Introduction

Contaminated sites exist throughout the United States and 

elsewhere that require cleanup to protect human health and 

the environment. Phytotechnologies are a set of techniques 

that make use of plants to achieve environmental goals. 

These techniques use plants to extract, degrade, contain, or 

immobilize pollutants in soil, groundwater, surface water, 

and other contaminated media. Phytotechnologies remediate 

contaminants using several different mechanisms dependent 

on the application; Tables 1 and 2 summarize these mechanisms and applications. 

Some phytotechnology applications could be primary 

methods of cleaning up or stabilizing contamination while 

others will supplement primary remedies. Phytotechnologies may potentially (1) clean up moderate to low levels of 

select elemental and organic contaminants over large areas, 

(2) maintain sites by treating residual contamination after 

completion of a cleanup, (3) act as a buffer against potential 

waste releases, (4) aid voluntary cleanup efforts, (5) facilitate nonpoint source pollution control, and (6) offer a more 

active form of monitored natural attenuation (McCutcheon 

and Schnoor 2003). Table 2 lists potential phytotechnology 

applications and associated mechanisms.

Phytotechnologies can treat a wide range of contaminants, 

including: organics, such as volatile organic compounds 

(VOC), polycyclic aromatic hydrocarbons (PAH), petroleum hydrocarbons, and munitions constituents; metals; 

and radionuclides—although not all mechanisms are applicable to all contaminants or all matrixes. This fact sheet 

(1) provides information that will help you evaluate whether 

phytotechnologies will work at your site, (2) summarizes the applications of phytotechnologies for various contaminants, and 

(3) includes links to additional sources of information.

WILL PHYTOTECHNOLOGIES WORK AT YOUR SITE?

As with all remediation strategies, phytotechnologies are site-specific, with applicability and performance that can vary 

widely based on parameters such as contamination and soil type, vegetation, and climate. It is best to evaluate a site early in 

the cleanup process to determine the possibility of using vegetation to achieve remediation, restoration, and/or containment 

goals. Because high concentrations of some contaminants may be toxic to plants and inhibit their growth, phytotechnologies 

are best applied at sites with low to moderate levels of contamination, used in conjunction with other treatment methods, or 

used as a final polishing step in site remediation. Finally, phytotechnologies can take significantly longer than other remedial 

technologies to achieve site goals because the plants must first establish well-developed roots and biomass to be effective. 

Nevertheless, phytotechnologies offer several significant advantages. Table 3 lists some advantages and disadvantages of 

applying phytotechnologies.

After reviewing site characteristics to determine if phytotechnologies would be effective at your site, it is important to 

select the appropriate phytotechnology mechanism and species. The mechanism and plants must be suitable to address 

contaminants of concern at the site and site characteristics such as soil type and climate. Ideally, the potential effectiveness 

of phytotechnology at a site is tested in a laboratory setting and through pilot field studies before full-scale application. 

Laboratory studies can determine if the target contaminant(s) can be removed under ideal conditions. If the lab study 

1

Fact Sheets on Ecological Revitalization

•	 This fact sheet is the fourth in a series of fact

sheets related to ecological revitalization 

developed by the U.S. Environmental Protection 

Agency (EPA) Technology Innovation and Field 

Services Division (TIFSD). The information in this 

fact sheet is intended for EPA and state agency 

site managers, consultants, and others interested 

in the ecological revitalization of contaminated 

sites.

•	 The first three fact sheets can be found at http://

cluin.org/ecorevitalization and include: (1) 

“Frequently Asked Questions about Ecological 

Revitalization of Superfund Sites,” EPA 542-F06-002; (2) “Revegetation of Landfills and Waste 

Containment Areas,” EPA 542-F-06-001; and (3) 

“Ecological Revitalization and Attractive Nuisance 

Issues,” EPA 542-F-06-003.

•	 Various information sources were used to prepare

this fact sheet. These and additional information 

resources are listed at the end of the fact sheet.

Phytotechnologies use plants to extract, degrade, 

contain, or immobilize pollutants in soil, groundwater, 

surface water, and other contaminated media.

PHYTOTECHNOLOGIES 

FOR SITE CLEANUP 
2

TABLE 2

PHYTOTECHNOLOGY APPLICATIONS

Application Media Mechanisms

Constructed Treatment Wetland/ 

Aquatic Plant Lagoon

Sediment

Surface Water

Phytodegradation

Phytoextraction

Phytovolatilization

Rhizodegradation

Field Crops/ Grass, Forb, Herb, or Fern 

Gardens

Soil

Sediment

Phytodegradation

Phytoextraction

Phytovolatilization

Rhizodegradation

Landfill Cover Soil

Sediment

Surface Water

Phytoextraction

Phytohydraulics

Phytosequestration

Riparian Buffer Soil

Sediment

Surface Water

Groundwater

Phytodegradation

Phytoextraction

Phytohydraulics

Phytosequestration

Phytovolatilization

Rhizodegradation

Tree Hydraulic Barrier Groundwater Phytoextraction

Phytohydraulics

Phytosequestration

Tree/Shrub Plantation Soil

Sediment

Groundwater

Phytodegradation

Phytoextraction

Phytovolatilization

Rhizodegradation

Sources: ITRC. 2009. Phytotechnology Technical and Regulatory Guidance and Decision Trees, Revised. McCutcheon, S.C. and J. L. Schnoor. 2003. 

Phytoremediation: Transformation and Control of Contaminants. John Wiley & Sons, Inc., Hoboken, New Jersey. ISBN: 0-471-39435-1. 987 pp.

