&EPA
United States
Environmental Protection
Agency
Research and Development (481)
Solid Waste and
Emergency Response (5102G)
EPA/542/F-99/026
November 1999
Phytoremediation of Organics
Action Team
RTDF
Remediation Technologies
Current RTDF
Action Teams
Bioremediation Consortium
IINERT Sott-Metals Action
Team , "-,' !';;;-;/ 1'/'/", ,:,',
Permeable Reactive
Barriers Action Team
Organics Action Team
Sediments Remediation
Action Team: -' - "V,_ , "
The Phytoremediation of Organics Action Team, established in
1997, is one of the five current Action Teams under the Remediation
Technologies Development Forum (RTDF). The U.S. Environmental
Protection Agency (EPA) created the RTDF in 1992 to foster collab-
oration between the public and private sectors in developing innova-
tive solutions to mutual hazardous waste problems. The
Phytoremediation of Organics Action Team includes representatives
from industry, government, and academia who share an interest in
further developing and validating the of use of plants and trees to
remediate organic hazardous wastes in soil and water.
Phytoremediation Processes
Phytoremediation is the use of certain plants to clean up soil, sedi-
ment, and water contaminated with metals and/or organic contami-
nants such as crude oil, solvents, and polyaromatic hydrocarbons
(PAHs). It is a name for the expansion of an old process that occurs
naturally in ecosystems as both inorganic and organic constituents
cycle through plants. Plant physiology, agronomy, microbiology,
hydrogeology, and engineering are combined to select the proper
plant and conditions for a specific site. Phytoremediation is an
aesthetically pleasing mechanism that can reduce remedial costs,
restore habitat, and clean up contamination in place rather than
entombing it in place or transporting the problem to another site.
Phytoremediation can be used to clean up contamination in several
ways:
• Degradation by plants. Organic contaminants are absorbed
inside the plant and metabolized (broken down) to non-toxic
molecules by natural chemical processes within the plant.
• Extraction. Plant roots can remove metals from contaminated
sites and transport them to leaves and stems for harvesting and
disposal or metal recovery through smelting processes.
• Microorganism stimulation. Plants excrete and provide
enzymes and organic substances from their roots that stimulate
growth of microorganisms such as fungi and bacteria. The
microorganisms in the root zone then metabolize the organic
contaminants.
• Volatilization. Plants take up water and organic contaminants
through the roots, transport them to the leaves, and release the
contaminants as a non-toxic gas (called volatilization) into the
atmosphere.
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• Stabilization. Plants prevent contaminants from
migrating by reducing runoff, surface erosion,
and ground-water flow rates. "Hydraulic
pumping" can occur when tree roots reach
ground water, take up large amounts of water,
control the hydraulic gradient, and prevent lateral
migration of contaminants within a ground water
zone.
Phytoremediation can be used in combination with
other traditional and innovative remediation tech-
nologies. Cleanup can be accomplished to depths
within the reach of plants' roots. Sites need to be
maintained (watered, fertilized, and monitored) and
results are slower (3+ years) than mechanical exca-
vation methods. "Attractive nuisance" and food
chain issues must be considered at each site and
care taken to avoid unwanted exposure of wildlife.
Cost savings compared to traditional remediation
can range from 20 to 80 percent.
The Action Team's Mission
The Action Team's mission is to bring together tech-
nological, environmental, and regulatory interests to
develop and demonstrate phytoremediation tech-
nologies that can clean up soils and ground water
contaminated with organics, and to achieve regula-
tory and public acceptance of these technologies.
The Action Team's Goals
The Action Team's goals are to:
• Assess the status of current phytoremediation
research
• Identify and determine ways to address key
research gaps
• Facilitate validation of phytoremediation
technologies
• Determine appropriate uses of phytoremediation
Accomplishments
• Trichloroethylene (TCE) in Ground Water
• Total Petroleum Hydrocarbons (TPH in Soil)
• Alternative Covers (long-term, self-sustaining,
low-maintenance plant covers, growing in or
over materials that pose environmental risk, that
serve to reduce this risk)
The Action Team has developed a large bibliography
of peer-reviewed journal articles, presentations and
posters from conferences, book chapters, and arti-
cles from newspapers and magazines. The bibliog-
raphy contains nearly 1,450 citations on phytoreme-
diation or closely related subjects. This bibliography
is available in searchable format on the Action
Team's home page on the RTDF World Wide Web
site. It is updated quarterly.
