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

June 2, 2000
12:00-1:30 p.m.

On June 2, 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)
Steve Geiger, ThermoRetec, Inc.
Peter Kulakow, Kansas State University
Royal Nadeau, U.S. Environmental Protection Agency (EPA)
Steve Rock, EPA
Ross Smart, Chevron Corporation
Greg Thoma, University of Arkansas
David Tsao, BP Amoco
Duane Wolf, University of Arkansas
Christine Hartnett of Eastern Research Group, Inc. (ERG), was also present.

REGULATORY ISSUES

The RTDF Phytoremediation Action Team met on May 3, 2000, in Boston, Massachusetts. During the meeting's morning session, members of the TPH in Soil Subgroup presented information on the Subgroup's protocol, sampling plan, and analytical plan. Also during the meeting, the Subgroup solicited input from regulators to obtain a better understanding of issues that concern them. Lucinda Jackson said concern was expressed about contaminant byproducts, ecological risks, and plant waste management. Royal Nadeau said that these issues all stem from a common concern: the potential for contaminants to accumulate in plants. He acknowledged that this concern may be valid at sites contaminated with heavy metals and volatile organics, but questioned whether it is at sites with petroleum hydrocarbon contaminants. He said that some researchers believe plants simply provide a substrate for microbial degradation processes in the rhizosphere. Nadeau said that plant tissues were analyzed at one of the sites that he is working on. The results indicated that no site-related petroleum compounds had accumulated in plant tissues. Steve Rock asked whether the Subgroup could cite this data to address regulatory concerns. Nadeau advised against this, noting that his data set is not big enough to serve as the basis for a definitive conclusion. At this point, he said, researchers may have to address plant uptake issues individually, at each site that they work on. Rock acknowledged that this is true, at least while phytoremediation is in its infancy.

Jackson said that plant uptake will be evaluated for each of the sites that are participating in the Subgroup's field study program. After a system has been established for about three years, she said, plant tissues will be collected and analyzed for hydrocarbons. Kulakow noted that some of the Subgroup's sites will need to collect these samples next year. Thus, he recommending initiating earnest efforts to (1) decide how to best optimize the sampling event, (2) identify a sample collection and handling plan, and (3) identify an appropriate method for analyzing plant tissue samples. Subgroup members agreed. Toward this end, Nadeau offered to share the methods that were used to analyze plant tissues at his site. Jackson thanked him, saying that this would be an excellent springboard. She asked call participants to provide information on any other methods that they know of. Nadeau said that the analytical method that he will distribute is similar to the one that the Arthur D. Little (ADL) laboratory uses to assess soils. He stressed that the method evaluates petroleum compounds, but does not provide data on breakdown products.

David Tsao questioned how reasonable it is to expect researchers to measure potential breakdown products, since so little is currently known about plant degradation pathways. At this point, he said, it is difficult even to predict what the byproducts are. Jackson said that Tsao's point was an excellent one. If non-parent hydrocarbons are detected in a plant, she said, how would the Subgroup determine whether they represent byproducts or naturally occurring hydrocarbons? Nadeau said that collecting background data from plants in cleaner soil could help answer Jackson's question. In fact, he said, this approach was used at a site that he has worked on.

Rock agreed that useful information will be gleaned from the Subgroup's plant uptake analyses, but noted that it will take at least a couple more years to gather data from all of the sites. Rock advised against waiting this long to address regulatory concerns about plant uptake. He recommended performing a literature review to identify: (1) published and unpublished data that address plant uptake in petroleum-contaminated soils, and (2) plant tissue sampling and analysis techniques. He said that the Subgroup could then compile and summarize the information, and release it as a Subgroup paper. Rock acknowledged that such a paper would not provide definitive conclusions. It would, however, assure regulators that the Subgroup is committed to addressing plant uptake issues.

UPDATE ON FIELD DEMONSTRATION SITES

The TPH in Soil Subgroup has created a field study program to evaluate how effectively plants degrade petroleum hydrocarbons across a range of test sites. Conference call participants provided site updates.

