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A new computer program, 1DTempPro, is presented for the analysis of vertical one-dimensional (1D) temperature profiles under saturated flow conditions. 1DTempPro is a graphical user interface to the U.S. Geological Survey code Variably Saturated 2-Dimensional Heat Transport (VS2DH), which numerically solves the flow and heat-transport equations. Pre- and postprocessor features allow the user to calibrate VS2DH models to estimate vertical groundwater/surface-water exchange and also hydraulic conductivity for cases where hydraulic head is known.
Categories: Publication; Types: Citation; Tags: Ground Water
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This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas (https://www.epa.gov/enviroatlas). The Food, Fuel, and Materials category in this web service includes layers illustrating the ecosystems and natural resources that provide or support the production of food, fuel, or other materials, the need or demand for these items, the impacts associated with their presence and accessibility, and factors that place stress on the natural environment's capability to provide these benefits. EnviroAtlas allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the conterminous United States. Additional descriptive...
Types: Citation; Tags: 12-digit HUCs, Agriculture, Air, Alabama, Alaska, All tags...
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A commercially available electromagnetic flowmeter is attached to a seepage cylinder to create an electromagnetic seepage meter (ESM) for automating measurement of fluxes across the sediment/water interface between ground water and surface water. The ESM is evaluated through its application at two lakes in New England, one where water seeps into the lake and one where water seeps out of the lake. The electromagnetic flowmeter replaces the seepage-meter bag and provides a continuous series of measurements from which temporal seepage processes can be investigated. It provides flow measurements over a range of three orders of magnitude, and contains no protruding components or moving parts. The ESM was used to evaluate...
Categories: Publication; Types: Citation; Tags: Ground Water
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To determine specific storage and porosity, areally limited and time-consuming aquifer tests are frequently done. Hydrogeologic studies often do not have the resources to collect such data and rely on existing data sources for aquifer properties. An alternative tool for determining these aquifer properties is the analysis of earth tides. The objective of this study was to determine whether existing water-level and barometric-pressure data could be used to determine aquifer properties, such as porosity and specific storage, on a regional scale. In this study, national databases from the Great Lakes Region were queried for continuous records of groundwater-level and barometric-pressure data. Records from 37 selected...
Categories: Publication; Types: Citation; Tags: Ground Water
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On March 8 and 9, 1992, a thermal-infrared-multispectral scanner (TIMS) was flown over two military ordnance disposal facilities at the Edgewood Area of Aberdeen Proving Ground, Maryland. The data, collected bythe National Aeronautics and Space Administration, in cooperation with the U.S. Army and the U.S. Geological Survey, were used to locate ground-water discharge zones in surface water. The images from the flight show areas where ground-water discharge is concentrated, as well as areas of diffuse discharge. Concentrated discharge is predominant in isolated or nearly isolated ponds and creeks in the study area. Diffuse dicharge is found near parts of the shoreline where the study area meets the surrounding estuaries...
Categories: Publication; Types: Citation; Tags: Ground Water
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Nitrate concentrations in ground water on Long Island, New York, have increased markedly in the last 30 years. A significant amount of this increase has been attributed to lawn and garden fertilizers in addition to cesspool and septic-tank discharges. The increase in nitrate concentration is of particular concern in the central and eastern part of the island, where ground water is the sole source of drinking water. Ground-water samples were collected from 14 wells screened near the water table in the sewered Twelve Pines housing development constructed in Medford, Suffolk County, in 1970. Samples were collected during 1972-79 and analyzed for total ammonium, organic nitrogen, and nitrate. Statistical analyses indicate...
Categories: Publication; Types: Citation; Tags: Ground Water
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A conceptual model of eolian transport is proposed to address the widely distributed, high concentrations of hexavalent chromium (Cr+6) observed in ground water in the Emirate of Abu Dhabi, United Arab Emirates. Concentrations (30 to more than 1000 μg/L Cr+6) extend over thousands of square kilometers of ground water systems. It is hypothesized that the Cr is derived from weathering of chromium-rich pyroxenes and olivines present in ophiolite sequence of the adjacent Oman (Hajar) Mountains. Cr+3 in the minerals is oxidized to Cr+6 by reduction of manganese and is subsequently sorbed on iron and manganese oxide coatings of particles. When the surfaces of these particles are abraded in this arid environment, they...
Categories: Publication; Types: Citation; Tags: Ground Water
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Because of the ubiquitous nature of anthropogenic nitrate (NO 3-) in many parts of the world, determining background concentrations of NO3- in shallow ground water from natural sources is probably impossible in most environments. Present-day background must now include diffuse sources of NO3- such as disruption of soils and oxidation of organic matter, and atmospheric inputs from products of combustion and evaporation of ammonia from fertilizer and livestock waste. Anomalies can be defined as NO3- derived from nitrogen (N) inputs to the environment from anthropogenic activities, including synthetic fertilizers, livestock waste, and septic effluent. Cumulative probability graphs were used to identify threshold concentrations...
