United States
                         Environmental Protection
                        Research and Development (481)
                        Solid Waste and
                        Emergency Response (5102G)
November 1997
Permeable Reactive Barriers
  Remediation Technologies
     Development Forum
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Sediments Remediation
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Phytoremediation of
Organics Action Team
             What Is the Permeable Reactive

             Barriers Action Team?

             The Permeable Reactive Barriers Action Team was established in March
             1995 as one of the seven Action Teams under the Remediation Technologies
             Development Forum (RTDF). The RTDF  was created by the  U.S.
             Environmental Protection Agency (EPA) in  1992 to foster collaboration
             between the public and private sectors in finding innovative solutions to
             mutual  hazardous waste problems. The Action Team has met to discuss
             ongoing research, to identify development  needs  not currently being
             addressed, to identify and promote the funding of priority research needs to
             advance the acceptance of the technology, and to develop plans for collab-
             orative field studies.

             What  Is the Action  Team's Mission?
             The mission of the Permeable Reactive Barriers Action Team is to acceler-
             ate the development of cost-effective permeable barrier technologies for mit-
             igating chlorinated solvents, metals, radionuclides, and other pollutants in
             ground water. The Action Team will undertake the development and evalua-
             tion efforts needed to achieve public and regulatory acceptance of this tech-
             nology. The efforts focus on:

             >• Defining the hydraulics, geochemistry, and reactions that occur in the
               media and aquifers

             *- Demonstrations that validate the technology's effectiveness
             >- Protocols, guidance, and issue papers for design and effective imple-

             >• Effective emplacement techniques and configurations (engineering
               design and constructability)
             >- Economic analysis of treatment cost
             >• Public/regulatory acceptance of the technology

             What Is a Permeable Reactive Barrier?
            A permeable reactive barrier is a passive in situ treatment zone of reactive
            material  that degrades or immobilizes contaminants as ground water flows
            through it. Permeable treatment walls are installed as permanent, semi-perma-
            nent, or replaceable units across the flow path of a contaminant plume. Natural
            gradients transport contaminants through strategically placed treatment media.
            The media degrade, sorb, precipitate, or remove chlorinated solvents,  metals,
            radionuclides, and other pollutants. These barriers may contain reactants for
            degrading volatile organics, chelators for immobilizing metals, nutrients and
            oxygen for microorganisms to enhance bioremediation, or other agents.

 Degradation barriers facilitate reactions that break down contaminants in the
 plume into harmless byproducts. Precipitation barriers react with contami-
 nants to form insoluble products that remain in the barrier as ground water
 continues to flow through. Sorption barriers adsorb or chelate contaminants.

Conceptual Configuration of Permeable Barrier System
                                        Permeable Reactive
                                            Ground Water
 What Activities Are Planned?
 Many Permeable Reactive Barriers Action Team members play active roles
 in research, development, technology transfer, and technical assistance for
 field sites throughout the world. The Air Force has asked the Action Team
 to participate in a study entitled "Catalytic In Situ Treatment of Chlorinated
 Solvents," to be conducted at Dover Air Force Base, Delaware. This study
 is being coordinated by the Air Force's Armstrong Laboratory under the
 Department of  Defense's  Strategic  Environmental  Research  and
 Development Program (SERDP). Several members of the Action Team are
 assisting with the design of this study, and field work is expected to begin
 in  1997.  The Action Team also is becoming increasingly involved in
 research and technology evaluation activities at the U.S. Coast Guard site
 near Elizabeth City, North  Carolina. This research site, originally devel-
 oped by  researchers from  EPA's National Risk  Management Research
 Laboratory  (NRMRL), is now being utilized by other  groups within the
 Action Team to evaluate long-term performance monitoring issues associ-
 ated with permeable reactive barriers.

 Who Are the Action  Team Members?
        Battelle Memorial Institute
        Clean Sites
EnviroMctal Technologies
General Electric
1CI Americas
        nU.S. Air Force
        U.S. Army Corps of Engineers
        U.S. Department of Energy
U.S. Environmental Protection Agency
U.S. Geological Survey
U.S. Naval Facilities Engineering
                                             New Mexico Tech
                                             University of Waterloo
                                             State University of New York at
                                                                                  Remediation Technologies
                                                                                    Development Forum
                                                                                 Would You


                                                                          More Information?

                                                                           For more information on the Permeable
                                                                            Reactive Barriers Action Team, please

                                                                                    Bob Puls, Ph.D.
                                                                            U.S. Environmental Protection Agency
                                                                            National Risk Management Research
                                                                                       P.O. 1198
                                                                                    Ada, OK 74820
                                                                                    Tel: 405-436-8543
                                                                              E-mail: puls@ad3100.ada.epa.gov

                                                                               Industry Co-Chair to be named

                                                                            For information on the RTDF or other
                                                                          Action Teams, please visit the RTDF World
                                                                          Wide Web site at www.rtdf.org or contact:

                                                                                    Robert Olexsey
                                                                            U.S. Environmental Protection Agency
                                                                             26 West Martin Luther King Drive
                                                                                  Cincinnati, OH 45268
                                                                                    Tel: 513-569-7861
                                                                            E-mail: olexsey.bob@epamail.epa.gov

                                                                               Walter W. Kovalick, Jr., Ph.D.
                                                                            U.S. Environmental Protection Agency
                                                                                 401 M Street, SW (5102G)
                                                                                  Washington, DC 20460
                                                                                    Tel: 703-603-9910
                                                                          E-mail: kovalick.walter@epamail.epa.gov
To request other RTDF fact sheets, please
           write/fax to:

11305 Reed Hartman Highway, Suite 219
        Cincinnati, OH 45241
         Fax: 513-489-8695
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