In addition, the TPH in Soil Subgroup is creating a
standardized field test protocol for determining the
efficacy of agricultural and non-crop plants for
degradation of petroleum hydrocarbons in soil at
multiple locations and under varied climatic condi-
tions. A working draft of the protocol, entitled
"Phytoremediation Action Team Field Study
Protocol, May 29, 1998 ," is available on the Action
Team's home page on the RTDF World Wide Web
site.
The Action Team's Plans
The Action Team plans to standardize protocols for
phytoremediation site evaluation, designs for imple-
mentation, and monitoring for efficacy/risks; and
determine what regulators need to know to approve
phytoremediation.
The Action Team selected three contaminant/media
combinations to explore as possible phytoremedia-
tion case studies and formed subgroups to investi-
gate issues and develop strategies for addressing
them. These are:
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Action Team Members
The Action Team includes representatives from
industry, government, non-profit, and academic
organizations, such as the following:
Industry
Amoco Research Center
ARM Group
Chevron
Exxon
Goodyear, Inc.
ManTech
Microbial Insights, Inc.
Phillips Petroleum Co.
PPG, Inc.
Rohm and Haas Company
Science Applications Intel Corp
ThermoRetec, Inc.
Union Carbide Corporation
Government
Argonne National Laboratory
California Environmental Protection Agency
California Integrated Waste Management Board
California Regional Water Quality Control Board
California Regional Water Resources Control Board
City of Cincinnati
Pacific Northwest National Laboratory (PNNL)
U.S. Department of Energy
U.S. Environmental Protection Agency
University of Wisconsin
U.S. Army
U.S. Air Force
U.S. Department of Energy
U.S. Environmental Protection Agency
U.S. Navy
Academia
Desert Research Institute
Kansas State University
University of Arkansas
University of Oklahoma
University of Tennessee
University of Washington
University of Wisconsin
OTHER PHYTOREMEDIATION RESOURCES
Phytoremediation Bibliography
http://www.rtdf.org/public/phyto/phytobib/biba-b.html
Phytoremediation of Petroleum Hydrocarbons in Soil Field Study Protocol
http://www.rtdf.org/public/phyto/protocol.htm
Phytoremediation of TCE in Groundwater using Populus
http://clu-in.org/products/phytotce.htm
Phytoremediation Research
U.S. Army Corps of Engineers, Waterways Experiment Station
http://www.wes.army.mil/el/phyto/
Phytoremediation Mailing List for the discussion of research and development of phytoremediation
http://www.engg.ksu.edu/HSRC/phytorem/
Phytoremediation Electronic Newsgroup Network (PHYTONET)
http://www.dsa.unipr.it/phytonet/
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RTDF
Would Yom Like
More Information?
For more information about the
Phytoremediation of Organics Action Team,
please contact the Team Co-chairs:
Steve Rock
U.S. Environmental Protection Agency
National Risk Management Research
Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
Tel: 513-569-7149 Fax: 513-569-7105
E-mail: rock.steven@epa.gov
Lucinda Jackson
Chevron Corporation
100 Chevron Way
P.O. Box 1627
Richmond, CA 94802-0627
Tel: 510-242-1047 Fax: 510-242-5577
E-mail: luaj@chevron.com
For information $% the 15TDF or other
Action Teams, please visit the RTDF Wortd
Wide Web Site Ht Www.irtdf.org or contact?
; Robert Otexsey
U.S. Environmental Protection Agency
26 West Martin I*rther Ki»g Drive
, Tel: 513-569-7861
E-mail: olexsey.bob@epamail.epa.govS
Walter W, Kovalick, Jr.,
If ,S, ErivironnjenM Protection Agency
Washington, DC 20460
"Tel: 703-603-9910
E-mail: kovalick.walter@epamail.epa.gov
; To ye^wst other RTDF &<# sheets, ptease
EPA/NSCEP
P.O. Box 42419
Cincinnati, OH 45242
800-490-919?
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