Contraction Scour at Bridges Founded on Clay Soils
With the federally mandated bridge scour program deadline of January 1997 approaching, scour evaluations are in full progress in many states around the country. A common physical situation...
A Cost-Effective approach to
A bioventing and groundwater treatment system designed to enhance the natural biodegradation of diesel fuel residuals in soil and prevent further groundwater degradation was installed...
Optimization of Soil Vapor Extraction System Design
Soil vapor extraction is a cost-effective technique for the removal of volatile organic compounds (VOCs) immobilized in the unsaturated zone. The design of a soil vapor extraction system...
Optimizing Municipal Wastewater Treatment in Cold Climates: Scale, Process and Benefits
Although conventional wisdom demands large, centralized facilities for municipal sewage treatment, much has recently been made of the potential of low tech, decentralized systems for wastewater...
Soil Water Chemistry of Irrigation with Drainwater
The use of drainwater for irrigation was demonstrated as a management option that reduces net farm drainage and provides control over water quality (O'Brien and Guitjens,...
Shallow and Surfacing Ground Water in an Arid Urban Environment
Return flow from landscape irrigation is now a major recharge source and the loss of phreatophytic vegetation has caused decreased evapotranspiration discharge in Henderson, Nevada. Lateral...
A Paradox at the Rocky Mountain Arsenal, Colorado: Benefits of Applied Research
The Rocky Mountain Arsenal (RMA), which is located north of Denver, Colorado, was a manufacturing site for chemical weapons during World War II and pesticides for several decades after...
Biopolymers for Geotechnical Applications
A number of bacteria, e.g.,
Use of Artificial Neural Networks for Agricultural Chemical Assessment of Rural Private Wells
The detection of agricultural chemicals in rural private wells has prompted for numerous studies at regional, state, and national levels. A principal concern arises from the fact that...
Neural Networks Predict Pesticide Leaching
The goal of this work was to determine whether artificial neural networks (ANN) can be used to predict the percentage of applied pesticide that leaches through 50 cm of turfgrass covered...
On Conductivity of Soils with Preferential Flow Paths
Laboratory soil column experiments were conducted to study the distribution of preferential flow paths resulting from removal of colloidal size clay particles. These experiments specifically...
A Comparative Study of the Transformed Methods for Solving Richards' Equation
The Richards' equation represents the movement of water in both saturated and unsaturated porous medium. The numerical solution to this equation is difficult because the algebraic...
Earth Spillway Design Using SITES Software
The USDA Natural Resources Conservation Service has, recently released new software for the design and analysis of water resource structure sites. This software, SITES, is based on the...
Long-term Consequences of Recycling Drainage Water for Irrigation
Several long.term field studies (i.e. 6 yrs or more) conducted by the USDA/ARS and the University of California have demonstrated that saline drainage water (ECw...
Alachlor Transport in Laboratory Soil Columns
Spraying of agricultural chemicals result in their travel downward through the unsaturated zone and adsorption to the surrounding soil. Infiltration from rainfall and irrigation solubilize...
Predicting Transport of Organics through Soil Columns using Distributed Mass-Transfer Rates
A numerical model to describe contaminant transport through soil columns, including distributed mass-transfer, is developed. Both a gamma distribution and a lognormal distribution are...
Delineating Subsurface Contamination Using Geostatistical and Non-Intrusive Geophysical Methodologies
Electromagnetic (EM) conductivity surveys are becoming a more practiced technique in screening for contamination of soil and groundwater. This non-intrusive geophysical approach detects...
Systems for Forecasting Flows and Their Uncertainty
Discussed are design issues of distributed systems for operational flow forecasting. Results of sensitivity analyses are presented which illustrate forecast flow dependence on model discretization...
Small Inocula Can Effect
This is the first report of colonization of soil by small numbers of a genetically engineered microorganism. The study suggests that the addition of small inocula of D5 to contaminated...
Studies on the Erosion of a Compacted Soil
In the management of water there are certain applications in which compacted soil is used (i.e., dams, embankments, levees, spiliways, and channels). Engineers rely primarily on field...
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