Original Date: 09/14/1998
Revision Date: 01/18/2007
Information : Research and Development Partnership
Over the years, Raytheon Missile Systems Company’s (RMSC’s) existing method for removing TCE from groundwater began leveling off due to high-permeability gravel layers; low-permeability clay layers; and the subsurface heterogeneity of water flow. In 1994, RMSC and the University of Arizona formed a partnership (funded through the Air Force) to identify solutions to this situation. Specifically, the group examined the controlling factors for removing contaminants in high concentration areas, and evaluated alternatives to enhance the efficiency of the existing pump and treat groundwater remediation systems.
The University of Arizona’s Site Characterization and Systems Optimization project was set up to gather information related to TCE’s behavior in groundwater and soil. By understanding this behavior, the group can improve the effectiveness of remediation, and increase the clean-up efforts at the contaminated AFP44 site. This project utilizes several components (e.g., laboratory studies, computer modeling, field tracer studies), which are designed to characterize how water and TCE travel through the aquifer.
The project’s ongoing work includes the design, testing, and pilot-scale implementation of two vertical circulation wells (Figure 3-2). To enhance these wells, cyclodextrin (sugar molecules) will be added to the influent as a way to attract TCE to the effluent. This cyclodextrin injection technology (similar to co-solvent technology) is a proven, but not currently practiced method. New technologies, like this, help reduce life cycle costs and improve the effectiveness of remediation efforts at RMSC and similar sites.
Besides identifying the cyclodextrin injection technology, the group created extensive 3-D models of the plume. The groundwater remediation 3-D modeling program, developed by the University of Arizona, is an advanced software program which allows the user to manipulate many variables such as TCE aging, geological conditions, pumping rates, and pressures. Through the partnership, Environmental Science graduate students come to RMSC, and develop sophisticated 3-D models based on actual remediation activities. The students get to participate in an excellent learning opportunity, and help accelerate RMSC’s remediation process. In addition, RMSC gains valuable information from the student’s models.
Figure 3-2. Enhanced Vertical Flushing
For more information see the
Point of Contact for this survey.