Welcome to ITRC’s Internet-based Training

“Phytotechnologies”

Sponsored by the ITRC, the EPA Office of Superfund Remediation and

Technology Innovation, BP &RTDF

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Phytotechnologies use plants to contain, stabilize, sequester, assimilate, reduce, detoxify, degrade, metabolize and/or mineralize contaminants in soil, ground water, surface water, or sediments. Phytotechnologies can be applied in-situ or ex-situ and can address organic compounds such as petroleum hydrocarbons, gas condensates, crude oil, chlorinated compounds, pesticides and explosive compounds plus inorganics including high salinity, heavy metals, metalloids and radioactive materials.

Attention on phytotechnologies led to a December 1999 publication of the ITRC Document titled, Phytoremediation Decision Tree. The decision tree was designed to allow users to input basic information from a site and, through a flowchart layout, decide if phytotechnologies are feasible.

The purpose of this training is to familiarize you with the recently released ITRC Phytotechnologies Technical and Regulatory Guidance and Phytoremediation Decision Tree. It provides technical and regulatory information to help you understand, evaluate and make informed decisions on phytotechnology proposals. Included is a description of the various sciences and engineering practices phytotechnologies require, regulatory considerations and policy issues, stakeholder concerns, case studies, and technical references.ITRC – Interstate Technology and Regulatory Council (www.itrcweb.org)EPA Office of Superfund Remediation and Technology Innovation (www.clu-in.org)RTDF = Remediation Technology Development Forum (www.rtdf.org)willITRC Course Moderator:Mary Yelken (myelken@earthlink.net)willill

ITRC – Shaping the Future of Regulatory Acceptance

2004 Course TopicsAlternative Landfill CoversConstructed Treatment WetlandsMunitions Response Historical Records ReviewTriad ApproachMitigation WetlandsSmalls Arms Firing Ranges: Best Management PracticesRemediation Process OptimizationPerformance Assessment of DNAPL RemediesIn Situ BioremediationIn Situ Chemical OxidationPhytotechnologiesRadiation Risk AssessmentSoils at Small Arms Firing RangesSurfactant/Cosolvent Flushing of DNAPLsPermeable Reactive Barriers

ITRC State Members

FederalPartners

Host Organization

CoordinatingOrganizations

Industry, Academia, Consultants, Citizen Stakeholders

DOE DODEPA

WGA SSEB

ITRC Member States

The Interstate Technology and Regulatory Council (ITRC) is a state-led coalition of regulators, industry experts, citizen stakeholders, academia and federal partners that work to achieve regulatory acceptance of environmental technologies and innovative approaches. ITRC consists of more than 40 states (and the District of Columbia) that work to break down barriers and reduce compliance costs, making it easier to use new technologies and helping states maximize resources. ITRC brings together a diverse mix of environmental experts and stakeholders from both the public and private sectors to broaden and deepen technical knowledge and advance the regulatory acceptance of environmental technologies. Together, we’re building the environmental community’s ability to expedite quality decision making while protecting human health and the environment. With our network approaching 7,500 people from all aspects of the environmental community, ITRC is a unique catalyst for dialogue between regulators and the regulated community.

For a state to be a member of ITRC their environmental agency must designate a State Point of Contact. To find out who your State POC is check out the “contacts” section at www.itrcweb.org. Also, click on “membership” to learn how you can become a member of an ITRC Technical Team.

Phytotechnologies for Chlorinated Solvent, Inorganic, and Radionuclide Contamination

Phytotechnology Presentation Overview

Overview of Phytotechnology CostsMechanismsQuestions and answersPhytotechnology ApplicationsSite CharacteristicsTreatment RequirementsRegulatory IssuesMonitoringQuestions and AnswersLinks to additional resourcesYour feedback

Logistical RemindersPhone Audience

Keep phone on mute* 6 to mute your phone and again to un-muteDo NOT put call on hold

