer, which was calibrated and validated for the period 1984-2005. The model analysis verified that groundwater levels in the region are subject to steep declines due to decades of intensive groundwater exploitation for agricultural and domestic purposes. The calibrated model was used to assess the effects of different water management scenarios for the period 2007-2025. If the base case (status quo) scenario continues, groundwater levels are in a continuous drawdown trend. Some wells would run dry by August 2017, and water demand may not be met without incurring in an overdraft. The optimistic scenario implies the achievement of the mean groundwater recharge and discharge. Groundwater level depletion could be stopped and restored. The sustainable scenario implies the reduction of current extraction (up to about 50 %), when groundwater level depletion could be stopped. A reduction in current extraction mitigates water stress in the aquifer but cannot solely reverse declining water tables across the region. The combination of reduced current extraction and an implemented alternative solution (such as groundwater artificial recharge), provides the most effective measure to stabilize and reverse declining groundwater levels while meeting water demands in the region.

Subsurface structure of the East Bay Plain ground-water basin: San Francisco Bay to the Hayward fault, Alameda County, California

USGS Publications Warehouse

Catchings, R.D.; Borchers, J.W.; Goldman, M.R.; Gandhok, G.; Ponce, D.A.; Steedman, C.E.

2006-01-01

The area of California between the San Francisco Bay, San Pablo Bay, Santa Clara Valley, and the Diablo Ranges (East Bay Hills), commonly referred to as the 'East Bay', contains the East Bay Plain and Niles Cone ground-water basins. The area has a population of 1.46 million (2003 US Census), largely distributed among several cities, including Alameda, Berkeley, Fremont, Hayward, Newark, Oakland, San Leandro, San Lorenzo, and Union City. Major known tectonic structures in the East Bay area include the Hayward Fault and the Diablo Range to the east and a relatively deep sedimentary basin known as the San Leandro Basin beneath the eastern part of the bay. Known active faults, such as the Hayward, Calaveras, and San Andreas pose significant earthquake hazards to the region, and these and related faults also affect ground-water flow in the San Francisco Bay area. Because most of the valley comprising the San Francisco Bay area is covered by Holocene alluvium or water at the surface, our knowledge of the existence and locations of such faults, their potential hazards, and their effects on ground-water flow within the alluvial basins is incomplete. To better understand the subsurface stratigraphy and structures and their effects on ground-water and earthquake hazards, the U.S. Geological Survey (USGS), in cooperation with the East Bay Municipal Utility District (EBMUD), acquired a series of high-resolution seismic reflection and refraction profiles across the East Bay Plain near San Leandro in June 2002. In this report, we present results of the seismic imaging investigations, with emphasis on ground water.

Groundwater-abstraction induced land subsidence and groundwater regulation in the North China Plain

NASA Astrophysics Data System (ADS)

Guo, H.; Wang, L.; Cheng, G.; Zhang, Z.

2015-11-01

Land subsidence can be induced when various factors such as geological, and hydrogeological conditions and intensive groundwater abstraction combine. The development and utilization of groundwater in the North China Plain (NCP) bring great benefits, and at the same time have led to a series of environmental and geological problems accompanying groundwater-level declines and land subsidence. Subsidence occurs commonly in the NCP and analyses show that multi-layer aquifer systems with deep confined aquifers and thick compressible clay layers are the key geological and hydrogeological conditions responsible for its development in this region. Groundwater overdraft results in aquifer-system compaction, resulting in subsidence. A calibrated, transient groundwater-flow numerical model of the Beijing plain portion of the NCP was developed using MODFLOW. According to available water supply and demand in Beijing plain, several groundwater regulation scenarios were designed. These different regulation scenarios were simulated with the groundwater model, and assessed using a multi-criteria fuzzy pattern recognition model. This approach is proven to be very useful for scientific analysis of sustainable development and utilization of groundwater resources. The evaluation results show that sustainable development of groundwater resources may be achieved in Beijing plain when various measures such as control of groundwater abstraction and increase of artificial recharge combine favourably.

Hydro-geochemistry and application of water quality index (WQI) for groundwater quality assessment, Anna Nagar, part of Chennai City, Tamil Nadu, India

NASA Astrophysics Data System (ADS)

Krishna kumar, S.; Logeshkumaran, A.; Magesh, N. S.; Godson, Prince S.; Chandrasekar, N.

2015-12-01

In the present study, the geochemical characteristics of groundwater and drinking water quality has been studied. 24 groundwater samples were collected and analyzed for pH, electrical conductivity, total dissolved solids, carbonate, bicarbonate, chloride, sulphate, nitrate, calcium, magnesium, sodium, potassium and total hardness. The results were evaluated and compared with WHO and BIS water quality standards. The studied results reveal that the groundwater is fresh to brackish and moderately high to hard in nature. Na and Cl are dominant ions among cations and anions. Chloride, calcium and magnesium ions are within the allowable limit except few samples. According to Gibbs diagram, the predominant samples fall in the rock-water interaction dominance and evaporation dominance field. The piper trilinear diagram shows that groundwater samples are Na-Cl and mixed CaMgCl type. Based on the WQI results majority of the samples are falling under excellent to good category and suitable for drinking water purposes.

Preliminary Investigation of Paleochannels and Groundwater Specific Conductance using Direct-Current Resistivity and Surface-Wave Seismic Geophysical Surveys at the Standard Chlorine of Delaware, Inc., Superfund Site, Delaware City, Delaware, 2008

USGS Publications Warehouse

Degnan, James R.; Brayton, Michael J.

2010-01-01

The U.S. Geological Survey (USGS), in cooperation with Region III of the U.S. Environmental Protection Agency (USEPA) and the State of Delaware, is conducting an ongoing study of the water-quality and hydrogeologic properties of the Columbia and Potomac aquifers and the extent of cross-aquifer contamination with benzene; chlorobenzene; 1,2-dichlorobenzene; 1,4-dichlorobenzene; and hydrogen chloride (hydrochloric acid when dissolved in water) in the vicinity of the Standard Chlorine of Delaware, Inc. (SCD), Superfund Site, Delaware City, Delaware. Surface geophysical surveys and well data were used to identify and correlate low-permeability units (clays) across the site and to search for sand and gravel filled paleochannels that are potential conduits and receptors of contaminated groundwater and (or) Dense Non-Aqueous Phase Liquid (DNAPL) contaminants. The combined surveys and well data were also used to characterize areas of the site that have groundwater with elevated (greater than 1,000 microsiemens per centimeter) specific conductance (SC) as a result of contamination. The most electrically conductive features measured with direct-current (DC) resistivity at the SCD site are relatively impermeable clays and permeable sediment that are associated with elevated SC in groundwater. Many of the resistive features include paleochannel deposits consisting of coarse-grained sediments that are unsaturated, have low (less than 200 microsiemens per centimeter) SC pore water, or are cemented. Groundwater in uncontaminated parts of the Columbia aquifer and of the Potomac aquifer has a low SC. Specific-conductance data from monitoring wells at the site were used to corroborate the DC-resistivity survey results. For comparison with DC-resistivity surveys, multi-channel analysis of surface wave (MASW) surveys were used and were able to penetrate deep enough to measure the Columbia aquifer, which is known to have elevated SC in some places. MASW survey results respond to solid

Sinkholes Due to Groundwater Withdrawal in Tazerbo Wellfield, SE Libya.

PubMed

Alfarrah, Nawal; Berhane, Gebremedhin; Hweesh, Abdelrahim; Walraevens, Kristine

2017-07-01

The desert of eastern Libya forms one of the most arid regions of the Sahara. The Great Man-Made River Project (GMRP) was established. It transports millions of cubic meters of water a day from desert wellfields to the coastal cities, where over 80% of the population lives. The Tazerbo Wellfield is one of the wellfields designed within the GMRP, delivering water to the eastern coast of Libya through an underground pipe network. Tazerbo Wellfield consists of 108 production wells; each well was designed to pump 100 L/s. The planned total groundwater withdrawal from all wells is 1 million m 3 /d. The deep sandstone aquifer (Nubian sandstone) is covered by a thick mudstone-siltstone aquitard and is being heavily pumped. The aquifer and fine-grained sediments of the aquitard may be compacted resulting in land subsidence as a result of high exploitation. Local sinkholes have developed in the area of Tazerbo since the start of the pumping from the wellfield in 2004. These sinkholes have been caused mainly by lowering of the piezometric heads due to the withdrawal of groundwater. In this study, a hydrogeological investigation is presented about the effect of large groundwater pumping from the Nubian sandstone aquifer in Tazerbo Wellfield, SE Libya, based on physical parameters for 108 production wells and 23 observation wells. © 2017, National Ground Water Association.

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

NASA Astrophysics Data System (ADS)

Morgenstern, Uwe; Daughney, Christopher J.

2012-08-01

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

Ground-water conditions in Georgia, 1999

USGS Publications Warehouse

Cressler, Alan M.

2000-01-01

Ground-water conditions in Georgia during 1999 and for the period of record were evaluated using data from U.S. Geological Survey ground-water-level and ground-water-quality monitoring networks. Data for 1999 included in this report are from continuous water-level records from 130 wells and chloride analyses from 14 wells. Data from one well is incomplete because data collection was discontinued. Chloride concentration in water from the Upper Floridan aquifer in most of coastal Georgia was within drinking-water standards established by the Georgia Department of Natural Resources and the U.S. Environmental Protection Agency. In the Savannah area, chloride concentration has not changed appreciably with time. However, chloride concentration in water from some wells that tap the Floridan aquifer system in the Brunswick area exceeds the drinking-water standards. Ground-water-level and ground-water-quality data are essential for water assessment and management. Ground-water-level fluctuations and trends can be used to estimate changes in aquifer storage resulting from the effects of ground-water withdrawal and recharge from precipitation. These data can be used to address water-management needs and to evaluate the effects of management and conservation programs. As part of the ground-water investigations conducted by the U.S. Geological Survey (USGS), in cooperation with the State of Georgia and city and county governments, a Statewide water-level-measurement program was started in 1938. Initially, this program consisted of an observation-well network in the coastal area of Georgia to monitor variations in ground-water storage and quality. Additional wells were later included in areas where data could be used to aid in water resources development and management. During 1999, periodic water-level measurements were made in 46 wells, and continuous water-level measurements were obtained from 165 wells. Continuous water-level records were obtained using analog (pen and chart

Groundwater Management Innovations in the High Plains Aquifer, USA: A possible path towards sustainability? (Invited)

NASA Astrophysics Data System (ADS)

Sophocleous, M. A.

2009-12-01

The U.S. High Plains aquifer, one of the largest freshwater aquifer systems in the world covering parts of eight US states, continues to decline, threatening the long-term viability of the region’s irrigation-based economy. The theory of the commons has meaningful messages for High-Plains jurisdictions as no private incentive exists to save for tomorrow, and agricultural prosperity depends on mining water from large portions of the aquifer. The eight High Plains states take different approaches to the development and management of the aquifer based on each state’s body of water laws that abide by different legal doctrines, on which Federal laws are superposed, thus creating difficulties in integrated regional water management efforts. Although accumulating hydrologic stresses and competing demands on groundwater resources are making groundwater management increasingly complex, they are also leading to innovative approaches to the management of groundwater supplies, and those are highlighted in this presentation as good examples for emulation in managing groundwater resources. The highlighted innovations include (1) the Texas Groundwater Availability Modeling program, (2) Colorado’s water-augmentation program, (3) Kansas’ Intensive Groundwater Use Control Area policy, (4) the Kansas Groundwater Management Districts’ “safe yield” policies, (5) the water-use reporting program in Kansas, (6) the Aquifer Storage and Recovery program of the City of Wichita, Kansas, and (7) Nebraska’s Natural Resources Districts. It is concluded that the fragmented and piecemeal institutional arrangements for managing the supplies and quality of water are unlikely to be sufficient to meet the water challenges of the future. A number of recommendations for enhancing the sustainability of the aquifer are presented, including the formation of an interstate groundwater commission for the High Plains aquifer along the lines of the Delaware and Susquehanna River Basins

Hydrologic conditions, stream-water quality, and selected groundwater studies conducted in the Lawrenceville area, Georgia, 2003-2008

USGS Publications Warehouse

Clarke, John S.; Williams, Lester J.

2010-01-01

Hydrologic studies conducted during 2003-2008 as part of the U.S. Geological Survey Cooperative Water Program with the City of Lawrenceville, Georgia, provide important data for the management of water resources. The Cooperative Water Program includes (1) hydrologic monitoring (precipitation, streamflow, and groundwater levels) to quantify baseline conditions in anticipation of expanded groundwater development, (2) surface-water-quality monitoring to provide an understanding of how stream quality is affected by natural (such as precipitation) and anthropogenic factors (such as impervious area), and (3) geologic studies to better understand groundwater flow and hydrologic processes in a crystalline rock setting. The hydrologic monitoring network includes each of the two watersheds projected for groundwater development?the Redland-Pew Creek and upper Alcovy River watersheds?and the upper Apalachee River watershed, which serves as a background or control watershed because of its similar hydrologic and geologic characteristics to the other two watersheds. In each watershed, precipitation was generally greater during 2003-2005 than during 2006-2008, and correspondingly streamflow and groundwater levels decreased. In the upper Alcovy River and Redland-Pew Creek watersheds, groundwater level declines during 2003-2008 were mostly between 2 and 7 feet, with maximum observed declines of as much as 28.5 feet in the upper Alcovy River watershed, and 49.1 feet in the Redland-Pew Creek watershed. Synoptic base-flow measurements were used to locate and quantify gains or losses to streamflow resulting from groundwater interaction (groundwater seepage). In September 2006, seepage gains were measured at five of nine reaches evaluated in the upper Alcovy River watershed, with losses in the other four. The four losing reaches were near the confluence of the Alcovy River and Cedar Creek where the stream gradient is low and bedrock is at or near the land surface. In the Redland

Nutrient dynamics and budget with the surface water-groundwater interaction in the tidal river in Japan

NASA Astrophysics Data System (ADS)

Onodera, S.; Saito, M.; Maruyama, Y.; Jin, G.; Miyaoka, K.; Shimizu, Y.

2013-12-01

In coastal megacities, sever groundwater depression and water pollution occurred. These impacts affected to river environment change. Especially, the river mouth area has been deposited the polluted matters. These areas have characteristics of water level fluctuation which causes river water-groundwater interaction and the associated change in dynamics of nutrients. However, these effects on the nutrient transport in tidal reaches and nutrient load to the sea have not been fully evaluated in previous studies. Therefore, we aimed to clarify the characteristics of the nutrient transport with the river water-groundwater interaction in the tidal river of Osaka metropolitan city. We conducted the field survey from the river mouth to the 7km upstream area of Yamato River, which has a length of 68km and a watershed area of 1070 km2. Spatial variations in radon (222Rn) concentrations and the difference of hydraulic potential between river waters and the pore waters suggest that the groundwater discharges to the river channel in the upstream area. In contrast, the river water recharged into the groundwater near the river mouth area. It may be caused by the lowering of groundwater level associated with the excess abstraction of groundwater in the urban area. The result also implies the seawater intrusion would accelerate the salinization of groundwater. The spatial and temporal variations in nutrient concentrations indicate that nitrate-nitrogen (NO3-N) concentrations changed temporally and it negative correlated with dissolved organic nitrogen (DON) concentrations. Inorganic phosphorous (PO4-P) concentrations showed the increasing trend with the increase of the river water level. Based on the mass balance, nutrient reproduction from the river bed was suggested in tidal reach. That was estimated to be 10 % of total nitrogen and 3% of phosphorus loads from the upstream.

Water conservation and hydrological transitions in cities in the United States

NASA Astrophysics Data System (ADS)

Hornberger, George M.; Hess, David J.; Gilligan, Jonathan

2015-06-01

Cities across the world have had to diversify and expand their water supply systems in response to demand growth, groundwater depletion and pollution, and instability and inadequacy of regional surface freshwater sources. In the U.S., these problems plague not only the arid Western cities but increasingly also cities in the Eastern portions of the country. Although cities continue to seek out new sources of water via Promethean projects of long-distance supply systems, desalinization plants, and the recharge of aquifers with surface water, they also pursue water conservation because of its low cost and other benefits. We examine water conservation as a complex sociotechnical system comprising interactions of political, sociodemographic, economic, and hydroclimatological factors. We provide quantitative data on the factors that affect more and less advanced transitions in water conservation regimes, and we show that water stress and other hydrological data can only partially predict the transition. We also provide qualitative case studies to identify institutional and political barriers to more advanced water conservation regimes. This interdisciplinary, mixed methods approach typifies the need for knowledge that informs hydrologists about how their research may or may not be adopted by decision-makers.

Data of heavy metals in soil and groundwater at Kiwi gardens of Amlash in Guilan Province, Iran.

PubMed

Naghipour, Dariush; Ashrafi, Seyed Davoud; Taghavi, Kamran

2018-06-01

Data on this paper describe the concentrations of arsenic, cadmium, copper, nickel, lead and zinc in the surface soils and groundwater's of Kiwi gardens and its relation to chemical fertilizers in Amlash city, Guilan Province, in Iran. The results of this study showed that the average concentration of heavy metals in groundwater and soils of the studied areas was less than the national standards of Iran for irrigation water, Dutch MPA for soils (except Cu and Ni) and Canadian MAC for inorganic fertilizers. Considering that after fertilizing to soils used in gardening, the concentration of heavy metals in groundwater and soil can be increased significantly, so that chemical fertilizers can be considered as an effective factor in increasing the amount of heavy metals in water and soil. The results of this research can be used by who concern about water and soil quality related to fertilizing and also can be used by Rural Water and Wastewater Company and Ministry of Jahad Agriculture of Iran.

