CONTAMINATED RIVERS - A GEOMORPHOLOGICAL-GEOCHEMICAL APPROACH TO SITE ASSESSMENT AND REMEDIATION

Increasingly, attention is being given to the remediation of contaminated river reaches, some of which cover 10s of kilometers of stream channel and the adjacent valley floor. Post-remediation reviews have shown that there is a critical need to morethoroughly incorporate knowledge of the catchment's geomorphology and surficial processes into site characterization, assessment, and remediation strategies. The primary purpose of this book is to provide students and professionals with an introductory understanding of fluvial geomorphic principles and how these principles can be integrated with geochemical data to cost-effectively characterize, assess and remediate contaminated rivers. We stress the importance of needing to understand both geomorphic and geochemical processes. A process-oriented approach is required because it goes beyond the simple description of the river channel and its associated drainage basin to enhance the predictive capabilities of models used in the investigationof riverine environments. Thus, the overall presentation is first an analysis of physical and chemical processes and, second, a discussion of how an understanding of these processes can be applied to specific aspects of site assessment and remediation. We also emphasize the need to take a catchment-scale approach when conducting site investigations, and the potential for changes in process rates through time as a result of both natural and anthropogenic disturbances. Such analyses provide the basis for a realistic prediction of the kinds of environmental responses that might be expected, for example, during future changes in climate or land-use.