Categories: Publication; Types: Citation; Tags: Ground Water
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A field-scale demonstration project was conducted to evaluate the capability of eastern cottonwood trees (Populus deltoides) to attenuate trichloroethene (TCE) contamination of ground water. By the middle of the sixth growing season, trees planted where depth to water was < 3 m delivered enough dissolved organic carbon to the underlying aquifer to lower dissolved oxygen concentrations, to create iron-reducing conditions along the plume centerline and sulfate-reducing or methanogenic conditions in localized areas, and to initiate in situ reductive dechlorination of TCE. Apparent biodegradation rate constants for TCE along the centerline of the plume beneath the phytoremediation system increased from 0.0002/d to 0.02/d...
Categories: Publication; Types: Citation; Tags: Ground Water
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The fate of disinfection byproducts during aquifer storage and recovery (ASR) is evaluated for aquifers in Southern Nevada. Rapid declines of haloacetic acid (HAA) concentrations during ASR, with associated little change in Cl concentration, indicate that HAAs decline primarily by in situ microbial oxidation. Dilution is only a minor contributor to HAA concentration declines during ASR. Trihalomethane (THM) concentrations generally increased during storage of artificial recharge (AR) water and then declined during recovery. The decline of THM concentrations during recovery was primarily from dilution of current season AR water with residual AR water remaining in the aquifer from previous ASR seasons and native ground...
Categories: Publication; Types: Citation; Tags: Ground Water
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Hydrographs of stream discharge were analyzed to determine ground-water recharge for two small basins draining into Mirror Lake, New Hampshire. Two methods of hydrograph analysis developed for determining ground-water recharge were evaluated, the instantaneous recharge method and the constant recharge method. For the instantaneous recharge method, recharge is assumed to be instantaneous and uniform over the basin. For the constant recharge method, recharge is assumed to be constant and uniform over the basin for a period of weeks to months. Both methods require that a ground-water recession slope be determined. The recession slope is used directly in the calculation for the instantaneous recharge method, and it...
Categories: Publication; Types: Citation; Tags: Ground Water
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The suitability of common-offset ground-penetrating radar (GPR) to detect free-phase hydrocarbons in bedrock fractures was evaluated using numerical modeling and physical experiments. The results of one- and two-dimensional numerical modeling at 100 megahertz indicate that GPR reflection amplitudes are relatively insensitive to fracture apertures ranging from 1 to 4 mm. The numerical modeling and physical experiments indicate that differences in the fluids that fill fractures significantly affect the amplitude and the polarity of electromagnetic waves reflected by subhorizontal fractures. Air-filled and hydrocarbon-filled fractures generate low-amplitude reflections that are in-phase with the transmitted pulse....
Categories: Publication; Types: Citation; Tags: Ground Water
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Spatially and temporally distributed measurements of processes, such as baseflow at the watershed scale, come at substantial equipment and personnel cost. Research presented here focuses on building a crowdsourced database of inexpensive distributed stream stage measurements. Signs on staff gauges encourage citizen scientists to voluntarily send hydrologic measurements (e.g., stream stage) via text message to a server that stores and displays the data on the web. Based on the crowdsourced stream stage, we evaluate the accuracy of citizen scientist measurements and measurement approach. The results show that crowdsourced data collection is a supplemental method for collecting hydrologic data and a promising method...
Categories: Publication; Types: Citation; Tags: Ground Water
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A variable-density groundwater flow and dispersive solute transport model was developed for the shallow coastal aquifer system near a municipal supply well field in southeastern Florida. The model was calibrated for a 105-year period (1900 to 2005). An analysis with the model suggests that well-field withdrawals were the dominant cause of salt water intrusion near the well field, and that historical sea-level rise, which is similar to lower-bound projections of future sea-level rise, exacerbated the extent of salt water intrusion. Average 2005 hydrologic conditions were used for 100-year sensitivity simulations aimed at quantifying the effect of projected rises in sea level on fresh coastal groundwater resources...
Categories: Publication; Types: Citation; Tags: Ground Water
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A field experiment consisting of geophysical logging and tracer testing was conducted in a single well that penetrated a sand-and-gravel aquifer at the U.S. Geological Survey Toxic Substances Hydrology research site on Cape Cod, Massachusetts. Geophysical logs and flowmeter/pumping measurements were obtained to estimate vertical profiles of porosity ϕ, hydraulic conductivity K, temperature, and bulk electrical conductivity under background, freshwater conditions. Saline-tracer fluid was then injected into the well for 2 h and its radial migration into the surrounding deposits was monitored by recording an electromagnetic-induction log every 10 min. The field data are analyzed and interpreted primarily through the...
Categories: Publication; Types: Citation; Tags: Ground Water


map background search result map search result map Effects of sea-level rise on salt water intrusion near a coastal well field in southeastern Florida EnviroAtlas - Food, Fuel, and Materials Metrics for Conterminous United States Effects of sea-level rise on salt water intrusion near a coastal well field in southeastern Florida EnviroAtlas - Food, Fuel, and Materials Metrics for Conterminous United States