Simulcast AudienceUse at top of each slide to submit questions

Course Time: 2 ¼ Hours

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No Associated Notes

Today’s Presenters

Kris Geller New Jersey Dept. of Environmental Protection

Kgeller@dep.state.nj.us

Steve RockUS Environmental Protection Agency-ORD

rock.steven@epa.gov

Dr. David TsaoBP Group Environmental Management Company

tsaodt@bp.com

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Kris Geller has been working for the State of New Jersey Department of Environmental Protection Bureau of Environmental Evaluation and Risk Assessment for 12 years. Mr. Geller provides technical assistance during all phases of site evaluation from preliminary assessment through site closure. Mr. Geller was part of a team that wrote The Technical Requirements for Site Remediation - NJAC 7:26E. Prior to his moving to the NJDEP Mr. Geller spent over 10 years working in the domestic and international petroleum industry. Mr. Geller has a BA in Biology for the SUC @ Oswego, NY and an MS in Geology from the University of KY.Steve Rock is an Environmental Engineer in the Remediation and Contaminant Branch at EPA’s National Risk Management Research Laboratory in Cincinnati, Ohio. Steve manages field projects using phytoextraction, phytodegradation, plume control and vegetative. He is the author of several phytotechnology publications, including acting as team leader on the EPA’s Introduction to Phytoremediation, and a chapter in the Standard Handbook of Environmental Engineering. He co-chairs the RTDF Action Team on Phytoremediation, and has three subgroups researching the phytoremediation issues of petroleum hydrocarbons, chlorinated solvents, and vegetative covers for waste containment. He participates in EPA in-house research, and provides technical assistance to EPA regional staff on questions of phytoremediation.Dr. David Tsao is an Environmental Engineer at the BP Naperville Complex in Naperville, IL. He is a three-time chemical engineering graduate of Purdue University (B.S., 1988, M.S., 1990, Ph.D., 1997) where his areas of research included plant biotechnology, pharmaceutical production, plant nutrition, and plant biomass production for space (NASA) applications. Upon graduation, David came to work for Amoco in the Environmental Technology Assessment and Development group where he specialized in the areas of phytoremediation and the remediation of gasoline oxygenate components. Currently, David is a member of the Hydrocarbon and Environmental Management group in BP’s Global Environmental Management Business Unit where he is responsible for developing the technical aspects of all phytoremediation efforts. He is also active in wetland technologies, landfarming, composting, native prairie restorations, ecosystem developments, biodiversity, and greenhouse gas emissions reduction. Furthermore, David actively participates in the development of these natural clean up technologies as well as the establishment of regulatory guidance on the use of these innovations through the US EPA’s Remediation Technologies Development Forum, the Interstate Technology and Regulatory Council, the American Petroleum Institute, and the Petroleum Environmental Research Forum.

PhytotechnologiesDefinition and Applicability

Different Mechanisms = Different Types of System DesignsVegetative, prairie, ET covers: infiltration control, stabilization, remediationTree hydraulic systems: plume control, remediationConstructed wetlands: water containment, treatment

Wide Range of Contaminants:Organic: hydrocarbons, chlorinated solvents, phenols, polycyclic aromatic

hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), agricultural wastesInorganic: metals, radionuclides, salinity, nitroaromatics, amines, excess

fertilizers, pesticides, CCA (chromium copper arsenic)Different Types of Impacted Media:

Solid phase: soils, sediments, sludgesLiquid phase: run-off, stormwater, wastewater, groundwater, leachateGaseous phase: greenhouse gases

Use of Vegetation to Contain, Sequester, Remove, or Degrade Organic and Inorganic Contaminants in Soils, Sediments, Surface Water, and Groundwater.

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Plant Physiological Processes:-Inorganic Nutrition-Production and Exudation of Phytochemicals-Stimulation and Support of Soil Organisms-Gas Exchange and TranspirationPhytotechnology Mechanisms: -Phytostabilization, Rhizodegradation, Phytoaccumulation, Phytodegradation, Phytovolatilization, Evapotranspiration -Each of these will be discussed in detailBroad Range of Contaminants and Media:-Most remediation technologies do not apply to inorganics and organics (nor simultaneously)

-Example: Dig and haul is very effective for inorganics and organics; however, it cannot be applied to all media-Example: Air stripping / air sparging technologies have been applied to all media; however, they are not effective for inorganics

-Phytotechnologies can be applied to address inorganics and organics in all media. And, it can do it SIMULTANEOUSLY (one of the primary advantages)

PhytotechnologiesOther Advantages

SafetyMinimized emissions & effluent and low secondary waste volumeControls erosion, runoff, rain infiltration, and dust emissions

EcologicalHabitat friendly, habitat creation, promotes biodiversitySequesters greenhouse gases (carbon dioxide)

Public / RegulatoryAcceptable brownfields applicationsAesthetics, green technologyIncreasing regulatory approval and standardization

Cost-EffectiveMultiple and mixed contaminants and mediaLow maintenance, passive, in situ, self regulatingSolar-powered, energy efficientRemote operation, large areas

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Safety:-Potential safety issues during installation (worker exposures) but longer-term safety is increased-Other issues to be discussed later (regulatory issues section) Ecological:-Wildlife Habitat Council provides support and guidance on enhancing former industrial areas for habitat value-Not only hardwood biomass, but sequestration in the root-zone (estimates of 50% of carbon from CO2 ends up in the subsurface)-Many of the humic substances are stable for centuriesPublic / Regulatory:-Creation of urban / industrial green spaces (aesthetically pleasing)

-Example: Larger facilities converted into golf courses-ITRC Phytotechnologies Tech & Reg Guidance Document / Training Courses-EPA RTDF standard protocolCost-Effective:-Broad applicability (discussed earlier); reduces the numbers of technologies that have to be applied at a site-Some capital savings, but long-term O&M costs are significantly reduced-Applicable in remote locations and large areas with limited utility access-Economic comparisons to follow

PhytotechnologiesLimitations (Common Regulatory Issues)

DepthOnly effective if within the relative rooting depth of the vegetation

TimeRequires longer periods to become effective (establishment)May requires longer periods to reach clean up targetsSeasonal effects

PhytotoxicityGenerally considered applicable for low to moderate concentrationsIn most cases, the vegetation must survive in order to operate

Media Transfer / Food Web ImpactsFate and transport often unclearAir emissions, leaf litterHarvesting, hazardous waste?Toxicity of parent vs. by-products

