Phosphorus Transport from Delaware's Rural Watershed
Phosphorus loads were estimated for 62 watersheds. Major land uses in the watersheds were cropland and forestland. Annual phosphorus loads varied from 0.42 to 1.19 kg/ha. Watersheds with...
Tributary Pollutant Effects in the Urban Stream Network
With considering unsteady flow and backwater effects, a linear water quality model is developed based on the finite difference approximation. The model is composed to two components which...
Effects of Drainage on Water, Sediment and Biota
The U.S. Department of the Interior started a program in 1985 to identify effects of irrigation-induced trace constituents in water, bottom sediment and biota. The program was developed...
Impact of Grid Orientation on Groundwater Contaminant Transport Modeling Using the U.S.G.S. MOC Model
The U.S.G.S. method of characteristics (MOC) model was enhanced to include the input of measured contaminant concentrations, the calculation of computed and measured contaminant plume...
Pitfalls Associated with the Assumption of a Constant Partition Coefficient in Modeling Sorbing Solute Transport Through the Subsurface
This paper presents several case studies where the estimation of the adsorption coefficient, Kd, by means of the Koc-foc...
Evaluating Probability Measures Related to Subsurface Flow and Transport: Overview of Technical Considerations and Modeling Philosophy
Probabilistic modeling approaches are being used increasingly in order to carry out quantified risk analysis and to evaluate the uncertainty existing in subsurface flow and transport analyses....
Overview and Objectives of the Macrodispersion Experiment
TVA is conducting large-scale field experiments to better define movement and dispersion of contaminants in groundwater. This will support groundwater protection by making possible more...
Second Natural-Gradient Tracer Experiment
The Tennessee Valley Authority (TVA) has begun a second large-scale groundwater field experiment at the Columbus Groundwater Research test site in Mississippi. This research is a continuation...
Measurement and Analysis of Hydraulic Conductivity Variability of a Heterogeneous Aquifer
The spatial variability of hydraulic conductivity of a shallow alluvial aquifer was investigated using borehole flowmeter measurements. The study was conducted at the site of a large-scale...
Groundwater Models and Aquifer Restoration: An Overview
In recent years, as the demand for water has increased, groundwater mining has intensified. Data on water use indicate that this trend will continue in the future, and competition is likely...
Monte Carlo Simulation of Transport from Reserve Pits
A mathematical modeling study was performed to evaluate potential health and environmental risks due to contaminant transport from exploration and production well freshwater drilling mud...
Prediction Method of Concentration Distribution of Groundwater Pollutants Using a Field Monitoring Network System
A method based on the extended Kalman filter is developed to identify the parameters of a two-dimensional stochastic convective-dispersion differential equation and to predict in real-time...
Simulation of Leachate Discharge from a Small Island into a Tidal Bay
A small island in a tidal bay was considered as a potential site for depositing large volumes of excavation material from a transportation project. The island is located in the inner part...
A Preliminary Evaluation of Model Uncertainty Given Parameter Sensitivity for Select Transport Codes
The ever-increasing use of mathematical models in groundwater management has raised concerns as to uncertainties associated with their abilities to simulate real-world pollution problems....
Risk Assessment and Management of an Oil Contaminated Aquifer: A Case History Study
This paper concerns the provision of the basic information needed for the decision-making process regarding the remedial measures leading to reutilization of an oil contaminated aquifer....
Application of Decision Analysis in Groundwater Remediation Design
The design of groundwater remediation systems involves selecting from a set of design alternatives under conditions of uncertainty. A risk-based decision analysis approach is presented...
Application of Tracer Tests in Groundwater Remediation Design
Recent advances in the area of field testing for the quantification of hydraulic conductivity have resulted in improved site characterization of aquifer hydraulics and greater reliability...
Predicting Microbial Contamination of Ground Water
As a result of the drinking water standards for viruses established by the United States Environmental Protection Agency in 1985, mandatory groundwater disinfection requirements were recently...
The Potential Use of Genetically Engineered Microorganisms in the Remediation of Environmental Pollution
Naturally occurring microorganisms express a broad range of metabolic activities which are being successfully applied to the field of bioremediation. Genetic engineering will enhance such...
Transport Models to Simulate Nitrate Contamination
Computer models can be used to simulate groundwater flow and contaminant transport in the vadose zone, the results of which can be used as input to simulate flow and transport in the saturated...
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