Modeling Nitrogen Movement Through Loess Soils
This study evaluates the ability of the Root Zone Water Quality Model (RZWQM) to track the movement and fate of nitrate (NO3--N)...

Two-Dimensional Analysis of Furrow Infiltration
A general applicable two-dimensional unsaturated-saturated model for transient soil-water flow conditions in heteogeneous soils was developed. The water flow model was applied to simulate...

Effects of Wastewater Irrigation on Aqueous Geochemistry
A comprehensive assessment of the environmental impact of a full-scale, operating overland flow (OLF) land treatment system was made of the Campbell Soup, Inc. OLF system in Paris, Texas....

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...

Predicting Incipient Fluidization of Fine Sands in Unbounded Domains
Fluidization systems in the coastal environment consist of a water pumping system and a source pipe buried in or near a tidal inlet to maintain a channel or to aid in sand bypassing. If...

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...

Practical Technology Resulting from MADE Research
As is often the case, when theoretical research is performed, practical technology is developed in the process. This has occurred with the Macrodispersion Experiment (MADE) conducted at...

Prematurely Terminated Slug Tests?A Field Application
Slug tests suffer problems of non-uniqueness to a greater extent than other well tests. Alternatively, a prematurely terminated slug test (PTST) or a systematized drillstem test is proposed,...

Type Curves for a Slug Test in an Infinitely or Semi-infinitely Thick Aquifer
Type curves are provided for a slug test in an infinitely or semi-infinitely thick aquifer, the latter with the single confining layer immediately above or immediately below the well....

Aquifer Measurements at Different Scales
Multilevel slug test data from five wells in a confined, sandy aquifer were analyzed to obtain an estimate of the vertical variation of the horizontal hydraulic conductivity, K(z). Hydraulic...

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...

Terrain Conductivity to Define Groundwater Pollution
Electromagnetic terrain conductivity surveys were conducted at four animal waste lagoon sites in South Carolina in an effort to delineate groundwater contamination from animal waste lagoon...

Soil-Pesticide Grouping for Water Quality Management
Pesticide and soil properties contribute to changes in runoff and groundwater quality. Because pesticides have been found in runoff and ground water, those managing water quality need...

Concentration Measurements in Dense Leachate Plumes Using a Gamma Radiation System
An automated, nonintrusive technique is discussed that determines salt concentrations in dense leachate plumes. The dense plumes were introduced from a line source into a relatively narrow...

Influence of Soil and Sediment pH and Redox Conditions on Degradation of Toxic Organics
The presence of toxic organics in soil and sediments has raised concern over persistence and bioaccumulation. In the absence of oxygen, microbial degradation of toxic organics proceeds...

Stepped Spillway Design for Flow Over Embankments
Many embankment dams have been identified as unable to pass their design flows without failure due to overtopping. The U.S. Bureau of Reclamation (Reclamation) is currently at the forefront...

Fluidization Pipe Hole Spacing
Two-dimensional fluidization experiments are performed on fine (d50 = 0.15 mm) and medium coarse (d50 = 0.45...

Modeling and Field Experiments for Tracer Gas Tests
Numerical modeling and field experiments were used to extend the tracer gas technique for determining surface gas transfer rates to shallow bays. Two-dimensional modeling was used to investigate...

Bridge Scour Vulnerability Assessment
Although the failure of the New York Throughway bridge over Schoharie Creek in 1987 has focused national attention on scour related failures, other failures reinforce the need for implementing...

 

 

 

 

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