Site A

Kulakow said that time two (T₂) sampling and assessment activities have been initiated. Plant biomass has been assessed, and a species identification evaluation has been completed. Kulakow said that species composition has changed over time at Site A. On June 5, 2000, soil samples will be collected.

Site B

Rock said that trees had to be replanted at Site B because many of the initial plantings died. The trees have been planted, he said, in a 3-foot by 3-foot grid. (Initially, plants were established in a 6-foot by 3-foot grid.) Since the replanting, Rock said, the demonstration project has been running smoothly and plants are growing well. This can be attributed, in part, to the significant quantity of rain that the site received over the spring. The cooperative attitude adopted by site owners has also played a role. (Site B's owners are willing to irrigate if the trees require it for establishment. Also, the owners have tilled control plots to make sure that they remain unvegetated.)

Rock said that samples were collected in spring 1999 (when plants were initially planted) and in fall 1999. Although the fall 1999 sampling event was supposed to represent time one (T₁) data, Rock considers it a time zero (T₀) event since so little growth occurred in the first year. Thus, Rock considers the spring 1999 and fall 1999 events to represent T_0A and T_0B. Kulakow said he thought it might be more suitable to consider the fall 1999 event a T₁ event.

Rock said that microbial data are being collected at Site B, but not as part of the Subgroup's project. Microbial data will be generated through a study that the University of Cincinnati is performing. (The University has established plots at Site B to assess natural attenuation.)

Site F

Steve Geiger said that the demonstration project at Site F is operating smoothly. Kulakow said that he received an e-mail from Sam Jackson; it said that Jackson's thesis report will provide information on plant growth and some of the soil characteristics that influence plant growth (e.g., soil bulk density).

Site G

Kulakow said that plots have been seeded at Site G. While plants have been established at many of the plots, it has been difficult to get native switchgrass to grow. (The switchgrass is being tested as the site's local optimized treatment.)

Site H

Tsao said that he would like to establish three types of treatment at Site H: (1) unvegetated, unfertilized; (2) unvegetated, fertilized; and (3) the Subgroup's standardized grass/legume mixture. Regulatory approval, however, has not yet been obtained for the demonstration project. Thus, Tsao could not predict when he would be allowed to initiate activities and seed the site. If approval is granted this summer, he said, planting could still be initiated this year. If approval is delayed past the summer, however, planting would have to be postponed until 2001. Tsao said that this concerns him, because he knows the Subgroup may not be willing to accept new sites into the field study program for much longer.

Tsao provided information on the regulatory issue that remains to be resolved. For more than a year, he said, BP Amoco has been working with state regulators to negotiate cleanup goals for the site. At one point, BP Amoco calculated cleanup levels and submitted these to the state. Tsao was under the impression that the state had accepted the proposed levels and had granted approval for the demonstration project. In May 2000, however, he learned that the state wanted to reopen negotiations and reassess the target levels. Tsao said that the state agency wants BP Amoco to use an absolute target rather than aiming for a certain reduction percentage. Also, the agency wants one cleanup level established rather than having different targets assigned to the site's distinct plumes.

Call participants brainstormed about how to hurdle the regulatory barrier that exists at Site H. The following were offered as suggestions:

• Ask the Interstate Technology and Regulatory Cooperation (ITRC) Work Group for help. One call participant noted that ITRC's main goal is to reduce state regulatory barriers that prohibit the use of innovative technologies. Tsao said that he has already tried to establish a connection between the state regulatory agency and ITRC. Unfortunately, his attempt was fruitless.

• Stress the fact that this is a demonstration project. Jackson said that regulators at Site A regard the Subgroup's field study as a demonstration project rather than a traditional remedial effort. As a result, they did not require absolute cleanup levels to be established; at this point, the regulators simply want to know whether phytoremedial systems can be used to achieve at least some reduction of contaminants. Tsao said that he has already made it clear that the project at Site H would be a demonstration. In fact, he said, the state regulators know that BP Amoco is willing to implement other remedial activities if the phytoremedial system cannot obtain adequate results. Regardless, the agency wants to have cleanup levels established before the demonstration project starts.