TABLE 1

PHYTOTECHNOLOGY MECHANISMS

Mechanism Description Cleanup Goal

Phytodegradation Ability of plants to take up and break down contaminants within plant 

tissues through internal enzymatic activity 

Remediation by destruction

Phytoextraction Ability of plants to take up contaminants into the plant and sequester 

the contaminant within the plant tissue

Remediation by removal 

of plants containing the 

contaminant

Phytohydraulics Ability of plants to take up and transpire water Containment by controlling hydrology

Phytosequestration Ability of plants to sequester certain contaminants into the rhizosphere 

through release of phytochemicals, and sequester contaminants on/

into the plant roots and stems through transport proteins and cellular 

processes

Containment 

Phytovolatilization Ability of plants to take up, translocate, and subsequently volatilize 

contaminants in the transpiration stream

Remediation by removal 

through plants

Rhizodegradation Ability of released phytochemicals to enhance microbial biodegradation of contaminants in the rhizosphereRemediation by destruction

Source: Interstate Technical Regulatory Council (ITRC). 2009. Phytotechnology Technical and Regulatory Guidance and Decision Trees, Revised.
3

is successful, the pilot study will demonstrate if the site 

conditions are compatible with the selected plants. These 

studies use site soil and/or groundwater samples containing 

a range of concentrations of the target contaminants 

to determine remedial effectiveness. As for many 

remedial approaches, sites undergoing treatment with 

phytotechnologies will be monitored to assess performance. 

Decision trees and other information to support evaluation 

of phytotechnology at a specific site are provided in 

Phytotechnology Technical and Regulatory Guidance and 

Decision Trees, Revised (ITRC 2009). 

TABLE 3

ADVANTAGES AND DISADVANTAGES FOR PHYTOTECHNOLOGIES

Advantages 

Substantial cost savings are possible.

Greater public acceptance may result from use of an environmentally-friendly “green” and low-tech remedial technology. 

Operation and maintenance costs are typically lower than those required for traditional remedies (such as soil vapor extraction), because the remedy is generally resilient and self-repairing.

Vegetation can help to reduce or prevent erosion and fugitive dust emissions.

Plants can also improve air quality and sequester greenhouse gases.

Plants can improve site aesthetics (visual appearance and noise).

Site soil structure and fertility are not negatively impacted (and likely are improved).

Remedy may be applicable at remote locations.

Can be used adjacent to and without damage to mature trees and shrubs, and hardscape like decks and slate walkways.

Phytotechnologies may be used in combination with other restoration or mitigation goals, such as a vegetated cap or creating ecological diversity. 

Potential to create new habitat or supplement existing habitat.

Final stages of a phytotechnology project can provide a land reuse/restoration asset upon completion.

Disadvantages

Phytotechnologies may not be appropriate for sites with contamination at significant depths due to the generally shallow 

distribution of plant roots. 

A longer time period than more traditional, intrusive cleanup technologies may be required to achieve remedial goals. 

A large land area may be required for effective treatment in certain situations. 

High initial contaminant concentrations at a site may be phytotoxic and inhibit or prevent plant growth. 

Amendments and cultivation practices might exert unintended effects on contaminant mobility.

Cultivation of vegetation can be more difficult under the adverse conditions of contaminated soil or groundwater; plant 

growth and associated remediation may not occur during winter season.

A risk analysis may be necessary before disposal of any contaminated plant material.

Potential to create new fate and transport pathways that may never have existed at the site prior to applying a particular 

phytotechnology (i.e., due to habitat creation).

Sampling and analysis of plant and core tissues may be required to verify contaminant transfer issues occurring within the 

plant.

Sources: ITRC. 2009. Phytotechnology Technical and Regulatory Guidance 

and Decision Trees, Revised. EPA. 2001a. Phytoremediation of Contaminated 

Soil and Ground Water at Hazardous Waste Sites, EPA 540-S-01-500. 

February.

Photograph 1: Collection of gas and water vapor from a poplar tree 

at the Oregon Poplar Superfund Site in Clackamas, Oregon. Native 

and hybrid poplar trees were planted on the site in 1998 to remediate 

groundwater contaminated with volatile organic compounds. Source: EPA. 

http://www.epa.gov/superfund/accomp/news/phyto.htm 
4

APPLICATIONS OF 

PHYTOTECHNOLOGIES

The effectiveness and economic viability of a phytotechnology depend on climate, elevation, precipitation, soil type 

and quality, the type, age, distribution, and concentration 

of contamination, media, and the viability of the plants and 

planting system used for each site. Results of research, 

laboratory studies, and field tests at similar sites can serve 

as a guide to determining whether phytotechnologies are 

appropriate for a site. Successful precedence can help you 

identify appropriate plant species for implementation at 

your site. If relevant existing local data are not available or 

applicable, then site specific studies may be needed. If local 

data are used, ensure that site conditions are similar to the 

surrounding, undisturbed areas.

This section discusses contaminants that have been successfully remediated or contained using phytotechnologies 

and contaminants for which applications have not proven 

effective. As phytotechnology is relatively new, methods, 

plant selection, and applications are constantly evolving 

and improving. The phytotechnology matrix in Table 4 lists 

mechanisms, applications, and levels of testing for contaminants that phytotechnologies have effectively removed or 

controlled.

Organic Compounds

Many organic compounds can be contained or remediated 

through phytodegradation, rhizodegradation, phytosequestration, and phytovolatilization. In addition, phytohydraulics 

can be used to contain or remediate groundwater contaminated with organic compounds. Information on how 

phytotechnologies apply to organic compounds is included 

below.