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

NASA Astrophysics Data System (ADS)

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

2018-06-01

Chronic groundwater decline is a concern in many of the world's major agricultural areas. However, a general lack of accurate long-term in situ measurement of groundwater depth and analysis of trends prevents understanding of the dynamics of these systems at landscape scales. This is particularly worrying in the context of future climate uncertainties. This study examines long-term groundwater responses to climate variability in a major agricultural production landscape in southern Queensland, Australia. Based on records for 381 groundwater bores, we used a modified Mann-Kendall non-parametric test and Sen's slope estimator to determine groundwater trends across a 26-year period (1989-2015) and in distinct wet and dry climatic phases. Comparison of trends between climatic phases showed groundwater level recovery during wet phases was insufficient to offset the decline in groundwater level from the previous dry phase. Across the entire 26-year sampling period, groundwater bore levels (all bores) showed an overall significant declining trend (p < 0.05) of an average 0.06 m year-1. Fifty-one bores (20%) exhibited significant declining groundwater levels (p < 0.05), 25 bores (10%) exhibited significant rising groundwater levels (p < 0.05), and 175 bores (70%) exhibited no significant change in groundwater levels (p > 0.05). Spatially, both declining and rising bores were highly clustered. We conclude that over 1989-2015 there is a significant net decline in groundwater levels driven by a smaller subset of highly responsive bores in high irrigation areas within the catchment. Despite a number of targeted policy interventions, chronic groundwater decline remains evident in the catchment. We argue that this is likely to continue and to occur more widely under potential climate change and that policy makers, groundwater users and managers need to engage in planning to ensure the sustainability of this vital resource.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Assessing river-groundwater exchange fluxes of the Wairau River, New Zealand

NASA Astrophysics Data System (ADS)

Wilson, Scott; Woehling, Thomas; Davidson, Peter

2014-05-01

Allocation limits in river-recharged aquifers have traditionally been based on static observations of river gains and losses undertaken when river flow is low. This approach to setting allocation limits does not consider the dynamic relationship between river flows and groundwater levels. Predicting groundwater availability based on a better understanding of coupled river - aquifer systems opens the possibility for dynamic groundwater allocation approaches. Numerical groundwater models are most commonly used for regional scale allocation assessments. Using these models for predicting future system states is challenging, particularly under changing management and climate scenarios. The large degree of uncertainty associated with these predictions is caused by insufficient knowledge about the heterogeneity of subsurface flow characteristics, ineffective monitoring designs, and the inability to confidently predict the spatially and temporally varying river - groundwater exchange fluxes. These uncertainties are characteristic to many coupled surface water - groundwater systems worldwide. Braided river systems, however, create additional challenges due to their highly dynamic morphological character and mobile beds which also make river flow measurements extremely difficult. This study focuses on the characterization of river - groundwater exchange fluxes along a section of the Wairau River in the Northwest of the South Island of New Zealand. The braided river recharges the Wairau Aquifer which is an important source for irrigation and municipal water requirements of the city of Blenheim. The Wairau Aquifer is hosted by the highly permeable Rapaura Formation gravels that extend to a depth of about 20 to 30 m. However, the overall thickness of the alluvial sequence forming the Wairau Plain may be up to 500 m. The landuse in the area is mainly grapes but landsurface recharge to the aquifer is considered to be considerably smaller than the recharge from the Wairau river

Development of Groundwater Management Model for Sustainable Groundwater Use in the Agricultural Region

NASA Astrophysics Data System (ADS)

Park, D.; Bae, G.; Lee, K.

2010-12-01

In many agricultural regions, high dependence of irrigation on groundwater has brought about serious concerns about unplanned groundwater developments and over-pumping. Various agricultural activities including fertilization and livestock husbandry usually result in groundwater contamination in those regions. Field works in Icheon, Korea showed that in this region the rice farming still requires a significant amount of water and continuous construction of greenhouse can make the contamination from the fertilization more serious. In this study, a groundwater management model based on the simulation-optimization methodology is developed to achieve sufficient groundwater supply and groundwater quality conservation together on regional-scale. This model can obtain the on-ground contaminant loading mass by integrating an analytical model for 1-D solute transport in unsaturated zone with 3-D groundwater flow and solute transport model, HydroGeosphere. The outputs of the 1-D unsaturated transport model, concentrations of the contaminant leaching on water table, work as contaminant sources in the 3-D solute transport model in saturated zone. This integrated simulation model is linked to genetic algorithm that searches the global optimum for the sustainable groundwater use. And, in order for the design on the contaminant sources to be more effective, it also links the backward transport model useful for evaluating the contamination from contaminant sources to each pumping well. The first objective of the management in this study is to obtain the optimal pumping rates that not only can supply sufficient amount of the groundwater but protect the groundwater from the excessive drawdown and contamination. The second objective is to control the periodic loading of the contaminant by suggesting the allowable contaminant loading mass. For this multi-objective groundwater management, the objective function to maximize both pumping rates and allowable contaminant loading mass and at

Management of city aquifers from anthropogenic activities: Example of the Windhoek aquifer, Namibia

NASA Astrophysics Data System (ADS)

Mapani, Benjamin S.; Schreiber, Ute

As the city of Windhoek is growing rapidly, it has become increasingly obvious that dangers to the underlying groundwater aquifer have become imminent, and need addressing immediately. Water infiltration and the transportation of contaminants from anthropogenic activities through soils into the bedrock and hence the aquifer involve soil maturity, chemical and microbial processes and the climate of a particular area. The thin immature soil horizon (circa 5-20 cm) over the Windhoek schist implies that most areas of the city are built directly on bedrock, making the aquifer vulnerable. Anthropogenic activities from the use of pesticides for weed control, oil spills, toxic chemical spills, dumping of undesired substances by residents and high fertilizer application rates for lawns can lead to the contamination of groundwater. The result of our study show that the soil composition in Windhoek lacks mature clay minerals and is enriched in micas, quartz and albite. Some areas in the northern and southern industrial areas show contamination in heavy metals Pb, Zn, Cu and Ni. To the west of the city, close to the textile factory, soils are contaminated with ammonium compounds. The hydrochemistry of these pesticides and fertilizers can cause severe pollution to the groundwater if the practice is not carefully monitored. In addition, the rapid expansion of uncontrolled settlements without proper sanitation and reticulation has made the problems much more difficult. The geology of the city of Windhoek consists of the Kuiseb Schist, locally known as the “Windhoek Schist” and amphibolites. The Kuiseb schist possesses pervasive cleavage that renders the underlying lithology to be permeable to percolating water and fluids from the surface into the aquifer. The fissility and fracture density of the schist imply that leakage of surface waters, phenols, septic tank spills and industrial contaminants may reach the aquifer in unusually high rainfall years. Organic fuels and oils

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

NASA Astrophysics Data System (ADS)

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

2009-04-01

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

Responses of the sustainable yield of groundwater to annual rainfall and pumping patterns in the Baotou Plain, North China

NASA Astrophysics Data System (ADS)

Liao, Z.; LONG, Y., Sr.; Wei, Y.; Guo, Z.

2017-12-01

Serious water deficits and deteriorating environmental quality are threatening the sustainable socio-economic development and the protection of the ecology and the environment in North China, especially in Baotou City. There is a common misconception that groundwater extraction can be sustainable if the pumping rate does not exceed the total natural recharge in a groundwater basin. The truth is that the natural recharge is mainly affected by the rainfall and that groundwater withdrawal determines the sustainable yield of the aquifer flow system. The concept of the sustainable yield is defined as the allowance pumping patterns and rates that avoid adverse impacts on the groundwater system. The sustainable yield introduced in this paper is a useful baseline for groundwater management under all rainfall conditions and given pumping scenarios. A dynamic alternative to the groundwater sustainable yield for a given pumping pattern and rate should consider the responses of the recharge, discharge, and evapotranspiration to the groundwater level fluctuation and to different natural rainfall conditions. In this study, methods for determining the sustainable yield through time series data of groundwater recharge, discharge, extraction, and precipitation in an aquifer are introduced. A numerical simulation tool was used to assess and quantify the dynamic changes in groundwater recharge and discharge under excessive pumping patterns and rates and to estimate the sustainable yield of groundwater flow based on natural rainfall conditions and specific groundwater development scenarios during the period of 2007 to 2014. The results of this study indicate that the multi-year sustainable yield only accounts for about one-half of the average annual recharge. The future sustainable yield for the current pumping scenarios affected by rainfall conditions are evaluated quantitatively to obtain long-term groundwater development strategies. The simulation results show that sufficient

Assessment of groundwater quality at a MSW landfill site using standard and AHP based water quality index: a case study from Ranchi, Jharkhand, India.

PubMed

Chakraborty, Shubhrasekhar; Kumar, R Naresh

2016-06-01

Landfill leachate generated from open MSW dumpsite can cause groundwater contamination. The impact of open dumping of MSW on the groundwater of adjacent area was studied. To assess the spatial and temporal variations in groundwater quality, samples were collected around an open MSW dumping site in Ranchi city, Jharkhand, India. Groundwater samples were analysed for various physicochemical and bacteriological parameters for 1 year. Results indicated that the groundwater is getting contaminated due to vertical and horizontal migration of landfill leachate. Extent of contamination was higher in areas closer to the landfill as indicated by high alkalinity, total dissolved solids and ammonia concentration. Metals such as lead, iron, and manganese were present at concentrations of 0.097, 0.97 and 0.36 mg/L, respectively exceeding the Bureau of Indian Standards (BIS) 10,500 for drinking water. Enterobacteriaceae were also detected in several groundwater samples and highest coliform count of 2.1×10(4) CFU/mL was recorded from a dug well. In order to determine the overall groundwater quality, water quality index (WQI) was calculated using weighted arithmetic index method and this index was further modified by coupling with the analytical hierarchy process (AHP) to get specific information. WQI values indicated that the overall groundwater quality of the region came under "poor" category while zone wise classification indicated the extent of impact of landfill leachate on groundwater.

Changes in shallow groundwater quality beneath recently urbanized areas in the Memphis, Tennessee area

USGS Publications Warehouse

Barlow, Jeannie R.; Kingsbury, James A.; Coupe, Richard H.

2012-01-01

Memphis, the largest city in the state of Tennessee, and its surrounding suburbs depend on a confined aquifer, the Memphis aquifer, for drinking water. Concern over the potential for downward movement of water from an overlying shallow aquifer to the underlying Memphis aquifer provided impetus for monitoring groundwater quality within the shallow aquifer. The occurrence of volatile organic compounds (VOCs), nitrate, and pesticides in samples from the shallow well network indicate a widespread affect on water quality from the overlying urban land use. Total pesticide concentration was generally higher in more recently recharged groundwater indicating that as the proportion of recent water increases, the occurrence of pesticides related to the current urban land use also increases. Groundwater samples with nitrate concentrations greater than 1.5 mg/l and detectable concentrations of the pesticides atrazine and simazine also had higher concentrations of chloroform, a VOC primarily associated with urban land use, than in other samples. The age of the water from these wells indicates that these concentrations are most likely not representative of past agricultural use, but of more recent urban use of these chemicals. Given that the median age of water represented by the shallow well network was 21 years, a lag time likely exists between changes in land use and the occurrence of constituents related to urbanization in shallow groundwater.

Groundwater Risk Management Handbook

DTIC Science & Technology

2008-01-01

restoration of groundwater to drinking water quality may not always be achievable due to technology limitations and, therefore, has developed a...extent (horizontal and vertical) of groundwater contamination • Future plans for groundwater use in the area, including local water resource planning...exposure (e.g., drinking water supplied by public water system and groundwater beneath the site is restricted for potable purposes) • Land use

Are megacities viable? A cautionary tale from Mexico City.

PubMed

Ezcurra, E; Mazari-hiriart, M

1996-01-01

This article describes the poor environmental and living conditions in Mexico City due to its huge size. Mexico City's size is a challenge to sustainability, and the outcome is unknown. Mexico City and the geographic basin surrounding it included about 18.5 million population in 1995. The basin and surrounding volcanic ranges include nine major environmental zones. Urban growth followed four stages. Different cultures applied different solutions to water supply problems. The basin shifted from self-sufficiency to reliance on 31% of supplies from external watersheds. The water table is declining and canals are polluted. Irrigated agriculture is disappearing. There is an average water deficit of over 800 million cubic meters per year. Mexico City is actually sinking due to groundwater exploitation. There is bacterial contamination of wells due to improper seals. About 75% of the population has access to wastewater treatment and sanitation, but sewage treatment plants operate at under 50% efficiency and treat only about 7% of the total wastewater. Atmospheric pollution from suspended particles has been a problem for decades. Ozone was the most significant air contaminant in 1994. Lead was the most harmful pollutant in 1986. Air pollutants may be the source of submucosal inflammations. Industrial areas are contaminated with suspended particles and sulfur dioxide. High traffic areas have high carbon monoxide levels. Atmospheric pollution has affected the quality of the rainwater. The city survives by importing food, energy, wood, water, building materials, and other products. The development model aims to improve quality of life. The city has been the center of political power since Aztec times, and its preeminent position forces government action. The author concludes that there are limits to urbanization, which the city is approaching rapidly.

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

NASA Astrophysics Data System (ADS)

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

2017-04-01

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

Sea-level rise risks to coastal cities

NASA Astrophysics Data System (ADS)

Nicholls, Robert J.

2017-04-01

Understanding the consequence of sea-level rise for coastal cities has long lead times and huge political implications. Civilisation has emerged and developed during a period of several thousand years during which in geological terms sea level has been unusually stable. We have now moved out of this period and the challenge will be to develop a long-term proactive assessment approach to manage this challenge. In 2005 there were 136 coastal cities with a population exceeding one million people and a collective population of 400 million people. All these coastal cities are threatened by flooding from the sea to varying degrees and these risks are increasing due to growing exposure (people and assets), rising sea levels due to climate change, and in some cities, significant coastal subsidence due to human agency (drainage and groundwater withdrawals from susceptible soils). In these cities we wish to avoid major flood events, with associated damage and potentially deaths and ultimately decline of the cities. Flood risks grow with sea-level rise as it raises extreme sea levels. As sea levels continue to rise, protection will have to be progressively upgraded. Even with this, the magnitude of losses when flood events do occur would increase as coastal cities expand, and water depths and hence unit damage increase with sea-level rise/subsidence. This makes it critical to also prepare for larger coastal flood disasters than we experience today and raises questions on the limits to adaptation. There is not an extensive literature or significant empirical information on the limits to adaptation in coastal cities. These limits are not predictable in a formal sense - while the rise in mean sea level raises the likelihood of a catastrophic flood, extreme events are what cause damage and trigger a response, be it abandonment, a defence upgrade or something else. There are several types of potential limits that could be categorised into three broad types: • Physical

Behavior of TOC in a Deep Confined Aquifer During Groundwater Artificial Recharge Process

NASA Astrophysics Data System (ADS)

Zhang, W.; He, H.; Shi, X.

2013-12-01

In recent years, environmental geological problems such as land subsidence, land collapse, land cracking and salt-water intrusion have become important factors limiting economic development in some cities due to severe overexploitation of groundwater. So, a number of cities have carried out artificial recharge projects, which have played a significant role in controlling these problems. However, with the increasing trend of organic pollution appeared in the surface water, organic contaminated problems should not be neglected during this process. Although the organic components were always following in a lower concentration level, whether it would make groundwater face the organic pollution crisis was unknown for its' higher toxicity and durability. Based on a typical artificial recharge test carried out in a deep confined aquifer in this study area (located in Eastern China, there are 10 monitoring wells and 1 recharge well) that decided to control the field land subsidence, Total Organic Carbon (TOC) was selected as the target components to reveal the organic elements' changing trend during groundwater artificial recharge process. The results (Fig. 1) showed that the concentration of TOC in each monitoring well was appeared in an increasing trend due to the mix influence of the recharge water (TOC was 1.88mg/L) and the origin groundwater (TOC was 0.58mg/L). But the maximum concentrations of TOC in J4, J5, J6 monitoring well (the distance from recharge well was 10m, 17m, 31m respectively) were lower than the recharge water 0.28, 0.49, 0.74 mg/L respectively, with non-linear growth. It indicated that except adsorption, microbial degradation might also occur in the aquifer during artificial recharge. With the groundwater environment from relatively anaerobic environment turn to aerobic environment, DO was able to characterize the relative strength of the TOC biodegradation. The average value of DO in recharge water was 4.33 mg/L, and the maximum value of DO in J4, J5

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

NASA Astrophysics Data System (ADS)

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

Water resources in the area of Snyderville Basin and Park City in Summit County, Utah

USGS Publications Warehouse

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

1998-01-01

Ground water is the primary source of water for residents living in the area of Synderville Basin and Park City in Summit County, Utah. Rapid residential and commercial development are placing increased demands on the ground-water resources in the area and increased ground-water withdrawals could affect appropriated surface-water resources. The quantity and quality of water in the area were assessed during 1993-97 in a study done by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights; Park City; Summit County; and the Weber Basin Water Conservancy District. This fact sheet presents a synopsis of the eports prepared for that study. Data collected during the 1994 and 1995 water years are presented in Downhour and Brooks (1996). A water year extends from October through September rather than January through December of a calendar year. Streamflow and surface-water quality; ground- water recharge, movement, discharge, and quality; water budgets; and snowmelt simulations are described in Brooks, Mason, and Susong (1998). The purpose of the study was to provide the Utah Division of Water Rights with data to assist them in- making water management decisions.