• Make sure that the state agency understands that the Subgroup may not be willing to accept new sites indefinitely. Rock asked whether state regulators would allow planting activities to start now if they were assured that their regulatory concerns would be addressed over the next six months. Tsao said that this was proposed and rejected last year, but that it is probably worthwhile to ask again.

• Ask Mike Reynolds for advice. Kulakow said that Reynolds had to identify specific cleanup levels for Sites C, D, and E. He advised Tsao to call Reynolds for information on how the levels were negotiated.

• Have Rock contact the state agency. Jackson said that Rock sent a letter to the regulators who had jurisdiction over Site A. This letter, which voiced support for the Subgroup's field protocol, helped the Subgroup get regulatory approval. Rock said that he would be willing to call or write a letter to the state agency that is involved with Site H if Tsao thought doing so would be useful. Tsao agreed to talk to one of his co-workers about Rock's offer before deciding how to proceed.

Site I

Tsao said that time initial (T_i) samples were collected and analyzed to help investigators decide where to establish treatment plots. Four types of treatments will be tested at the site: (1) unvegetated, unfertilized; (2) unvegetated, fertilized; (3) the Subgroup's standardized grass/legume mixture; and (4) a local optimized mixture. Tsao said that planting will take place during the week of June 5, 2000.

Tsao said that Purdue University will perform microbial analyses at Site I. Also, Stacey Lewis Hutchinson will install soil moisture probes to monitor how changes in soil moisture impact microbial degradation.

Site J

Wolf said that T₀ samples were collected and cool season grasses were seeded in fall 1999. (The grasses are growing reasonably well on three of the four plots that were seeded.) A couple of weeks ago, Wolf continued, Bermuda grass was sprigged and established as the site's second vegetated treatment.

Wolf said that two sampling events will be initiated in 2000. The first, referred to as T_1A, will occur in June 2000, marking the end of the cool-season grass-growing season. The other sampling event, referred to as T_1B, is tentatively scheduled for October 2000--the end of the warm-season grass-growing season.

Site K

Rock said that samples were collected at Site K in May 2000.

Potential New Sites

Kulakow talked about adding new sites to the Subgroup's field study program. At one point, Kulakow said, Reynolds' had noted that sites in Korea were being considered for phytoremediation studies. Kulakow said that a potential candidate site has also been identified within the United States. This site has a phytoremediation project ongoing. The demonstration project was established two years ago, Kulakow said, and its experimental design is consistent with the Subgroup's protocol. Kulakow said that site managers have expressed some interest in working with the Subgroup to evaluate samples during the project's third, fourth, and fifth years. Kulakow said that this would be advantageous, because most of the Subgroup's sites will probably stop collecting data after phytoremedial systems have been operational for only three years.

Kulakow asked call participants whether they knew of any other sites to add to the Subgroup's field study program. Rock noted that Nadeau is working on a site, and asked Nadeau whether it would be appropriate to include it under the Subgroup's field program. Nadeau described the site briefly. It underwent a progression of treatments, starting with classic land farming, before being planted as a phytoremediation project. Alfalfa and other high-maintenance plants are now being tested, but investigators hope to start using native plants soon. (Efforts are being made to identify low-maintenance plants because investigators will not be able to provide onsite support after a few more years. Nadeau has started talking to local groups to see if they are interested in performing light maintenance and collecting samples after investigators leave.) At this point, Nadeau said, the site should not be considered a Subgroup site. If fantastic results are achieved, however, data will be shared and the site can be included under the Subgroup's program.

AN UPDATE ON CONTRACTUAL ISSUES

For many of the Subgroup's sites, activities are being conducted under Cooperative Research and Development Agreements. Jackson asked whether agreements have been finalized for Sites H, I, and J. Rock said that they had.

