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

April 19, 2001
12:30 p.m.–2:00 p.m.

On April 19, 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)
Phil Sayre, U.S. Environmental Protection Agency (EPA) (Subgroup Co‑Chair)
Marcos Alvarez, Environment Canada
Steve Geiger, ThermoRetec, Inc.
Peter Kulakow, Kansas State University (KSU)
Terry McIntyre, Environment Canada
Mike Reynolds, U.S. Army Corps of Engineers, Cold Regions Research and Engineering Laboratory
Steve Rock, EPA
David Tsao, BP Amoco

UPDATE ON FIELD DEMONSTRATION SITES

Existing 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.

• Site A. Lucinda Jackson said that Site A’s time three (T₃) samples will be collected before the end of the month. The plant tissues collected as part of this sampling effort will be frozen and stored until the Subgroup identifies an appropriate protocol for analyzing hydrocarbon uptake. Although the demonstration project at Site A was scheduled to end this year, Jackson noted, permission has been granted to leave the planted plots intact at least for one more year. It is not yet clear, however, whether funds will be available to analyze more samples.
  
  
• Site B. Steve Rock said that the trees at Site B look healthy, noting that their leaves are starting to bud. Time one (T₁) samples were collected several months ago and submitted to the Arthur D. Little Laboratory (ADL). Peter Kulakow, who recently talked to an ADL representative, said that results should be available in about six weeks.
  
  
• Sites C, D, and E. Mike Reynolds said that demonstration projects at Sites C, D, and E have been ongoing for several years. A large amount of data has been collected. These data will be organized and forwarded to Kulakow. The data are “noisy,” Reynolds said: it is difficult to discern the impact phytoremediation has had. He is confident, however, that the plants did help move remediation processes in the right direction. He plans to use a “multiple lines of evidence” approach to demonstrate this point. Reynolds said that some microbial data have already been collected, and that studies involving phospholipid fatty acid analysis techniques are currently underway.
  
  
• Site F. Steve Geiger said that he is waiting to receive results from Site F’s time two (T₂) samples.
  
  
• Site G. Kulakow said that the analytical results from Site G’s time one (T₁) samples indicate that contaminant concentrations have decreased substantially. At first glance, Kulakow said, it looks like decreases are more pronounced in the vegetated plots than they are in the nonvegetated plots. It is unclear whether this treatment effect was caused by the plants, the fertilizer, or the combination of the two.
  
  
• Site H. David Tsao said that regulatory approval has been granted for a demonstration project at Site H. The whole site will be planted some time this year.
  
  
• Site I. Tsao said that time initial (T_I) samples were collected at Site I, but the sampling effort did not follow the Subgroup’s protocol. He agreed to send information about contaminant concentration ranges to Kulakow for inclusion in the Subgroup’s annual report.
  
  
• Site J. Samples will be collected from Site J in May 2001.
  
  
• Site K. Sampling will be conducted at Site K in May 2001.

New Sites

Terry McIntyre and Marcos Alvarez, representatives from Environment Canada, expressed interest in joining the Subgroup and contributing two sites to the Subgroup’s field study program. Call participants were enthusiastic about this proposal. Alvarez said that the sites, which are both contaminated with petroleum products, will be set up and designed according to the Subgroup’s protocol. (See http://www.rtdf.org/public/phyto/protocol/protocol99.htm.) Alvarez plans to ask the University of Saskatchewan to perform the chemical analyses. Kulakow said that was fine, as long as the University’s analytical techniques are comparable to those being used by the other laboratories that are analyzing Subgroup samples. To demonstrate comparability, Kulakow said, the University could analyze a standard sample with a known concentration of polycyclic aromatic hydrocarbons (PAHs). Alvarez said that Environment Canada also plans to investigate microbial activity in the rhizosphere. Kulakow and Alvarez agreed to talk offline about the two new sites so that Kulakow can obtain a better understanding of the level of support that KSU, which provides analytical support for the other Subgroup sites, will need to provide for the two new Canadian sites. If KSU’s role is extensive, McIntyre said, a mechanism can be identified to transfer money from Environment Canada to KSU.

