SUMMARY OF THE REMEDIATION TECHNOLOGIES DEVELOPMENT FORUM
PHYTOREMEDIATION ACTION TEAM
TOTAL PETROLEUM HYDROCARBON IN SOIL SUBGROUP
CONFERENCE CALL

July 27, 2000
12:30-2:00 p.m.

On July 27, 2000, 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)
Peter Kulakow, Kansas State University
Royal Nadeau, U.S. Environmental Protection Agency (EPA)
C. M. (Mike) Reynolds, U.S. Army Cold Regions
Steve Rock, EPA

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

UPDATE ON FIELD DEMONSTRATION SITES

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:

Sites C, D, and E

Mike Reynolds said that phytoremediation demonstration projects have been initiated at Sites C, D, and E. Four types of treatment plots have been established at each site: (1) unplanted/fertilized, (2) unplanted/unfertilized, (3) vegetated/fertilized, and (4) vegetated/unfertilized. The vegetated plots, Reynolds said, were planted with the standardized grass/legume mixture that is recommended in the Subgroup's protocol; the grasses have become the dominant species over time. Reynolds said that soil samples are collected from each site twice a year and are analyzed for a variety of parameters.¹ Reynolds provided an update on the results collected from each site:

• Site C. Reynolds said that plants have grown on Site C's vegetated plots, but noted that growth is not too thick. Nevertheless, results indicate that the plants have enhanced contaminant degradation rates. Reynolds said that degradation rates are higher in the vegetated/unfertilized plots than they are in the vegetated/fertilized plots. He expressed some surprise about this finding, but said that he has identified one possible explanation: too much fertilizer may have been added to the fertilized plots and this may have caused an inhibitory effect.

• Site D. Reynolds said that the demonstration project at Site D is essentially done. Contaminant concentrations, which were low to start with, do not appear to be decreasing anymore. Reynolds said that the demonstration project was a success. Results indicated that plants enhanced contaminant degradation rates. (A statistically significant difference in contaminant reduction rates was observed between plots that had plants [i.e., the vegetated/fertilized and vegetated/unfertilized plots], and those that did not.) Reynolds said that this held true at both of the sampling depths that were evaluated. Royal Nadeau asked what regulators think about the results, and whether they agree that the demonstration has been a success. Reynolds said that the regulators may require investigators to collect another set of samples and have them analyzed at a state-certified laboratory. Then, if contaminants are shown to be below established cleanup targets, the regulators would consider the project a success. (Reynolds said that the target levels keep changing, noting that he just received a revised version of the state's regulations the other day.) Reynolds said that the demonstration project at Site D was performed in a dry and well-drained area. Some consideration is being given, he said, to initiating another project at the site, focusing investigations on a swampy area instead.

• Site E. Reynolds said that Site E, which is fairly wet, has been contaminated by a wide range of petroleum wastes. As a result, contaminant distribution and composition varies greatly across the site. This variability presents a challenge: it will be difficult to show that plants are causing any statistically significant reduction in contaminant concentrations. (Reynolds said that efforts have been made to normalize the data, but these have had limited success. Peter Kulakow was not surprised because the contaminants at the site do not come from the same source. If they had, Kulakow said, it may have been possible to normalize the data using biomarkers.) Reynolds said that investigators have identified another way, however, to show that plants could be promoting cleanup. That is, they hope to show that the vegetated plots support more robust communities of hydrocarbon-degrading microbes. So far, such an effect has not been observed in the vegetated plots, but has been seen in the unvegetated/fertilized plots.

Call participants thanked Reynolds for the comprehensive site updates. Kulakow followed up by asking one question: if the phytoremediation demonstrations prove successful, will efforts be made to implement full-scale remediation projects? Reynolds said that this is the ultimate goal, at least for Site E, where there is hope that a full-scale phytoremediation project will be implemented and then maintained by Native American communities. Nadeau said that he thought this was an excellent idea, noting that he is also working on a phytoremediation site that is supposed to be transitioned to community groups in the future.

Other RTDF Subgroup Sites

• Site A. Kulakow said that time two (T₂) samples have been collected from Site A and are being analyzed by the Arthur D. Little Laboratory (ADL).

• Site B. Kulakow said that he just recently received results for Site B's September 1999 sampling event.

• Site J. Kulakow said that ADL is in the process of analyzing Site J's samples. Results will be released in two batches, the first of which will be released in early August 2000.

• Site K. Steve Rock said that Battelle is analyzing samples that were collected from Site K. Results should be available soon.

SUBGROUP'S ANNUAL REPORT

Call participants noted that Kulakow has written the first of a series of annual Subgroup reports. They said that the report should be published after being peer-reviewed. Call participants agreed that Nadeau and Al Venosa would be excellent reviewers. Thus, Rock agreed to send the report to both of them, along with an official review form. Kulakow asked whether all of the Subgroup members should be listed as the report's authors. Rock said that Kulakow should be listed as the author, and that all Subgroup members who contributed data should be listed in an acknowledgments paragraph.

The complete version of the annual report will only be distributed among Subgroup members at this point. (Some Subgroup members want to keep site-specific data protected for the next few years.) However, call participants agreed that it would be fine to post the report on the Internet if the Subgroup's raw data are removed first. Kulakow agreed to contact David Tsao to make sure that he agrees with this plan.