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2 Major Limitations are Depth and Time:-Typically, phyto is only effective within the root-zone of the plants; however, due to the process of transpiration (water uptake), plants can move contaminants into the root-zone from zones not directly inundated with roots.-Several planting techniques are also developed which can increase effective rooting depths (boreholes, root growth restriction barriers, mycorrhizal fungi, etc.)-Typically, a long-term technology (not something that will address immediate risks to human health and the environment, but can be useful for sites with low risk, no immediate demand for re-use/redevelopment)-Seasonal growth habit (system ‘turns off’ in the winter/dormant growing periods)-Phytotoxicity:-Very species, contaminant, and concentration dependent.-Some plant survivabilities can be in the percent range, others in the low ppb range-EXAMPLE: Some species are able to tolerate TPH up to 20% or more

Media Transfer / Food Web Impacts:-For organic contaminants, accumulation is typically not an issue (discussed later –Phytodegradation)-For inorganic contaminants, accumulation and subsequent handling, food web impacts, etc. are active regulatory issues being investigated and considered-EXAMPLE: Some studies indicate that the uptake of metals is a natural form of a pest-repellent (or pesticide)

Phytotechnology Mechanisms“Overview”

Mechanism Process Goal Media Typical Contaminants

Phytostabilization Containment SSS As, Cd, Cr, Cu, Pb, Zn

Rhizodegradation Remediation by destruction

SSS GW

Organic compounds (TPH, PAHs, BTEX, pesticides, chlorinated solvents, PCBs)

Phytoextraction Remediation by extraction and capture

SSS Metals: Ag, Au, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Zn; Radionuclides: Sr, Cs, Pu, U

Phytodegradation Remediation by destruction

SSS GW SW

Organics compounds, chlorinated solvents, phenols, pesticides, munitions

Phytovolatilization Remediation by extraction and release to air

SSS GW

Chlorinated solvents, MTBE, some inorganics (Se, Hg, and As)

Evapotranspiration Containment and erosion control

GW SW STW

Water soluble organics and inorganics

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Overview-Quick reference for Goal (Containment vs. Remediation), Media Types, Typical Contaminants, and Plant Types-These mechanisms are often combined in the final application (discussed in the next section)

-Example: Old leaded gasoline releases - Phytoextract lead while rhizodegrading the petroleum-Example: TCE degrades in both the rhizosphere (rhizodegradation) as well as in trees (phytodegradation)-Example: TCE can be degraded (rhizo- and phyto-degradation) using trees that also provide containment (evapotranspiration)

-Each mechanism will be described in detail

Media Key:-GW = Groundwater / SSS = Soils, sediments, sludges / STW = Stormwater / SW = Surface Water

What is the Rhizosphere?-1-3 mm of soil surrounding each root-Contains a high proliferation of soil organisms (yeast, fungi, bacteria, viruses, etc.)

-General populations: 1-2 orders of magnitude higher than non-vegetated soil-Specific microbes: 3-4 orders of magnitude higher; dominant organisms

Why there is such a proliferation of microbes?-Plants exude chemicals of all kinds into the subsurface

-Alcohols, phenols, sugars, carbohydrates, organic acids, inorganic nutrients - NPK-Plants produce and release various enzymes

-Dehalogenases, nitroreductases, glutathione, phenoloxidases, oxygenases, nitrilases, phosphatases

-Plants also provide oxygen and water-Direct production (0.5 mol O2 per m2 surface area) -Creating root channels for diffusion from the atmosphere

Root Turnover:-Annual event (winter)-Portion of the root system gets sloughed off because it is not needed to maintain the dormant plant

Phyto Picture

PHYTOSTABILIZATION:-Consists of three mechanisms: 1) In the Soil, 2) On the Root, and 3) In the Root

1) In the Soil:-Plant produce exudates (E1) that can cause precipitation or immobilization of contaminants-Example: Organic acids / bases alter the soil pH which changes the solubility of contaminants

2) On the Root:-Plants produce enzymes (E2) or proteins that can bind contaminants-Example: Carboxyl ligands (normally used to acquire inorganic nutrients – NPK) that irreversible bind specific heavy metals to prevent uptake (protection)

3) In the Root:-Dissolved contaminants can be taken in through the transpirational stream (water uptake) –discussed later-Plants can compartmentalize (C0) dissolved constituents into different portions of the cell -Waste receptacle (non-essential constituents) = Vacuole of the cells-Example: Allocation of nutrient minerals

Roots behave as a large filtration system for the plant

RHIZODEGRADATION:-Consists of two mechanisms: 1) Enhanced Biodegradation and 2) Co-Metabolic Biodegradation

1) Enhanced Biodegradation:-Increased oxygen in the subsurface maintains aerobic biodegradation (faster that anaerobic)

Phyto Picture

Phyto Within the PlantPhytoextraction of Inorganics

Inorganic(Heavy Metals)

Grow Plants into SoilHyperaccumulators- 1,000 to 10,000x Normal

Metal Concentrations- Indian Mustard, Sunflower,

Many OthersHalophytes- 3 to 7x Normal Salinity - Salt Cedar, Mangrove, etc.

