This IMA Volume in Mathematics and its Applications RESOURCE RECOVERY, CONFINEMENT, AND REMEDIATION OF ENVIRONMENTAL HAZARDS contains papers presented at two successful one-week workshops: Confine­ ment and Remediation of Environmental Hazards held on January 15-19, 2000 and Resource Recovery, February 9-13, 2000. Both workshops were integral parts of the IMA annual program on Mathematics in Reactive Flow and Transport Phenomena, 1999-2000. We would like to thank John Chadam (University of Pittsburgh), Al Cunningham (Montana State Uni­ versity), Richard E. Ewing (Texas A&M University), Peter Ortoleva (In­ diana University), and Mary Fanett Wheeler (TICAM, The University of Texas at Austin) for their excellent work as organizers of the meetings and for editing the proceedings. We take this opportunity to thank the National Science Foundation for their support of the IMA. Series Editors Douglas N. Arnold, Director of the IMA Fadil Santosa, Deputy Director of the IMA v PREFACE Advances in resource recovery, and confinement/remediation of envi­ ronmental hazards requires a coordinated, interdisciplinary effort involving mathematicians, scientists and engineers. The intent of this collection of papers is to summarize recent theoretical, computational, and experimen­ tal advances in the theory of phenomena in porous media, with the intent to identify similarities and differences concerning applications related to both resource recovery and confinement and remediation of environmental hazards.