Alvarez also noted that Environment Canada is working on other phytoremediation projects, but said that these are not appropriate for inclusion under the Subgroup’s field study program. For example, he said, trees are being used to treat ground water at two sites. Rock said that he also knew of a project that would interest the Subgroup, even though it was not appropriate for inclusion under the Subgroup’s project. This site, he said, is using the Subgroup’s protocol to clean up contaminated sediments.

PLANT TISSUE ANALYSIS

Jackson said that the Subgroup needs to identify a protocol to use for plant tissue analysis. During the last conference call, Subgroup members debated whether it is necessary to wash shoot samples before analyzing them for hydrocarbons. If they are not washed, the samples will include contaminated dust adhering to the shoots, and it will be difficult to determine whether detected hydrocarbons represent contaminants that blew onto the plant or contaminants taken up from the soil. Jackson asked call participants to revisit the “washing”debate.

Subgroup members agreed that they must decide what question the sampling effort is intended to answer to determine whether washing should be performed to remove dust. Rock and Jackson said that the sampling effort is being performed to address regulatory concerns about ecological risk. Regulators want to be assured, Rock said, that animals will not be adversely affected if they eat vegetation that has been planted in contaminated areas. He advised against washing the shoot samples, noting that animals don’t wash their food before they eat it.

Although call participants agreed that the main intent of the sampling effort should be to provide insight on ecological risk, some also expressed interest in determining exactly how much hydrocarbon enters plants via uptake. These call participants proposed washing plant shoots, saving the rinsate, and analyzing the shoots and rinsate separately. They recommended using the data as follows:

Hydrocarbon in washed plant + Hydrocarbon in rinsate = The amount of hydrocarbon an animal is exposed to

Hydrocarbon in washed plant = The amount of hydrocarbon taken up from soil and incorporated in plant tissue

Kulakow pointed out a flaw in the second equation, noting that PAHs in ambient air can also be absorbed by plants and incorporated into tissues. All of the hydrocarbon detected in a washed shoot would not necessarily originate from the soil. Phil Sayre asked whether using “stable isotope” techniques could help discriminate between hydrocarbons taken up from soil and those absorbed from ambient air. Reynolds thought this was an interesting idea. Call participants noted other problems with the suggestion made about analyzing rinsate. First, one call participant said, it might be difficult to detect small quantities of hydrocarbon in large volumes of rinsate. Second, Kulakow said, analyzing rinsate will increase the overall cost of the sampling effort. (ADL has indicated that it will cost about $300 per sample to analyze for extended PAHs.) If Subgroup members do decide that it is necessary to analyze rinsate, Kulakow said, it might be wise to pool funds and perform a detailed analysis at just a few sites.

Call participants brainstormed to identify sources of information for plant tissue analysis protocols. They identified the following:

• Pacific Northwest National Laboratory. Jackson said that Michael Huesemann is performing a literature review on protocols that are used to measure PAHs in plant samples. She agreed to send Huesemann’s e-mail to Kulakow.
  
  
• EPRI. Kulakow said that EPRI has performed a literature review and greenhouse study on plant hydrocarbon uptake.
  
  
• EPA’s Office of Research and Development (ORD). Sayre said that he would ask scientists at ORD for information on hydrocarbon extraction.
  
  
• Bermuda Biological Station. Sayre agreed to ask a scientist from the Bermuda Biological Station for pertinent information on plant tissue analysis.
  
  
• Battelle Laboratories. Reynolds agreed to contact Battelle to determine whether it has a plant tissue protocol to recommend.
  
  
• BP Amoco’s environmental forensics team. At one site, Tsao said, the veins of eucalyptus trees have turned black. BP Amoco’s scientists are developing techniques to analyze the leaves. Tsao will check to determine whether the methods being generated would be of use to the Subgroup.

Call participants talked about which hydrocarbons to analyze. So far, they have only talked about evaluating plant samples for PAHs. This is because PAHs are the hydrocarbons that are of the most regulatory concern and most likely to be detected. Rock said that he was unsure whether analytical methods have been developed to analyze non-PAH hydrocarbons in plant tissues. Thus, the Subgroup will not be collecting information on light-end linear or branched hydrocarbons. Kulakow said that the Subgroup sites are unlikely to have light-end products anyway, noting that the sites’ contaminants are weathered.