Inorganic Taken Up- Translocation in Xylem- Taken in with Transpiration Water

Essential Plant Nutrients:- NO3/NH4, PO4, K, Ca, Mg, SO4- Fe, Cl, Zn, Cu, Mn, B, Mo- Mechanisms for inorganic uptake- Contaminant substitution

Harvest for Removal- Dry ash / burn off carbon- 90-95% reduction in mass

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PHYTOACCUMULATION:-Plants have developed physiological processes for acquiring inorganic nutritionfrom the subsurface (transport proteins and channels)-Essential Plant Nutrients: NO3 / NH4, PO4, K, Ca, Mg, SO4, Fe, Cl, Cu, Zn, Mn, B, Mo

-Required for growth or reproduction-Certain heavy metals or metalloid elements can substitute on the transport protein or enter through the channels-Plants also translocate the inorganics through the vascular tissues known as the xylem

-Transport from root to shoot to leaves-Leads to the accumulation in the terrestrial portion of the plant -Incorporate a harvesting program in the O&M plan

-Dry ash or burn off the carbon material leaving behind a mineral-rich ash to be disposed of properly.-Estimated 90-95% reduction in mass to be disposed (cost-savings)

Hyperaccumulators and Halophytes:-Accumulate concentrations of the mineral or salt that is 1,000-10,000 times normal (by definition)-Example: Brassica juncea (Indian mustard) hyperaccumulates Pb (Magic Marker site)-Example: Helianthus annuus (sunflower) hyperaccumulates a wide range of

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Contaminant

Phyto Within the PlantPhytodegradation of Organics

Octanol-Water Partition Coefficient (log Kow)Uptake: 1 to 3.5Too polar: <1Not soluble: >3.5BTEX: 1.8 to 3.2MTBE: 1.0 to 1.3PAHs: >4.1

(Naphthalene: 3.4)

Plant EnzymesDehalogenases

(Cl reduction)Nitroreductases

(munitions)Oxidases and

Oxygenases(hydrocarbons)

Intermediate

Photosynthetic OxidationPSI & PSII systemsOxidize CO2 & H2O

to C, H, and O used for biomass

CO2 + H2O

SOILand / or

GROUNDWATER

PHYTODEGRADATION:-IF the organic contaminant is able to get through the rhizosphere, can it get into the plant?

-Chemical property: Log Kow (octanol-water partition coefficient) between 1 and 3.5-<1 too polar to pass through the lipid bilayer of the root membrane (non-polar barrier)->3.5 not sufficiently soluble to enter with the transpirational water

-Example: BTEX (1.8 to 3.2) / MTBE (1.0 to 1.3)-Example: PAHs 3.35 (naphthalene) and higher (all others >4.07)

-Plant-produced enzymes:-Dehalogenases = remove Cl ions from chlorinated solvents-Nitroreductases = reduce nitroaromatics (munitions)-Glutathione and oxygenases = oxidize TCE, MTBE, others-Phenoloxidases (laccases, peroxidases, tyrosinases) = oxidize TCE, phenolic compounds-Niltrilases and phosphatases = degrade various pesticides

-Photosynthetic Cycle:-Conversion of solar energy into chemical energy entails the production of very strong oxidants that can even break apart water molecules-Oxidation-reduction process (Z-Scheme) initiated by chlorophyll absorption of lightOxidants capable of interacting with organic contaminants taken up into

Critical Chemical Parameters“Table A-1”

Chemical Log Kow Solubility Henry’s Constant Vapor Pressure TSCF RCF

UPTAKE 1 – 3.5 <1.0 >1.0

benzene 2.13 1.64 0.2250 0.90 0.71 3.6

toluene 2.69 2.25 0.2760 1.42 0.74 4.5

ethylbenzene 3.15 2.80 0.3240 1.90 0.63 6.0

m-xylene 3.20 2.77 0.2520 1.98 0.61 6.2

TCE 2.33 2.04 0.4370 1.01 0.74 3.9

aniline 0.90 0.41 2.2x105 2.89 0.26 3.1

nitrobenzene 1.83 1.77 0.0025 3.68 0.62 3.4

phenol 1.45 0.20 >1.0x105 3.59 0.47 3.2

pentachlorophenol 5.04 4.27 1.5x104 6.75(a) 0.07 54

atrazine 2.69 3.81 1.0x107 9.40(a) 0.74 4.5

trichlorobenzene 4.25 3.65 0.1130 3.21 0.21 19

RDX 0.87 4.57 - - - - - - 0.25 3.1

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Critical Chemical Properties:-Log Kow: Ability to get into the plant-Solubility: Presence / concentration in the transpirational stream (units -log mol/L)-Henry’s Constant and Vapor Pressure: Preference to remain in aqueous phase or volatilize

Transpiration Stream Concentration Factor (TSCF):-Ratio of the concentration in the transpirational stream (xylem sap) to the concentration in the soil water-TSCFs are all less than 1 which indicates that the plant is taking up more water than thecontaminant-Could indicate that the plants dilute the contaminants to reduce toxicity in the terrestrial portion of the plant