Kulakow noted that the Petroleum Environmental Research Forum (PERF) is also establishing an agreement with EPA. Jackson, one of the PERF members, said that she signed the contract, but it has still not been finalized by all PERF members. She did not know of any problems that would stand in the way of finalizing the contract.

SAMPLE ANALYSIS

Samples collected from the Subgroup sites are being analyzed either in-house, by the ADL laboratory, or by Battelle. The Subgroup is using two different branches of Battelle. Samples from C, D, and E are being sent to a laboratory in Duxbury, Massachusetts; Site K's samples are being sent to a laboratory in Columbus, Ohio.

Call participants discussed the following issues that pertain to sampling analysis:

• Turn-around times. Several Subgroup members have sent samples to ADL. Some expressed dissatisfaction with how long they have had to wait for results. (Wolf has been waiting for Site J's T₀ results for three or four months. He did not expect the turn-around time to be so long, and is considering running future analyses in-house. Rock has been waiting to obtain Site B's results for even longer than Wolf has.) Kulakow agreed to call ADL to ask when analyses will be complete. In the future, Kulakow will track how long it takes to obtain results. If it takes longer than three months, Kulakow will call ADL and encourage them to release the results more promptly.

• Making sure that the laboratories are running the Subgroup's full suite of analyses. Kulakow said that some samples were collected from Site K and analyzed by Battelle's Columbus laboratory before the site officially entered the Subgroup's field program. As a result, not all of the Subgroup's mandatory parameters were assessed. (Data were provided for polycyclic aromatic hydrocarbons, but not TPH.) Kulakow agreed to contact the laboratory to find out what analyses it plans to perform on Site K's May 2000 samples. (Rock will send Kulakow a contact name for the Battelle laboratory.)

• Making sure that the laboratories are using the same protocols. Call participants noted that data generated must be comparable across the Subgroup's sites. Kulakow said that the Subgroup had identified a way to make sure of this: have each laboratory run a standard. Kulakow said that the Subgroup has prepared a standard and is willing to distribute it to all participating laboratories. He said that ADL failed to run the standard at first, but that the laboratory now understands that the standard must be run with every batch of Subgroup samples. Kulakow agreed to call Battelle's Columbus laboratory and make sure that it knows about the Subgroup's standard.

PLANT ASSESSMENTS

Kulakow has traveled to several of the Subgroup's field sites to evaluate shoot density, cover, root depth, and root density. Kulakow said that he hopes to visit Sites I, J, and K during their fall 2000 sampling events. Tsao, Wolf, and Rock agreed to let Kulakow know when these events are scheduled.

Wolf said that the University of Arkansas is also performing root assessments. For example, he said, Greg Thoma is working on a model, and efforts are underway to collect data on root length and surface area. Wolf and Kulakow agreed that it will be useful to compare the data that Kulakow collects with the data generated by the University of Arkansas. Also, Kulakow said, Thoma might be able to use the plant assessment data from other Subgroup sites in his modeling efforts.

SUBGROUP'S ANNUAL REPORT

Jackson said that the Subgroup's first annual report was presented at the May 3 RTDF meeting in Boston. She said that audience members commented on the report and suggested:

• Obtaining an EPA peer review. Jackson said that one audience member recommended having the Subgroup's report peer-reviewed. Jackson asked call participants what they thought of this suggestion. After some debate, the Subgroup decided that the report should receive an EPA peer review so that it can be published with EPA's logo. They believe that the report will have more clout among regulators if it is released this way. Rock agreed to talk to Phil Sayre about this and to consider EPA's Al Venosa and Steve McCutcheon as potential reviewers. Reviewers from outside EPA may also be invited to review the report, Rock said. Kulakow said that the Hazardous Substances Research Center's technology transfer committee has already started reviewing it. Jackson said that Jerry Schnoor might also be a good person to ask.