Chlorinated Solvents and Volatile Organic 

Compounds (VOC)

Poplar trees, whose roots can grow up to 15 feet, have 

proven successful at many sites for groundwater control and 

contaminant removal through rhizodegradation, phytodegradation, and phytovolatilization of chlorinated solvents 

through leaves and bark, as well as sorption of contaminants 

to plant tissues (Compton et al. 2003). Phytovolatilization can potentially release some contaminants into the 

atmosphere. However, high levels of chlorinated solvents 

have not been found in the air around the vegetation (EPA 

2001b). 

Studies have shown that poplar trees can create a hydraulic 

barrier by extracting large amounts of shallow groundwater (RTDF 2005). For example, at the Aberdeen Proving 

Ground site, plantings of poplars reversed groundwater flow 

during the summer months (Van Den Bos 2002). However, 

water uptake, as well as contaminant uptake in soil, essentially stops during the winter when plants are dormant. 

Rhizodegradation continues but at a reduced rate. During 

project design, it is important to model seasonal variations in 

water uptake by the trees. If the model shows that the plume 

will travel beyond the trees by the end of the dormant season, then a backup system would be needed (ITRC 2009).

Munitions

Phytotechnologies show considerable promise for explosives 

remediation, especially for treatment of large volumes of 

lightly contaminated soil and groundwater through phytodegradation (McCutcheon and Schnoor 2003). The Department of Defense has conducted extensive research into using 

phytotechnologies for cleanup of ground and surface water 

contaminated with explosives, including trinitrotoluene (TNT), 

cyclotrimethylenetrinitramine (RDX), and similar compounds. 

Most research studies have been conducted using wetland 

plants and have shown promising results. For example, two 

engineered wetlands were constructed at the Iowa Army 

Ammunition Plant to phytoremediate explosives-contaminated surface water. The wetlands successfully remediated RDX 

in surface water from approximately 800 parts per billion to 

non-detect levels (Kiker et al. 2001). 

In addition, research is being conducted on the development 

of transgenic plants (see Transgenics Section of this fact 

sheet) that are able to phytoremediate RDX-contaminated 

soils. The plants have an enzyme that uses bacteria to break 

down RDX and decrease toxicity of the contaminant (Rylott et 

al 2006). 

Perchlorate is a common munitions constituent. A laboratory 

study by the University of Georgia showed that perchloratecontaminated water could be remediated through phytodegradation and rhizodegradation under anaerobic conditions. 

Laboratory studies for perchlorate-contaminated soil (simulating field conditions) also showed removal of perchlorate 

(Willey 2007). 

Persistent Organic Pollutants (POP)

POPs consist of a group of contaminants, mainly pesticides 

and polychlorinated biphenyls (PCB), with the following 

characteristics: toxicity, persistence, bioaccumulation, and 

long-range transport. Phytotechnologies are generally not 

considered to be feasible for stockpiles of PCB-contaminated 

soil but can be used as a polishing technology for residual 

contamination in soil. While a pilot study using three differPhotograph 2: Trees planted by Argonne National Laboratory in Murdock, Nebraska in 2005. Phytoextraction is one of the technologies used 

to remediate groundwater contaminated with carbon tetrachloride. Source: 

Argonne National Laboratory.
5

ent types of plants (zucchini, sedge, and fescue) showed insight for future studies, none of the species in this study were 

likely to provide a cost-effective alternative to traditional 

treatment methods. Soil samples after one growing season 

revealed no detectable decrease in soil PCB concentrations, 

and the study reported that it could take several growing 

cycles before a decrease in soil PCB concentration might be 

observed (Whitfield Aslund et al. 2006). 

POPs have been treated using phytostabilization and phytohydraulics. Laboratory research has shown the potential for 

rhizodegradation and phytoextraction of PCBs. Preliminary 

research has identified plant species that effectively accumulate highly weathered pesticide and PCB residues from the 

soil. Research from the Ukraine and Kazakhstan has shown 

that bean plants can accumulate and even decompose the 

pesticide dichlorodiphenyltrichloroethane (DDT) (EPA 2006). 

Pesticides such as dichlorodiphenyldichloroethylene (DDE) 

have been detected in the roots of a variety of vegetables, 

but translocation of these contaminants from the roots to the 

shoots has been found only in zucchini and pumpkin (Willey 2007). For example, a pilot study was conducted that 

compares the ability of closely related species (zucchini and 

squash) to take up DDE from contaminated soil as well as 

from hydroponic solutions. Results from the study show that 

zucchini roots and stems extracted 12 times more DDE than 

squash tissue. In addition, in hydroponic solutions, squash 

was significantly more sensitive to DDE exposure than zucchini (Chhikara, S. and others 2010). 

Petroleum Products

Petroleum products that have impacted soil, surface water, 

or groundwater have been successfully remediated, generally through rhizodegradation. Most commonly, studies 

on rhizodegradation of petroleum products used grasses; 

but other species, such as hybrid poplars, willows, and 

legumes, were also used. However, the presence of mixtures 

of contaminants at a site poses greater difficulty for designing and selecting a successful phytoremediation approach. 

Moreover, high molecular weight PAHs and aged petroleum 

products are less bioavailable and not successfully remediated by phytotechnologies (Van Epps 2006). 

Laboratory and field studies have shown that lower weight 

PAHs can be remediated using various combinations of 

grasses through rhizodegradation and phytovolatilization. 

Native grasses, perennial ryegrass (Lolium perenne), introduced cool-season and warm-season grasses, and legumes 

have been used (EPA 2001a). 