Root Concentration Factor (RCF):-Ratio of the concentration in the root tissues to the concentration in the soil water-RCFs are all greater than 1 which indicates that the plant is accumulating the contaminant in its root tissues-Could indicate that the plants are filtering the contaminants and protecting the sensitive tissues in the terrestrial portions of the plant (i.e. reproductive tissues)

Root-Zone

START OF RAINEVENT

Evapo-Transpiration (ET)Evaporation – Rain Interception Capacity

AFTER RAINEVENT

Evapotranspiration

Retrieval by Plants

Leaf Structures: Wide vs. NarrowLeaf Surfaces: Waxy vs. HairyLeaf Positions: Vertical vs. HorizontalLeaf Densities: Layers in Canopy

Species % InterceptionNatural Grass Pasture 14-19% BL Mixed Species 26% BLBuffalo Grass 31%Alfalfa 34%Big Bluestem 57%Tall Panic Grass 57%Little Bluestem 50-60%Oak Trees 24%Ash Trees 24%Spruce and Fir Trees 30%

Data Based on 0.5” Rain Event in ½ Hour

InterceptedRain

Plant Rain Interception Capacities:-Useful in phytotechnologies to control hydraulics (surface or rain water)-Plant leaves create a canopy (umbrella) that catches rain water

-Prevents water from reaching ground surface which prevents it from infiltrating-Reduced infiltration = reduced groundwater recharge

-Typical values for a natural pasture represent the “baseline” from which to improve (up to 20%)-Tree canopies are on the same order of magnitude as the “baseline” or slightly better (10-30%)-Certain prairie grasses contain interception capacities that are substantially better than the “baseline” (50-60%)

-These are based on 0.5 inches of rain in 30 minutes is a substantial down pour-Why certain species are better:

-Leaf Cuticle: waxy vs. hairy (hairy better to retain droplets)-Leaf Orientation / Structure: flat vs. vertical / fan-like vs. blade-like (fan-like + vertical better creating crevices)-Canopy Structure: number of leaf layers (more layers better)

15TranspirationDriving ForcesSolar RadiationThermal energyWindMechanical energyConvective transportHumidityDiffusion gradientsClimate-Driven

Leaf Area IndexRatio of leaf area to ground areaCanopy closure = Max. transpirationTypical LAI = 3 to 4

Leaf StomataMicroscopic Openings in LeavesTypically: undersidePoplars: both sides

How does the contaminant get from the subsurface, to the plant root, into the plant, up into the leaves, and out into the atmosphere?-This is the process of transpiration

-Connects the soil-plant-atmosphere continuum-Influenced by humidity, thermal radiation, wind

-Brings in dissolved contaminants from the subsurface into the rhizosphere (1st line of defense)-Transpiration can be used as a phytotechnology tool:

-The uptake of water from the subsurface can be used to control subsurface hydraulics

-Canopy Closure and Leaf Area Index, LAI:-LAI = Ratio of leaf area to ground surface area-LAIs can range up to 6 or 7 for certain species; typical LAIs are 3 to 4(canopy closure occurs)-Maximum transpiration occurs when the trees reach closure

TranspirationPublished Plant Rates

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Woody SpeciesPoplars

(1-2 yrs)

(5 yrs)

(10+ yrs)

1.6 - 10

13 - 200

7.0 - 53

Live Oak (1-2 yrs)

(40+ yrs)

1.0

10 - 100

Cypress (1-2 yrs)

(40+ yrs)

0.3

11 - 18

0 50 100 150Transpiration (gpd per tree)

200

300 – 800 per acre

300 – 800 per acre

300 – 1200 per acre

Willows(1-2 yrs)

(20+ yrs)

2.0 - 13 170 – 300 per acre

10 - 45

Herbaceous SpeciesRyegrass 4.1 – 9.2

Alfalfa 1.7 – 10.5

Grass/Clover 3.0 – 7.7

Rye 2.1 – 7.1

Coneflower 2.0 – 5.6Goldenrod 1.7 – 4.9

Bluestem 1.7 – 7.8

Switchgrass 1.7 – 8.5Bermuda 4.5 – 14.1

Cattail 8.5 – 28.2Cordgrass 8.0 – 21.9

ReedBulrush

1.4 – 8.52.5 – 7.8

Sedge 6.2 – 10.5

0 5 10 15 20 25Transpiration (mm/day)

-High and Low Rates are taken from literature values that depend on climate conditions and time of year-Grasses, herbaceous species, and wetland species vary widely with the species (see left set of bars)

-Domestic and agriculture species generally are not good water users (actually a good thing for less irrigation requirements)-Wetland and prairie species are especially good water users

-Trees vary widely with age and leaf density (right set of bars) -Age: 2 year old cottonwood (1st bar) vs. a 15 year old cottonwood stand (4th bar) – mature pumps substantially more-Planting Density: Young 5 year old poplars (3rd bar) pump more than mature 20 year old willows (2nd bar)

-Planting densities used in figure based on typical landscaping densities-Canopy Closure: Mature stand of cottonwoods (4th bar) and a mature stand of alders (5th bar), both with closed canopies pump approximately the same