• Listing full names rather than codes for sites that do not require anonymity. Jackson noted that one participant suggested only using codes for those sites that require anonymity. This might make it easier, call participants agreed, for readers to figure out the coded sites' identities. Thus, call participants decided to continue coding all of the Subgroup's sites.

Jackson said that there are some data sensitivity issues associated with the annual report. Some Subgroup members want to keep site-specific data protected for the next few years. Thus, the Subgroup still needs to decide how and when to release the annual report. Kulakow said that he plans to post the annual report on the Internet after removing some data from it. He asked for guidance on which information should be removed. Jackson and Tsao agreed to follow up with Kulakow after giving this issue some thought. Jackson said that she will also call Evelyn Drake to discuss the matter with her.

COST ESTIMATES

Jackson said that the Subgroup plans to track the costs for their demonstration projects and to make predictions on how expensive it would be to perform full-scale projects. Geiger said that spreadsheets have been created to track this information; these have been distributed to Subgroup members. (Kulakow said that he will resend the spreadsheets if anyone needs them.) Call participants agreed to submit cost information to Kulakow by July 17, 2000. Before the next Subgroup conference call, Kulakow will work with Geiger to compile the cost information and redistribute it to Subgroup members.

THE TPH CRITERIA WORKING GROUP (TPHCWG) METHODOLOGY

Kulakow said that Geiger did an excellent job demonstrating the TPHCWG methodology at the May 2 RTDF meeting. He asked what can be done to encourage Subgroup members to use this approach. Geiger agreed to send Subgroup members a template and a set of spreadsheets that they can use in performing the TPHCWG method. The spreadsheets are a bit outdated, he said; they have been revised, but the revised version is not yet available to the public. (PERF was involved with creating the new spreadsheets. All of PERF's products are kept out of the public domain for at least two years.)

MISCELLANEOUS TOPICS

• Rock said that Sayre hopes to visit one of the Subgroup's sites. He asked conference call participants to contact Sayre if they want him to visit during a sampling event.

• In an upcoming issue, Rock said, the Journal of Phytoremediation will cover EPA's Phytoremediation State of the Science Conference that was held in Boston. Rock will serve as a guest editor.

ACTION ITEMS

• Nadeau offered to share the methods he has used to analyze plant tissues for hydrocarbons. (He will send the method to ERG. ERG will distribute it to all Subgroup members.) Jackson asked call participants to provide information on any other methods that they know of.

• Rock asked call participants to consider writing a paper that summarizes what is currently known about plant uptake at sites that are contaminated with petroleum hydrocarbons.

• Tsao agreed to talk to one of his co-workers about Rock's offer to contact Site H's state regulators.

• Rock will send Kulakow contact information for Battelle's Columbus, Ohio, laboratory.

• Kulakow will contact Battelle's Columbus laboratory to (1) ask what analyses it plans to perform at Site K, and (2) make sure that it knows about the Subgroup's standard.

• Kulakow will contact ADL to find out when analyses will be completed for Site B and Site J's samples. In the future, Kulakow will track how long it takes to obtain results. If it takes longer than three months, Kulakow will call ADL and encourage them to release the results more promptly.

• Tsao, Wolf, and Rock will let Kulakow know when the fall 2000 sampling events are established for Sites I, J, and K.

• Rock will talk to Sayre about having the Subgroup's annual report peer-reviewed.

• Kulakow plans to post the Subgroup's annual report on the Internet after removing some site-specific data from it. He asked for guidance on which information should be removed. Jackson and Tsao will follow up with Kulakow on this issue. Jackson will also call Evelyn Drake to discuss the matter with her.

• Call participants agreed to submit cost information to Kulakow by July 17, 2000. Before the next Subgroup conference call, Kulakow will work with Geiger to compile the cost information and redistribute it to Subgroup members.

• ERG agreed to set up the next conference call for July 27, 2000, between 12:30 and 2:00 Eastern Daylight Time.

• Geiger agreed to send Subgroup members a template and a set of spreadsheets that can be used to perform the TPHCWG method.

• Rock asked call participants to contact Sayre about field visit opportunities.