Vulnerability assessment of groundwater-dependent ecosystems based on integrated groundwater flow modell construction

NASA Astrophysics Data System (ADS)

Tóth, Ádám; Simon, Szilvia; Galsa, Attila; Havril, Timea; Monteiro Santos, Fernando A.; Müller, Imre; Mádl-Szőnyi, Judit

2017-04-01

Groundwater-dependent ecosystems (GDEs) are highly influenced by the amount of groundwater, seasonal variation of precipitation and consequent water table fluctuation and also the anthropogenic activities. They can be regarded as natural surface manifestations of the flowing groundwater. The preservation of environment and biodiversity of these GDEs is an important issue worldwide, however, the water management policy and action plan could not be constructed in absense of proper hydrogeological knowledge. The concept of gravity-driven regional groundwater flow could aid the understanding of flow pattern and interpretation of environmental processes and conditions. Unless the required well data are available, the geological-hydrogeological numerical model of the study area cannot be constructed based only on borehole information. In this case, spatially continuous geophysical data can support groundwater flow model building: systematically combined geophysical methods can provide model input. Integration of lithostratigraphic, electrostratigraphic and hydrostratigraphic information could aid groundwater flow model construction: hydrostratigraphic units and their hydraulic behaviour, boundaries and geometry can be obtained. Groundwater-related natural manifestations, such as GDEs, can be explained with the help of the revealed flow pattern and field mapping of features. Integrated groundwater flow model construction for assessing the vulnerability of GDEs was presented via the case study of the geologically complex area of Tihany Peninsula, Hungary, with the aims of understanding the background and occurrence of groundwater-related environmental phenomena, surface water-groundwater interaction, and revealing the potential effect of anthropogenic activity and climate change. In spite of its important and protected status, fluid flow model of the area, which could support water management and natural protection policy, had not been constructed previously. The 3D

Assessment of On-site sanitation system on local groundwater regime in an alluvial aquifer

NASA Astrophysics Data System (ADS)

Quamar, Rafat; Jangam, C.; Veligeti, J.; Chintalapudi, P.; Janipella, R.

2017-12-01

The present study is an attempt to study the impact of the On-site sanitation system on the groundwater sources in its vicinity. The study has been undertaken in the Agra city of Yamuna sub-basin. In this context, sampling sites (3 nos) namely Pandav Nagar, Ayodhya Kunj and Laxmi Nagar were selected for sampling. The groundwater samples were analyzed for major cations, anions and faecal coliform. Critical parameters namely chloride, nitrate and Faecal coliform were considered to assess the impact of the On-site sanitation systems. The analytical results shown that except for chloride, most of the samples exceeded the Bureau of Indian Standard limits for drinking water for all the other analyzed parameters, i.e., nitrate and faecal coliform in the first two sites. In Laxmi Nagar, except for faecal coliform, all the samples are below the BIS limits. In all the three sites, faecal coliform was found in majority of the samples. A comparison of present study indicates that the contamination of groundwater in alluvial setting is less as compared to hard rock where On-site sanitation systems have been implemented.

Evaluation of the fast orthogonal search method for forecasting chloride levels in the Deltona groundwater supply (Florida, USA)

NASA Astrophysics Data System (ADS)

El-Jaat, Majda; Hulley, Michael; Tétreault, Michel

2018-02-01

Despite the broad impact and importance of saltwater intrusion in coastal aquifers, little research has been directed towards forecasting saltwater intrusion in areas where the source of saltwater is uncertain. Saline contamination in inland groundwater supplies is a concern for numerous communities in the southern US including the city of Deltona, Florida. Furthermore, conventional numerical tools for forecasting saltwater contamination are heavily dependent on reliable characterization of the physical characteristics of underlying aquifers, information that is often absent or challenging to obtain. To overcome these limitations, a reliable alternative data-driven model for forecasting salinity in a groundwater supply was developed for Deltona using the fast orthogonal search (FOS) method. FOS was applied on monthly water-demand data and corresponding chloride concentrations at water supply wells. Groundwater salinity measurements from Deltona water supply wells were applied to evaluate the forecasting capability and accuracy of the FOS model. Accurate and reliable groundwater salinity forecasting is necessary to support effective and sustainable coastal-water resource planning and management. The available (27) water supply wells for Deltona were randomly split into three test groups for the purposes of FOS model development and performance assessment. Based on four performance indices (RMSE, RSR, NSEC, and R), the FOS model proved to be a reliable and robust forecaster of groundwater salinity. FOS is relatively inexpensive to apply, is not based on rigorous physical characterization of the water supply aquifer, and yields reliable estimates of groundwater salinity in active water supply wells.

Estimating groundwater recharge

USGS Publications Warehouse

Healy, Richard W.; Scanlon, Bridget R.

2010-01-01

Understanding groundwater recharge is essential for successful management of water resources and modeling fluid and contaminant transport within the subsurface. This book provides a critical evaluation of the theory and assumptions that underlie methods for estimating rates of groundwater recharge. Detailed explanations of the methods are provided - allowing readers to apply many of the techniques themselves without needing to consult additional references. Numerous practical examples highlight benefits and limitations of each method. Approximately 900 references allow advanced practitioners to pursue additional information on any method. For the first time, theoretical and practical considerations for selecting and applying methods for estimating groundwater recharge are covered in a single volume with uniform presentation. Hydrogeologists, water-resource specialists, civil and agricultural engineers, earth and environmental scientists and agronomists will benefit from this informative and practical book. It can serve as the primary text for a graduate-level course on groundwater recharge or as an adjunct text for courses on groundwater hydrology or hydrogeology.

Human interactions with ground-water

USGS Publications Warehouse

Zaporozec, A.

1983-01-01

Ground-Water could be considered as an immense reservoir, from which only a certain amount of water can be withdrawn without affecting the quantity and quality of water. This amount is determined by the characteristics of the environment in which ground-water occurs and by the interactions of ground-water with precipitation, surface water, and people. It should be recognized that quantity and quality of ground-water are intimately related and should be considered accordingly. Quantity refers to usable water and water is usable for any specific purpose only so long as its quality has not deteriorated beyond acceptable limits. Thus an overall quantitative and qualitative management of ground water is inevitable, and its should also involve the uses of ground-water reservoirs for purposes other than water supply. The main objective of ground-water management is to ensure that ground-water resources will be available in appropriate time and in appropriate quantity and quality to meet the most important demands of our society. Traditional, and obvious uses of ground-water are the extraction of water for water supplies (domestic, municipal, agricultural, and industrial) and the natural discharge feeding lakes and maintaining base flow of streams. Not so obvious are the uses of ground-water reservoirs, the very framework within which ground-water occurs and moves, and in which other fluids or materials can be stored. In the last two decades, ground-water reservoirs have been intensively considered for many other purposes than water supplies. Diversified and very often conflicting uses need to be evaluated and dealt with in the most efficient way in order to determine the importance of each possible use, and to assign priorities of these uses. With rising competition for the use of ground-water reservoirs, we will also need to increase the potential for effective planning of ground-water development and protection. Man's development and use of ground-water necessarily

High-fluoride groundwater.

PubMed

Rao, N Subba

2011-05-01

Fluoride (F(-)) is essential for normal bone growth, but its higher concentration in the drinking water poses great health problems and fluorosis is common in many parts of India. The present paper deals with the aim of establishment of facts of the chemical characteristics responsible for the higher concentration of F(-) in the groundwater, after understanding the chemical behavior of F(-) in relation to pH, total alkalinity (TA), total hardness (TH), carbonate hardness (CH), non-carbonate hardness (NCH), and excess alkalinity (EA) in the groundwater observed from the known areas of endemic fluorosis zones of Andhra Pradesh that have abundant sources of F(-)-bearing minerals of the Precambrians. The chemical data of the groundwater shows that the pH increases with increase F(-); the concentration of TH is more than the concentration of TA at low F(-) groundwater, the resulting water is represented by NCH; the TH has less concentration compared to TA at high F(-) groundwater, causing the water that is characterized by EA; and the water of both low and high concentrations of F(-) has CH. As a result, the F(-) has a positive relation with pH and TA, and a negative relation with TH. The operating mechanism derived from these observations is that the F(-) is released from the source into the groundwater by geochemical reactions and that the groundwater in its flowpath is subjected to evapotranspiration due to the influence of dry climate, which accelerates a precipitation of CaCO(3) and a reduction of TH, and thereby a dissolution of F(-). Furthermore, the EA in the water activates the alkalinity in the areas of alkaline soils, leading to enrichment of F(-). Therefore, the alkaline condition, with high pH and EA, and low TH, is a more conducive environment for the higher concentration of F(-) in the groundwater.

Deterministic modeling of the impact of underground structures on urban groundwater temperature.

PubMed

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

2016-12-01

Underground structures have a major influence on groundwater temperature and have a major contribution on the anthropogenic heat fluxes into urban aquifers. Groundwater temperature is crucial for resource management as it can provide operational sustainability indicators for groundwater quality and geothermal energy. Here, a three dimensional heat transport modeling approach was conducted to quantify the thermally affected zone (TAZ, i.e. increase in temperature of more than +0.5°C) caused by two common underground structures: (1) an impervious structure and (2) a draining structure. These design techniques consist in (1) ballasting the underground structure in order to resist hydrostatic pressure, or (2) draining the groundwater under the structure in order to remove the hydrostatic pressure. The volume of the TAZ caused by these underground structures was shown to range from 14 to 20 times the volume of the underground structure. Additionally, the cumulative impact of underground structures was assessed under average thermal conditions at the scale of the greater Lyon area (France). The heat island effect caused by underground structures was highlighted in the business center of the city. Increase in temperature of more than +4.5°C were locally put in evidence. The annual heat flow from underground structures to the urban aquifer was computed deterministically and represents 4.5GW·h. Considering these impacts, the TAZ of deep underground structures should be taken into account in the geothermal potential mapping. Finally, the amount of heat energy provided should be used as an indicator of heating potential in these areas. Copyright © 2016 Elsevier B.V. All rights reserved.

Urban waste landfill planning and karstic groundwater resources in developing countries: the example of Lusaka (Zambia)

NASA Astrophysics Data System (ADS)

De Waele, J.; Nyambe, I. A.; Di Gregorio, A.; Di Gregorio, F.; Simasiku, S.; Follesa, R.; Nkemba, S.

2004-06-01

Lusaka, the capital city of Zambia with more than two million inhabitants, derives approximately 70% of its water requirements from groundwater sourced in the underlying karstic Lusaka aquifer. This water resource is, therefore, extremely important for the future of the population. The characteristics of the aquifer and the shallow water table make the resource vulnerable and in need of protection and monitoring. A joint project between the Geology Departments of the University of Cagliari and the School of Mines of the University of Zambia, to investigate the "Anthropogenic and natural processes in the Lusaka area leading to environmental degradation and their possible mitigation" was carried out in July 2001. The main objective of the study was to evaluate the extent of the present environmental degradation, assessing the vulnerability of the carbonatic aquifer and the degree of pollution of the groundwater and to make proposals to mitigate adverse environmental effects. Analyses of water samples collected during project indicate some areas of concern, particularly with respect to the levels of ammonia, nitrates and some heavy metals. As groundwater quality and quantity are prerogatives for a healthy and sustainable society, the study offers guidelines for consideration by the local and national authorities. Uptake of these guidelines should result in a number of initiatives being taken, including: (a) closure or reclamation of existing waste dumps; (b) upgrading of existing waste dumps to controlled landfills; (c) establishing new urban waste landfills and plants in geo-environmentally suitable sites; (d) local waste management projects in all compounds (residential areas) to prevent and reduce haphazard waste dumping; (e) enlarging sewerage drainage systems to all compounds; (f) enforcing control on groundwater abstraction and pollution, and demarcation of zones of control at existing drill holes; (g) providing the city with new water supplies from outside the

Ground-water and geohydrologic conditions in Queens County, Long Island, New York

USGS Publications Warehouse

Soren, Julian

1971-01-01

Queens County is a heavily populated borough of New York City, at the western end of Long Island, N. Y., in which large amounts of ground water are used, mostly for public supply. Ground water, pumped from local aquifers, by privately owned water-supply companies, supplied the water needs of about 750,000 of the nearly 2 million residents of the county in 1967; the balance was supplied by New York City from surface sources outside the county in upstate New York. The county's aquifers consist of sand and gravel of Late Cretaceous and of Pleistocene ages, and the aquifers comprise a wedge-shaped ground-water reservoir lying on a southeastward-sloping floor of Precambrian(?) bedrock. Beds of clay and silt generally confine water in the deeper parts of the reservoir; water in the deeper aquifers ranges from poorly confined to well confined. Wisconsin-age glacial deposits in the uppermost part of the reservoir contain ground water under water-table conditions. Ground water pumpage averaged about 60 mgd (million gallons per day) in Queens County from about 1900 to 1967. Much of the water was used in adjacent Kings County, another borough of New York City, prior to 1950. The large ground-water withdrawal has resulted in a wide-spread and still-growing cone of depression in the water table, reflecting a loss of about 61 billion gallons of fresh water from storage. Significant drawdown of the water table probably began with rapid urbanization of Queens County in the 1920's. The county has been extensively paved, and storm and sanitary sewers divert water, which formerly entered the ground, to tidewater north and south of the county. Natural recharge to the aquifers has been reduced to about one half of the preurban rate and is below the withdrawal rate. Ground-water levels have declined more than 40. feet from the earliest-known levels, in 1903, to 1967, and the water table is below sea level in much of the county. The aquifers are being contaminated by the movement of

Response of the microbial community to seasonal groundwater level fluctuations in petroleum hydrocarbon-contaminated groundwater.

PubMed

Zhou, Ai-xia; Zhang, Yu-ling; Dong, Tian-zi; Lin, Xue-yu; Su, Xiao-si

2015-07-01

The effects of seasonal groundwater level fluctuations on the contamination characteristics of total petroleum hydrocarbons (TPH) in soils, groundwater, and the microbial community were investigated at a typical petrochemical site in northern China. The measurements of groundwater and soil at different depths showed that significant TPH residue was present in the soil in this study area, especially in the vicinity of the pollution source, where TPH concentrations were up to 2600 mg kg(-1). The TPH concentration in the groundwater fluctuated seasonally, and the maximum variation was 0.8 mg L(-1). The highest TPH concentrations were detected in the silty clay layer and lied in the groundwater level fluctuation zones. The groundwater could reach previously contaminated areas in the soil, leading to higher groundwater TPH concentrations as TPH leaches into the groundwater. The coincident variation of the electron acceptors and TPH concentration with groundwater-table fluctuations affected the microbial communities in groundwater. The microbial community structure was significantly different between the wet and dry seasons. The canonical correspondence analysis (CCA) results showed that in the wet season, TPH, NO3(-), Fe(2+), TMn, S(2-), and HCO3(-) were the major factors correlating the microbial community. A significant increase in abundance of operational taxonomic unit J1 (97% similar to Dechloromonas aromatica sp.) was also observed in wet season conditions, indicating an intense denitrifying activity in the wet season environment. In the dry season, due to weak groundwater level fluctuations and low temperature of groundwater, the microbial activity was weak. But iron and sulfate-reducing were also detected in dry season at this site. As a whole, groundwater-table fluctuations would affect the distribution, transport, and biodegradation of the contaminants. These results may be valuable for the control and remediation of soil and groundwater pollution at this site

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

PubMed

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

2014-11-01

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

Social Perception of Public Water Supply Network and Groundwater Quality in an Urban Setting Facing Saltwater Intrusion and Water Shortages

NASA Astrophysics Data System (ADS)

Alameddine, Ibrahim; Jawhari, Gheeda; El-Fadel, Mutasem

2017-04-01

Perceptions developed by consumers regarding the quality of water reaching their household can affect the ultimate use of the water. This study identified key factors influencing consumers' perception of water quality in a highly urbanized coastal city, experiencing chronic water shortages, overexploitation of groundwater, and accelerated saltwater intrusion. Household surveys were administered to residents to capture views and perceptions of consumed water. Concomitantly, groundwater and tap water samples were collected and analyzed at each residence for comparison with perceptions. People's rating of groundwater quality was found to correlate to the measured water quality both in the dry and wet seasons. In contrast, perceptions regarding the water quality of the public water supply network did not show any correlation with the measured tap water quality indicators. Logistic regression models developed to predict perception based on salient variables indicated that age, apartment ownership, and levels of total dissolved solids play a significant role in shaping perceptions regarding groundwater quality. Perceptions concerning the water quality of the public water supply network appeared to be independent of the measured total dissolved solids levels at the tap but correlated to those measured in the wells. The study highlights misconceptions that can arise as a result of uncontrolled cross-connections of groundwater to the public supply network water and the development of misaligned perceptions based on prior consumption patterns, water shortages, and a rapidly salinizing groundwater aquifer.

Social Perception of Public Water Supply Network and Groundwater Quality in an Urban Setting Facing Saltwater Intrusion and Water Shortages.

PubMed

Alameddine, Ibrahim; Jawhari, Gheeda; El-Fadel, Mutasem

2017-04-01

Perceptions developed by consumers regarding the quality of water reaching their household can affect the ultimate use of the water. This study identified key factors influencing consumers' perception of water quality in a highly urbanized coastal city, experiencing chronic water shortages, overexploitation of groundwater, and accelerated saltwater intrusion. Household surveys were administered to residents to capture views and perceptions of consumed water. Concomitantly, groundwater and tap water samples were collected and analyzed at each residence for comparison with perceptions. People's rating of groundwater quality was found to correlate to the measured water quality both in the dry and wet seasons. In contrast, perceptions regarding the water quality of the public water supply network did not show any correlation with the measured tap water quality indicators. Logistic regression models developed to predict perception based on salient variables indicated that age, apartment ownership, and levels of total dissolved solids play a significant role in shaping perceptions regarding groundwater quality. Perceptions concerning the water quality of the public water supply network appeared to be independent of the measured total dissolved solids levels at the tap but correlated to those measured in the wells. The study highlights misconceptions that can arise as a result of uncontrolled cross-connections of groundwater to the public supply network water and the development of misaligned perceptions based on prior consumption patterns, water shortages, and a rapidly salinizing groundwater aquifer.

Simulating groundwater-induced sewer flooding

NASA Astrophysics Data System (ADS)

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

2016-12-01

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

A multiphased approach to groundwater investigations for the Edwards-Trinity and related aquifers in the Pecos County region, Texas

USGS Publications Warehouse

Thomas, Jonathan V.

