Understanding and Responding to Hazardous Substances at Mine Sites in the Western United States

This volume documents interesting approaches, techniques, and practical scientific considerations associated with mine site remediation. It also highlights how various federal, state, and local agencies and organizations are trying to bring the best science possible to bear on this serious problem. Some chapters focus on specific methods for characterization, particular contaminant issues, and impacts from the release of hazardous substances from mine and mill sites. Others describe successful response actions, technologies, or practical approaches for addressing contaminant releases to the environment.
Management of mine process effluents in arid environments Available to Purchase
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Published:January 01, 2007
Abstract
Modern large-scale gold mining by cyanide leaching of low-grade ore generates a large volume of process fluids. Reduction and disposal of these fluids presents unique challenges. Leaching solutions, tailings dewatering, and even postmining pit lakes must be managed both in the immediate short term and over decades or longer. Methods for reducing influx to these sources with covers and capillary breaks as well as attenuating, reducing, and disposing of them via above and subsurface land application, evaporation, and vegetation, both xeric and in engineered wetlands, among other techniques, are an evolving art still requiring an adequate base of data and observable experience. Predictive modeling of fluid volume and behavior has proved very inaccurate over both shorter and longer time intervals. Climatic extremes and intensity of precipitation events compound the problem in arid areas. Ecological risk assessment is used to estimate exposure to contaminants of concern. Experience has demonstrated the inadequacy of predictions about process fluid management postclosure, and the need for comprehensive fluids bonding both for short-term contingencies such as bankruptcy and for long-term effluent disposal maintenance and monitoring.
- arid environment
- bonding
- capillary pressure
- constructed wetlands
- cyanides
- decontamination
- ecology
- effluents
- evapotranspiration
- fluid dynamics
- ground water
- heap leaching
- heavy metals
- hydrology
- land use
- leaching
- lysimeters
- mines
- pH
- planning
- retention
- revegetation
- risk assessment
- tailings
- tailings ponds
- terrestrial environment
- unsaturated zone
- waste management
- waste rock
- water quality
- wetlands