PLANT TISSUE ANALYSIS

After demonstration projects have been established for 30 months, plant tissues will be collected and analyzed to determine whether hydrocarbons accumulated within them. Kulakow said that he talked to Henry Camp, a representative from ADL, about methodologies that are used to assess plant tissues. Kulakow said that Camp agreed to look into methods that ADL has used and to get back to him. In the meantime, Kulakow said, Camp recommended trying to find out whether Chevron has generated methodologies. Nadeau said that he knew of a methodology for extracting hydrocarbons from plant tissue. He agreed to distribute the paper to Subgroup members.

SOIL SAMPLE ANALYSIS

Kulakow noted that the Subgroup's soil samples are not all being evaluated at the same laboratory. To make sure that results are comparable, he said, a standard sample is supposed to be analyzed with each batch of Subgroup samples that are evaluated. Kulakow said that he does not think the standard sample was ever sent to Battelle's Columbus laboratory. It should be, he said, before fall 2000. Kulakow said that he called a representative from the Battelle laboratory recently and asked for information about the analytical method that the laboratory is using to evaluate Site K's samples. Kulakow was advised to obtain a copy of the site's Quality Assurance Project Plan to obtain the information that he seeks.

COST ESTIMATES

The Subgroup plans to track the costs that are associated with their demonstration projects and to make predictions on how expensive it would be to perform full-scale projects. Kulakow said that cost data are needed for all of the Subgroup's sites, but he has not received data for any yet. Lucinda Jackson said that she has gathered these data for Site B and agreed to fax the information to Kulakow. Jackson said that it might be helpful if Kulakow sent e-mails to Subgroup members, reminding them to submit their cost data.

REGULATORY ISSUES

Nadeau said that a presidential order has been issued to address invasive species. It states that native species should be used on all federal projects if possible. For this reason, Nadeau said, he is trying to use native species in many of the phytoremediation and restoration projects that he is working on. (Nadeau said that a presidential order does not carry the same level of legality as a regulation does, but said that people who work for the federal government are obliged to acknowledge it.)

Jackson asked whether efforts have been initiated to write regulations for phytoremediation technologies. Rock and Nadeau said that they did not know of any. Rock said that he doubted such regulations would ever be written, noting that regulations are rarely written to address specific technologies. That is not to say, Rock stressed, that phytoremediation would not have to meet existing regulations. For example, he said, phytoremediation could not be used if it were shown to release gases in quantities that exceeded emission standards. Also, plants would have to be disposed of according to waste disposal regulations if they were shown to accumulate hazardous contaminants within their tissues.

PHYTOREMEDIATION PAPERS

Nadeau said that he recently read a paper entitled Assessment of Phytoremediation As an In Situ Technique for Cleaning Oil-Contaminated Sites that offered a comprehensive review of phytotechnologies. He asked whether call participants knew if the paper was citable. Rock said that he thought the paper could be cited as an Environment Canada document. Nadeau said that he would try to find a publication number for the paper.

Call participants also talked about papers that are currently being written. Rock said that Steve McCutcheon is leading an effort to generate a comprehensive book on phytotechnologies. Jackson said that Advances in Biochemical Engineering/Biotechnology is writing a special edition that will focus on phytoremediation, and that she, Tsao, and Evelyn Drake have all agreed to contribute to it. Kulakow said that he will too.

MISCELLANEOUS TOPICS

• Reynolds said that he is working on phytoremediation demonstration projects at two sites in Korea. (These sites are not RTDF Subgroup sites.) At both sites, he said, evidence suggests that vegetation enhances cleanup. TPH values have not been significantly impacted, he said, but significant reductions in large (i.e., three to four rings) polycyclic aromatic hydrocarbons have been observed in vegetated/fertilized plots and vegetated/unfertilized plots.

• Nadeau asked if plants have been used to clean up tars. None of the call participants knew of projects that have addressed these materials.

• The Interstate Technology and Regulatory Cooperation Work Group plans to release a technical and regulatory guidance document in the near future. Rock asked whether Kulakow and Jackson would be interested in reviewing the document. They agreed to do so.

• Rock said that he will present training materials and a case study at a phytoremediation workshop that is being held for EPA project managers. Rock agreed to send Jackson a copy of the materials and the case study. He said that he has also been asked to make the materials available via the Internet and CD-Rom.

ACTION ITEMS

• Call participants agreed that Nadeau and Al Venosa would be excellent reviewers for the Subgroup's annual report. Rock agreed to send the report to both of them, along with an official review form.

• Call participants agreed that it would be fine to post the annual report on the Internet if the Subgroup's raw data are removed first. Kulakow agreed to contact Tsao to make sure he agrees with this plan.

• Nadeau said that a methodology for plant tissue analysis is available. He agreed to distribute it to Subgroup members before the next Subgroup conference call.

• Kulakow said that cost data are needed for all of the Subgroup's sites. Jackson said that she has gathered these data for Site B and agreed to fax the information to him. Jackson said that it might be helpful if Kulakow sent e-mails to Subgroup members, reminding them to submit their cost data.

• Nadeau agreed to find out whether a publication number has been assigned to a paper entitled Assessment of Phytoremediation As an In Situ Technique for Cleaning Oil-Contaminated Sites.

• The Interstate Technology and Regulatory Cooperation Work Group plans to release a technical and regulatory guidance document in the near future. Kulakow and Jackson agreed to serve as reviewers.

• Rock agreed to send Jackson training materials and a case study.

• ERG agreed to set up the next conference call for September 14, 2000, between 12:30 and 2:00 p.m., Eastern Daylight Time.

1 Parameters analyzed include TPH, biomarkers, and the 16 priority polycyclic aromatic hydrocarbon pollutants. Efforts have been made to analyze some of the samples using the TPH Criteria Working Group methodology. Limited funds prevent investigators from analyzing every sample for a full suite of parameters, however.