Metals and Other Inorganics 

Metals and other inorganics cannot be degraded through 

phytotechnology mechanisms. Generally, phytotechnologies 

have had limited success in efforts to extract metals. An 

alternative is to stabilize the metals and ecologically restore 

the site using soil amendments. “The Use of Soil Amendments for Remediation, Revitalization and Reuse” (EPA 

542-R-07-013) provides additional information on this topic 

(EPA 2007) and is available at: http://www.clu-in.org/

download/remed/epa-542-R-07-013.pdf. “Chelators” can 

be added to soil to enhance the plant-availability of contaminants, but some types of amendments may also increase 

the bioavailability and mobility of these chemicals, and may 

cause leaching of the chelated pollutants into groundwater 

(Chaney et al. 2007).

Some metals and metal-complexes in soils can be remediated by phytoextraction and phytosequestration. Phytovolatilization can occur with some metals (specifically, mercury 

and selenium). Phytohydraulics can also be used to contain 

and treat groundwater contaminated with certain metals. 

High-biomass plants extract low levels of metals as essential 

nutrients, while hyperaccumulators can take up and concentrate a particular contaminant up to 100 or 1,000 times 

greater than the concentration in soil; this higher concentration of metals in the leaves may discourage animal consumption of the plants (Pollard and Baker 1997) or provide an 

advantage to plants in colonizing harsh soils. Phytotechnology applications for a variety of metals are discussed below.

Arsenic 

Arsenic contaminated soil and groundwater have been successfully remediated through phytoextraction. Some ferns, 

such as Pteris vittata, have been shown to hyperaccumulate 

arsenic effectively (Ma et al. 2001). These ferns grow in 

areas with mild climates and have roots that extend about 

12 inches into the soil, depending on soil texture and arsenic 

concentration in the soil (Liao et al. 2004). Therefore, appropriate sites for this application are limited to those in mild 

climates with relatively shallow contamination. Phytoextraction of arsenic is applicable for small or large sites. 

At appropriate sites, hyperaccumulating ferns, such as Pteris 

vittata and Pityrogramma calomelanos, can accumulate over 

2 percent arsenic in their biomass (Gonzaga et al. 2006); 

EdenfernTM can accumulate arsenic in its fronds at levels up 

to 100 times the underlying soil concentration (Edenspace 

2010). While Pteris vittata is considered a hyperaccumulator for arsenic, the plant converts arsenate to arsenite (a 

highly toxic form of arsenic), so caution is required if using 

these plants (Peer 2005). At a contaminated site, fronds 

can be harvested for recycling or landfill disposal. Where 

recycling is feasible, arsenic in the fronds can be recovered 

at rates greater than 70 percent through fluid extraction; 

recovered arsenic can be reused in industrial applications. 

Cadmium

Phytoextraction of cadmium contaminated soil has been 

shown to be very slow because of the low biomass and 

slow growth rate of cadmium-specific hyperaccumulators. 

However, research studies show that the process can be 

enhanced by using two-phase planting of the hyperaccumulator Cress (Rorippa globosa). In two-phase cultivation, 

the plants are transplanted into contaminated soils twice in 

one year by harvesting the plants when they are flowering. 

Research results are promising, but literature reviewed for 

this fact sheet does not document field applications (Wei and 

Zhou 2006). 
6

Phytosequestration

Rhizodegradation

Phytohydraulics

Phytoextraction

Phytodegradation

Phytovolatilization

Constructed Treatment 

Wetland/Aquatic Plant Lagoon

Field Crops/Gardens

Landfill Cover

Riparian Buffer

Tree Hydraulic Barrier

Tree/Shrub Plantation

Hydroponic Solutions

Sorption to plant tissues

Hyper-accumulation

Greenhouse

Laboratory

Field 

Pilot

Full-scale

BTEXChlorinated SolventsPCBsMunitionsPAHsPesticidesPetroleum Products

Inorganics

ArsenicCadmiumChromiumCopper

NickelSeleniumRadionuclides

Notes:

BTEX

PAH

PCB

RDX

TNT Trinitrotoluene

Benzene, toluene, ethylbenzene, and xylenesPolycyclic aromatic hydrocarbonPolychlorinated biphenyl

Cyclotrimethylenetrinitramine

Organic Compounds

Phytotechnology

Mechanism

Contaminant

Applications Scale

General

TABL

PHYTOTECHNO

Poplars, willows, grasses, and legumes have beesoil and groundwater. Poplar trees take up chlorinated solvents from cogroundwater.Not feasible for stockpiles of PCB-contaminated as a polishing technology. Wetland plants take up TNT, RDX, and similar cBean plants have been shown to accumulate and Zucchini roots and stems can extract DDE and aDDE exposure than squash tissue. Hybrid poplariparian buffer strips.Aged petroleum products are not usually bioavaisuccessfully treated via phytotechnologies. Low PAHs have been remediated using native grasses(Lolium perenne), introduced cool-season and wand legumes.Appropriate for sites with contaminants in the tosoil. Poplars used to control landfill leachate in landfill.Uptake of cadmium into plants is slow. Willow and Birch trees take up chromium but it Tumbleweed and Russian thistle accumulate chr

pp 

Soil amendments can increase copper uptake in Ifield tests are needed to determine feasibility.Plants in the mustard family accumulate nickel. Duckweed and Water hyacinth have been used to using wetlands, and Indian mustard and Canola pselenium.Sunflower plants remove uranium, cesium, and shydroponic solutions. Soil amendments can incruptake in Johnson grass.

* 

Additional Comments 

Bioconcentration is a concern for metals.

