On January 16, 2001, the following members of the Remediation Technologies Development Forum’s (RTDF’s) Phytoremediation Action Team, Total Petroleum Hydrocarbon (TPH) in Soil Subgroup, met in a conference call:

Lucinda Jackson, Chevron Corporation (Subgroup Co-Chair)
Jim Brown, Lockheed Martin
Steve Geiger, ThermoRetec, Inc.
Peter Kulakow, Kansas State University (KSU)
Royal Nadeau, U.S. Environmental Protection Agency (EPA)
Steve Rock, EPA
David Tsao, BP Amoco
Duane Wolf, University of Arkansas

The TPH in Soil Subgroup has created a field study program to evaluate how effectively plants degrade petroleum hydrocarbons. Call participants provided updates on sites that are participating in the program.

• Site A. Lucinda Jackson noted that fertilizer was recently applied to Site A. Soon after, the site received much rain; thus, robust growth is anticipated.

• Site B. Steve Rock said that trees were first established at this site about two years ago. Since the project’s inception, several replanting events have taken place. Peter Kulakow said that he is currently processing root samples that were collected from trees at Site B.

• Sites C, D, and E. Mike Reynolds is the Subgroup member involved with Sites C, D, and E. Jackson asked whether anyone had talked to Reynolds recently to obtain an update on the sites. None of the call participants had done so.

• Site F. Steve Geiger said that he and Kulakow visited Site F in October 2000. Willows were planted at this site about two years ago, Geiger said; the trees are now about 15 feet tall. Kulakow said that he collected root samples from the willows. Geiger also indicated that time two (T₂) samples were recently collected from the site and that these samples have been forwarded to the Arthur D. Little Laboratory (ADL).

• Site G. Kulakow said that Site G’s time one (T₁) samples have been collected and sent to ADL for analysis.

• Site H. David Tsao said that the fate of Site H is still uncertain. A phytoremediation demonstration project has not been established yet; it is unclear whether such a project will come to fruition.

• Site I. Tsao said that a phytoremediation project has been initiated at Site I. Sample collection activities are underway. (Some of the samples were collected before a recent snowfall. The rest will be collected once the snow melts.)

• Site J. Duane Wolf said that samples will be collected from Site J in the spring—before the second growing season starts.

Royal Nadeau said that he is working on phytoremediation projects at two sites, neither of which are currently listed as official "Subgroup" sites. He said that plant growth has not been overly robust at one of the sites, noting that arid and saline conditions have posed challenges. At the other site, located in Pennsylvania, much rain falls and plant growth is strong. Nadeau said that soil at this site, which was impacted when heating oil tanks leaked, has been contaminated with petroleum products similar to Number 4 oil. As part of the phytoremediation demonstration project, he said, one cold season grass and several warm season grasses have been planted. The former serves as a "nurse" crop for the latter. The only danger associated with nurse crops, Nadeau said, is that excessively robust growth of the nurse crop can impede the growth of warm season grasses if too much shade is provided. Nadeau said that contaminant concentrations have decreased at the site, but noted that degradation rates in vegetated plots are indistinguishable from those in nonvegetated plots. Thus, it is not possible, at least at this point, to say whether the plants are responsible for the desirable outcome.

EPA’s Office of Research and Development has issued a request for proposals for phytoremediation research projects. The proposals must be submitted by January 22, 2001. Rock said that EPA will probably award the grants by June 2001.

Wolf said that he and his colleagues are submitting a proposal. Their proposed project involves evaluating phytoremediation’s impact on microbial community structure, Wolf said, noting that phospholipid fatty acid analysis techniques could be used to determine which microbial species are causing oil to degrade at Subgroup sites E and J.

Kulakow said that he plans to submit two proposals, asking for funds to:

• Evaluate polycyclic aromatic hydrocarbon bioavailability at Subgroup sites A, B, F, G, I, and J. Kulakow said that KSU hopes to collect soil samples from six Subgroup sites at the end of each site’s third growing season. Soils collected from nonvegetated and vegetated plots would be evaluated, he noted, using a variety of bioavailability assays to determine whether plants cause changes in bioavailability. Jackson asked whether Kulakow had talked to Kirk O’Reilly about the proposal, noting that O’Reilly has expressed reservations about using bioassay tests to measure bioavailability. Kulakow said that he did talk briefly with O’Reilly, but would initiate a more detailed dialogue in the near future. This proposal, said Kulakow, also outlines greenhouse studies that the research team hopes to perform. In addition, it indicates that the team plans to evaluate some mature rhizosphere conditions to obtain an understanding of the long-term potential of phytoremediation.

• Monitor soil temperature and moisture at Subgroup sites G, I, and J. Kulakow said that KSU and EPA’s Stacy Lewis Hutchinson are collaborating on this effort. Tsao agreed to send Kulakow letters that pertain to Site I; this information is needed for the proposal.

Subgroup members agreed that it would be useful to hold a meeting in fall 2001. They identified two options for their meeting:

• Hold a meeting in conjunction with the October 22–25, 2001, Contaminated Soils Conference in Amherst, Massachusetts. Rock said that the Subgroup might be able to schedule a meeting immediately before or after the Contaminated Soils Conference. He also said that it might be useful to have an RTDF member give a presentation during one of the Contaminated Soils Conference’s sessions. Call participants were enthusiastic about Rock’s suggestions. They agreed that at least one Subgroup member should attend the Contaminated Soils Conference to give a presentation. Kulakow agreed to submit an abstract on the Subgroup’s behalf by February 15, 2001.