2014-01-01

The Edwards-Trinity aquifer is a vital groundwater resource for agricultural, industrial, and public supply uses in the Pecos County region of western Texas. Resource managers would like to understand the future availability of water in the Edwards-Trinity aquifer in the Pecos County region and the effects of the possible increase or temporal redistribution of groundwater withdrawals. To provide resource managers with that information, the U.S. Geological Survey (USGS), in cooperation with the Middle Pecos Groundwater Conservation District, Pecos County, City of Fort Stockton, Brewster County, and Pecos County Water Control and Improvement District No. 1, completed a three-phase study of the Edwards-Trinity and related aquifers in parts of Brewster, Jeff Davis, Pecos, and Reeves Counties. The first phase was to collect groundwater, surface-water, geochemical, geophysical, and geologic data in the study area and develop a geodatabase of historical and collected data. Data compiled in the first phase of the study were used to develop the conceptual model in the second phase of the study. The third phase of the study involved the development and calibration of a numerical groundwater-flow model of the Edwards-Trinity aquifer to simulate groundwater conditions based on various groundwater-withdrawal scenarios. Analysis of well, geophysical, geochemical, and hydrologic data contributed to the development of the conceptual model in phase 1. Lithologic information obtained from well reports and geophysical data was used to describe the hydrostratigraphy and structural features of the groundwater-flow system, and aquifer-test data were used to estimate aquifer hydraulic properties. Geochemical data were used to evaluate groundwater-flow paths, water-rock interaction, aquifer interaction, and the mixing of water from different sources in phase 2. Groundwater-level data also were used to evaluate aquifer interaction, as well as to develop a potentiometric-surface map

The effect of hydrogeological conditions on variability and dynamic of groundwater recharge in a carbonate aquifer at local scale

NASA Astrophysics Data System (ADS)

Dvory, Noam Zach; Livshitz, Yakov; Kuznetsov, Michael; Adar, Eilon; Yakirevich, Alexander

2016-04-01

Groundwater recharge in fractured karstic aquifers is particularly difficult to quantify due to the rock mass's heterogeneity and complexity that include preferential flow paths along karst conduits. The present study's major goals were to assess how the changes in lithology, as well as the fractured karst systems, influence the flow mechanism in the unsaturated zone, and to define the spatial variation of the groundwater recharge at local scale. The study area is located within the fractured carbonate Western Mountain aquifer (Yarkon-Taninim), west of the city of Jerusalem at the Ein Karem (EK) production well field. Field monitoring included groundwater level observations in nine locations in the study area during years 1990-2014. The measured groundwater level series were analyzed with the aid of one-dimensional, dual permeability numerical model of water flow in variably saturated fractured-porous media, which was calibrated and used to estimate groundwater recharge at nine locations. The recharge values exhibit significant spatial and temporal variation with mean and standard deviation values of 216 and 113 mm/year, respectively. Based on simulations, relationships were established between precipitation and groundwater recharge in each of the nine studied sites and compared with similar ones obtained in earlier regional studies. Simulations show that fast and slow flow paths conditions also influence annual cumulative groundwater recharge dynamic. In areas where fast flow paths exist, most of the groundwater recharge occurs during the rainy season (60-80% from the total recharge for the tested years), while in locations with slow flow path conditions the recharge rate stays relatively constant with a close to linear pattern and continues during summer.

Evaluating Adult Groundwater Education.

ERIC Educational Resources Information Center

Gerakis, Argyrios

1998-01-01

One-day groundwater education workshops held to educate soil conservation personnel were assessed for effect on participant knowledge using a quasiexperimental design. Participants were tested on their groundwater knowledge and attitude toward groundwater conservation before and after the training. Participant scores improved significantly in only…

75 FR 11580 - Florida Power Corporation, City of Alachua, City of Bushnell, City of Gainesville, City of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-11

...- 0096] Florida Power Corporation, City of Alachua, City of Bushnell, City of Gainesville, City of Kissimmee, City of Leesburg, City of New Smyrna Beach and Utilities Commission, City of New Smyrna Beach, City of Ocala, Orlando Utilities Commission and City of Orlando, Seminole Electric Cooperative, Inc...

Interaction of coastal urban groundwater with infrastructure due to tidal variation

NASA Astrophysics Data System (ADS)

Su, X.; Prigiobbe, V.

2017-12-01

The urbanization of coastal areas has been increasing during the last century. For these areas, groundwater is one of major source of potable water for the population, the industry, and the agriculture, with an average demand of 30 m3/s [1,2]. Simultaneously, the rate of sea-level rise has been recorded to be approximately 40 mm/yr [3], with potential negative consequences on the coastal groundwater. As the sea-level rises, sea-water intrusion into potable aquifers may become more important [4] and the water table of the shallow aquifer underneath the coastal areas may rise [5]. Therefore, the water quality of the aquifer decreases and interaction between the shallow aquifer and infrastructure may occur. In particular, in the latter case, disruptive events may become more frequent, such as infiltration of groundwater into damaged sewer causing discharge of untreated sewage (combined sewer overflows, CSOs). Here, a study is presented on the modeling of urban groundwater in coastal areas to identify the cause of frequent CSOs in dry weather conditions, i.e., CSOs are not expected to occur. The evolution of the water table was described in response of tidal variation to quantify the interaction between the shallow aquifer and an aging sewer. The watershed of the city of Hoboken (NJ), at the estuary of Hudson river, was implemented in MODFLOW. The model was built using dataset from various sources. Geostatistic was applied to create the aquifer geology and measurements of the water table from monitoring wells within the urban area were used as boundary conditions and model validation. Preliminary results of the simulations are shown the figure, where the water table over a period of 7 months was calculated. The groundwater model with the sewer will help identifying the parts of the network that might be submerged by the groundwater and, therefore, subjected to infiltration. Combining groundwater and sewer modeling with the hydrograph separation method [6], the model

Groundwater modelling as a tool for the European Water Framework Directive (WFD) application: The Llobregat case

NASA Astrophysics Data System (ADS)

Vázquez-Suñé, E.; Abarca, E.; Carrera, J.; Capino, B.; Gámez, D.; Pool, M.; Simó, T.; Batlle, F.; Niñerola, J. M.; Ibáñez, X.

The European Water Framework Directive establishes the basis for Community action in the field of water policy. Water authorities in Catalonia, together with users are designing a management program to improve groundwater status and to assess the impact of infrastructures and city-planning activities on the aquifers and their associated natural systems. The objective is to describe the role of groundwater modelling in addressing the issues raised by the Water Framework Directive, and its application to the Llobregat Delta, Barcelona, Spain. In this case modelling was used to address Water Framework Directive in the following: (1) Characterisation of aquifers and the status of groundwater by integration of existing knowledge and new hydrogeological information. Inverse modelling allowed us to reach an accurate description of the paths and mechanisms for the evolution of seawater intrusion. (2) Quantification of groundwater budget (mass balance). This is especially relevant for those terms that are difficult to asses, such as recharge from river infiltration during floods, which we have found to be very important. (3) Evaluation of groundwater-related environmental needs in aquatic ecosystems. The model allows quantifying groundwater input under natural conditions, which can be used as a reference level for stressed conditions. (4) Evaluation of possible impacts of territory planning (Llobregat river course modification, new railway tunnels, airport and docks enlargement, etc.). (5) Definition of management areas. (6) The assessment of possible future scenarios combined with optimization processes to quantify sustainable pumping rates and design measures to control seawater intrusion. The resulting model has been coupled to a user-friendly interface to allow water managers to design and address corrective measures in an agile and effective way.

Study on Law of Groundwater Evolution under Natural and Artificial Forcing with Case study of Haihe River Basin

NASA Astrophysics Data System (ADS)

You, Jinjun; Gan, Hong; Wang, Lin; Bi, Xue; Du, Sisi

2010-05-01

The evolution of groundwater is one of the key problems of water cycle study. It is a result of joint effect of natural condition and human activities, but until now the driving forces of groundwater system evolution were not fully understood due to the complexity of groundwater system structures and the uncertainty of affecting factors. Geology, precipitation and human activity are the main factors affecting the groundwater system evolution and interact each other, but the influence of such three factors on groundwater system are not clarified clearly on a macroscopic scale. The precipitation changes the volume of water recharge and the groundwater pumping effect the discharge of groundwater. Another important factor influencing balance of groundwater storage is the underlaying that affects the renewablility of groundwater. The underlaying is decided mainly by geological attributes but also influenced by human activited. The macroscopic environment of groundwater evolves under the natural and anthropic factors. This paper study the general law of groundwater evolution among the factors based on the case study in Haihe River Basin, a typical area with dramatic groundwater change under natural precipitation attenuation and gradually increase of water suuply. Haihe River Basin is located in north-China, covers an area of 320,041 km2 with over 40% plain areas. The plain area of Haihe Basin is densely populated with many large and medium-sized cities, including metropolis of Beijing and Tianjin, and concentrated irrigated areas, playing important roles in China's economy and food production. It is the unique basin where groundwater occupies majority of total water supply in China. Long-term groundwater over-exploitation causes a series of ecological and environmental problems that threats the sustainable development. In this paper, the historical process of groundwater balance in Haihe Basin is divided into three phases by decrease of rainfall and increase of water

Preliminary report on ground-water conditions in the Cloquet area, Carlton County, Minnesota

USGS Publications Warehouse

Akin, P.D.

1951-01-01

A study of the geology and ground-water conditions in the.area including Cloquet, Minn., was begun by the United States Geological Survey in 1948 in financial cooperation with the Minnesota State Department of Conservation, at the request of the city of Cloquet for assistance in locating large additional ground-water supplies for industrial and municipal use. The location of the area is show on figure 1. Although the present municipal wells provide a fairly adequate supply for current municipal needs, which averaged about three-quarters of a million gallons a day in 1946, there is great need for large supplies of good water, on the order of 10 million gallons a day, for use by the paper mills and other industries there. At present the industries are using water from the St. Louis River, but the water is unsatisfactory and expensive to use because it contains a large amount of objectionable organic material.

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

USGS Publications Warehouse

Juckem, Paul F.

2009-01-01

water withdrawals. Tributary rivers act as 'partially penetrating' hydraulic boundaries such that groundwater can flow underneath them through the deep sandstone aquifers. The model also demonstrates the effects of development on groundwater in the study area. Water-level declines since predevelopment (no withdrawal wells) are most pronounced where pumping is greatest and flow between layered aquifers is impeded by confining units or faults. The maximum simulated water-level decline is about 40 feet in the deep Mount Simon aquifer below the city of Hudson, Wisconsin. Three inset models were extracted from the regional model to demonstrate the process and additional capabilities of the U.S. Geological Survey MODFLOW code. Although the inset models were designed to provide information about the groundwater-flow system, results from the inset models are presented for demonstration purposes only and are not sufficiently detailed or calibrated to be used for decisionmaking purposes without refinement. Simulation of groundwater/lake-water interaction around Twin Lakes near Roberts, in St. Croix County, Wisconsin, showed that groundwater represents approximately 5 to 20 percent of the overall lake-water budget. Groundwater-contributing areas to streams in western Pierce County are generally similar in size to the surface-water-contributing areas but do not necessarily correspond to the same land area. Transient streamflow simulations of Osceola Creek in Polk County demonstrate how stream base flow can be influenced not only by seasonal precipitation and recharge variability but also by systematic changes to the system, such as groundwater withdrawal from wells.

Summary of chemical data from onsite and laboratory analyses of groundwater samples from the surficial aquifer, Las Vegas, Nevada, April and August 1993 and September 1994

USGS Publications Warehouse

Reddy, Michael M.; Gunther, Charmaine D.

2012-01-01

Samples were collected from groundwater wells in and about the city of Las Vegas, Nevada, and were analyzed for selected major, minor and trace constituents. Analyses of blank and reference samples are summarized as mean and standard deviation values for all positive results.

The occurrence and distribution of a group of organic micropollutants in Mexico City's water sources.

PubMed

Félix-Cañedo, Thania E; Durán-Álvarez, Juan C; Jiménez-Cisneros, Blanca

2013-06-01

The occurrence and distribution of a group of 17 organic micropollutants in surface and groundwater sources from Mexico City was determined. Water samples were taken from 7 wells, 4 dams and 15 tanks where surface and groundwater are mixed and stored before distribution. Results evidenced the occurrence of seven of the target compounds in groundwater: salicylic acid, diclofenac, di-2-ethylhexylphthalate (DEHP), butylbenzylphthalate (BBP), triclosan, bisphenol A (BPA) and 4-nonylphenol (4-NP). In surface water, 11 target pollutants were detected: same found in groundwater as well as naproxen, ibuprofen, ketoprofen and gemfibrozil. In groundwater, concentration ranges of salicylic acid, 4-NP and DEHP, the most frequently found compounds, were 1-464, 1-47 and 19-232 ng/L, respectively; while in surface water, these ranges were 29-309, 89-655 and 75-2,282 ng/L, respectively. Eleven target compounds were detected in mixed water. Concentrations in mixed water were higher than those determined in groundwater but lower than the detected in surface water. Different to that found in ground and surface water, the pesticide 2,4-D was found in mixed water, indicating that some pollutants can reach areas where they are not originally present in the local water sources. Concentration of the organic micropollutants found in this study showed similar to lower to those reported in water sources from developed countries. This study provides information that enriches the state of the art on the occurrence of organic micropollutants in water sources worldwide, notably in megacities of developing countries. Copyright © 2013 Elsevier B.V. All rights reserved.

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

NASA Astrophysics Data System (ADS)

Holm, R.; Felsot, A.

2012-12-01

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

Comparing the NPS MBA Resident and Distance Programs

DTIC Science & Technology

2017-06-01

17 D. ARTICLES ON HYBRID DELIVERY OF EDUCATION .................21 E. BENEFITS AND COSTS OF DL...isolation, potentially reducing the student stress reported by Ni (2013) that can occur in DL programs. E. BENEFITS AND COSTS OF DL Both tangible...PROGRAMS June 2017 By: Mara F. Rosenthal Advisors: Marigee Bacolod Latika Hartmann Approved for public release. Distribution

Preliminary investigation of the effects of sea-level rise on groundwater levels in New Haven, Connecticut

USGS Publications Warehouse

Bjerklie, David M.; Mullaney, John R.; Stone, Janet R.; Skinner, Brian J.; Ramlow, Matthew A.

2012-01-01

Global sea level rose about 0.56 feet (ft) (170 millimeters (mm)) during the 20th century. Since the 1960s, sea level has risen at Bridgeport, Connecticut, about 0.38 ft (115 mm), at a rate of 0.008 ft (2.56 mm + or - 0.58 mm) per year. With regional subsidence, and with predicted global climate change, sea level is expected to continue to rise along the northeast coast of the United States through the 21st century. Increasing sea levels will cause groundwater levels in coastal areas to rise in order to adjust to the new conditions. Some regional climate models predict wetter climate in the northeastern United States under some scenarios. Scenarios for the resulting higher groundwater levels have the potential to inundate underground infrastructure in lowlying coastal cities. New Haven is a coastal city in Connecticut surrounded and bisected by tidally affected waters. Monitoring of water levels in wells in New Haven from August 2009 to July 2010 indicates the complex effects of urban influence on groundwater levels. The response of groundwater levels to recharge and season varied considerably from well to well. Groundwater temperatures varied seasonally, but were warmer than what was typical for Connecticut, and they seem to reflect the influence of the urban setting, including the effects of conduits for underground utilities. Specific conductance was elevated in many of the wells, indicating the influence of urban activities or seawater in Long Island Sound. A preliminary steady-state model of groundwater flow for part of New Haven was constructed using MODFLOW to simulate current groundwater levels (2009-2010) and future groundwater levels based on scenarios with a rise of 3 ft (0.91 meters (m)) in sea level, which is predicted for the end of the 21st century. An additional simulation was run assuming a 3-ft rise in sea level combined with a 12-percent increase in groundwater recharge. The model was constructed from existing hydrogeologic information for the

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

NASA Astrophysics Data System (ADS)

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

2017-09-01

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

Is it worth protecting groundwater from diffuse pollution with agri-environmental schemes? A hydro-economic modeling approach.

PubMed

Hérivaux, Cécile; Orban, Philippe; Brouyère, Serge

2013-10-15

In Europe, 30% of groundwater bodies are considered to be at risk of not achieving the Water Framework Directive (WFD) 'good status' objective by 2015, and 45% are in doubt of doing so. Diffuse agricultural pollution is one of the main pressures affecting groundwater bodies. To tackle this problem, the WFD requires Member States to design and implement cost-effective programs of measures to achieve the 'good status' objective by 2027 at the latest. Hitherto, action plans have mainly consisted of promoting the adoption of Agri-Environmental Schemes (AES). This raises a number of questions concerning the effectiveness of such schemes for improving groundwater status, and the economic implications of their implementation. We propose a hydro-economic model that combines a hydrogeological model to simulate groundwater quality evolution with agronomic and economic components to assess the expected costs, effectiveness, and benefits of AES implementation. This hydro-economic model can be used to identify cost-effective AES combinations at groundwater-body scale and to show the benefits to be expected from the resulting improvement in groundwater quality. The model is applied here to a rural area encompassing the Hesbaye aquifer, a large chalk aquifer which supplies about 230,000 inhabitants in the city of Liege (Belgium) and is severely contaminated by agricultural nitrates. We show that the time frame within which improvements in the Hesbaye groundwater quality can be expected may be much longer than that required by the WFD. Current WFD programs based on AES may be inappropriate for achieving the 'good status' objective in the most productive agricultural areas, in particular because these schemes are insufficiently attractive. Achieving 'good status' by 2027 would demand a substantial change in the design of AES, involving costs that may not be offset by benefits in the case of chalk aquifers with long renewal times. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2015-11-01

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

Modeling stream-groundwater interactions and associated groundwater salinization in an urban floodplain

NASA Astrophysics Data System (ADS)

Ledford, S. H.; Lautz, L.