LE 4

OLOGY MATRIX
8

Chromium 

While a chromium-specific hyperaccumulator has not been 

identified, recent studies indicate that certain plant species can be applied to address chromium contamination 

in soil, surface water, or groundwater by removal through 

phytoextraction and phytostabilization. For example, 

willow (Salix spp.) and birch (Betula spp.) trees are able to 

take up chromium and could be used to treat chromiumcontaminated groundwater; however, chromium stays mainly 

within the roots (Pulford et al. 2001). In addition, chromium 

in estuaries (specifically, high saline coastal waters) can be 

absorbed by agricultural waste material, or bagasse (fiber 

remaining after juice is removed from sugarcane) (Krishnani 

et al. 2004). Finally, tumbleweed or Russian thistle (Salsola 

kali) has been shown to accumulate chromium, specifically chromium(VI); this indicates that this plant might be 

considered for phytoextraction of chromium in soil (GardeaTorresdey et al. 2005).

Copper

No known hyperaccumulator has been identified for phytoextraction of copper. Initial studies using a greenhouse 

hydroponic system (i.e., plants grown in a media nutrient 

solution) have shown that black willow (Salix nigra) accumulates more copper than other willow species, but field studies 

are necessary to determine the feasibility of this species for 

phytoextraction of copper (Kuzovkina et al. 2004). In addition, soil amendments, such as phosphate, can increase copper uptake as shown in initial studies using Indian mustard 

(Brassica juncea) plants, and could be further researched for 

phytotechnology applications (Wu et al. 2004).

Lead

The use of soil amendments and planted systems to stabilize 

lead in soil is quite effective (EPA 2007). However, because 

lead is only sparingly bioavailable in soil, phytoextraction 

is ineffective. Significant research has gone into the use of 

soil chelators to enhance bioavailability of lead, but these 

amendments can cause the indiscriminate increase of lead 

mobility, and leaching of the chelated lead into surface and 

groundwater while not being very effective for increasing 

lead uptake by plants (Chaney et al. 2007).

Nickel

Mine sites with nickel impacted soils have been successfully 

remediated by phytoextraction using the hyperaccumulators 

Alyssum sp., which include plants in the mustard family. In 

addition, Alyssum hybrids have been developed to allow 

phytomining (that is, extracting nickel from the plants by 

drying and combusting the plants) (Chaney et al. 2007). 

Selenium

Selenium impacted soil, sediment, and surface water have 

been successfully remediated through phytoextraction, 

phytosequestration, and phytovolatilization, depending on 

the plants used. For example, the aquatic plants duckweed 

(Lemnaoideae) and water hyacinth (Eichhornia spp.) can 

effectively remediate selenium using constructed treatment 

wetlands (EPA 2001a). In addition, Indian mustard (Brassica juncea) and canola (Brassica napus) have been used in 

phytovolatilization of selenium; in this application, selenate 

is converted to a less-toxic dimethyl selenite gas and released to the atmosphere (EPA 2000).

Zinc 

Pilot studies to date have shown that phytoextraction is likely 

not effective for removing zinc from soil. Many plant species 

are not able to accumulate significant amounts of zinc. 

Those that do effectively remove zinc are slow growing, or 

do not have much biomass. Moreover, although a few plant 

species can accumulate zinc (for example, Thlaspi caerulenscens), the presence of other contaminants commonly found 

with zinc, such as copper, can limit the growth of these 

plants and their uptake of zinc (Lombi et al. 2001). 

Radionuclides

Phytoextraction has been considered for remediation of 

soil and water contaminated with radionuclides. Some 

studies show that the potential of phytoextraction could be 

greater for addressing technetium (Tc) than other radionuclides. While Tc appears to be less bioavailable in terrestrial ecosystems, aquatic plants have a strong potential to 

accumulate and retain Tc. Regarding other radionuclides, 

sunflower plants effectively remove uranium, cesium, and 

strontium from hydroponic solutions. In addition, plants 

such as redroot pigweed take up cesium and strontium from 

contaminated soil (EPA 2004). 

Soil amendments can increase plant uptake of radionuclides. 

One study showed that Johnson grass (Sorhgum halpense) 

planted in soil amended with poultry litter accumulated 

greater amounts of cesium and strontium than did other 

plant species in soil amended with poultry litter or other soil 

amendments. 

Transgenics

No full-scale applications of transgenic, or genetically 

altered, plants for site remediation are known. A few 

laboratory and pilot studies have shown promising results in 

using transgenic plants for phytoextraction of contaminants 

(for cases where effective natural plants have not been 

identified). Transgenic research on a variety of applications 

is occurring for constructed treatment wetlands, field crops, 

and tree plantations for several contaminants. Much of the 

current transgenic research is focused on understanding the 

genomics behind the ability of some plants and bacteria 

to modify or remove pollutants (Doty 2008). This section includes some examples of transgenic research being 

conducted.

Permits from U.S. Department of Agriculture and or 

state agencies may be needed prior to testing or using 

transgenic plants. For additional information on USDA 

permits for studies and other applications involving 

transgenic plants, see: http://www.aphis.usda.gov/

permits/brs_epermits.shtml. 
9

Phytotechnology Success Stories on Superfund Sites

•	 Aberdeen Proving Grounds, J-Fields, Maryland: Hybrid poplar trees were used to remove TCE and 

tetrachloroethylene (PCE) contamination from the groundwater. http://www.epa.gov/reg3hscd/super/sites/

MD2210020036/index.htm 

•	 Combustion, Inc., Louisiana: Poplars, native willows, and eucalyptus were used to remediate PCB 

contamination in groundwater. http://www.epa.gov/region6/6sf/pdffiles/0600472.pdf 

