SUMMARY OF THE REMEDIATION TECHNOLOGIES DEVELOPMENT FORUM
PHYTOREMEDIATION ACTION TEAM
CHLORINATED SOLVENTS SUBGROUP
CONFERENCE CALL

July 6, 2000
2:00 p.m.-3:30 p.m.

On July 6, 2000, the following members of the Remediation Technologies Development Forum's (RTDF's) Phytoremediation Action Team, Chlorinated Solvents Subgroup, met in a conference call:

Milton Gordon, University of Washington (Subgroup Co-chair)
Keith Rose, U.S. Environmental Protection Agency (EPA) (Subgroup Co-chair)
Bob Tossell, GeoSyntec Consultants (Subgroup Co-chair)
Kelly Madalinski, EPA, Technology Innovation Office
Steve Rock, EPA

Also present was Christine Hartnett of Eastern Research Group, Inc. (ERG).

THE SUBGROUP'S PROTOCOL

The Chlorinated Solvents Subgroup is writing a protocol. Bob Tossell said that an outline has been created for the document, text has been generated for the first two sections, and the document's reference section has been started. Saying that the latest version of the document was distributed to Subgroup members on June 27, 2000, Tossell asked whether call participants had any comments to offer. Steve Rock, Milton Gordon, and Keith Rose said that Tossell had done a good job synthesizing the text that Subgroup members submitted for Sections 1 and 2. Call participants listed the sections that appear under and before these two sections:

Foreword
About This Document
Acknowledgments
List of Acronyms
Executive Summary
1.0 Introduction
       1.1 Purpose of Report
2.0 Background
       2.1 Chlorinated Solvent Properties
       2.2 Phytoremediation for Chlorinated Solvent Management
       2.3 Fate and Attenuation of Chlorinated Solvents in the Subsurface
              2.3.1 Dissolution
              2.3.2 Adsorption
              2.3.3 Advection and Dispersion
              2.3.4 Volatilization
              2.3.5 Microbial Attenuation
                   2.3.5.1 Chlorinated Ethenes
                   2.3.5.2 Chlorinated Ethane
                   2.3.5.3 Chlorinated Methane Degradation Mechanisms
              2.3.6 Plant Attenuation
       2.4 Phytoremediation Approaches
              2.4.1 Hydraulic Control of Contaminated Ground Water
                   2.4.1.1 Plume Interception
                   2.4.1.2 Source Control
                   2.4.1.3 Recharge Control
              2.4.2 Treatment of Contaminated Ground Water
                   2.4.2.1 "Standard" Systems
                   2.4.2.2 Aquifer Dewatering
                   2.4.2.3 Recycling Systems
                   2.4.2.4 Wetland Treatment Systems
                   2.4.2.5 Polishing Systems
              2.4.3 Innovative and Potential New Applications
                   2.4.3.1 Deep Ground-Water Control

Conference call participants offered the following comments on the draft document:

• Call participants discussed where to place "Section 2.4: Phytoremediation Approaches." Rose suggested addressing the topic in a stand-alone section. Rock recommended moving it to the front of Section 3.0.

• Call participants suggested shortening the text that is presented for "Section 2.3.5: Microbial Attenuation." Tossell said that he plans to do so.

• Gordon acknowledged that the University of Washington must complete a literature review before "Section 2.3.6: Plant Attenuation" can be completed. He said that a graduate student is working on this.

• Gordon noted that the draft document references information that was presented at conferences. He questioned whether this was acceptable, noting that some publications advise against including references of this sort, or referring to any other source that is not widely available to the public. Tossell said that some of the information cited comes from books that were compiled from Battelle conferences. He said that these books are readily available. Gordon's comment prompted Rock to peruse the document's reference list. He expressed some concern about references to submitted papers. If they were submitted a long time ago and have not yet been published, Rock said, it may not be wise to include them. Call participants agreed to discuss the topic of references in more detail at a later date.

• Rock said that he could help Tossell draft the "Acknowledgments" section.

• Tossell asked for comments on the document's title: A Guide for the Evaluation of Phytoremediation for Management of Chlorinated Solvents in Soil and Ground Water. Rock recommended eliminating "A Guide For."

• Rose asked whether the document will discuss how to manage chlorinated solvents that are present in soils. Tossell said that this topic will be addressed, and that the text will note that some plants are capable of stimulating both aerobic and anaerobic conditions in the subsurface.

Tossell asked Subgroup members to review the draft carefully and to submit comments to him by July 27, 2000. He said that he will incorporate the comments into the draft and release a new one before the next Subgroup conference call. In addition, Tossell said, he will continue to work with Jim Jordahl on Sections 3 and 4 of the document.

BOOKS AND JOURNAL PUBLICATIONS

Rock said that several people are working toward publishing information on phytoremediation. For example, he said, Steve McCutcheon and Jerry Schnoor are working together to create a book. Rock said that the book will be voluminous (about 600 to 700 pages long), will include several chapters, and will have numerous contributing authors. Two of the chapters will discuss trichloroethylene. In addition, Rock said, the Journal of Phytoremediation is putting together an issue that will summarize the proceedings of EPA's Phytoremediation State of the Science Conference that was held in Boston, Massachusetts, in May 2000. Rock said that one of the articles in the journal will summarize the session that Gordon, William Doucette, and Valentine Nzengung delivered on the fate of chlorinated solvents. Rock said that it might be possible for the Subgroup to write the review paper, noting that the information that was compiled for the Subgroup's protocol would serve as a useful springboard. If the Subgroup agreed to take on this project, he said, an article would need to be completed in August 2000. Rock asked whether Gordon had been planning to write a review paper. Gordon said that he is planning to write something, but he is reluctant to prepare a detailed review at this time. This is because some of the data that he presented were generated by one of his graduate students. He believes that she plans to publish the data soon, and does not want her to be unable to do so because some other entity already has the copyright on it.

ACTION ITEMS

• ERG will set up a conference call for August 3, 2000, between 1:30 and 3:00 P.M., Eastern Daylight Time.

• Subgroup members agreed to submit comments on the Subgroup's draft protocol to Tossell by July 27, 2000. Tossell will incorporate the comments and release a revised version before the Subgroup's August 3, 2000, conference call. Tossell will also continue to work with Jim Jordahl on Sections 3 and 4 of the document.