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

1:00 p.m.-2:00 p.m.
March 14, 2002

On Thursday, March 14, 2002, the following members of the Remediation Technologies Development Forum's (RTDF's) Chlorinated Solvents Subgroup met in a conference call:

Bob Tossell, CH2M Hill, Inc.
Harry Compton, U.S. Environmental Protection Agency (EPA)
Linda Fiedler, EPA
Jim Jordahl, CH2M Hill, Inc.
Valentine Nzengung, University of Georgia
Xiujin Qiu, The Dow Chemical Company

Also participating in the call was Christine Hartnett from Eastern Research Group, Inc. (ERG).

SUBGROUP PROTOCOL

The Subgroup has been working on a protocol that describes how to assess phytoremediation at chlorinated solvent sites. Bob Tossell said that a revised version of the protocol was distributed on March 13, 2002. The following comments were provided during the call:

• Terminology. Valentine Nzengung advised being consistent with terminology. He noted that "phytotechnology" is used in some parts of the text, while "phytoremediation" is used in others. Call participants agreed to use "phytoremediation" throughout the document, defining the term the first time it is used and making it clear that phytoremediation is one type of phytotechnology.



• Plant pumping rates and plant density. Call participants agreed that it would be useful to provide some rough numbers on: (1) the amount of water that trees pump and (2) the plant density that is required to achieve certain pumping rates. If at all possible, Nzengung said, efforts should be made to provide information on how the numbers differ across different soils and climatic regions. Nzengung, Tossell, Harry Compton, and Jim Jordahl will work together on this section.



• Plant selection. Call participants agreed that the document should discuss the drawbacks associated with monoculture. (If a disease enters a plantation, for example, all of the trees could be killed.) Tossell agreed that it is important to advocate a sustainable system that will be viable over the long term. Thus, the protocol will point out the merits associated with mixed-plant phytoremediation plantations. Xiujin Qiu said that she has a document that addresses this topic; she will send it to Tossell.



• Cost. Qiu and Compton agreed to send Tossell information on the cost associated with phytoremediation sites. In addition, Linda Fiedler will provide a list of cost items that phytoremediation users should keep track of. (She will gather this information from a Federal Remediation Technologies Roundtable document.)



• Site enhancement. Nzengung said that some phytoremediation sites that are labeled "failures" may simply require a design enhancement to achieve success. He agreed to write a section that discusses the importance of evaluating systems to determine whether they require enhancement.



• Methodologies. Compton will provide text for the air monitoring section. Nzengung will provide input on plant sampling.



• Analytical protocols. Qiu agreed to provide input on this section.

Tossell asked Subgroup members to send him written comments and new text by April 4, 2002. He agreed to incorporate this information and to distribute a revised protocol by April 11, 2002. The new protocol will be discussed during the Subgroup's April 18, 2002, conference call.