•	 Tibbetts Road, New Hampshire: A wooded phytoremediation area was planted to treat soil and 

groundwater contaminated with chlorinated and non-chlorinated solvents. http://www.wildlifehc.org/

ewebeditpro/items/O57F3072.pdf 

•	 Aberdeen Pesticide Dumps, North Carolina: Trees were planted to remediate groundwater contaminated 

with VOCs, pesticides, semi-volatile organic compounds (SVOC), and metals. http://www.epa.gov/region04/

waste/npl/nplnc/aberdnnc.htm 

•	 Fort Wainwright, Alaska: Willows were planted to remediate soil and groundwater contaminated with 

pesticides. http://www.clu-in.org/products/phyto/search/phyto_details.cfm?ProjectID=44 

•	 Bay Road, California: Eucalyptus and tamarisk were planted for hydraulic control of groundwater 

contaminated with arsenic within a slurry wall. http://www.clu-in.org/products/phyto/search/phyto_details.

cfm?ProjectID=64 

•	 McCormick and Baxter Superfund site, Oregon: Hybrid poplars and perennial rye grasses were used 

to remediate shallow soil contaminated with PAHs and pentachlorophenol (PCP). http://www.deq.state.or.us/lq/

cu/nwr/McCormickBaxter/ 

•	 Hanford 100-N Area, Washington: Phytoremediation was selected as a polishing step for groundwater 

contaminated with strontium 90. http://www.hanford.gov/docs/gpp/science/em21/phyto%20work%20plan.pdf 

•	 Naples Truck Stop, Utah: Poplars were used to remediate groundwater contaminated with petroleum 

products. http://www.clu-in.org/products/phyto/search/phyto_details.cfm?ProjectID=190 

•	 Palmerton Zinc Pile Superfund Site, Pennsylvania: Grasses were used for hydraulic control and 

stabilization of soil, sediment, and groundwater contaminated with metals. http://www.epa.gov/reg3hscd/super/

sites/PAD002395887/index.htm

•	 Fort Drum Gasoline Alley, New York: Willows were used to remediate surface water contaminated with 

benzene, toluene, ethylbenzene, and xylenes (BTEX). http://www.clu-in.org/products/phyto/search/phyto_

details.cfm?ProjectID=229

•	 East Multnomah County Groundwater Contamination, Cascade Corporation Site (OU 2),

Oregon: Poplars were used to remediate groundwater contaminated with TCE. http://www.deq.state.or.us/lq/

ECSI/ecsidetail.asp?seqnbr=635 

•	 Edward Sears Poplar Site, New Jersey: Hybrid Poplars were used to remediate groundwater 

contaminated with volatile organic compounds. http://costperformance.org/profile.cfm?ID=62&CaseID=62 

•	 Kauffman and Minteer Site, New Jersey: Native black willows and hybrid poplars were planted in this 

pilot study to remediate soil and groundwater contaminated with chlorinated solvents. http://cluin.org/download/

techfocus/phyto/RemediationJ-13-3-21.pdf (p. 31)

•	 Oregon Poplar Site, Oregon: Native and hybrid poplar trees were planted on the site in 1998 to remediate 

groundwater contaminated with volatile organic compounds. http://www.epa.gov/superfund/accomp/news/

phyto.htm
10

The transgenic plants Arabidopsis thaliana L. and tobacco 

(Nicotiana tobacum) can transform methyl-mercury into 

elemental mercury before releasing it into the atmosphere. 

From a regulatory perspective, however, such mercury 

releases are not acceptable; therefore, these genetically 

altered plants are not recommended for phytovolatilization 

of mercury. A research team at the University of Georgia 

successfully developed a transgenic yellow poplar (Liriodendron tulipifera) that is fast growing, pest resistant, and 

effective at absorbing mercury. This transgenic poplar transformed ionic mercury to a much less toxic and less volatile 

metallic mercury (Meagher 1999; Dhankher and Meagher 

2003). Additional research is focusing on (1) increasing 

plant tolerance to mercury and arsenic, (2) transforming the 

toxic elements to promote transport from roots to shoots, (3) 

transforming these toxic elements to promote storage in the 

aboveground plant parts, (4) enhancing the plants’ ability to 

trap toxicants aboveground, and (5) enhancing transporters 

for uptake and storage (Meagher 2007). 

In 2007, researchers at the University of Washington 

published promising results regarding the development of a 

transgenic poplar for phytoremediation of trichloroethylene 

(TCE), vinyl chloride, carbon tetrachloride, benzene, and 

chloroform in water and air (Doty and others 2007).

Field studies completed using transgenic Indian mustard 

plants to phytoremediate soil contaminated with selenium 

and boron show promise. The transgenic plants accumulated much more selenium in their leaves and tolerated the 

contaminated soil better than natural Indian mustard plants 

(growing much more successfully in contaminated soil) 

(Banuelos 2005). 

Additional examples of phytotechnology research, including 

the use of transgenic plants and endophytes, or bacteria that 

reside within plant tissue, can be found in Doty’s “Enhancing phytoremediation through the use of transgenics and 

endophytes” (2008).

Resources Used for this Fact 

Sheet

Banuelos, Gary and others. 2005. “Field Trial of Transgenic Indian Mustard Plants Shows Enhanced Phytoremediation of Selenium-Contaminated Sediment.” Environmental 

Science and Technology. Vol. 39, No. 6, pp. 1771-1777. 

http://chemphys.armstrong.edu/nivens/Chem3300/

phyto3.pdf

Chaney, Rufus L., Minnie Malik, Yin M. Li, Sally L. Brown, 

Eric P. Brewer, J. Scott Angle, and Alan J. M. Baker. 1997. 