• Hold a stand-alone RTDF Phytoremediation Action Team meeting. Rock noted that the TPH in Soil Subgroup is one of three Subgroups within the RTDF Phytoremediation Action Team. All three Subgroups could gather, he said, for a two-day meeting. Call participants agreed that this was an interesting possibility, and listed the following cities as potential meeting locations: Cincinnati, Ohio; Denver, Colorado; St. Louis, Missouri; and Manhattan, Kansas. If either of the latter two locations were chosen, call participants noted, it might be possible to visit a Subgroup site.

Call participants did not decide which of the above-listed options they preferred. They agreed to think about the possibilities and make a decision over the next couple months. Rock said that he would also contact Terry McIntyre to determine whether he plans to hold a meeting in fall 2001.

Kulakow has received cost data for Sites B and F, but still needs data from the remaining Subgroup sites. Rock acknowledged that generating cost data is difficult, noting that some team members are reluctant to release numbers because they fear them to be non-precise. Rock encouraged call participants to generate their best estimates and send data to Kulakow before the next Subgroup conference call.

Kulakow said that he will generate cost estimates for Site G. At this site, contaminated soil was excavated from one location and spread over the demonstration area. Kulakow asked whether the cost estimate should include costs associated with moving the soil. Geiger said it should, noting that site F’s estimates included such costs. He reminded Subgroup members that two cost spreadsheets are being generated: one that tracks costs associated with demonstration projects and one that predicts how expensive it would be to perform full-scale projects. When pulling together costs for the demonstration project, he said, one should include all costs associated with the effort.

Call participants asked for the most recent versions of the cost spreadsheet templates. Geiger and Kulakow agreed to post these on the password-protected area of the RTDF Web site.

Call participants talked about the following miscellaneous topics:

• Using trees to clean up petroleum-contaminated sites. Nadeau asked why trees, rather than grasses, are being used at some Subgroup sites. Rock and Kulakow cited two reasons: (1) tree roots have broader reach, and (2) forest communities are the native ecosystem at some of the sites.

• Plant tissue analysis. Jackson said that a protocol for analyzing plant tissue must be developed by June 2001. Kulakow said that he has gathered information that might help with protocol development but has not yet compiled this information into a cohesive methodology.

• Follow up with ADL. Jackson noted that the following had been listed as an action item during the last Subgroup call: "Subgroup members will contact Henry Camp to let him know when samples will be sent to ADL. Call participants will remind Camp that results are needed in a timely fashion." Jackson asked whether any call participants had followed up on this action item. Rock and Kulakow did. Kulakow said that he thought ADL would provide analytical results on the Subgroup samples by June 2001, in time for inclusion in the Subgroup’s annual report.

• International interest in phytoremediation. Call participants noted that phytoremediation is on the agenda of several international meetings. At some point, Rock said, the United States may want to reach across the oceans to collaborate with researchers from other countries.

• A software program that measures vegetative cover. During the last conference call, Jackson noted, Wolf described a software program that can be used to measure vegetative cover. She asked Wolf to describe how it works. Wolf said it estimates ground cover percentages by distinguishing between colors in digital photographs. He said that he has not had a chance to gather additional information about the software program, but agreed to do so before the next Subgroup conference call.

• Funding for KSU. Jackson noted that KSU has been supporting the Subgroup by processing raw data, tracking the progress of Subgroup field sites, performing site visits and plant assessments, and writing annual reports. Funding for KSU’s support will cease in July 2001, but EPA’s Technology Innovation Office (TIO) has indicated interest in extending the funding through 2003. Kulakow agreed to create a proposal to formally request the continued funding.

• The Subgroup’s annual report. Rock said that the Subgroup’s first annual report has been posted and is available to the public. Kulakow said that the second annual report will be completed in June 2001. Call participants agreed that the June 2001 report should be peer-reviewed before being released to the public. Rock said that formal reviewers will be identified; they will be asked to review the report at the same time that other Subgroup members are reviewing it.

• Call participants agreed that it would be useful for Kansas State University to continue supporting the Subgroup. Kulakow agreed to prepare a proposal to ask for continued funding.

• Kulakow agreed to talk to O’Reilly offline about using bioassay tests to measure bioavailability.

• Tsao agreed to fax Kulakow some letters that pertain to Site I.

• Wolf and Kulakow will complete proposals for grants that are being offered by EPA’s Office of Research and Development.

• Call participants agreed that at least one Subgroup member should present information about the Subgroup at an October 2001 meeting that is scheduled to take place in Amherst, Massachusetts. Kulakow agreed to submit an abstract to ensure that the Subgroup obtains a spot on the meeting’s agenda. (Abstracts are due on February 15, 2001.)

• Rock will call McIntyre to determine whether he plans to hold a meeting in October 2001. Rock will also ask McIntyre whether Phytorem is available. (Phytorem is a database that lists plants that accumulate, tolerate, or hyperaccumulate metals.)

• Wolf described a software program that uses digital photographs to provide information about vegetative cover. He agreed to obtain more information about the software.

• Call participants agreed to start posting materials on the password-protected section of the RTDF Web site.

• Call participants agreed to send Kulakow cost information before the next Subgroup conference call.

• ERG agreed to set up the next TPH in Soil Subgroup conference call for February 27, 2001, between 12:30 and 2:00 Eastern Standard Time.