On November 3, 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:
Phil Sayre, U.S. Environmental Protection Agency (EPA) (Subgroup Co-Chair)
Steve Geiger, ThermoRetec, Inc.
Peter Kulakow, Kansas State University
Steve Rock, EPA
Duane Wolf, University of Arkansas
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 gave updates
on sites that are participating in the program:
- Site A. Peter Kulakow said that the Arthur D. Little Laboratory (ADL)
has finished analyzing Site A’s time two (T2) samples.
- Site B. Steve Rock said that time one (T1) samples will
be collected from Site B in November 2000.
- Site C. Duane Wolf said that samples were collected from Site C on
September 17, 2000.
- Site E. Wolf said that samples will be collected from Site E in November
2000.
- Site F. Steve Geiger said that T2 samples will be collected
from Site F in November 2000.
- Site G. Kulakow said that Site G’s T1 samples have been
collected and sent to ADL for analysis.
- Site J. Wolf said that a Cooperative Research and Development Agreement
(CRADA) was signed on March 23, 2000. He also said that T1A samples
have been collected and are being stored in a freezer at the University of
Arkansas. T1B samples are scheduled to be collected in November
2000. Wolf said that he has not decided which laboratory he will use to analyze
Site J’s samples. To obtain results more quickly, Wolf said, he is considering
having the University of Arkansas analyze the samples rather than ADL. Wolf
summarized some of the microbial data that have been collected at Site J:
samples collected 6 months after planting indicate that alkane degrader concentrations
are higher in vegetated/fertilized plots than in control plots. Wolf could
not say, however, whether the increased activity of these degraders has translated
into enhanced polycyclic aromatic hydrocarbon degradation. While preliminary
data do suggest that this may be the case, additional analyses must be performed
to determine whether contaminant concentration decreases observed in the treated
plots are actually statistically significant. Wolf said that roots have also
been collected from Site J and analyzed; results on rooting depth, surface
area, and volume are currently available.
- Site K. Rock said that T2 samples will be collected from
Site K in November 2000.
THE POTENTIAL FOR ADDITIONAL RESEARCH PROJECTS AT RTDF SUBGROUP SITES
Call participants noted that EPA’s Office of Research and Development (ORD)
is offering grants for phytoremediation research projects and that proposals
are due by the end of January 2001. These grants, Phil Sayre said, will be awarded
to academic or nonprofit organizations. Subgroup members expressed hope that
some of the grants would be used to perform additional research at the Subgroup’s
field sites. They described two avenues by which this could happen:
- Research performed by current Subgroup members. There are currently
three academic institutions (Kansas State University, Purdue University, and
the University of Arkansas) that are participating in the RTDF’s TPH in Soil
Subgroup. Call participants talked about the possibility of having one of
these institutions submit a proposal.
- Research performed by non-Subgroup members. Rock said that many potential
grant applicants are searching for sites where they can perform phytoremediation-related
research. Many of these researchers, he said, might be interested in working
at one or more of the Subgroup’s sites. Rock said that information on the
ORD grants has been posted to the Internet along with contact names for a
variety of potential demonstration sites. Rock agreed to call those who are
listed as contacts to make sure they are aware of the work that is being performed
at the RTDF’s Subgroup sites.
Call participants agreed that it would be useful to compose a "wish list"
that summarizes the types of projects that they would like performed at the
Subgroup’s field sites. They brainstormed briefly on topics to include on the
list and identified the following:
- Bioavailability. At some sites, Geiger said, researchers will probably
find that phytoremediation does little to decrease the concentrations of recalcitrant
compounds such as benzo(a)pyrene. If, however, phytoremediation technologies
are shown to decrease contaminant bioavailability, this information could
be used in a risk assessment to show that phytoremediation reduces risks to
human health and the environment. Thus, Geiger said, it would be very useful
to perform studies to assess bioavailability and environmentally acceptable
endpoints.
- Microbial community responses. Call participants noted that it would
be useful to learn about the impact that phytoremediation has on microbial
community structure. Wolf said that he and Mike Reynolds have talked about
performing phospholipid fatty acid analysis (PFLA) on some of the Subgroup
sites. Wolf also noted that whole soil fatty acid methyl ester (FAME) analyses
have been performed across 12 to 15 Southeastern sites. The results indicate
that there are distinct differences in the microbial structures of different
soil types. Wolf said that it might be interesting to perform FAME analyses
at the Subgroup sites to evaluate how community structures differ across sites
and how these structures change as cleanup progresses.
- Root modeling. Wolf said that the University of Arkansas’ Greg Thoma
is interested in learning more about plant rooting depth, distribution, and
turnover. Ideally, Wolf said, obtaining these types of information will allow
researchers to develop models that predict root growth. Kulakow said that
he too thinks these topics are interesting and worthy of additional study.
- Optimization techniques. Kulakow noted that the Subgroup would benefit
by learning more about the best way to perform phytoremediation projects.
For example, he said, it might be interesting to learn more about how irrigation
and fertilization rates impact phytoremediation’s efficacy.
Call participants agreed to discuss their "wish list" in more detail
during their next conference call. Once the list is compiled, it will be posted
to the RTDF Web site. That way, people who are interested in performing research
at the Subgroup’s sites will be aware of the kinds of projects that the RTDF
Subgroup would welcome.
ACTION ITEMS
- Call participants agreed to identify projects that they would like performed
on the RTDF Subgroup plots. These proposed projects will be compiled into
a "wish list" during the next Subgroup conference call.
- EPA’s ORD is offering grants for phytoremediation research. Rock noted that
ORD’s Web site has information about the grants, as well as contact names
for a variety of potential demonstration sites. Rock agreed to talk to the
listed contacts to make sure they are aware of the work that is being performed
at the RTDF’s Subgroup sites.
- Call participants agreed that information about the ORD grants should be
posted to the RTDF Web site. Rock will be listed as a contact. During the
next conference call, Rock will indicate whether anyone has contacted him
about performing research on Subgroup sites.
- Wolf will remind Reynolds to send data to Kulakow so that they can be included
in the Subgroup’s second annual report.
- Wolf will ask Greg Thoma to attend the next Subgroup conference call.
- Subgroup members agreed to send cost data to Kulakow as soon as possible.
- Rock agreed to contact Al Venosa and Royal Nadeau to find out whether they
have reviewed the Subgroup’s annual report.
- Kulakow said that a revised version of the Subgroup’s report has been created.
This, he said, will be posted to the Kansas State University Web site. He
encouraged Subgroup members to review the document and to send him their comments
as soon as possible. Kulakow agreed to talk with Carolyn Perroni about linking
the Subgroup’s annual report to the RTDF Web site.
- ERG agreed to set up the next Subgroup conference call for November 14,
2000, between 12:30 and 2:00 Eastern Standard Time.