This research will improve the practice of terrestrial remediation by developing a tool to help engineers design sequential ex-situ remediation. Ex-situ remediation is one of the fundamental strategies for remediating terrestrial contamination, but is infrequently considered because it is believed to be inappropriate or prohibitively expensive. However, there are situations where ex-situ remediation can be an excellent choice, including sites with numerous, distributed zones of contamination or Brownfield sites dominated by the problems of `old` soil contamination. Ex-situ containment avoids the expense of individual campaigns against distributed sources, and allows reuse of large portions of sites while small areas accomplish remediation. Ex-situ containment also allows use of aggressive processes that would not be advisable in situ. For cases where sequential ex-situ remediation is appropriate, it can improve the degree of remediation, reduce the cost of remediation and improve the confidence that performance goals have been achieved. Unfortunately, the greatest impediment to implementing ex-situ remediation is the lack of a design/analysis tool to help engineers identify opportunities and to help configure and control a sequence of ex-situ remediation steps. This research will develop an analysis tool to help engineers examine the merits of a sequence of remedial actions applied ex-situ at low cost. This will be designed as a simulation engine interfacing with a large set of remediation process subprograms. The simulation engine will define the structure of the problem (geometric containment, soil structure, barrier systems, environmental interfaces, state variables, etc.). The subprograms will implement a wide variety of remediation processes (vapor extraction, bio-venting, bioremediation, soil washing, soil leaching, etc.) from arbitrary conditions and material fluxes provided by the simulation engine. The package will help engineers configure treatment sequence, and design control strategies for sequence operation. This will be a microcomputer analysis package constructed to run at acceptable speed on conventional `advanced` microcomputers. The package will be designed with user-friendly interfaces, with graphical data displays and with extensive report authoring capabilities.