“Phytoremediation of soil metals.” Environmental Biotechnology. Vol. 8, pp. 279-284.

Chaney, Rufus L., J. Scott Angle, C. Leigh Broadhurst, 

Carinne A. Peters, Ryan V. Tappero, and Donald L. Sparks. 

2007. “Improved Understanding of Hyperaccumulation 

Yields Commercial Phytoextraction and Phytomining Technologies.” Journal of Environmental Quality. Vol. 36, pp. 

1429-1443.

Chhikara, Sudesh, Bibin Paulose, Jason C. White, and Om 

Parkash Dhankher. 2010. Understanding the Physiological 

and Molecular Mechanism of Persistent Organic Pollutant 

Uptake and Detoxification in Cucurbit Species (Zucchini and 

Squash). Environ. Sci. Technol. Accepted April 21, 2010.

Compton, Harry R., George R. Prince, Scott C. Fredericks, 

and Christopher D. Gussman. 2003. “Phytoremediation 

of Dissolved Phase Organic Compounds: Optimal Site 

Considerations Relative to Field Case Studies.” Remediation. 

Summer Edition.

Dhankher, Om Parkash and Richard B. Meagher. 2003. 

Strategies for the Engineered Phytoremediation of Mercury 

and Arsenic Pollution. 

Doty, Sharon L. and others. 2007. “Enhanced Phytoremediation of Volatile Environmental Pollutants with Transgenic 

Trees.” Proceedings of the National Academy of Sciences of 

the United States of America. Vol. 104, No. 43, pp. 16816 

– 16821. http://www.pnas.org/content/104/43/16816.

full

Doty, S.L. 2008. “Enhancing phytoremediation through the 

use of transgenics and endophytes.” New Phytologist. Vol. 

179, pp. 318-333.

Edenspace. 2010. Phytoremediation of Arsenic-Contaminated Soils. Edenspace Systems Corporation; SBIR Success 

Stories. http://www.edenspace.com/products/envirosolutions.html?expandable=1

Gardea-Torresdey JL, G. de la Rosa, J.R. Peralta-Videa, M. 

Montes, G. Cruz-Jimenez, and I. Cano- Aguilera. 2005. 

“Differential uptake and transport of trivalent and hexavalent 

chromium by tumbleweed (Salsola kali).” Arch Environ 

Contam Toxicol. PMID:15696348.

Gonzaga, Maria Isidoria Silva, Jorge Antonio Gonzaga 

Santos, and Lena Qiying Ma. 2006. “Arsenic Phytoextraction and Hyperaccumulation by Fern Species.” Scientia 

Agricola. (Piracicaba, Braz.). Vol. 63, No. 1. Piracicaba 

Jan./Feb. http://www.scielo.br/scielo.php?script=sci_arttext

&pid=S0103-90162006000100015

Interstate Technical Regulatory Council (ITRC). 2009. Phytotechnology Technical and Regulatory Guidance and Decision 

Trees, Revised.

Kiker, Jackson H., Steve Larson, Donald D. Moses, and 

Randy Sellers. 2001. “Use of Engineered Wetlands to 

Phytoremediate Explosives Contaminated Surface Water 

at the Iowa Army Ammunition Plant, Middletown, Iowa.” 

Proceedings of the 2001International Containment and 

Remediation Technology Conference and Exhibition. http://

www.containment.fsu.edu/cd/content/pdf/416.pdf

Krishnani, K., V. Parimala, and X.G. Meng. 2004. “Detoxification of chromium(VI) in coastal water using lignocellulosic agricultural waste.” Water SA. Vol. 30, pp. 541-545.

Kuzovkina, Y.A., M. Knee, and M.F. Quigley. 2004. 

“Cadmium and copper uptake and translocation in five wil-
11

low (Salix L.) species.” Int J Phytoremediation. Vol. 6, pp. 

269-287.

Liao, X.-Y., T.-B. Chen, M. Lei, Z.-C. Huang, X.-Y. Xiao, and 

Z.-Z. An. 2004. “Root distributions and elemental accumulations of Chinese brake (Pteris vittata) from As-contaminated 

soils.” Plant and Soil. Vol. 261, No. 1-2, pp. 109-116. 

Lombi, E., F. J. Zhao, S. J. Dunham, and S. P. McGrath. 

2001. ”Phytoremediation of Heavy Metal-Contaminated 

Soils : Natural Hyperaccumulation versus Chemically 

Enhanced Phytoextraction.” J. Environ. Qual. Vol. 30, pp. 

1919-1926.

Ma, L. Q., K.M. Komar, C. Tu, W.H. Zhang, Y. Cai, and E.D. 

Kennelley. (2001). “A fern that hyperaccumulates arsenic: 

a hardy, versatile, fast-growing plant helps to remove arsenic 

from contaminated soils.” Nature. Vol. 409, p. 579.

McCutcheon, S.C. and J. L. Schnoor. 2003. Phytoremediation: Transformation and Control of Contaminants. John 

Wiley & Sons, Inc., Hoboken, New Jersey. ISBN: 0-471-

39435-1. 987 pp. 

Meagher, Richard B. 1999. Phytoremediation of Ionic and 

Methyl Mercury Pollution. DOE-EMSP 6/14/1999. http://

www.osti.gov/em52/1999projsum/54837.pdf 

Meagher, R.B. (2007). Multigene strategies for engineering 

the phytoremediation of mercury and arsenic. In: Biotechnology and Sustainable Agriculture 2006 and Beyond: 

Proceeding of the 11th IAPTC&B Congress, Z. Xu, J. Li, Y. 