2014-12-01

The salinization of freshwater in the Northeastern United States from road salt application is well documented by the observed long-term increases in chloride concentrations in groundwater over the last fifty years. However, the processes controlling exchange of chloride between surface water and groundwater have not been fully investigated, particularly in urban streams where stream-groundwater interactions can be reduced due to bank armoring and channelization. Our research builds on previous findings that showed the potential for an urban riparian floodplain to buffer seasonal changes in chloride concentrations in an urban stream, resulting in smaller annual ranges of chloride in areas with intact riparian floodplains. A reach of Meadowbrook Creek, in Syracuse, New York, that is disconnected from the groundwater had large seasonal shifts in chloride concentration, varying from 2173 mg/L Cl- in the winter to 161.2 mg/L Cl- in the summer. This is in contrast to a downstream reach of the stream that receives groundwater discharge from a riparian floodplain, where chloride concentrations ranged from 657.0 mg/L in the winter to 252.0 mg/L in the summer. We originally hypothesized that winter snowmelt events caused overbank flooding of saline surface water, which recharged the floodplain groundwater, causing salinization. This saline water was then slowly discharged as baseflow throughout the year and was replaced with freshwater overbank events in the summer. However, a three dimensional model of the floodplain created using Visual MODFLOW indicates that surface water-groundwater interactions, such as hyporheic exchange, may have a greater control on winter salt input than overbank events, while summer flooding recharges the aquifer with freshwater. The model was compared to riparian aquifer samples collected from May 2013 until June 2014 to qualitatively study the impact of different types of surface water-groundwater interactions (e.g. groundwater recharge and

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

NASA Astrophysics Data System (ADS)

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

2016-09-01

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

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

NASA Astrophysics Data System (ADS)

Al-Charideh, A.; Kattaa, B.

2016-02-01

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

Ground-Water Quality and Potential Effects of Individual Sewage Disposal System Effluent on Ground-Water Quality in Park County, Colorado, 2001-2004

USGS Publications Warehouse

Miller, Lisa D.; Ortiz, Roderick F.

2007-01-01

In 2000, the U.S. Geological Survey, in cooperation with Park County, Colorado, began a study to evaluate ground-water quality in the various aquifers in Park County that supply water to domestic wells. The focus of this study was to identify and describe the principal natural and human factors that affect ground-water quality. In addition, the potential effects of individual sewage disposal system (ISDS) effluent on ground-water quality were evaluated. Ground-water samples were collected from domestic water-supply wells from July 2001 through October 2004 in the alluvial, crystalline-rock, sedimentary-rock, and volcanic-rock aquifers to assess general ground-water quality and effects of ISDS's on ground-water quality throughout Park County. Samples were analyzed for physical properties, major ions, nutrients, bacteria, and boron; and selected samples also were analyzed for dissolved organic carbon, human-related (wastewater) compounds, trace elements, radionuclides, and age-dating constituents (tritium and chlorofluorocarbons). Drinking-water quality is adequate for domestic use throughout Park County with a few exceptions. Only about 3 percent of wells had concentrations of fluoride, nitrate, and (or) uranium that exceeded U.S. Environmental Protection Agency national, primary drinking-water standards. These primary drinking-water standards were exceeded only in wells completed in the crystalline-rock aquifers in eastern Park County. Escherichia coli bacteria were detected in one well near Guffey, and total coliform bacteria were detected in about 11 percent of wells sampled throughout the county. The highest total coliform concentrations were measured southeast of the city of Jefferson and west of Tarryall Reservoir. Secondary drinking-water standards were exceeded more frequently. About 19 percent of wells had concentrations of one or more constituents (pH, chloride, fluoride, sulfate, and dissolved solids) that exceeded secondary drinking-water standards

Ground-water provinces of Brazil

USGS Publications Warehouse

Schneider, Robert

1962-01-01

As part of a study of the status of investigations and development of ground water in Brazil, made under the auspices of the United States International Cooperation Administration and with the cooperation of the Government of Brazil, the country was divided into seven ground-water provinces. The identification and delineation of the provinces were based on the regional distribution of the dominant geologic units which are known or inferred to have distinctive water-bearing characteristics. Three of the provinces, covering most of the country, are underlain by Precambrian crystalline rocks. Three others coincide in part with four extensive sedimentary basins--the Parnaiba or Maranhfio basin and the contiguous Sao Francisco basin in the northeast and east, the Amazon basin in the north and northwest, and the Paranfi basin in the south and southwest. In addition, the narrow, discontinuous coastal plain is considered as a province. the occurrence of ground water is discussed briefly, and pertinent data are given on the more important aquifers, together with information on some existing wells. Because of the widespread distribution of crystalline rocks of low permeability, it is difficult in many areas to develop large or even adequate ground-water supplies. In general, satisfactory supplies of water are available in most of the rest of the country. Some problems include the relative deficiency of rainfall in the northeast together with the occurrence, in parts of this region, of mineralized water in the crystalline rocks. Also, there is a potential problem of excessive lowering of water levels and interference among wells in the intensively developed area of the city of Sao Paulo.

Groundwater contamination by polycyclic aromatic hydrocarbon due to diesel spill from a telecom base station in a Nigerian City: assessment of human health risk exposure.

PubMed

Ugochukwu, Uzochukwu Cornelius; Ochonogor, Alfred

2018-03-26

Diesel pollution of groundwater poses great threat to public health, mainly as a result of the constituent polycyclic aromatic hydrocarbons (PAHs). In this study, the human health risk exposure to polycyclic aromatic hydrocarbons (PAHs) in diesel contaminated groundwater used by several families at Ring Road, Jos, Nigeria (as caused by diesel spill from a telecom base station) was assessed. Prior to the groundwater being treated, the residents were using the water after scooping off the visible diesel sheen for purposes of cooking, washing, and bathing. Until this study, it is not clear whether the groundwater contamination had resulted in sub-chronic exposure of the residents using the water to polycyclic aromatic hydrocarbons (PAHs) to the extent of the PAHs posing a health risk. The diesel contaminated groundwater and uncontaminated nearby groundwater (control) were collected and analyzed for PAHs using gas chromatography-mass spectrometry (GC-MS). The dosage of the dermal and oral ingestion entry routes of PAHs was determined. The estimation of the non-carcinogenic health risk was via hazard quotients (HQ) and the associated hazard index (HI), while the estimation of the carcinogenic health risk was via lifetime cancer risks (LCR) and the associated risk index (RI). Obtained results indicate that the exposure of the residents to the PAHs may have made them susceptible to the risk of non-carcinogenic health effects of benzo(a)pyrene and the carcinogenic health effects of benzo(a)anthracene and benzo(a)pyrene.

The Role of Trans Tensional Structures and Lake Mead Reservoir in Groundwater Flow in Black Canyon, Lake Mead National Recreation Area, NV-AZ

NASA Astrophysics Data System (ADS)

Justet, L.; Beard, S.

2010-12-01

Hot springs and seeps discharging into Black Canyon (BC) along the Colorado River in north Colorado River Valley (CRV) support endemic riparian ecosystems in the Lake Mead National Recreation Area. Increases in groundwater development in southern NV and northwestern AZ may impact spring discharge. Sources of spring discharge in BC were evaluated using geochemical methods. Kinematic analysis and geologic mapping of structures associated with BC springs were used to evaluate structural controls on groundwater flow in BC. Geochemical analysis indicates groundwater discharge near Hoover Dam (HD) and along the faulted edge of the Boulder City Pluton is derived from Lake Mead, high δ87Sr Proterozoic or Tertiary crystalline rock and, possibly, Tertiary sedimentary rock. Reducing conditions indicated by 234U/238U and δ34S concentrations suggest the groundwater is confined and/or derived from greater depths while carbon isotopes indicate the groundwater is old. Lighter δD and δO-18, modern tritium concentrations, post-Dam U disequilibrium ages, and occurrence of anthropogenic perchlorate support the presence of a young Lake Mead component. South of the pluton, the Lake Mead component is absent. More oxidizing conditions in this part of BC, indicated by the U and S isotope concentrations, suggest the groundwater is less confined and/or derived from shallower depths compared to groundwater discharging near HD. Older apparent groundwater ages and heavier δD and δO-18 values south of the pluton indicate slower flow paths from a lower elevation or latitude source. Clarifying the nature of groundwater flow in eastern NV, the analyses indicate that hydraulic connection between the regional carbonate aquifer and BC is unlikely. Instead, the data indicate sources of BC springs are derived relatively locally in CRV and, possibly, south Lake Mead Valley. Results of the geologic and kinematic analyses indicate faults that formed from the interaction of E-W extension related to

Groundwater inventory and monitoring technical guide: Remote sensing of groundwater

USDA-ARS?s Scientific Manuscript database

The application of remotely sensed data in conjunction with in situ data greatly enhances the ability of the USDA Forest Service to meet the demands of field staff, customers, and others for groundwater information. Generally, the use of remotely sensed data to inventory and monitor groundwater reso...

Subsurface urban heat islands in German cities.

PubMed

Menberg, Kathrin; Bayer, Peter; Zosseder, Kai; Rumohr, Sven; Blum, Philipp

2013-01-01

Little is known about the intensity and extension of subsurface urban heat islands (UHI), and the individual role of the driving factors has not been revealed either. In this study, we compare groundwater temperatures in shallow aquifers beneath six German cities of different size (Berlin, Munich, Cologne, Frankfurt, Karlsruhe and Darmstadt). It is revealed that hotspots of up to +20K often exist, which stem from very local heat sources, such as insufficiently insulated power plants, landfills or open geothermal systems. When visualizing the regional conditions in isotherm maps, mostly a concentric picture is found with the highest temperatures in the city centers. This reflects the long-term accumulation of thermal energy over several centuries and the interplay of various factors, particularly in heat loss from basements, elevated ground surface temperatures (GST) and subsurface infrastructure. As a primary indicator to quantify and compare large-scale UHI intensity the 10-90%-quantile range UHII(10-90) of the temperature distribution is introduced. The latter reveals, in comparison to annual atmospheric UHI intensities, an even more pronounced heating of the shallow subsurface. Copyright © 2012 Elsevier B.V. All rights reserved.

Beach groundwater dynamics

NASA Astrophysics Data System (ADS)

Horn, Diane P.

2002-11-01

An understanding of the interaction between surface and groundwater flows in the swash zone is necessary to understand beach profile evolution. Coastal researchers have recognized the importance of beach watertable and swash interaction to accretion and erosion above the still water level (SWL), but the exact nature of the relationship between swash flows, beach watertable flow and cross-shore sediment transport is not fully understood. This paper reviews research on beach groundwater dynamics and identifies research questions which will need to be answered before swash zone sediment transport can be successfully modelled. After defining the principal terms relating to beach groundwater, the behavior, measurement and modelling of beach groundwater dynamics is described. Research questions related to the mechanisms of surface-subsurface flow interaction are reviewed, particularly infiltration, exfiltration and fluidisation. The implications of these mechanisms for sediment transport are discussed.

Status of Ground-Water Levels and Storage Volume in the Equus Beds Aquifer Near Wichita, Kansas, January 2003-January 2006

USGS Publications Warehouse

Hansen, Cristi V.

2007-01-01

The Equus Beds aquifer northwest of Wichita, Kansas, was developed to supply water to Wichita residents and for irrigation in south-central Kansas. Ground-water pumping for city and agricultural use from the aquifer caused water levels to decline in a large part of the aquifer northwest of Wichita. Irrigation pumpage in the area increased substantially during the 1970s and 1980s and accelerated water-level declines. A period of water-level rises associated with greater-than-average precipitation and decreased city pumpage from the area began in 1993. An important factor in the decreased city pumpage was increased use of Cheney Reservoir as a water-supply source by the city of Wichita; as a result, city pumpage from the Equus Beds aquifer during 1993-2005 decreased to quantities similar to those pumped in the 1940s and went from being about 60 percent to about 40 percent of Wichita's water usage. Since 1995, the city also has been investigating the use of artificial recharge in the study area to meet future water-supply needs and to protect the aquifer from the intrusion of saltwater from sources to the west. During January 2006, the direction of ground-water flow in the Equus Beds aquifer in the area was generally from west to east, similar to the direction prior to development of the aquifer. Water-level changes since 1940 for the period January 2003-January 2006 ranged from a decline of more than 36 feet to a rise of more than 2 feet. Almost all wells in the area had small cumulative water-level rises from January 2003 to January 2006 and larger rises from October 1992 (period of maximum storage loss) to January 2006. The water-level rises from October 1992 to January 2006 probably are due principally to decreases in city pumpage, with increases in recharge due to increased precipitation during the period also a contributing factor. Irrigation pumpage increased during the period, so irrigation did not contribute to the rises in water levels between the beginning

Depth and Well Type Related to Groundwater Microbiological Contamination

PubMed Central

Maran, Nayara Halimy; Crispim, Bruno do Amaral; Iahnn, Stephanie Ramirez; de Araújo, Renata Pires; Grisolia, Alexeia Barufatti; de Oliveira, Kelly Mari Pires

2016-01-01

Use of groundwater from private wells in households has increased considerably, owing to a better cost/benefit ratio than that of water provided by local utilities for a fee. However, this water is usually untreated, which makes it a vehicle for diseases. Thus, monitoring this water is necessary to ensure its integrity and quality. We aimed to evaluate the physical, chemical, and microbiological parameters of untreated groundwater drawn from different types of wells, and the antimicrobial susceptibility profile of the bacteria isolated from this water. Wellwater samples were collected in two Brazilian cities. Although physical and chemical parameters of the water were suitable for drinking, Escherichia coli was detected in 33% of the samples. E. coli contaminated 65% of dug wells and 10.25% of drilled wells. Many bacteria isolated were resistant to multiple antibacterial agents, including β-lactams. Microbial contamination of this water was related to the well depth, and was more common in dug wells, making this water unfit for human consumption. Consumption of such contaminated and untreated water is a public health concern. Thus, individuals who regularly use such water must be alerted so they may either take preventive measures or connect to the water distribution system operated by local utilities. PMID:27775681

Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

NASA Astrophysics Data System (ADS)

Back, W.; Lesser, J. M.

1981-05-01

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

Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

USGS Publications Warehouse

Back, W.; Lesser, J.M.

1981-01-01

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

Groundwater-quality data and regional trends in the Virginia Coastal Plain, 1906-2007

USGS Publications Warehouse

McFarland, Randolph E.

2010-01-01

as a result of broad contrasts between sediment permeabilities. Paths of differential flushing are also focused along the inverted zones, which follow stratigraphic and structural trends southeastward into North Carolina and northeastward beneath the chloride mound across the outer impact crater. Brine within the inner impact crater has probably remained unflushed. Regional movement of the saltwater-transition zone takes place over geologic time scales. Localized movement has been induced by groundwater withdrawal, mostly along shallow parts of the saltwater-transition zone. Short-term episodic withdrawals result in repeated cycles of upconing and downconing of saltwater, which are superimposed on longer-term lateral saltwater intrusion. Effective monitoring for saltwater intrusion needs to address multiple and complexly distributed areas of potential intrusion that vary over time. A broad belt of large groundwater fluoride concentrations underlies the city of Suffolk, and thins and tapers northward. Fluoride in groundwater probably originates by desorbtion from phosphatic sedimentary material. The high fluoride belt possibly was formed by initial adsorbtion of fluoride onto sediment oxyhydroxides, followed by desorbtion along the leading edge of the advancing saltwater-transition zone. Large groundwater iron and manganese concentrations are most common to the west along the Fall Zone, across part of the saltwater-transition zone and eastward, and within shallow groundwater far to the east. Iron and manganese initially produced by mineral dissolution along the Fall Zone are adsorbed eastward and with depth by clay and glauconite, and subsequently desorbed along the leading edge of the advancing saltwater-transition zone. Iron and manganese in shallow groundwater far to the east are produced by reaction of sediment organic matter with oxyhydroxides. Large groundwater nitrate and ammonium concentrations are mostly limited to shallow depths. Most nitrate a

Groundwater environmental tracer data collected from the Chicot, Evangeline, and Jasper aquifers in Montgomery County and adjacent counties, Texas, 2008

USGS Publications Warehouse

Oden, Timothy D.

2011-01-01

The Gulf Coast aquifer system is the primary water supply for Montgomery County in southeastern Texas, including part of the Houston metropolitan area and the cities of Magnolia, Conroe, and The Woodlands Township, Texas. The U.S. Geological Survey, in cooperation with the Lone Star Groundwater Conservation District, collected environmental tracer data in the Gulf Coast aquifer system, primarily in Montgomery County. Forty existing groundwater wells screened in the Gulf Coast aquifer system were selected for sampling in Montgomery County (38 wells), Waller County (1 well), and Walker County (1 well). Groundwater-quality samples, physicochemical properties, and water-level data were collected once from each of the 40 wells during March-September 2008. Groundwater-quality samples were analyzed for dissolved gases and the environmental tracers sulfur hexafluoride, chlorofluorocarbons, tritium, helium-4, and helium-3/tritium. Water samples were collected and processed onsite using methods designed to minimize changes to the water-sample chemistry or contamination from the atmosphere. Replicate samples for quality assurance and quality control were collected with each environmental sample. Well-construction information and environmental tracer data for March-September 2008 are presented.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Students' understanding of a groundwater system and attitudes towards groundwater use and conservation

NASA Astrophysics Data System (ADS)

Pan, Yi-Ting; Liu, Shu-Chiu

2018-03-01

The purpose of this study was to investigate students' understanding of groundwater as a system, and to further examine whether and how their understanding is related to attitudes towards groundwater use and conservation. A total of 676 junior high school students completed a groundwater survey including a drawing activity and a questionnaire. An additional group of university students with environmental science majors were recruited for the survey for the purpose of determining reasonable expectations and validating interpretations of the results. Analysis of student drawings indicated that students generally held an incomplete and unconnected understanding of the groundwater system. Correlation analysis showed that student levels of understanding were associated with their perceptions of environmental impacts as well as environmental concern regarding groundwater problems. These findings re-emphasised the importance of promoting students' understanding of environmental systems, as well as their ability to think systemically.

The Use of Hydrograph Analysis and Impulse Response Functions to Improve Understanding of Groundwater Flooding: A Case Study from the Chalk Aquifer, United Kingdom.

NASA Astrophysics Data System (ADS)

Ascott, M.; Bloomfield, J.; Macdonald, D.; Marchant, B.; McKenzie, A.

