Objective:
The Department of Defense (DoD) is responsible for managing thousands of chlorinated solvent sites. As indicated by a series of research initiatives, expert panels, and other efforts, defining the benefits of dense nonaqueous phase liquid (DNAPL) source remediation remains a difficult engineering challenge. Uncertainties in the cost and performance of source and plume remediation technologies complicate decision making. Predicting the impact of the source remediation efforts on plume response is hindered by the lack of tools that explicitly relate source remediation to the downgradient plume over time and space. Leveraging recent SERDP and ESTCP efforts, this project will develop an integrated modeling tool to assist site managers in simulating the changes in DNAPL source zones and dissolved plumes over time, both with and without source remediation, source containment, and/or plume remediation; exploring site management decisions in a probabilistic framework so uncertainty becomes an integral part of the decision-making process; and comparing the cost, risk, and performance of source treatment to plume management approaches. Technology Description: A new analytical model, Remediation Evaluation Model for Chlorinated solvents (REMChlor), will serve as the technical foundation for this project. This model, developed under SERDP project ER-1295, represents a significant improvement on existing chlorinated solvent transport models because it can account for both source and plume remediation simultaneously. In this project, the functionality of REMChlor will be expanded by (1) building a probabilistic framework around the REMChlor source/plume remediation code so that uncertainty in hydrogeologic variables, remediation performance, source loading, plume response, risk factors, and cost can be accounted for and visualized by users of the new software; (2) providing tools so users can express key process data as probability density functions and therefore access the probabilistic nature of the new tool; (3) compiling and presenting results of recent research projects addressing cost and performance of source remediation (such as SERDP project ER-1292) in the form of probability density functions as background information for users of the new tool; and (4) incorporating a vapor transport module so the critical indoor air pathway can be evaluated. The vapor transport module will include key results from ESTCP project ER-0423 so that users will have the option of including mass flux limitations and radon-based dilution attenuation factors. Expected Benefits: The integrated modeling tool will provide users a single platform where cost, source treatment, plume management, monitored natural attenuation, and risk assessment all can be evaluated together and where uncertainty can be incorporated into the site decision-making process. This single platform will allow users to combine site-specific data with key results from recent SERDP and ESTCP efforts. (Anticipated Project Completion - 2010) Principal Investigator: Dr. Ron Falta Clemson University Geology & Environmental Engineering Brackett Hall, Room 340C Clemson, SC 29634-0919 Telephone: (864) 656-0125 Fax: (864) 656-1041 E-mail: faltar@clemson.edu DoD Liaison: Ms. Carmen Lebrón Naval Facilities Engineering Service Center Restoration Development Branch 1100 23rd Avenue, ESC-411 Port Hueneme, CA 93043-4370 Telephone: (805) 982-1616 Fax: (805) 982-4304 E-mail: carmen.lebron@navy.mil | 