Projecting Water Usage

VT = 0.2263 x BA - 2.5144R2 = 0.99

0

5

10

15

20

25

30

35

40

45

0 20 40 60 80 100 120 140 160 180 200Mean Basal Area (cm2)

VT (L

/day

)

CottonwoodLinear (Cottonwood)

Newly Planted1-3 Years Old

Trees

VT = Water Usage (L/day)BA = Basal Area of Trunk (cm2)

~10 Year OldTree Growing

in Same Climate

Probable CurveRelated to Canopy

Closure

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Data taken from field measurements using Thermal Dissipation Probes (TDPs)-TDPs are ‘pin probes’ that are inserted into the trunk of a tree. These probes are thermocouples where one also contains a heating source. Basic operation is the measurement of the dissipation of heat as sap transpires through the tree.-Probable Water Usage Curve in red includes the concept of canopy closure (individual tree transpiration rates will ‘max-out’ once branches from adjacent trees begin to overlap).

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Contaminant

Phyto Occurring Thru the PlantPhytovolatilization

Octanol-Water Partition Coefficient (log Kow)Uptake: 1 to 3.5Too polar: <1Not soluble: >3.5BTEX: 1.8 to 3.2MTBE: 1.0 to 1.3PAHs: >4.1

(Naphthalene: 3.4)

IntermediateChemicalVolatilityHenry’s ConstantVapor Pressure

Organicor

Some Inorganics

OrganicPhoto-degradesAir Emissions?Inorganic Regulatory IssueRisk Reduction?

Phytovolatilization:-Certain contaminants (organic and inorganic) can get into the plant and be translocated upwards into the terrestrial portion-There, the contaminant can reach the leaves where it can be volatilized (depends on the chemical properties)

-Example: TCE has been found in the transpirational gases coming off of trees-TCE has all the correct chemical properties (soluble, volatile, correct log Kow, etc)-Mass loading issue for TCE (can be rhizodegraded and phytodegraded)

-Example: Methyl-Mercury-Tobacco plants have been genetically modified to take up and convert Me-Hg to Hg(II) and then to Hg(0)-The Hg(0) can then be volatilized into the atmosphere-Advantage: Toxicity of Hg(0) 106 times less than Me-Hg-Regulatory Issue

Section Summary“Phytotechnology Mechanisms”

Definition:Use of Vegetation to Contain, Sequester, Remove, or Degrade Organic and Inorganic Contaminants is Soils, Sediments, Surface Waters, and Groundwater.Robust Technology – wide applicability

Additional Advantages:Safety, Ecological, Public/Regulatory, Cost-Effective

Mechanisms:Phytostabilization, RhizodegradationPhytoaccumulation, PhytodegradationPhytovolatilization, Evapotranspiration

Applications: (discussed next)Containment vs. Remediation Strategies

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Definition: Wide applicability (primary advantage)Other Advantages: Can help in the decision-making process to utilize phytotechnologiesMechanisms: Complex; three regimes-In the rhizosphere: Phytostabilization, Rhizodegradation-In the plant: Phytoaccumulation, Phytodegradation -Through the plant: Phytovolatilization. EvapotranspirationApplications:-Involves combining several of the mechanisms to achieve site goals-Containment, Remediation, or Both

Questions & Answers

Questions

and

Answers

For more information on ITRC training opportunities visit: www.itrcweb.org

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No Associated Notes

Applications“Containment, Degradation, Extraction “

Vegetative CoversPhytoremediation

Enhanced RhizodegradationPhytodegradation

PhytoextractionPhytominingRhizofiltration

Groundwater Plume ControlSurface Water ProtectionPhytovolatilization

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No Associated Notes

Vegetative Coversfor “Infiltration Control”

DURING RAINEVENT

AFTER RAINEVENT

START OF RAINEVENT

Run-Off

Shallow Infiltration

Evapotranspiration

Root-Zone

InterceptionCapacityExceededIntercepted

Rain

DURING RAINEVENT

AFTER RAINEVENT

START OF RAINEVENT

Run-Off

Water Storage

Evapotranspiration

Root-ZoneRetrieval by Plantsor Percolation

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Riparian Buffers are vegetated area that protect adjacent water resources from non-point source pollution (surface run-off), provide bank stabilization, and habitats for aquatic and other wild life. Wetlands that grow in the edge of a stream also can be considered as Riparian buffers.

Phytoremediation“Surface Soil Remediation”

Rhizodegradation or

PhytometabolismPetroleum HydrocarbonsPAH’sLight chlorinated solventsmunitions

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This is an exitu technology where the contaminated water is pumped to plants that are cultivated. Alternatively the contaminated water stream can be pumped through artificial planted system known as hydroponics system. Typically plants to be used for clean-up are raised in a green house. Once the plant have developed large root the contaminated water is pumped into the plants. Alternatively plants can be transported to hazardous waste site.

Clarified D ischarge

Constructed W etlands

Organic Stabilized in Tissue

Industrial or Urban Com plex

Interm ediateOrganic

Inorganic Precipitated in Sedim ent

Volatilization

Transpiration

Inorganic Taken Up into Tissue

Organic as Biomass

Phytoremediation“Constructed Wetlands”

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No Associated Notes

Phytoremediation“Extraction”

edenspaceedenspaceSome Plants accumulate metals in shoots and leaves.

