Program Brief

Statement of Problem: Steam injection/vapor extraction (SIVE) of contaminated groundwater and soil is a highly promising technology in the remediation of environmentally contaminated sites. The technology has been endorsed by the U.S. Environmental Protection Agency and state-level environmental departments as an innovative and effective means to clean up contaminated and degraded locations. A major challenge to implementation of the SIVE technology is the ability to simulate numerically the complex heat and mass transfer processes that result. This study used the CNWRA^®-developed MULTIFLO code to simulate SIVE.

Approach and Accomplishments: The MULTIFLO code was used to simulate the flow of steam through geologic material at laboratory and field scales. Various design alternatives were evaluated, including multiple points of steam injection and liquid and vapor extraction. Simulation of steam injection into geologic material was successfully simulated for different geologic media. Modeling results were used to evaluate the design of a SIVE remediation design system. Critical design flaws were discovered during the simulation process that otherwise would not have been detected until implementation.

Client Benefits: Successful prediction of steam and solute movement through geologic media requires the appropriate rendering of complex thermodynamic processes into manageable numerical simulations. The MULTIFLO code is capable of predicting the movement of steam and chemical species through unsaturated and saturated porous media. This tool provides CNWRA with the capability to predict the results of SIVE of contaminated groundwater and soil. This approach permits the SIVE system to be designed to ensure the system (i) can be effective and appropriate for the target geologic setting, (ii) is not over designed and unnecessarily expensive, and (iii) is designed to satisfy the target performance criteria without requiring system redesign or secondary remediation approaches.