On November 13, 2002, the following people participated in a conference call for the Remediation Technologies Development Forum's (RTDF's) Phytoremediation Action Team, Total Petroleum Hydrocarbon (TPH) in Soil Subgroup:
Phil Sayre, U.S. Environmental Protection Agency (EPA) (Subgroup Co-Chair)
Henry Camp, ICF Consulting
Rich Farrell, University of Saskatchewan
Steve Geiger, ThermoRetec, Inc.
Peter Kulakow, Kansas State University (KSU)
Jessica Patino, Syracuse University
Richard Purdy, ICF Consulting
Steve Rock, EPA
Greg Thoma, University of Arkansas
David Tsao, BP America
Sarah Dun of Eastern Research Group, Inc., (ERG) was also present.
The TPH in Soil Subgroup has created a field study program to evaluate how effectively plants degrade petroleum hydrocarbons over a 3-year period. The following updates were provided on sites that are participating in the field study program:
Sites A and K. Sampling activities have been completed at Sites A and K, Peter Kulakow said. Data analysis is underway.
Site B. Time three (T3) soil samples were recently collected for Site B, Steve Rock said. The samples have been sent to ICF Consulting for analysis. During the sampling event, plant roots were found in the top of the clay, in the oil smear zone.
Sites C, D, and E. Kulakow said that Mike Reynolds is analyzing the data that have been collected for these three sites
Site F. Jessica Patino said that permission has been granted to extend sampling activities beyond the third growing season at this site. In fact, time four (T4) samples have already been collected and will be sent to ICF Consulting soon. Plant roots have grown laterally at Site F, infiltrating the site's control plots. It will be interesting to see, Steve Geiger said, what effect this will have on the control plots. In December, data on additional field parameters (e.g., willow biomass) will be collected.
Site G. Kulakow said that Site G's T3 samples have been collected and sent to ICF Consulting.
Site H. David Tsao said that time two (T2) samples have been collected from Site H and sent to ICF Consulting. The demonstration project at this site may have to be terminated prematurely: the site might be sold soon and redeveloped for residential usage.
Site I. T2 samples have been collected from Site I and sent to ICF Consulting for analysis.
Site J. Greg Thoma said that T3 samples will be collected from this site in December 2002. Efforts are underway to obtain funds for a T4 sampling event.
Site L. Plants were established at Site L in summer 2002, and time one (T1) samples were collected in October 2002. The planted plots looked very healthy, Rich Farrell said, until August, when grasshoppers raided the site. Some of the plants may have been killed by the grasshoppers; some replanting might be necessary.
Site M. Farrell said that plants will be established at this site in spring 2003.
Kulakow said that he and one of KSU's statisticians have been analyzing the field study program's data. Significant progress has been made analyzing individual variables, and efforts are now underway to start performing multivariate statistical analyses. Kulakow talked briefly about efforts that have been made to normalize Site F's data. At this site, which is a former manufactured gas plant (MGP), hopane cannot be used as a biomarker because it is not present at high enough concentrations. Alternative biomarkers are being examined, Kulakow said. He and his KSU colleagues have tried using a large polycyclic aromatic hydrocarbon (PAH) to normalize Site F's data, but this alternative has not proven to be very useful. In fact, Kulakow said, the normalization process created more noise and variability than it took away. (As analysis of variance test was performed on Site F's original data set and its normalized data set. A larger error value was associated with the normalized data set.) Kulakow asked call participants to send him suggestions if they know of other normalization techniques that might be useful. He is hopeful that some of the variability in Site F's T3 data set will disappear if he finds the correct normalization technique. Henry Camp expressed concern that the high degree of variability observed at Site F might be a reflection of analytical variability. He said that MGP sites typically have high PAH concentrations. When concentrations are very high and analytical instruments have been calibrated to detect low levels (as has been the case with Site F), several sample dilutions must be performed. This can lead to analytical errors.
Rock said that a large phytoremediation conference is scheduled to take place in Chicago, Illinois, in March 2003. A time slot will be reserved on the agenda for the TPH in Soil Subgroup. Kulakow recommended delivering two presentations: one on sample analysis issues (perhaps to be delivered by Camp), and one on the Subgroup's field study program results. In addition, call participants suggested setting up a poster session at the conference and preparing posters for each Subgroup site. Rock thought this was an excellent idea. Call participants also expressed interest in reserving time for a small breakout session so that Subgroup members could talk face to face in an informal setting.
Kulakow, who is working on the Subgroup's final report, asked whether the report will be released as an EPA document. Rock said it would, but encouraged Subgroup members to use the report as a springboard for additional articles and publications. Kulakow said that the final report will contain much of the same information that has been included in previous Subgroup annual reports. He recommended adding the following:
A list of projects and publications connected to the Subgroup's field study program. The Subgroup sites, Kulakow said, have attracted the interest of many people. As a result, several outside groups have performed studies on these sites. In addition, some investigators have used the Subgroup's protocol to set up additional (non-Subgroup-related) demonstration projects. Kulakow expressed interest in generating a list of all the projects and publications that have spun off from the Subgroup's efforts. This will help show how others have leveraged money spent on the Subgroup.
Detailed chapters about side projects and studies. Much of the research that has been performed at the Subgroup field sites goes above and beyond what the Subgroup's protocol specifies as mandatory. For example, detailed microbial analyses and root studies are being performed at some of the sites. Kulakow recommended including chapters on these topics and asking the researchers working on these topics to submit text. Rock thought at least one chapter should be dedicated to auxiliary research efforts.
The Department of Energy is soliciting proposals for projects that explore bioavailability issues. Proposals are only being accepted, however, for projects that focus on basic research. Geiger said that he is working with representatives from Lawrence Berkeley National Laboratory to develop a research project. The goal will be to evaluate contaminant sequestration and long-term bioavailability in organic matter.
Kulakow also hopes to perform some research on bioavailability issues. For example, he hopes to evaluate how contaminant bioavailability differs in soils that have been infiltrated by plant roots versus those that have not. Kulakow said that he may contact Subgroup members individually to find out whether they want these types of analysis performed on soil from their site.
Farrell will communicate with Camp to obtain the Subgroup's reference standard sample. (Farrell will send Camp information on where to ship the sample.)
Camp will be traveling for a few weeks. He will send Kulakow information on who to contact in his absence. Kulakow will distribute the contact information to Subgroup members.
Kulakow asked Subgroup members to send him a list of any projects, publications, or theses that have been even tangentially associated with the Subgroup's sites. In addition, he asked Subgroup members to let him know of any sites that are using the Subgroup's protocol.
Kulakow asked all Subgroup members to send him cost data for their sites.
Kulakow will send Rock and Sayre an estimate of the funds that KSU would need to continue supporting Subgroup activities through 2004. (Call participants said that KSU's support has been invaluable, noting that they hope KSU does indeed obtain additional funds.)
ERG agreed to set up the next TPH in Soil Subgroup conference call for January 8, 2003, between 1:00 p.m. and 2:30 p.m. Eastern Standard Time.