Ground-Water Treatments Gain Ground
Ground water is the main source of the nation's public water supplies and is also used extensively for agricultural and industrial purposes. Yet our reserves are constantly...
Seismic Solutions for Steel Frame Buildings
After the Northridge Earthquake, damage in steel moment resisting frame connections stunned engineers. Now those engineers are scrambling to find and test new kinds of connections. This...
Blasting Densifies Volcanic Debris (Available only in
The relatively new ground improvement technology of blast densification overcame soil problems posed by volcanic ash at Mount St. Helens National Volcanic Monument. In 1993 WSDOT began...
Fracturing for In-situ Bioremediation (Available only in
A pilot-scale evaluation of an integrated pneumatic fracturing and bioremediation system demonstrated the enhanced removal of BTX from a gasoline-contaminated, low-permeability soil formation....
A New Direction in Remediation
Engineers have always had to rely on wells for onsite soil and ground water remediation systems. During the past several years, horizontal drilling technology, adapted from oil recovery...
Influence of Backwater on Headcut Advance
A study was performed to examine the influence of backwater level downstream of an overfall on headcut advance. The discharge, overfall height, and soil type were held constant while varying...
An Extended Relaxation Technique for Unsteady Flows in Networks
A recent enhancement to the FLD WAY model is the addition of an extended relaxation technique for modeling unsteady flows in a dendritic (tree-type) network of channels with tributaries...
Dormant Season Evaporation: Challenges to the Current Models
Dormant season evaporation is a critical component of the hydrologic balance and can be considered as the winter period or the time in which there is not a crop actively growing. It is...
Permeability of Clay Liners with Contaminants
Clays are increasingly used as liners for waste disposal facilities. Chemical compatibility studies with hydraulic conductivity tests must be performed to determine the effect of the waste...
Santa Ana River Salt Marsh Restoration: Orange County, California, U.S.A.
As part of the All-River Plan of the Santa Aria River, the 92 acre Santa Ana River Marsh (Marsh) was constructed at the Pacific Ocean outlet in Orange County, California. This project...
Design and Implementation of a Multi-Faceted Site Remediation
This technical paper presents a case history of the design, construction, and start-up of a multi-faceted site remediation system. The case history includes a description of the site background,...
Secondary Containment Design Practices
Over the past several decades the design approach to containment of spills has not been consistent resulting in release of hazardous substances into the environment. The increased discovery...
Dynamic vs. Quasi-Static Effluent Limits
Selenium water quality objectives are currently being exceeded in the San Joaquin River, California due to agricultural subsurface drainage discharges. The Federal Clean Water Act requires...
Rethinking Well Efficiency
Many authors have suggested ways to evaluate water well efficiency. Most of these have either compared some form of measured drawdown with theoretical drawdown or measured the fraction...
Significance of Geologic Features on the Contaminant Migration from Landfill Sites
Contaminants (leachate) migration pathways in various media at hazardous waste and landfill sites are primarily defined by the local geologic features at such sites, namely:stratigraphy,...
Development of a Regional Atmospheric-Hydrologic Model for the Study of Climate Change in California
An integrated model of atmospheric and hydrologic processes at regional scale over California has been developed in order to translate the large scale atmospheric conditions of critical...
Estimation of Flash Flood Potential for Large Areas
A methodology for determining the potential for flash floods in small basins within large geographical areas is presented. Geographical Information Systems (GIS) technology is used to...
Hazardous Soil Remediation: A Cooperative Effort between Industry and Government
E. I. du Pont de Nemours and Company's Antioch Works (Dupont) is on the San Joaquin River 30 miles east of San Francisco, California. For about 25 years, ending in 1981, Dupont...
Enhanced Trichloroethene Desorption from Long-Term Contaminated Soil Using Triton X-100 and pH Increases
Laboratory experiments were conducted to study the effect of Triton X-100 and pH changes on trichloroethene (TCE) desorption from field-contaminated soil to water. In laboratory batch...
Geochemical Modeling of Lead in Vadose Zone
In recent years, researchers have used multicomponent reactive transport models to study the mobility of potentially toxic heavy metals in the subsurface. In this study, such a mathematical...
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