Hyperaccumulators are plants that store many times the soil concentration of a metal in the plant tissue.

Sunflower and Indian Mustard are commonly tried accumulators of lead.

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No Associated Notes

Rhizofiltration“Hydroponic Greenhouse or Constructed Wetlands”

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No Associated Notes

Ground Water Plume Control“Hydraulic Barriers”

-3

-4

0

-1

-2

-3Groundwater

Contours(Gray Lines)-4

GroundwaterFlow Vectors

(Blue Lines)

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Remedial objective (i.e. Control and containment Vs reduction and remove or supplementing an existing treatment system) is to meet the remediation criteria usually driven by regulations.

Design issues include applicability and limitations of this technology for a particular situation of cleanup. Identifies some regulatory barriers.

Since most regulations are performance based this section identifies some of the of thee performance criteria needed to satisfy regulators. Since this is a new technology needs pilot studies satisfy the performance standard of the regulations specificallySite characteristics or climatic conditions are not entirely favorable for the application of Phytoremediation.The contaminant of concern, plant species, or the combination of the two does not appear in the current Phytoremediation database.Data regarding the fate and transport (i.e., bioavailability, toxicity, food chain accumulations, ecological exposures, transfer to other media, and/or transformation by-products) are unknown or questionable.

Fate & Transport Issues- Phytovolatilization, Biotoxicity and Bioavailabilty

Riparian Buffers“Surface Water Protection”

28

No Associated Notes

Riparian Buffers“Surface Water Protection”

Hybrid poplars planted at Amana, Iowa, (left) planted by Dr. Lou Licht and colleagues filter run-off from cropland.

29

No Associated Notes

Contaminant Concentration

Soil type

Geochemistry

Microbial Studies

Hydrogeology

Climate Conditions

Site Characteristics30

No Associated Notes

Supplemental Systems

Irrigation (by leachate)

Soil AmendmentsFertilizerpH balance

Plant enhancementsMycorryhzal inoculationSilica gel

31

No Associated Notes

SoilsClassificationSalinityElectrical conductivityCation exchange capacityOrganic matter contentWater holding capacityNutrient level

Site Characteristics32

• Slower than some alternatives; seasonally, climatically dependent• Difficulty in establishing plant growth at some sites• Biological methods not capable of 100% reduction• May not be applicable to all mixed wastes• May require large available surface area• Restricted to shallow, low- to moderate levels of contamination• Regulators unfamiliar with technology• Lack of recognized performance data

GeochemistryOxygenCarbon dioxideMethane gas concentrationRedox potentialpHSoil moistureWater high in TDS or high salts may not be favorable

Site Characteristics33

• Low cost• Preserves topsoil and minimizes environmental disruption• Produces less waste than other technologies• Applicable to a broad range of heavy metals• In situ, permanent treatment solution• Application to variety of contaminants, including some recalcitrants• Applicable to sites with large area where other technologies may be too expensive

• Public acceptance; aesthetically pleasing• Reduces volume of contaminated material requiring disposal• Compatible with risk-based remediation, Brownfields, etc.

Site Characteristics

HydrogeologyGround water levelsTemperatureFlow velocityPorosityHydraulic conductivitySite heterogeneityDepth to aquitardContinuity and thickness of aquitard

34

No Associated Notes

Site Characteristics

Climatic ConditionsAltitudeLength of growing season

Temperature

Humidity

Precipitation

Wind

Probabilities of flood or drought25, 50 & 100 year events

35

In 1999 the bigger part of US share market goes to organic contaminants in groundwater (7-12 M$), control of landfill leachate (5-8), organics in soil (5-7), metals from soil (4.5-6). These amounts are doubled in comparison to the year before, mainly due to an increase in the number of companies.

Common Design Conditions for Phyto Applications

A Greenhouse Treatability StudySufficient areaClimate/growing seasonSufficient period of timeNon-Toxic to plantsCost effectiveness

36

No Associated Notes

Treatment Design Requirements

Plant Selection

Fate & TransportMass balanceFood chain transfer

Cost Elements

Operation & Maintenance

37

Firms and techniques, USAThe list contains dedicated companies, their preferred plants, main applications and type of phytoremediation applied.

Some of them have patented proprietary technologies or plants.Several of these use trees but some use also grasses and hyperaccumulators.

Treatment Design Requirements“Plant Selection / Plant Screening”

Tolerance of Contaminant Concentration

Growth Habit - Above Ground and Root

Architecture

Climate Zone & Altitude

Hybrid, Native, Genetically Altered

38

Tolerance - Contaminants, Temperature, Moisture, Disease, Pests,

Growth Habit - Annual, Perennial, Biennial, Evergreen vs. Deciduous

Climate Zone & General Form - Grass, Leafy Plant, Shrub, Tree

Species - Native, Pre-existing (tolerance), Literature species (Applicable Research), Hybrid, Genetically Engineered

Plant Pest Act (7U.S.C. 150 aa et seq)Plant Quarantine Act (7 U.S.C. 2801 et seq)Noxious Weed Act (7 U.S.C. 280 et seq)TSCA Section 5FIFRAFFDCA

Agronomic Optimization - Do site conditions support plant growth?