2017-12-01

The Cretaceous Chalk, the most important aquifer in the United Kingdom (UK) for public water supply, underlies many large cities in southern and eastern England including parts of London, however, it is prone to groundwater flooding. We have developed a new approach to analyse the spatio-temporal extent of groundwater flooding using statistical analysis of groundwater level hydrographs and impulse response functions (IRFs) applied to a major Chalk groundwater flooding event in the UK during winter 2013/14. Using monthly groundwater levels for 26 boreholes in the Chalk and a new standardised index for groundwater flooding, we have: estimated standardised series; grouped them using k-means cluster analysis; and, cross-correlated the cluster centroids with the Standardised Precipitation Index accumulated over time intervals between 1 and 60 months. This analysis reveals two spatially coherent groups of standardised hydrographs which respond to precipitation over different timescales. We estimate IRF models of the groundwater level response to effective precipitation for three boreholes in each group. The IRF models support the SPI analysis showing different response functions between the two groups. If we apply identical effective precipitation inputs to each of the IRF models we see differences between the hydrographs from each group. It is proposed that these differences are due to the intrinsic, hydrogeological properties of the Chalk and of overlying relatively low permeability superficial deposits. Consequently, it is concluded that the overarching controls on groundwater flood response are a complex combination of antecedent conditions, rainfall and catchment hydrogeological properties. These controls should be taken into consideration when anticipating and managing future groundwater flood events.

Hydrogeologic Investigation, Water Chemistry Analysis, and Model Delineation of contributing Areas for City of Tallahassee Public-Supply Wells, Tallahassee, Florida

USGS Publications Warehouse

Davis, J. Hal; Katz, Brian G.

2007-01-01

Ground water from the Upper Floridan aquifer is the sole source of water supply for Tallahassee, Florida, and the surrounding area. The City of Tallahassee (the City) currently operates 28 water-supply wells; 26 wells are distributed throughout the City and 2 are located in Woodville, Florida. Most of these wells yield an ample supply of potable water; however, water from several wells has low levels of tetrachloroethylene (PCE). The City removes the PCE from the water by passing it through granular-activated carbon units before distribution. To ensure that water-supply wells presently free of contamination remain clean, it is necessary to understand the ground-water flow system in sufficient detail to protect the contributing areas. Ground-water samples collected from four public-supply wells were analyzed for tritium (3H), chlorofluorocarbons (CFCs), and sulfur hexafluoride (SF6). Using data for the CFC compounds, apparent ground-water ages ranged from 7 to 31 years. For SF6, the apparent ages tended to be about 5 to 10 years younger than those from CFCs. Apparent ages based on the tritium/tritiogenic helium-3 (3H/3Hetrit) method ranged from 26 to 33 years. The three dating methods indicate that the apparent age of ground water generally decreases from northern to southern Leon County. This southward trend of decreasing ages is consistent with increasing amounts of recharge that occur as ground water moves from north to south. The ground-water age data derived by geochemical and tracer analyses were used in combination with the flow model and particle tracking to determine an effective porosity for the Hawthorn clays and Upper Floridan aquifer. The effective porosities for the Upper Floridan aquifer that resulted in best model matches were averaged to produce an effective porosity of 7 percent, and the effective porosities for the Hawthorn clays that resulted in a match were averaged to produce an effective porosity of 22 percent. Probabilistic contributing areas

Integrated groundwater data management

USGS Publications Warehouse

Fitch, Peter; Brodaric, Boyan; Stenson, Matt; Booth, Nathaniel; Jakeman, Anthony J.; Barreteau, Olivier; Hunt, Randall J.; Rinaudo, Jean-Daniel; Ross, Andrew

2016-01-01

The goal of a data manager is to ensure that data is safely stored, adequately described, discoverable and easily accessible. However, to keep pace with the evolution of groundwater studies in the last decade, the associated data and data management requirements have changed significantly. In particular, there is a growing recognition that management questions cannot be adequately answered by single discipline studies. This has led a push towards the paradigm of integrated modeling, where diverse parts of the hydrological cycle and its human connections are included. This chapter describes groundwater data management practices, and reviews the current state of the art with enterprise groundwater database management systems. It also includes discussion on commonly used data management models, detailing typical data management lifecycles. We discuss the growing use of web services and open standards such as GWML and WaterML2.0 to exchange groundwater information and knowledge, and the need for national data networks. We also discuss cross-jurisdictional interoperability issues, based on our experience sharing groundwater data across the US/Canadian border. Lastly, we present some future trends relating to groundwater data management.

Radium isotopes in groundwater around Fuji Volcano, Japan -application for groundwater dating on volcanic area-

NASA Astrophysics Data System (ADS)

Ohta, T.; Mahara, Y.

2010-12-01

Young groundwater dating less than 100 years is possible to be obtained from environmental radioactivity with short half life, 3H+3He, 85Kr, or chemical material, CFC-12. The 3H+3He dating method is excellent method to estimate the residence time of shallow groundwater. The one of advantage of the method is small sample volume. The 3He in groundwater is originated by 3 sources, tritiogenic He, mantle He, radiogenic He produced in rock. Especially, as the contribution of the mantle He is greater than the radiogenic and triogenic, when 3H+3He dating apply for groundwater dating on volcanic area, we have to determine ratio of 3 sources. On the other hand, as 85Kr is only originated from atmosphere, it is excellent groundwater dating tracer on volcanic area. However, as 85Kr is ultra low concentration in groundwater, 85Kr is needed to separate from large amount of ground water about 10^5 L. Young groundwater dating by these methods has both advantages and disadvantages, but the disadvantages of the individual methods can be offset by using multiple tracers. Development of a lot of groundwater dating techniques is desired. Therefore, an application of radium isotopes which is simple origin to groundwater dating on volcanic area was tried. Ra-228 and Ra-226 are progenies of Th and U, respectively. The 228Ra/226Ra in ground waters depends on the Th/U in the relevant rocks. As the 228Ra and 226Ra in shallow groundwater on volcanic area are originated from only rock, and the collection of radium isotopes from groundwater is easier than that of 85Kr, implying that it is possible to be good tracer for volcanic area. We aim that groundwater age obtain from 228Ra/226Ra in groundwater and relevant rock on volcanic area. We determined that 228Ra/226Ra observed with river waters and the relevant rocks. The method applied for Kakitagawa around Fuji Volcano, Japan. The relevant rock of Kakitagawa is Mishima lava flow. Our method compared with 3H+3He dating. The residence time of

Using hydrochemical data and modelling to enhance the knowledge of groundwater flow and quality in an alluvial aquifer of Zagreb, Croatia.

PubMed

Marković, Tamara; Brkić, Željka; Larva, Ozren

2013-08-01

The Zagreb alluvial aquifer system is located in the southwest of the Pannonian Basin in the Sava Valley in Croatia. It is composed of Quaternary unconsolidated deposits and is highly utilised, primarily as a water supply for the more than one million inhabitants of the capital city of Croatia. To determine the origin and dynamics of the groundwater and to enhance the knowledge of groundwater flow and the interactions between the groundwater and surface water, extensive hydrogeological and hydrochemical investigations have been completed. The groundwater levels monitored in nested observation wells and the lithological profile indicate that the aquifer is a single hydrogeologic unit, but the geochemical characteristics of the aquifer indicate stratification. The weathering of carbonate and silicate minerals has an important role in groundwater chemistry, especially in the area where old meanders of the Sava River existed. Groundwater quality was observed to be better in the deeper parts of the aquifer than in the shallower parts. Furthermore, deterioration of the groundwater quality was observed in the area under the influence of the landfill. The stable isotopic composition of all sampled waters indicates meteoric origin. NETPATH-WIN was used to calculate the mixing proportions between initial waters (water from the Sava River and groundwater from "regional" flow) in the final water (groundwater sampled from observation wells). According to the results, the mixing proportions of "regional" flow and the river water depend on hydrological conditions, the duration of certain hydrological conditions and the vicinity of the Sava River. Moreover, although the aquifer system behaves as a single hydrogeologic unit from a hydraulic point of view, it still clearly demonstrates geochemical stratification, which could be a decisive factor in future utilisation strategies for the aquifer system. Copyright © 2013 Elsevier B.V. All rights reserved.

Arkansas Groundwater-Quality Network

USGS Publications Warehouse

Pugh, Aaron L.; Jackson, Barry T.; Miller, Roger

2014-01-01

Arkansas is the fourth largest user of groundwater in the United States, where groundwater accounts for two-thirds of the total water use. Groundwater use in the State increased by 510 percent between 1965 and 2005 (Holland, 2007). The Arkansas Groundwater-Quality Network is a Web map interface (http://ar.water.usgs.gov/wqx) that provides rapid access to the U.S. Geological Survey’s (USGS) National Water Information System (NWIS) and the U.S. Environmental Protection Agency’s (USEPA) STOrage and RETrieval (STORET) databases of ambient water information. The interface enables users to perform simple graphical analysis and download selected water-quality data.

Groundwater Pollution and Vulnerability Assessment.

PubMed

Kurwadkar, Sudarshan

2017-10-01

Groundwater is a critical resource that serve as a source of drinking water to large human population and, provide long-term water for irrigation purposes. In recent years; however, this precious resource being increasingly threatened, due to natural and anthropogenic activities. A variety of contaminants of emerging concern such as pharmaceuticals and personal care products, perfluorinated compounds, endocrine disruptors, and biological agents detected in the groundwater sources of both developing and developed nations. In this review paper, various studies have been included that documented instances of groundwater pollution and vulnerability to emerging contaminants of concern, pesticides, heavy metals, and leaching potential of various organic and inorganic contaminants from poorly managed residual waste products (biosolids, landfills, latrines, and septic tanks etc.). Understanding vulnerability of groundwater to pollution is critical to maintain the integrity of groundwater. A section on managed artificial recharge studies is included to highlight the sustainable approaches to groundwater conservation, replenishment and sustainability. This review paper is the synthesis of studies published in last one year that either documented the pollution problems or evaluated the vulnerability of groundwater pollution.

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

PubMed

Yihdego, Yohannes; Danis, Cara; Paffard, Andrew

2017-12-01

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

Emerging contaminants in urban groundwater sources in Africa.

PubMed

Sorensen, J P R; Lapworth, D J; Nkhuwa, D C W; Stuart, M E; Gooddy, D C; Bell, R A; Chirwa, M; Kabika, J; Liemisa, M; Chibesa, M; Pedley, S

2015-04-01

The occurrence of emerging organic contaminants within the aquatic environment in Africa is currently unknown. This study provides early insights by characterising a broad range of emerging organic contaminants (n > 1000) in groundwater sources in Kabwe, Zambia. Groundwater samples were obtained during both the dry and wet seasons from a selection of deep boreholes and shallow wells completed within the bedrock and overlying superficial aquifers, respectively. Groundwater sources were distributed across the city to encompass peri-urban, lower cost housing, higher cost housing, and industrial land uses. The insect repellent DEET was ubiquitous within groundwater at concentrations up to 1.8 μg/L. Other compounds (n = 26) were detected in less than 15% of the sources and included the bactericide triclosan (up to 0.03 μg/L), chlorination by-products - trihalomethanes (up to 50 μg/L), and the surfactant 2,4,7,9-tetramethyl-5-decyne-4,7-diol (up to 0.6 μg/L). Emerging contaminants were most prevalent in shallow wells sited in low cost housing areas. This is attributed to localised vulnerability associated with inadequate well protection, sanitation, and household waste disposal. The five-fold increase in median DEET concentration following the onset of the seasonal rains highlights that more mobile compounds can rapidly migrate from the surface to the aquifer suggesting the aquifer is more vulnerable than previously considered. Furthermore it suggests DEET is potentially useful as a wastewater tracer in Africa. There was a general absence of personal care products, life-style compounds, and pharmaceuticals which are commonly detected in the aquatic environment in the developed world. This perhaps reflects some degree of attenuation within the subsurface, but could also be a result of the current limited use of products containing emerging contaminants by locals due to unaffordability and unavailability. As development and population increases in Africa, it is

Water-balance and groundwater-flow estimation for an arid environment: San Diego region, California

NASA Astrophysics Data System (ADS)

Flint, L. E.; Flint, A. L.; Stolp, B. J.; Danskin, W. R.

2012-03-01

The coastal-plain aquifer that underlies the San Diego City metropolitan area in southern California is a groundwater resource. The understanding of the region-wide water balance and the recharge of water from the high elevation mountains to the east needs to be improved to quantify the subsurface inflows to the coastal plain in order to develop the groundwater as a long term resource. This study is intended to enhance the conceptual understanding of the water balance and related recharge processes in this arid environment by developing a regional model of the San Diego region and all watersheds adjacent or draining to the coastal plain, including the Tijuana River basin. This model was used to quantify the various components of the water balance, including semi-quantitative estimates of subsurface groundwater flow to the coastal plain. Other approaches relying on independent data were used to test or constrain the scoping estimates of recharge and runoff, including a reconnaissance-level groundwater model of the San Diego River basin, one of three main rivers draining to the coastal plain. Estimates of subsurface flow delivered to the coastal plain from the river basins ranged from 12.3 to 28.8 million m3 yr-1 from the San Diego River basin for the calibration period (1982-2009) to 48.8 million m3 yr-1 from all major river basins for the entire coastal plain for the long-term period 1940-2009. This range of scoping estimates represents the impact of climatic variability and realistically bounds the likely groundwater availability, while falling well within the variable estimates of regional recharge. However, the scarcity of physical and hydrologic data in this region hinders the exercise to narrow the range and reduce the uncertainty.

Geohydrology and simulated ground-water flow in northwestern Elkhart County, Indiana

USGS Publications Warehouse

Arihood, L.D.; Cohen, D.A.

1998-01-01

In 1994, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency and the City of Elkhart, developed a ground-water model of the Elkhart, Indiana, area to determine the avail-ability and source of water at potential new well fields. The modeled area covered 190 square miles of northwestern Elkhart County and a small part of southern Michigan. Three Superfund sites and several other sites in this area are undergoing environmental cleanup. The model would be used to guide the location of well fields so that Superfund sites and environmental cleanup areas would not be within recharge areas for the well fields. The City of Elkhart obtains its water supply from two aquifers separated by a generally continuous confining unit. The upper aquifer is composed primarily of sand and gravel of glacial origin. Thickness of the upper aquifer ranges from 0 to 116 feet and averages 47 feet. The lower aquifer is composed of sand and gravel with interbedded lenses of silt and clay. Thickness of the lower aquifer ranges from 1 to 335 feet and averages 35 feet. The intervening confining unit is composed of silt and clay with interbedded sand and gravel; the confining unit ranges from 0 to 177 feet, with an average thickness of 27 feet. Flow through the aquifers is generally horizontal vertically downward from the upper aquifer, through the confining unit, and into the lower aquifer, except where flow is vertically upward at the St. Joseph River and other large streams. The hydraulic characteristics of the aquifers and confining unit were estimated by analyzing aquifer-test data from well drillers? logs and by calibration of the model. The horizontal hydraulic conductivity of the upper aquifer is 170 feet per day within about 1 mile of the St. Joseph and Elkhart Rivers and 370 feet per day at distances greater than about 1 mile. The horizontal hydraulic conductivity of the lower aquifer is 370 feet per day throughout the modeled area, with the exception

Estimating the Change of Groundwater Salinization in the Central North China Plain for Sustainable Groundwater Utilization

NASA Astrophysics Data System (ADS)

Zhan, Y.; He, X.; Zheng, C.; Guo, Z.

2017-12-01

Due to the growing demand of food supplies and limited freshwater resources, North China Plain (NCP) is highly dependent on the groundwater resources. Groundwater overdraft has made NCP a closed hydrologic basin, where the connection between surface and groundwater has been cut off, which can lead to salt accumulation in the groundwater system. Thus it is imperative to investigate the overall salt balance in the region for sustainable utilization of groundwater resources, as well as to better understand the salt accumulating processes caused by groundwater pumping and return flow. The central plain of NCP (excluding the piedmont plain and coastal plain) is selected in the present study, where the groundwater salt content is mainly controlled by precipitation, irrigation, groundwater pumping and rock-water interaction in vertical direction; therefore, a conceptual 1-D mixing model is developed for salt balance calculation, where the salt content is expressed by the concentration of Total Dissolved Solid (TDS) in groundwater. Geological structures and regional water balance data are obtained from numerical groundwater models previously developed in the area. The simulation starts in year 1900 with a 50-year time step and groundwater vertical flow velocity starting with 2 m/y. TDS concentration is then calculated through salt input and output in each layer, with consideration of soil salt accumulation, change of precipitation, rock-water interaction etc. The results suggest that in a closed hydrologic basin, groundwater pumping and return flow will gradually increase salt content in the groundwater body from upper layers to lower layers resulting from the flushing of salt accumulated in the top soil layer. After two time steps, the model is able to reproduce the observed TDS concentration in present time with reasonable accuracy; and after six time steps, which correspond to 300 years, the whole central plain of NCP will be under the influence of high salinity, which

Groundwater and organic chemicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawson, H.E.

1995-12-01

Groundwater is a major source of drinking water for many communities. Unfortunately, organic chemicals such as dry cleaning fluids, solvent, fuels, and pesticides have contaminated groundwater in many areas, rendering the groundwater useless as a drinking water resource. In many cases, the groundwater cannot be cleaned up with current technologies, particularly if the groundwater has been contaminated with immiscible (low solubility) organic liquids. In this talk, I will describe the path I have followed from geologist to geochemist and finally to environmental engineer. As a geologist, I studied the chemistry of rock metamorphosis. As a geochemist, I explored for goldmore » and other metals. Now as an environmental engineer, I investigate the behavior of organic liquids in the subsurface. While these fields all appear very different, in reality I have always focused on the interaction of rocks or sediments with the fluids with which they come in contact.« less

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

NASA Astrophysics Data System (ADS)

Glennon, R.