Xue, and W. Yang, eds (Beijing, China: Springer), 49-

60. http://ersdprojects.science.doe.gov/workshop_pdfs/

new_orleans_2003/first_session/Dhanker.pdf

Peer, Wendy Ann and others. 2005. Phytoremediation and 

Hypeaccumulator Plants.

Pollard, A. Joseph and Alan J. M. Baker. 1997. “Deterrence of herbivory by zinc hyperaccumulation in Thlaspi 

caerulescens (Brassicaceae).” New Phytologist. Vol. 135, 

Issue 4, pp. 655-658.

Poynton, CY, J.W. Huang, M.J. Blaylock, L.V. Kochian, and 

M.P. Elless. 2004. “Mechanisms of arsenic hyperaccumulation in Pteris species: root as influx and translocation.” 

Planta. Vol. 219, No. 6, pp. 1080-1088.

Pulford, I. D., C. Watson, and S.D. McGregor. 2001. 

“Uptake of chromium by trees: prospects for phytoremediation.” Environmental Geochemistry and Health. Vol 23, pp. 

307–311.

U.S. Environmental Protection Agency (U.S. EPA). 2000. 

Introduction to Phytoremediation, EPA 600-R-99-107. 

February.

U.S. EPA. 2001a. Phytoremediation of Contaminated 

Soil and Ground Water at Hazardous Waste Sites, EPA 

540-S-01-500. February. http://www.epa.gov/nrmrl/

pubs/540s01500/epa_540_s01_500.pdf

U.S. EPA. 2001b. Evaluation of Phytoremediation for 

Management of Chlorinated Solvents in Soil and Groundwater, EPA 542-R-05-001. http://www.rtdf.org/public/phyto/

chlor_solv_management.pdf

U.S. EPA. 2004. Radionuclide Biological Remediation 

Resource Guide, EPA 905-B-04-001. August. http://www.

cluin.org/download/remed/905b04001.pdf

U.S. EPA. 2006. Reference Guide to Non-combustion 

Technologies for Remediation of Persistent Organic Pollutants in Stockpiles and Soil, EPA-542-R-05-006. December. 

http://www.clu-in.org/download/remed/542r05006/

final_pops_report_web.pdf

U.S. EPA. 2007. The Use of Soil Amendments for Remediation, Revitalization and Reuse, EPA 542-R-07-013. December.

U.S. EPA. 2005. Evaluation of Phytoremediation for 

Management of Chlorinated Solvents in Soil and Groundwater, EPA 542-R-05-001. Prepared by the Remediation 

Technologies Development Forum (RTDF), Phytoremediation 

of Organics Action Team, Chlorinated Solvents Workgroup. 

January.

Van Den Bos, Amelie. 2002. Phytoremediation of Volatile 

Organic Compounds in Groundwater: Case Studies in 

Plume Control. Prepared for EPA Office of Solid Waste and 

Emergency Response, Technology Innovation Office. Washington DC. August. http://www.clu-in.info/download/

studentpapers/vandenbos.pdf

Van Epps, Amanda. 2006. Phytoremediation of Petroleum 

Hydrocarbons. Prepared for EPA Office of Solid Waste and 

Emergency Response, Office of Superfund Remediation and 

Technology Innovation. Washington, DC. August. http://

clu-in.org/download/studentpapers/A_Van_Epps-Final.pdf

Wei, S.H. and Q.Z. Zhou. 2006. “Phytoremediation of 

Cadmium-contaminated Soils by Rorippa globosa using 

Two-Phase Planting.” Environ Sci Pollut Res Int. Vol. 13, 

number 3 (May), pp. 151-155. http://www.ncbi.nlm.nih.

gov/pubmed/16758704

Wenzel, W.W., D.C. Adrians, D. Salt, and R. Smith. 1998. 

“Phytoremediation: A Plant-Microbe-Based Remediation 

System. Bioremediation of Contaminated Soils.” Agronomy 

Monograph, No. 37, pp. 457-508.

Willey, Neil. 2007. Phytoremediation: Methods and 

Reviews. Humana Press. 

Wu, L. H., H. Li, Y. M. Luo, and P. Christie. 2004. “Nutrients can enhance phytoremediation of copper-polluted 

soil by Indian mustard.” Environmental Geochemistry and 

Health. Vol. 26, pp. 331-335.
12

EPA 542-F-10-009

September 2010

www.epa.gov

Office of Superfund Remediation 

and Technology Innovation

(5203P)

Additional EPA Resources 

•	 Clu-in Technical Focus on Phytoremediation: http://www.cluin.org/techfocus/default.focus/sec/

Phytotechnologies/cat/Overview

•	 Phytotechnology Project Profiles: http://www.cluin.org/products/phyto

Additional Information Resources 

•	 Phytotechnology Technical and Regulatory Guidance and Decision Trees, Revised.

•	 Interstate Technology and Regulatory Council (ITRC) Phytotechnologies Team. 2009. 

•	 PHYTO-3, 187 pp. http://www.itrcweb.org/Documents/PHYTO-3.pdf 

•	 International Journal of Phytoremediation: http://www.tandf.co.uk/journals/titles/15226514.asp

•	 International Society of Phytotechnologies: http://www.phytosociety.org

•	 U.S. Department of Agriculture Plants Database: http://plants.usda.gov

•	 Phytoremediation Electronic Newsgroup Network: http://www.dsa.unipr.it/phytonet

WHO CAN I CONTACT FOR MORE INFORMATION?

If you have any questions or comments on this fact sheet, please contact:

Steven Rock, EPA

rock.steven@epa.gov

Linda Fiedler, EPA

fiedler.linda@epa.gov