Assessing the Performance of Surface and Subsurface Engineered Barriers

National Academy Of Sciences, Washington DC

Investigators

Abstract

This action provides partial support for the study by the National Research Council "Assessing the Performance of Surface and Subsurface Engineered Barriers." These systems are relied upon to retain fluids in heap leach treatment in mining, to ensure safe disposal of a variety of waste, to complement remediation programs for contaminated sites, and for other applications. Recent advances in technology and understanding, as well as assessment of past barrier performance, provide an opportunity to improve upon current design, evaluation, and monitoring methods. Surface and subsurface containment systems include caps, bottom liners, and vertical barriers constructed with a variety of materials, e.g., concrete, geomembranes, compacted clays. This study will develop and describe an improved framework for assessing surface and subsurface engineered barriers. In 1997, the National Research Council completed a workshop report, "Barrier Technologies for Environmental Management" (NRC, 1997). The workshop discussions focused on several themes. The current study will build on some of these themes and will provide an improved components-based framework for assessing engineered barriers. It will be conducted by an ad hoc committee under the aegis of the Committee on Geological and Geotechnical Engineering, a standing committee under the Board on Earth Sciences and Resources. The ad hoc committee will consist of approximately 10 professionals with expertise in areas such as municipal/hazardous/radioactive waste containment; hydrogeology; environmental engineering; mining; geochemistry; geotechnical/geological engineering; instrumentation/sensor technology; geology; risk assessment; and environmental regulation. The ad hoc panel will consider the performance and effective lifetimes of current and emerging types of engineered barriers and will summarize the state of science and engineering for risk assessment methodology, system installation, performance monitoring, and sustainability. In addition, the study will identify data gaps and research needs. This study will benefit operators and regulators by defining the key components of design and implementation that define barrier performance effective lifetimes, thereby helping to ensure protection of public health, reduce potential risks for barrier failure, maximize reliability of systems, and minimize overall costs. In addition, the study's assessment of data gaps will help to focus research programs on efforts that will most directly result in improved performance. The study report will be available for public distribution in accordance with NRC policy, and will also be posted on the NAS World Wide Web site.