2002-12-01

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

Quantifying renewable groundwater stress with GRACE

NASA Astrophysics Data System (ADS)

Richey, Alexandra S.; Thomas, Brian F.; Lo, Min-Hui; Reager, John T.; Famiglietti, James S.; Voss, Katalyn; Swenson, Sean; Rodell, Matthew

2015-07-01

Groundwater is an increasingly important water supply source globally. Understanding the amount of groundwater used versus the volume available is crucial to evaluate future water availability. We present a groundwater stress assessment to quantify the relationship between groundwater use and availability in the world's 37 largest aquifer systems. We quantify stress according to a ratio of groundwater use to availability, which we call the Renewable Groundwater Stress ratio. The impact of quantifying groundwater use based on nationally reported groundwater withdrawal statistics is compared to a novel approach to quantify use based on remote sensing observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. Four characteristic stress regimes are defined: Overstressed, Variable Stress, Human-dominated Stress, and Unstressed. The regimes are a function of the sign of use (positive or negative) and the sign of groundwater availability, defined as mean annual recharge. The ability to mitigate and adapt to stressed conditions, where use exceeds sustainable water availability, is a function of economic capacity and land use patterns. Therefore, we qualitatively explore the relationship between stress and anthropogenic biomes. We find that estimates of groundwater stress based on withdrawal statistics are unable to capture the range of characteristic stress regimes, especially in regions dominated by sparsely populated biome types with limited cropland. GRACE-based estimates of use and stress can holistically quantify the impact of groundwater use on stress, resulting in both greater magnitudes of stress and more variability of stress between regions.

Quantifying renewable groundwater stress with GRACE

PubMed Central

Richey, Alexandra S.; Thomas, Brian F.; Lo, Min‐Hui; Reager, John T.; Voss, Katalyn; Swenson, Sean; Rodell, Matthew

2015-01-01

Abstract Groundwater is an increasingly important water supply source globally. Understanding the amount of groundwater used versus the volume available is crucial to evaluate future water availability. We present a groundwater stress assessment to quantify the relationship between groundwater use and availability in the world's 37 largest aquifer systems. We quantify stress according to a ratio of groundwater use to availability, which we call the Renewable Groundwater Stress ratio. The impact of quantifying groundwater use based on nationally reported groundwater withdrawal statistics is compared to a novel approach to quantify use based on remote sensing observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. Four characteristic stress regimes are defined: Overstressed, Variable Stress, Human‐dominated Stress, and Unstressed. The regimes are a function of the sign of use (positive or negative) and the sign of groundwater availability, defined as mean annual recharge. The ability to mitigate and adapt to stressed conditions, where use exceeds sustainable water availability, is a function of economic capacity and land use patterns. Therefore, we qualitatively explore the relationship between stress and anthropogenic biomes. We find that estimates of groundwater stress based on withdrawal statistics are unable to capture the range of characteristic stress regimes, especially in regions dominated by sparsely populated biome types with limited cropland. GRACE‐based estimates of use and stress can holistically quantify the impact of groundwater use on stress, resulting in both greater magnitudes of stress and more variability of stress between regions. PMID:26900185

Students' Understanding of a Groundwater System and Attitudes towards Groundwater Use and Conservation

ERIC Educational Resources Information Center

Pan, Yi-Ting; Liu, Shu-Chiu

2018-01-01

The purpose of this study was to investigate students' understanding of groundwater as a system, and to further examine whether and how their understanding is related to attitudes towards groundwater use and conservation. A total of 676 junior high school students completed a groundwater survey including a drawing activity and a questionnaire. An…

Global scale groundwater flow model

NASA Astrophysics Data System (ADS)

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

2013-04-01

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

Anthropogenic Influence On Groundwater Quality In Jericho and And Adjoining Wadis (Lower Jordan Valley, Palestine)

NASA Astrophysics Data System (ADS)

Geyer, S.; Khayat, S.; Roediger, T.; Siebert, C.

2008-12-01

The Lower Jordan Valley is part of the Jordan-Dead Sea Rift. The graben is filled by sedmiments of limnological and marine origin. Towards the Dead Sea, the occurance of gipseous and salty sediments on the valley floor increase. The southern part of the Lower Jordan Valley, where the city of Jericho is situated, is an arid area (<150 mm precipitation/year), with less amount of exploitable fresh groundwater or surface water. Jericho was founded on an alluvial fan, closely to the western mountain range in front of mouth of Wadi Qilt. The fan serves as reservoir for infiltrating water from wadi runoff and groundwater from the crataceous aquifers of the western shoulder. The fan is surrounded by unsuitable aquifers of the graben, which are filled with saline water. The aim of this study, which takes place inside the multilateral SMART-project, is to understand the vulnerability of the Jericho groundwater aquifers in connection with lowering the groundwater table by overexploitation and the intensively use of pesticides Jericho and its vicinity are of most importance for the Palestinians. However, beside the about 25,000 residents, the tourism industry and the vital agriculture depend on sufficient and expoitable fresh water resources. Because the demand of water is increasing, overexpoitaion takes place. Due to over extraction of groundwater a huge depression cone is evolving during the dry season which is filled up again according to the groundwater recharge in the rainy season. Concomitantly, depression cone in the fresh water aquifers leads to an infiltration of the surrounding saltwater. The amount of saltwater which infiltrates into the freshwater resource was calculated by different stable isotope methods (d2H, d18O) and hydrochemical analyses of wellwater. The agriculture is main consumer of groundwater - over 60% of the pumped water is used for inefficient irrigation. Additionally, an intensive use of pesticides in concentrated liquid and gaseous forms for

Ground-water levels, water quality, and potential effects of toxic-substance spills or cessation of quarry dewatering near a municipal ground-water supply, southeastern Franklin County, Ohio

USGS Publications Warehouse

Sedam, A.C.; Eberts, S.M.; Bair, E.S.

1989-01-01

A newly completed municipal ground-water supply that produces from a sand and gravel aquifer in southern Franklin County, Ohio, may be susceptible to potential sources of pollution. Among these are spills of toxic substances that could enter recharge areas of the aquifer or be carried by surface drainage and subsequently enter the aquifer by induced infiltration. Ground water of degraded quality also is present in the vicinity of several landfills located upstream from the municipal supply. Local dewatering by quarrying operations has created a ground-water divide which, at present, prevents direct movement of the degraded ground water to the municipal supply. In addition, the dewatering has held water levels at the largest landfills below the base of the landfill. Should the dewatering cease, concern would be raised regarding the rise of water levels at this landfills and transport of contaminants through the aquifer to the Scioto River and subsequently by the river to the well field. From June 1984 through July 1986, the U.S. Geological Survey, in cooperation with the City of Columbus, Ohio, investigated the relations among the ground-water supply and potential sources of contamination by means of an observation-well network and a program of measuring water levels and sampling for water quality. Sample collections included those made to determine the baseline levels of organic chemicals and metals, as well as periodic sampling and analysis for common constituents to evaluate any changes taking place in the system. Finally, a steady-state, three-dimensional numerical model was used to determine ground-water flow directions and average ground-water velocities to asses potential effects of toxic-substance spills. The model also was used to simulate changes in the ground-water flow system that could result if part or all of the quarry dewatering ceased. Few of the organic-chemical and metal constituents analyzed for were present at detectable levels. With respect to

CAPSTONE REPORT ON THE APPLICATION, MONITORING, AND PERFORMANCE OF PERMEABLE REACTIVE BARRIERS FOR GROUND-WATER REMEDIATION: VOL. 2 LONG-TERM MONITORING OF PRBS: SOIL AND GROUND WATER SAMPLING

EPA Science Inventory

This report discusses soil and ground-water sampling methods and procedures used to evaluate the long-term performance of permeable reactive barriers (PRBS) at two sites, Elizabeth City, NC, and the Denver Federal Center near Lakewood, CO. Both PRBs were installed in 1996 and hav...

Assessment of major ions and trace elements in groundwater supplied to the Monterrey metropolitan area, Nuevo León, Mexico.

PubMed

Mora, Abrahan; Mahlknecht, Jürgen; Rosales-Lagarde, Laura; Hernández-Antonio, Arturo

2017-08-01

The Monterrey metropolitan area (MMA) is the third greatest urban area and the second largest economic city of Mexico. More than four million people living in this megacity use groundwater for drinking, industrial and household purposes. Thus, major ion and trace element content were assessed in order to investigate the main hydrochemical properties of groundwater and determine if groundwater of the area poses a threat to the MMA population. Hierarchical cluster analysis using all the groundwater chemical data showed five groups of water. The first two groups were classified as recharge waters (Ca-HCO 3 ) coming from the foothills of mountain belts. The third group was also of Ca-HCO 3 water type flowing through lutites and limestones. Transition zone waters of group four (Ca-HCO 3 -SO 4 ) flow through the valley of Monterrey, whereas discharge waters of group 5 (Ca-SO 4 ) were found toward the north and northeast of the MMA. Principal component analysis performed in groundwater data indicates four principal components (PCs). PC1 included major ions Si, Co, Se, and Zn, suggesting that these are derived by rock weathering. Other trace elements such as As, Mo, Mn, and U are coupled in PC2 because they show redox-sensitive properties. PC3 indicates that Pb and Cu could be the less mobile elements in groundwater. Although groundwater supplied to MMA showed a high-quality, high mineralized waters of group 5 have NO 3 - concentrations higher than the maximum value proposed by international guidelines and SO 4 2- , NO 3 - , and total dissolved solid concentrations higher than the maximum levels allowed by the Mexican normative.

Summary of water-quality data for City of Albuquerque drinking-water supply wells, 1988-97

USGS Publications Warehouse

Bexfield, Laura M.; Lindberg, William E.; Anderholm, Scott K.

1999-01-01

The City of Albuquerque has collected and analyzed more than 5,000 water-quality samples from 113 water-supply wells in the Albuquerque area, including many drinking-water supply wells, since May of 1988. As a result, a large water-quality data base has been compiled that includes data for major ions, nutrients, trace elements, carbon, volatile organic compounds, radiological constituents, and bacteria. These data are intended to improve the understanding and management of the ground-water resources of the region, rather than demonstrate compliance with Federal and State drinking-water standards. This report gives summary statistics for selected physical properties and chemical constituents for ground water from wells used by the City of Albuquerque for drinking-water supply between 1988 and 1997. Maps are provided to show the general spatial distribution of selected parameters and water types around the region. Although the values of some parameters vary substantially across the city, median values for all parameters included in this report are less than their respective maximum contaminant levels in each drinking-water supply well. The dominant water types are sodium plus potassium / carbonate plus bicarbonate in the western part of the city and calcium / carbonate plus bicarbonate in the eastern part of the city.

Wyoming groundwater-quality monitoring network

USGS Publications Warehouse

Boughton, Gregory K.

2011-01-01

A wide variety of human activities have the potential to contaminate groundwater. In addition, naturally occurring constituents can limit the suitability of groundwater for some uses. The State of Wyoming has established rules and programs to evaluate and protect groundwater quality based on identified uses. The Wyoming Groundwater-Quality Monitoring Network (WGQMN) is a cooperative program between the U.S. Geological Survey (USGS) and the Wyoming Department of Environmental Quality (WDEQ) and was implemented in 2009 to evaluate the water-quality characteristics of the State's groundwater. Representatives from USGS, WDEQ, U.S. Environmental Protection Agency (USEPA), Wyoming Water Development Office, and Wyoming State Engineer's Office formed a steering committee, which meets periodically to evaluate progress and consider modifications to strengthen program objectives. The purpose of this fact sheet is to describe the WGQMN design and objectives, field procedures, and water-quality analyses. USGS groundwater activities in the Greater Green River Basin also are described.

Defining groundwater age: Chapter 3

USGS Publications Warehouse

Torgersen, T.; Purtschert, R.; Phillips, F.M.; Plummer, Niel; Sanford, W.E.; Suckow, A.

2013-01-01

This book investigates applications of selected chemical and isotopic substances that can be used to recognize and interpret age information pertaining to ‘old’ groundwater (defined as water that was recharged on a timescale from approximately 1000 to more than 1 000 000 a). However, as discussed below, only estimates of the ‘age’ of water extracted from wells can be inferred. These groundwater age estimates are interpreted from measured concentrations of chemical and isotopic substances in the groundwater. Even then, there are many complicating factors, as discussed in this book. In spite of these limitations, much can be learned about the physics of groundwater flow and about the temporal aspects of groundwater systems from age interpretations of measured concentrations of environmental tracers in groundwater systems. This chapter puts the concept of ‘age’ into context, including its meaning and interpretation, and attempts to provide a unifying usage for the rest of the book.

Geologic map of the Stephens City quadrangle, Clark, Frederick, and Warren Counties, Virginia

USGS Publications Warehouse

Weary, D.J.; Orndorff, R.C.; Aleman-Gonzalez, W.

2006-01-01

The Stephens City 1:24,000-scale quadrangle is one of several quadrangles in Frederick County, Virginia being mapped by geologists from the U.S. Geological Survey in Reston, VA with funding from the National Cooperative Geologic Mapping Program. This work is part of a project being lead by the U.S. Geological Survey Water Resources Discipline, Virginia District, to investigate the geologic framework and groundwater resources of Frederick County as well as other areas in the northern Shenandoah Valley of Virginia and West Virginia.

Basewide Groundwater Operable Unit. Groundwater Operable Unit Remedial Investigation/Feasibility Study Report. Volume 3

DTIC Science & Technology

1994-06-01

technologies were organized into five categories: * In Situ Biological Treatment * In Situ Physical/Chemical Treatment * Ex Situ Biological Groundwater...Technology FIGURE 11-3 PRIMARY SCORING SUMMARY EX SITU BIOLOGICAL GROUNDWATER TREATMENT TECHNOLOGIES GROUNDWATER OPERABLE UNIT RIIFS McCLELLAN AIR FORCE... Biological Treatment CometabolicAnaerobic Anaerobic/Aerobic In Situ Physical/Chemical Treatment Sparging/Soil Vapor Extraction Ex Situ Biological

Groundwater: A Community Action Guide.

ERIC Educational Resources Information Center

Boyd, Susan, Ed.; And Others

Designed to be a guide for community action, this booklet examines issues and trends related to groundwater contamination. Basic concepts about groundwater and information about problems affecting it are covered under the categories of (1) what is groundwater? (2) availability and depletion; (3) quality and contamination; (4) public health…

Urban hydrology in mountainous middle eastern cities

NASA Astrophysics Data System (ADS)

Grodek, T.; Lange, J.; Lekach, J.; Husary, S.

2011-03-01

The Mediterranean climate together with the type of urban setting found in mountainous Middle Eastern cities generate much lower runoff yields than previously reported and than usually estimated for urban design. In fact, a close analysis shows that most of the rainwater remains within the cities as a possible source for urban groundwater recharge. The present study examined two locales - Ramallah, an old traditional Palestinian Arab town, and Modiin, a new township in Israel - both situated on the karstic Yarkon Taninim aquifer. This aquifer supplies the only high-quality drinking water in the region (one quarter of the Israeli-Palestinian water demand), which is characterized by dense populations and limited water resources. This paper provides the first measured information on the hydrological effects of urbanization in the area. It was found that the shift of the mountainous natural steep slopes into a series of closed-terraces with homes and gardens create areas that are disconnected from the urban runoff response. Roofs drained into the attached gardens create favorable recharge units. Mainly low-gradient roads became the principal source for urban runoff already following 1-4 mm of rainfall. Parallel roads converted single peak hydrographs towards multi-peak runoff responses, increasing flow duration and reducing peak discharges. The remaining urban area (public parks, natural areas, etc.) generated runoff only as a result of high-magnitude rainstorms. All of the above conditions limited urban runoff coefficients to an upper boundary of only 35% and 30% (Ramallah and Modiin, respectively). During extreme rainstorms (above 100 mm) similar runoff coefficients were measured in urban and natural catchments as a result of the limited areas contributing to runoff in the urban areas, while natural terrain does not have these artificial limits. Hence, the effects of urbanization decrease with event magnitude and there is significant potential for urban groundwater

Urban hydrology in mountainous middle eastern cities

NASA Astrophysics Data System (ADS)

Grodek, T.; Lange, J.; Lekach, J.; Husary, S.

2010-09-01

The Mediterranean climate together with the type of urban setting found in mountainous Middle Eastern cities generate much lower runoff yields than previously reported and than usually estimated for urban design. In fact, a close analysis shows that most of the rainwater remains within the cities as a possible source for urban groundwater recharge. The present study examined two locales - Ramallah, an old traditional Palestinian Arab town, and Modiin, a new township in Israel - both situated on the karstic Yarkon Taninim aquifer. This aquifer supplies the only high-quality drinking water in the region (one quarter of the Israeli-Palestinian water demand), which is characterized by dense populations and limited water resources. This paper provides the first measured information on the hydrological effects of urbanization in the area. It was found that the shift of the mountainous natural steep slopes into a series of closed-terraced homes and gardens created areas that are disconnected from the urban runoff response. Roofs drained into the attached gardens and created favorable recharge units. Mainly low-gradient roads became the principal source for urban runoff already following 1-4 mm of rainfall. Parallel roads converted single peak hydrographs towards multi-peak runoff responses, increasing flow duration and reducing peak discharges. The remaining urban area (public parks, natural areas, etc.) generated runoff only as a result of high-magnitude rainstorms. All of the above conditions limited urban runoff coefficients to an upper boundary of only 22% and 30% (Ramallah and Modiin, respectively). During extreme rainstorms (above 100 mm) similar runoff coefficients were measured in urban and natural catchments as a result of the limited areas contributing to runoff in the urban areas, while natural terrain does not have these artificial limits. Hence, it was found, the effects of urbanization decrease with event magnitude and there is significant potential for

Brackish groundwater in the United States

USGS Publications Warehouse

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

2017-04-05

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

Data on assessment of groundwater quality for drinking and irrigation in rural area Sarpol-e Zahab city, Kermanshah province, Iran.

PubMed

Soleimani, Hamed; Abbasnia, Abbas; Yousefi, Mahmood; Mohammadi, Ali Akbar; Khorasgani, Fazlollah Changani

2018-04-01

In present study 30 groundwater samples were collected from Sarpol-e Zahab area, Kermanshah province of Iran in order to assess the quality of groundwater in subjected area and determining its suitability for drinking and agricultural purposes. Also the variations in the quality levels of groundwater were compared over the years of 2015 and 2016. Statistical analyses including Spearman correlation coefficients and factor analysis display good correlation between physicochemical parameters (EC, TDS and TH) and Na + , Mg 2+ , Ca 2+ , Cl - and [Formula: see text] ionic constituents. Also in order to assess water quality for irrigation we used the United States Department of Agriculture (USDA) classification which is based on SAR for irrigation suitability assessment. In addition, the residual sodium carbonate (RSC), %Na, PI, KR, SSP, MH, EC characteristics were calculated for all samples and used for assessment of irrigation suitability. Based on these indicators, for every two years, the quality of water for agriculture is in good and excellent category. The Piper classification for hydro geochemical facies indicates that the water in the study area is of Ca-HCO 3 - type. However, the study of water hardness shows that more than 80% of samples are in hard and very hard water class. Therefore, there is a need for decisions to refine and soften the water.