Reynolds said that useful information about hydrocarbon uptake could be obtained by simply comparing chromatograms generated from plants grown in clean versus contaminated soil. Jackson liked this idea quite a bit, but did not think it would be possible to find control areas at most of the sites.

NEXT FACE-TO-FACE MEETING

Call participants agreed that a Subgroup meeting should be held in fall 2001. Rock suggested meeting in Austin, Texas, in September 2001. He said that the Alternative Cover Assessment Program (ACAP)—one of the other Phytoremediation Action Team Subgroups—is meeting in Austin during the week of September 10, 2001. (Also, the Interstate Technology and Regulatory Cooperation Work Group will be offering a training session in conjunction with the ACAP meeting.) Sayre, Jackson, Tsao, Kulakow, and McIntyre expressed interest in attending the ACAP meeting. Therefore, Rock agreed to find out whether a TPH in Soil Subgroup meeting can be held immediately before or after the ACAP meeting. Rock also said that he would find out whether there is any flexibility in the date proposed for the ACAP meeting. (Sayre will not be able to attend if the meeting is held the week of September 10.) Call participants agreed to start thinking about the format and agenda for the TPH in Soil meeting. They will send their ideas to Rock, and let him know if they think outside speakers should be invited to give presentations.

COST SPREADSHEETS

Jackson said that the Subgroup is trying to track the costs incurred at demonstration sites. Data have been submitted for six sites, she said; the costs listed are all in the same ballpark. Kulakow said that Site A’s information is not complete. He asked Jackson to provide information on chemical analysis costs, and Jackson agreed to do so. Geiger said that costs are not being reported in a consistent fashion across the sites. For example, while Site I’s estimates include labor costs, Site B’s do not. (At Site B, Rock said, a post-doc is performing operation and maintenance. This person is not paid with the project’s money. Tsao recommended adding the cost of labor to Site B’s estimate even though it is not being paid for out of the project’s budget.)

MISCELLANEOUS TOPICS

Call participants talked about the following miscellaneous topics:

• The Subgroup’s annual report. Kulakow plans to complete the Subgroup’s annual report by June 30, 2001. Although he had hoped to include T₀ data for Site I, T₁ data for Sites B and G, and T₂ data for Sites A and F, it does not appear that these data will be available before the report’s deadline. Kulakow agreed to call ADL to determine whether there is any way to expedite analysis. Kulakow asked Subgroup members to let him know whether data have been collected on metals at their sites, and if so, if these can be included in the annual report. Jackson agreed to find out whether metals data from Sites A and B can be included.
  
  
• Canada’s phytoremediation program. McIntyre said that a national phytoremediation program is being developed in Canada. The program should be operational before the end of the year.

ACTION ITEMS

• Reynolds will organize the data collected at Sites C, D, and E, and forward those data to Kulakow.
  
  
• Tsao agreed to send Kulakow information about Site I’s contaminant concentration ranges.
  
  
• Kulakow and Alvarez agreed to talk offline about the two new Canadian sites that are being added to the Subgroup’s demonstration project.
  
  
• Call participants agreed to ask a number of different people for information on plant tissue analysis protocols. Jackson will send Huesemann’s e-mail to Kulakow. Sayre will contact people from ORD and Bermuda Biological Station. Reynolds will contact laboratory technicians from Battelle. Tsao will contact BP Amoco’s environmental forensics team.
  
  
• Rock agreed to find out whether a TPH in Soil Subgroup meeting can be held immediately before or after the September 2001 ACAP meeting. He will also find out whether there is any flexibility in the date proposed for the ACAP meeting.
  
  
• Call participants agreed to think about the format and agenda for the TPH in Soil meeting. They will send ideas to Rock, and let him know if they think outside speakers should be invited to give presentations.
  
  
• Jackson agreed to send Kulakow cost information on Site A’s chemical analyses.
  
  
• Kulakow will call ADL to determine whether there is any way to expedite analysis.
  
  
• Jackson agreed to find out whether metals data from Sites A and B can be included in the Subgroup’s annual report.
  
  
• ERG will set up the next TPH in Soil Subgroup conference call for May 16, 2001, between 12:30 and 2:00 p.m. Eastern Daylight Time.