The papers in this volume arose out of two workshops entitled 'Confinement and Remediation of Environmental Hazards', and 'Resource Recovery', as part of the IMA 1999-2000 program year. These workshops brought together mathematicians, engineers and scientists to summarize recent theoretical, computational, and experimental advances in the theory of phenomena in porous media. The first workshop focused on the mathematical problems which arise in groundwater transport of contamination, and the spreading, confinement and remediation of biological, chemical and radioactive waste. In the second...