Coupled modelling of groundwater flow-heat transport for assessing river-aquifer interactions

NASA Astrophysics Data System (ADS)

Engeler, I.; Hendricks Franssen, H. J.; Müller, R.; Stauffer, F.

2010-05-01

A three-dimensional finite element model for coupled variably saturated groundwater flow and heat transport was developed for the aquifer below the city of Zurich. The piezometric heads in the aquifer are strongly influenced by the river Limmat. In the model region, the river Limmat looses water to the aquifer. The river-aquifer interaction was modelled with the standard linear leakage concept. Coupling was implemented by considering temperature dependence of the hydraulic conductivity and of the leakage coefficient (via water viscosity) and density dependent transport. Calibration was performed for isothermal conditions by inverse modelling using the pilot point method. Independent model testing was carried out with help of the available dense monitoring network for piezometric heads and groundwater temperature. The model was tested by residuals analysis with the help of measurements for both groundwater temperature and head. The comparison of model results and measurements showed high accuracy for temperature except for the Southern part of the model area, where important geological heterogeneity is expected, which could not be reproduced by the model. The comparison of simulated and measured head showed that especially in the vicinity of river Limmat model results were improved by a temperature dependent leakage coefficient. Residuals were reduced up to 30% compared to isothermal leakage coefficients. This holds particularly for regions, where the river stage is considerably above the groundwater level. Furthermore additional analysis confirmed prior findings, that seepage rates during flood events cannot be reproduced with the implemented linear leakage-concept. Infiltration during flood events is larger than expected, which can be potentially attributed to additional infiltration areas. It is concluded that the temperature dependent leakage concept improves the model results for this study area significantly, and that we expect that this is also for other

Factor weighting in DRASTIC modelling for assessing the groundwater vulnerability in Salatiga groundwater basin, Central Java Province, Indonesia

NASA Astrophysics Data System (ADS)

Kesuma, D. A.; Purwanto, P.; Putranto, T. T.; Rahmani, T. P. D.

2017-06-01

The increase in human population as well as area development in Salatiga Groundwater Basin, Central Java Province, will increase the potency of groundwater contamination in that area. Groundwater quality, especially the shallow groundwater, is very vulnerable to the contamination from industrial waste, fertilizer/agricultural waste, and domestic waste. The first step in the conservation of groundwater quality is by conducting the mapping of the groundwater vulnerability zonation against the contamination. The result of this research was groundwater vulnerability map which showed the areas vulnerable to the groundwater contamination. In this study, groundwater vulnerability map was assessed based on the DRASTIC Method and was processed spatially using Geographic Information System. The DRASTIC method is used to assess the level of groundwater vulnerability based on weighting on seven parameters, which are: depth to the water table (D), recharge (R), aquifer material (A), soil media (S), topography (T), impact of vadose zone (I), and hydraulic conductivity (C). The higher the DRASTIC Index will result in the higher vulnerability level of groundwater contamination in that area. The DRASTIC Indexes in the researched area were 85 - 100 (low vulnerability level), 101 -120 (low to moderate vulnerability level), 121 - 140 (moderate vulnerability level), 141 - 150, (moderate to high vulnerability level), and 151 - 159 (high vulnerability level). The output of this study can be used by local authority as a tool for consideration to arrange the policy for sustainable area development, especially the development in an area affecting the quality of Salatiga Groundwater Basin.

Improving Groundwater Data Interoperability: Results of the Second OGC Groundwater Interoperability Experiment

NASA Astrophysics Data System (ADS)

Lucido, J. M.; Booth, N.

2014-12-01

Interoperable sharing of groundwater data across international boarders is essential for the proper management of global water resources. However storage and management of groundwater data is often times distributed across many agencies or organizations. Furthermore these data may be represented in disparate proprietary formats, posing a significant challenge for integration. For this reason standard data models are required to achieve interoperability across geographical and political boundaries. The GroundWater Markup Language 1.0 (GWML1) was developed in 2010 as an extension of the Geography Markup Language (GML) in order to support groundwater data exchange within Spatial Data Infrastructures (SDI). In 2013, development of GWML2 was initiated under the sponsorship of the Open Geospatial Consortium (OGC) for intended adoption by the international community as the authoritative standard for the transfer of groundwater feature data, including data about water wells, aquifers, and related entities. GWML2 harmonizes GWML1 and the EU's INSPIRE models related to geology and hydrogeology. Additionally, an interoperability experiment was initiated to test the model for commercial, technical, scientific, and policy use cases. The scientific use case focuses on the delivery of data required for input into computational flow modeling software used to determine the flow of groundwater within a particular aquifer system. It involves the delivery of properties associated with hydrogeologic units, observations related to those units, and information about the related aquifers. To test this use case web services are being implemented using GWML2 and WaterML2, which is the authoritative standard for water time series observations, in order to serve USGS water well and hydrogeologic data via standard OGC protocols. Furthermore, integration of these data into a computational groundwater flow model will be tested. This submission will present the GWML2 information model and results

The general description of major ion concentrations in groundwater of Latvia

NASA Astrophysics Data System (ADS)

Kalvāns, A.; Delina, A.

2012-04-01

sulphate ion prevails. The freshwater composition seems to be mostly controlled by three minerals - calcite, dolomite and gypsum. It is suggested that clay minerals can play a significant role in controlling the relative concentrations of cations, but this is not strictly proven jet. Well documented modern seawater intrusion induced by water abstraction is found in the territory of Liepāja city. The upwelling of slat water from below can be spotted across the territory as well. These zones are usually associated with tectonic faults, enabling the upwelling of salty water across regional aquicludes. Particularly prominent is the saltwater body in the vicinity of the Riga city. Three major rives are discharging in the sea there making it a natural confluence zone of groundwater as well. The intensive groundwater abstraction in the city probably enhanced the upwelling of saltwater here, but primary it is a natural phenomenon. The interesting question is if there is any paleogroundwater trapped in the active or slow water exchange zone of the sedimentary basin that could be distinguished from modern infiltration water due to particular isotope signal originating in the quaternary cold stages or chemical composition - remains of relict sea water or sedimentation water. This study is supported by the ESF project No. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060.

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

NASA Astrophysics Data System (ADS)

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

2018-01-01

organic matter in subsurface sediments coupled to sulfate reduction and possibly methanogenesis. The large loads of nutrient-rich groundwater seepage into the deepest polders indirectly affect surface water quality in the surrounding area, because excess water from the deep polders is pumped out and used to supply water to the surrounding infiltrating polders in dry periods. The study shows the importance of the connection between groundwater and surface water nutrient chemistry in the greater Amsterdam area. We expect that taking account of groundwater-surface water interaction is also important in other subsiding and urbanising deltas around the world, where water is managed intensively in order to enable agricultural productivity and achieve water-sustainable cities.

The Evolution of Groundwater Management Paradigms in Kansas, USA

NASA Astrophysics Data System (ADS)

Sophocleous, M. A.

2011-12-01

The purpose of this presentation is to trace the evolution of key water-related laws and management practices in Kansas, from the enactment of the Kansas Water Resources Appropriation Act of 1945 to the present, in order to highlight the state's efforts to create a more sustainable water future and in hopes that others will benefit from Kansas' experience. The 1945 Act provides the basic framework of water law (prior appropriation) in Kansas. Progression of groundwater management in the state encompasses local ground-water management districts (GMDs) and their water-management programs, minimum-streamflow and TMDL standards, water-use reporting and water metering programs, use of modified safe-yield policies in some GMDs, the subbasin water-resources-management program, the integrated resource planning/Aquifer Storage and Recovery project of the City of Wichita, the Central Kansas Water Bank, enhanced aquifer subunits management, and various water conservation programs. While these have all contributed to the slowing down of declines in groundwater levels in the High Plains aquifer and in associated ecosystems, they have not yet succeeded in halting those declines. Based on the assumption that the different management approaches have to operate easily within the prevailing water rights and law framework to succeed, a number of steps are suggested here that may help further halt the declines of the High Plains aquifer. These include eliminating the "use it or lose it" maxim in the prior-appropriation framework, broadening the definition of "beneficial use," regulating domestic and other "exempt" wells, encouraging voluntary "sharing the shortage" agreements, and determining to what extent water rights may be regulated in the public interest without a compensable "taking." Further necessary measures include determining to what extent water-rights holders might be subjected to reasonable dictates without having the security of their rights altered.

Seismic Landslide Hazard for the City of Berkeley, California

USGS Publications Warehouse

Miles, Scott B.; Keefer, David K.

2001-01-01

This map describes the possible hazard from earthquake-induced landslides for the city of Berkeley, CA. The hazard depicted by this map was modeled for a scenario corresponding to an M=7.1 earthquake on the Hayward, CA fault. This scenario magnitude is associated with complete rupture of the northern and southern segments of the Hayward fault, an event that has an estimated return period of about 500 years. The modeled hazard also corresponds to completely saturated ground-water conditions resulting from an extreme storm event or series of storm events. This combination of earthquake and ground-water scenarios represents a particularly severe state of hazard for earthquake-induced landslides. For dry ground-water conditions, overall hazard will be less, while relative patterns of hazard are likely to change. Purpose: The map is intended as a tool for regional planning. Any site-specific planning or analysis should be undertaken with the assistance of a qualified geotechnical engineer. This hazard map should not be used as a substitute to the State of California Seismic Hazard Zones map for the same area. (See California Department of Conservation, Division of Mines and Geology, 1999). As previously noted for maps of this type by Wieczorek and others (1985), this map should not be used as a basis to determine the absolute risk from seismically triggered landslides at any locality, as the sole justification for zoning or rezoning any parcel, for detailed design of any lifeline, for site-specific hazard-reduction planning, or for setting or modifying insurance rates.

Potable water for a city: a historic perspective from Bruges, Belgium

NASA Astrophysics Data System (ADS)

Vandenbohede, A.; Vandevyvere, E.

2014-06-01

Contributing to the optimisation of drinking-water supplies is a key responsibility for professional hydrogeologists. Thus, it is interesting to look back and put current-day practices in the framework of historic evolution and past achievements. The water supply of Bruges (Belgium), with an innovative supply system already established by the end of the 13th century, forms an interesting case study. The supply system consisted of an underground network of pipes feeding public and private wells. A special construction, the Water House, was built to overcome a topographical height difference. Population growth and industrial expansion during the 19th century increased the water demand and new solutions were necessary. Tap water became available from 1925 onwards and, as a stopgap measure to meet demand, deep groundwater was used. This invoked a lively debate among the city council, scientists and entrepreneurs, whereby both water quality and quantity were discussed. Although based on a lack of modern understanding of the groundwater system, some arguments, both pro or contra, look very familiar to current-day hydrogeologists.

Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia

NASA Astrophysics Data System (ADS)

Cui, Tao; Raiber, Matthias; Pagendam, Dan; Gilfedder, Mat; Rassam, David

2018-03-01

Understanding the response of groundwater levels in alluvial and sedimentary basin aquifers to climatic variability and human water-resource developments is a key step in many hydrogeological investigations. This study presents an analysis of groundwater response to climate variability from 2000 to 2012 in the Queensland part of the sedimentary Clarence-Moreton Basin, Australia. It contributes to the baseline hydrogeological understanding by identifying the primary groundwater flow pattern, water-level response to climate extremes, and the resulting dynamics of surface-water/groundwater interaction. Groundwater-level measurements from thousands of bores over several decades were analysed using Kriging and nonparametric trend analysis, together with a newly developed three-dimensional geological model. Groundwater-level contours suggest that groundwater flow in the shallow aquifers shows local variations in the close vicinity of streams, notwithstanding general conformance with topographic relief. The trend analysis reveals that climate variability can be quickly reflected in the shallow aquifers of the Clarence-Moreton Basin although the alluvial aquifers have a quicker rainfall response than the sedimentary bedrock formations. The Lockyer Valley alluvium represents the most sensitively responding alluvium in the area, with the highest declining (-0.7 m/year) and ascending (2.1 m/year) Sen's slope rates during and after the drought period, respectively. Different surface-water/groundwater interaction characteristics were observed in different catchments by studying groundwater-level fluctuations along hydrogeologic cross-sections. The findings of this study lay a foundation for future water-resource management in the study area.

Climate Sensitivity to Shallow Groundwater Dynamics Inferred from Historical Groundwater Level Observations and Climate Data

NASA Astrophysics Data System (ADS)

Seyoum, W. M.; Wahls, B.

2017-12-01

The effect of land surface processes (e.g., change in vegetation and snow cover, and change in soil moisture) on climate is well understood. However, the connection between shallow groundwater fluctuation and regional climate variability is still unresolved. This project focuses on sensitivity of climate to shallow groundwater dynamics by analyzing the impact of shallow groundwater on soil moisture and precipitation. The study use co-located measurements of daily soil moisture, depth to groundwater level (DGWL), and climate (precipitation (R) and air temperature) data. Statistical relationship between soil moisture and DGWL at different depth established. Frequency, mean and cumulative climate extremes (R90, R99, R < 1mm) examined and compared with depth to groundwater level information at Bellville station, IL. Result indicate soil moisture has a strong inverse relationship with depth to groundwater level (r -0.75) when DGWL is between 0 to 2 m (critical depth) depth from the ground. Beyond this depth, there is no statistically significant correlation or trend between soil moisture and GWL. Within this critical depth, soil moisture is more or less constant during wet days (R ≥ 1mm) even though DGWL is fluctuating. However, soil moisture decrease exponentially as DGWL declining during dry days (R < 1mm). Thus, soil moisture is highly likely dependent on groundwater feedback in the critical depth. Comparison of DGWL with frequency and cumulative of subsequent summer and fall extreme precipitation (DGWL leading by 4-7 months) indicate higher frequency and magnitude of extreme wet precipitation (Rm > 150 mm) occur when DGWL is within the critical depth. As DGWL decreases below 2 m, frequency and magnitude of extreme precipitation diminishes. On the other hand, DGWL has no significant relationship with subsequent extreme dry condition, there is no statistically significant trend between frequency of R < 1mm and DGWL. Generally, depth to groundwater level influence

Quantifying shallow and deep groundwater inputs to rivers with groundwater dating in hydrological observatories.

NASA Astrophysics Data System (ADS)

Aquilina, Luc; Marçais, Jean; Gauvain, Alexandre; Kolbe, Tamara; de Dreuzy, Jean-Raynald; Labasque, Thierry; Abbott, Benjamin W.; Vergnaud, Virginie; Chatton, Eliot; Thomas, Zahra; Ruiz, Laurent; Bour, Olivier; Pinay, Gilles

2017-04-01

River water derives in part from groundwater—water that has spent some time in the subsurface (e.g. soil, unsaturated zone, saturated zone). However, because groundwater residence times vary from months to millennia, determining the proportion of shallow and deep groundwater contribution can be challenging. Groundwater dating with anthropogenic gases and natural geochemical tracers can decipher the origin of groundwater contribution to rivers, particularly when repeat samplings are carried out in different hydrological conditions. Here, we present two different applications of this approach from three hydrological observatories (H+ hydrogeological network; Aghrys and Armorique observatories) in western France, all these observatories belonging to the OZCAR national network. We carried out a regional investigation of mean groundwater ages in hard rock aquifers in Brittany, using long-term chronicles from hydrological observatories and regional monitoring sites. We determined the mean residence-time (RT) and annual renewal rate (RR) of four compartments of these aquifers: the direct contribution of a very young water component (i.e. RT less than 1-2 yr), the upper variably saturated zone (RR 27-33%), the weathered layer (RR 1.8-2.1%) and the fractured zone (RR 0.1%). From these values and a nitrate chronicle, we were able to determine the respective contributions of each compartment to the largest river in Brittany, the Vilaine, which drains 30% of the region. We found that the deep fractured compartment with very slow renewal times contributed to 25-45% of river water in winter and 30-60% in summer. The very young water which includes direct precipitation and soil fluxes constituted 40-65% of the winter river water (Aquilina et al., 2012). To complement these estimates, we investigated the relationship between dissolved silica and groundwater age in the Armorique hydrological observatory in northern Brittany. We computed the silica concentration expected along the

Coastal groundwater discharge for the U.S. East and Gulf Coasts calculated with three-dimensional groundwater flow models

NASA Astrophysics Data System (ADS)

Befus, K. M.; Kroeger, K. D.; Smith, C. G.; Swarzenski, P. W.

2017-12-01

Fresh groundwater discharge to coastal environments contribute to the physical and chemical conditions of coastal waters. At regional scales, groundwater fluxes remain poorly constrained, representing uncertainty in both water and chemical budgets that have implications for downstream ecosystem health and for how human activities alter coastal hydrologic processes. Coastal groundwater discharges remain widely unconstrained due to the interconnectedness of highly heterogeneous hydrogeologic frameworks and hydrologic conditions. We use regional-scale, three-dimensional groundwater flow models with the best available hydrostratigraphic framework data to calculate the magnitude of groundwater discharging from coastal aquifers to coastal waterbodies along the eastern U.S. In addition, we constrain the inland areas that contribute to coastal groundwater discharges using particle tracking. We find that 27 km3/yr of groundwater enters coastal waters of the eastern U.S. and Gulf of Mexico and was over 175,000 km2. The contributing areas to coastal groundwater discharge extended kilometers inland and often were supplied by recharge occurring tens of kilometers inland. These results suggest that coastal groundwater discharges rely on larger contributing areas and potentially transport more dissolved constituents than previously calculated, which are important factors for constraining the role of groundwater in coastal chemical budgets and its impacts on coastal ecosystems.

Groundwater pumping by heterogeneous users