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

May 30, 2001
1:00 p.m.-2:30 p.m.

On May 30, 2001, the following members of the Remediation Technologies Development Forum's (RTDF's) Phytoremediation Action Team, Chlorinated Solvents Subgroup, met in a conference call:

Bob Tossell, CH2M Hill, Inc.
Milton Gordon, University of Washington
Steve Rock, U.S. Environmental Protection Agency (EPA)
Keith Rose, EPA

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

THE SUBGROUP'S DOCUMENT

The Chlorinated Solvents Subgroup is developing a document that describes what tests need to be performed to determine whether phytoremediation is appropriate to use at a contaminated site. The document is intended to serve as a useful tool for regulators, as well as consultants and site owners who are interested in testing phytoremediation technologies. Call participants talked about the progress being made on the text, and discussed how the document should be structured to maximize its usefulness. The current version of the document, Steve Rock said, is detailed and provides a thorough introduction to phytoremediation concepts. Although this type of detailed text has great value, Rock said, it might be wiser for the Subgroup to focus its efforts on creating a more concise protocol that follows a "checklist" format. He envisioned a five-page document that lists the tests that are needed to prove, beyond a reasonable doubt, that phytoremediation is successful at a site. Appendices could be added, Rock said, to provide additional information about test methodologies. This type of approach was used by the RTDF's TPH in Soil Subgroup, Rock said, and has been very successful. (A copy of the TPH in Soil Subgroup's protocol can be found at http://www.rtdf.org/public/phyto/protocol/protocol99.htm.) Bob Tossell agreed that it is important to generate a concise step-by-step "recipe," noting that he was planning to include one as a subsection to the Subgroup's document. Call participants agreed that it is difficult to determine exactly how much information to provide when trying to maximize the usefulness of a document. One document that did a good job striking a balance, Rock said, is Jonathan Chappell's Phytoremediation of TCE in Groundwater using Populus. (This document is available at http://www.clu-in.org.)

EXPANDING THE SUBGROUP'S MEMBERSHIP/ESTABLISHING A LINK WITH THE CENTER FOR WASTE REDUCTION TECHNOLOGIES (CWRT)

Tossell noted that only a small number of people are currently serving as the Subgroup's core membership. He asked whether additional members should be recruited, and if efforts should be made to identify members who can contribute funds to the Subgroup's efforts. He noted that other RTDF groups have pursued this avenue, and have recruited members who bring funds to the table. As the Subgroup's protocol approaches completion, Keith Rose and Milton Gordon agreed, it would be useful to recruit people who are interested in applying the protocol in the field. Gordon said that representatives from the National Institute of Environmental Health Sciences (NIEHS) might be able to contribute to the group.

Tossell said that it might be useful to establish a link between the Chlorinated Solvents Subgroup and the CWRT, noting that the latter consists of a consortium of companies, many of which are Fortune 500 chemical companies. Tossell said that CWRT has been interested in phytoremediation for quite some time. In fact, a couple years ago, CWRT hired CH2M Hill, Inc. to write a document on different ways that phytoremediation can be applied. Tossell said that CWRT is interested in testing phytoremediation's ability to clean up chlorinated ethanes and ethenes, as well as chlorinated benzenes. Tossell recently learned that CWRT is interested in performing a three-year phytoremediation pilot study at a site in the eastern part of the country. If enough CWRT members express interest in the pilot study proposal, Tossell said, CWRT will put forth funds to conduct the demonstration project and will initiate field activities in spring 2002. Tossell believes there is some common ground between the CWRT and the Chlorinated Solvents Subgroup. Thus, he recommended establishing communication between the groups. None of the call participants expressed opposition to this idea. Tossell said that he would like input from more Subgroup members before establishing a link; thus, this topic will be discussed again during the next Subgroup conference call.

MISCELLANEOUS TOPICS

Call participants talked about the following miscellaneous topics:

• Work being performed by the University of Washington. Gordon said that the University has performed experiments to compare the efficacy of willows and cottonwoods. Under certain circumstances, he said, the former do a better job taking up water and metabolizing compounds. In addition, Gordon said, research efforts are underway to determine how well evergreens perform in moderate climates. Also, Gordon noted, field studies that the University has been conducting with Occidental Chemical Corporation's help are slated to continue for another four years.
• A phytoremediation project in Wyoming. Rock and Tossell said that willow trees and cottonwoods are being used at a site in Wyoming. The willows have been planted in low-lying areas close to the water table; the cottonwoods have been planted at higher elevations. The site is located about 7,200 feet above sea level, is subject to strong winds, and has a short growing season.
• Publishing data on phytoremediation projects. Several phytoremediation studies are currently ongoing throughout the country. With so much work going on, Tossell said, it is surprising that so little data have been published. Data need to be published, he said, so that phytoremediation becomes a better known technology. Rock thought this was an excellent point, noting that some regulators have never even heard of phytoremediation. Gordon said that the University of Washington hopes to publish some papers soon.
• Next Subgroup conference call. The next Chlorinated Solvents call will be held on June 21, 2001, between 1:00 p.m. and 2:30 p.m., Eastern Daylight Time.