&EPA
                         United States
                         Environmental Protection
                         Agency
                          Research and Development (481)
                          Solid Waste and
                          Emergency Response (5102G)
EPA/542/F-99/029
November 1999
Permeable Reactive  Barriers
Action Team
       BTDF
 Meumediaficm Technologies
 CurrentRTDF
  Action Teams
Bioremediation Consortium
Team  !l

 ermeable Reactive
Phytoremediation of
Qrganics Action Team

Sediments Remediatioii   ;  ?
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 sec-
              tors 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 collaborative field studies.


              The 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-permanent, or replace-
              able 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 bioremedi tion, or other agents.
              Degradation barriers facilitate reactions that break down contaminants in the
              plume into harmless byproducts. Precipitation barriers react with contaminants to
              form insoluble products that remain in the barrier as ground water continues to
              flow through. Sorption barriers adsorb or chelate contaminants.

              The Action  Team's  Mission
              The mission of the Permeable Reactive Barriers Action Team is to accelerate the
              development of cost-effective permeable barrier technologies. The Action Team
              undertakes development and evaluation efforts needed to achieve public and regu-
              latory acceptance of this technology. The efforts focus on:

                Defining the hydraulics, geochemistry, and reactions that occur in the
                media and aquifers
                Demonstrating  and validating the technology's effectiveness
                Developing protocols, guidance, and issue papers on design and effective
                implementation
                Documenting effective emplacement techniques and  configurations
                (engineering design and constructability)
                Conducting an economic analysis of treatment cost
              Accomplishments
                                       Action Team members assisted with the design of the U.S. Air Force study, enti-
                                       tled "Catalytic In Situ Treatment of Chlorinated Solvents," and field work for the
                                       pilot-scale demonstration at the Area 5 site, Dover Air Force Base, Delaware. The
                                       Action Team also is actively involved in research and technology evaluation activ-
                                       ities at the U.S. Coast Guard (USCG) site near Elizabeth City, North Carolina.

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The Action Team, in cooperation with EPA's Office of Research and
Development, published "Permeable Reactive Barrier Technologies for
Contaminant Remediation" in 1998. The document provides the most recent
information on permeable reactive barrier (PRB) technologies. The document is
available on the Team's home page on the RTDF World Wide Web site.

Conceptual ConGguration of Permeable Barrier System
            RTDF
                                           Permeable Reactive
                                                 Barrier
                                                  Treated
                                               Ground Water
 Also in 1998, the Action Team prepared a status report on the use of permeable
 reactive barriers (PRBs) for ground-water remediation in the United States,
 Canada, and selected locations abroad. The report, available on the Team's home
 page on the RTDF Web site, includes profiles of about 30 ongoing and completed
 pilot- and full-scale PRB demonstrations and full-scale installations and a search-
 able bibliography of PRB-related articles and publications.


 The Action  Team's Plans

 The Action Team, in partnership with the Interstate Technology Regulatory
 Cooperation (ITRC) Permeable Barriers Working Group, has developed a training
 course and manual to assist regulatory professionals in overseeing the design,
 implementation, and monitoring of ground-water remedies that involve the
 deployment of permeable reactive barriers (PRBs). The course will be offered in
 each EPA Region in 1999 and 2000.

 The Action Team's Steering Committee has launched a coordinated research
 effort focusing on the long-term performance of PRB's (i.e. how long will they
 work), the major issue restricting further acceptance and deployment of this tech-
 nology. The project will involve use of common techniques and monitoring
 approaches at selected PRB sites, collection and sharing of comparable data
 about PRB performance at each site over time, and development of peer-reviewed
 final reports on project milestones.


Action Team  Members

 The Action Team includes representatives from industry, government, and acade-
 mic organizations, such as the following:

         Industry
         DuPont Company
         EnviroMcial Technologies
 EnviroSources
 General Electric
 Ckornaiax
 In Situ Burners
 MtcMurcus Resources
n                                          Government

                                          U.S. Air Force
                                          U.S. Army Corps of Engineers
                                 U.S. Department of Energy
                                 U.S. Environmental Protection Agency
                                 U.S. Geological Survey
                                          Academia

                                          University of Waterloo
        Would You

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Moire Information?
  For more information on the Permeable
  Reactive Barriers Action Team, please
      contact the Team Co-chairs:
           Bob Puls, Ph.D.
  U.S. Environmental Protection Agency
      National Risk Management
         Research Laboratory
              P.O. 1198
           Ada, OK 74820
          Tel: 580-436-8543
      Email: puls.robert@epa.gov
           John Vidumsky
     Superfund Program Manager
      DuPont Specialty Chemicals
       Jarley Mill Plaza 27/2226
:     Lancaster Pike and Route 141
                                                                                       Tel: 3024$>2-1378
                                                                            FB*- Bun* irtfarmatiofl oft &E HHB? or other,
                                                                            Action Teams, please visit the RTDF World
                                                                            Wide Web site 3<: ywByrtdf.org or contact:
                                                                              "US. Environmental Proteetidti .Agtncy
                                                                                26 West Martin Luther King Drive
                                                                                     Cincinnati, OH 05268
                                                                             ' E-niailt olexsey.bob@epiimail.epa.gov
                                                                              *     Walter Kovalick, Jr., Ph.D.
                                                                              U,S, Environmental Protection Agency
                                                                                   401 M Street, SW (51026)
                                                                                    Washington, DC 24060
                                                                                       Tjsfc
 To request other RTDIf fact sheets, please
             write/call:
,,, ,  ,       EPA/NSCEP
           RO, Box 42419
 , -'     aaclana^ OH 45243
         Phone;
                                                                           djipied on Recycled Paper

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