From Ground Water Currents, September 1996, Issue No. 16

Chlorinated Solvents Consortium

The Bioremediation of Chlorinated Solvents Consortium (Consortium) is one of the five Action Teams of the Remediation Technologies Development Forum (RTDF). The RTDF was created by EPA in 1992 to foster collaboration between the public and private sectors. The specific mission of the Consortium, created in May 1993, is to accelerate the development of the most cost-effective in-situ bioremediation processes for degrading chlorinated solvents. The Consortium is composed of representatives from various companies (Beak International, Ciba-Geigy Corporation, Dow Chemical Company, DuPont, General Electric, ICI Americas, Monsanto Company and Zeneca, Inc.), universities, EPA, the Departments of Defense (DoD) and Energy (DOE) and the U.S. Air Force.

To accomplish their mission, each of the Consortium members jointly participates in the research, development, demonstration and evaluation efforts necessary to achieve public and regulatory acceptance of these biological processes. Consortium members contribute personnel, equipment, laboratory facilities and funding. The companies are sharing proprietary information, patented technologies and their collective understanding and experience in bioremediation mechanisms and kinetics, hydrogeology and nutrient delivery systems to support development and testing. The Federal sector brings substantial bioremediation expertise and laboratory experience, tools for microbial characterization and site characterization and experience in the development and field testing of bioventing processes.

Shortly after the Consortium was formed, they began developing a comprehensive research plan to test and evaluate the effectiveness of three complimentary in-situ bioremediation processes for degrading chlorinated solvents — natural attenuation, accelerated anaerobic degradation and cometabolic bioventing. Three Phase I field tests began at Dover Air Force Base in Dover, Delaware in early 1995. (See the article, Natural Attenuation Research at Dover, in this issue of Ground Water Currents for a detailed discussion of the natural attenuation research.) These Phase I projects will continue until 1998.

The three technologies have been identified as the remediation methods of choice in the Record of Decision (ROD) for the specific sites at Dover. Data from the first year of the Phase I field and laboratory studies are being analyzed by Consortium members. Extensive geological and hydrological characterization efforts have been completed to provide significant insight into the subsurface conditions. Initial laboratory biodegradation studies in batch, column, fed batch and differential soil bioreactors have been completed for each technology. Microbial characterization efforts have been initiated to determine the nature of the indigenous microorganisms responsible for degrading chlorinated solvents at the site. A number of characterization techniques, such as Most Probable Number direct count, Phospholipid Fatty Acid Analysis and molecular approaches (16sRNA) have been employed to this end. The Consortium also initiated modeling efforts to develop a tool that will help predict the performance of each of the bioremediation processes at other sites. Planning is underway to conduct field studies for each of the three processes at second sites.

The Consortium is in the process of gathering and analyzing characterization data for sites that might be appropriate for the Phase II studies. The Strother Field Industrial Park Site in Winfield, Kansas, has been selected for the Phase II Accelerated Anaerobic Biodegradation Study and the Intrinsic Bioremediation Study. Complementary efforts will be undertaken to validate the conclusions drawn from Phase I. Efforts to locate a suitable site for the Phase II Bioventing Study are in progress.

In addition, the Consortium has been in contact with the Western Governors Association (WGA) and the WGA's Interstate Technology and Regulatory Cooperation (ITRC) subgroup. The ITRC will provide assistance during the development and validation of the technology protocols, which will facilitate the transfer of the technologies to other sites.

For more information on the Consortium and the other RTDF Action Teams (LasagnaTM Partnership, Permeable Barriers, Sediments Remediation and IINERT Soil-Metals), contact EPA's Robert Olexsey at 76 West Martin Luther King Drive, Cincinnati, OH 45268 (telephone: 513-569-7861; or e-mail: olexsey.bob@epamail.epa.gov) or Walter Kovalick, Jr., Ph.D., at 401 M Street, S.W. (5102G), Washington, D.C. 20460 (telephone: 703-603-9910; or e-mail: kovalick.walter@epamail.epa.gov). To request copies of RTDF fact sheets, send a request to EPA/NCEPI by mail at 11305 Reed Hartman Highway, Suite 219, Cincinnati, OH 45241 or by FAX at 513-670-3815.