Design Plant Selection“Root Architecture, Depth, and Density”

39

Regulatory remediation program authority can vary depending on theclassification of a site (i.e. NPL listing, RCRA site, etc.)different remedial objective i.e: Containment VS Removal) and the specific technology (i.e. wetland, Phytoextraction etc)Class of contaminant (i.e. hazardous, or non-hazardous)Media to be treated (i.e. water, soil, sludge or surface water).

Determine No Media Transfer

Uptake or translocations

Labeling

Treatment Design Requirements“Fate & Transport”

Locust prefers clean plant to Zinc Uptake; Pollard U of Ga.

40

No Associated Notes

Treatment Design Requirements“Mass Balance “

Studies Might Be Required to Determine Efficacy

In Greenhouse

In Plant Chambers

In Field on Liners

Pot Studies to Determine Plant Degradation Efficacy

41

No Associated Notes

Treatment Design Requirements“Unique Phyto Costs”

Possible Phytotechnology Specific Cost ElementsPlant or tree stock or seeds Soil microbial sampling

and analysesFertilizer, pesticides or othersoil amendments

Weather stations, w/ Solar panels and data loggers

Amendment application &tillageIrrigation equipment, water

Sap flow sensors, Leaf area meters, soil moistureprobes, stem gauges, dendrometers

Mulch, trunk guards, otherpest control device

Plant litter collection, maintenance, pruning,mowing

Tissue sampling supplies andanalyses

Plant disposal

Agronomic sampling andanalyses

Lysimeter, Weirs, gates orother flow control device

42

No Associated Notes

Phyto Specific Cost Elements

Electric Fence

Replanting 10-20%

Insect ControlHawk poles to control rodents

43

No Associated Notes

Design Summary

Application Goals Determine Appropriate Phytotechnology Site Specific Design

Plant SelectionEfficacySafety

Unique Cost Elements

44

No Associated Notes

Regulatory, Stakeholder and Policy Issues

45

Details are Specific to the Regulatory ProgramRCRA or State Equivalent or BothCERCLAState Voluntary Cleanup ProgramsNon-RCRA Sites i.e USTSDWACWANPDESCAA

The regulatory issues are as much related to the program under which the clean up is being conducted as they are to phytotechnologies. . For example certain regulations may exist when one is conducting a remediation under RCRA than if in a voluntary cleanup program. Certain rules may apply if considering meeting target standards under the Safe Drinking Water Act or the Clean Water Act etc.

Regulatory, Stakeholder, and Policy Issues

Most Concerns Are Common to All Cleanups9 Criteria From NCP

Protect Human Health and the EnvironmentCompliance with ARARSLong Term Effectiveness and PermanenceReduction of Contaminant Toxicity, Mobility, VolumeShort Term EffectivenessImplementabilityCostState AcceptanceCommunity Acceptance

Regulatory, Stakeholder or Policy Issues

47

Phytotechnologies

Includes at least six mechanisms

Seven or more applications

Those mechanisms are phytostablilization, pytodegredation, phytoaccumulation, phytodegradation, phytostabilization, and evapotranspiration. Applications include two types of vegetative covers two infiltration prevention, exposure prevention even a third soil stabilization, two types of tree stands hydraulic control extraction , treatment wetlands , Riparian buffers, or hydroponic systems. There are other applications not detailed. es.

60

MECHANISMS APPLICATIONS POTENTIAL LIMITATION

Ph

ytos

tabi

liza

tio

n

Rhi

zod

egra

dat

ion

Phy

toac

cum

ula

tio

n

Phy

tod

egra

dat

ion

Phy

tovo

lati

liza

tio

n

Eva

potr

ansp

irat

ion

Veg

etat

ive

Cov

ers

(Inf

iltra

tio

n C

ontr

ol)

Gro

undw

ater

Hyd

rau

lic

Bar

rier

s

Tree

Sta

nds

(Rem

edia

tion

)

Lim ited da tabase and perform . data

X

X

X

X

X

Potential tr ansfer to secondary media

X

X

X

By-products m ay be more toxic

X

X

X

Bioaccumulation of contam inants in vegeta tion

X

X

U nfamiliar ity by pub lic /regulatory communit ies

X

X

X

X

X

X

X

X

X

48

This table is included to illustrate the difficulties in trying to provide a one size fits all set of guidelines covering regulatory issues. The issues of concern to regulators are listed in the lefthand column. Some of these issues are applicable to many of the technologies where as others are more focused on specific technologies. This is an abridged version of table 5 in the Technical and Regulatory Guidance Document.

Regulatory, Stakeholder or Policy Issues

49

Most Common ConcernsTimelinessContaminated plant disposalEcological concernsAre the contaminant levels too high for this technologyMedia transfer Toxicity of by-productsHealth and safety

ImplementationOperationClosure

Despite the variations of mechanisms there seems to be consistent issues raised when considering phytoremediation as a remedial option. TIME - many programs have time limits on cleanups, Mass. is 5 years, Three is often pressure to get properties into productive or marketable condition. Plant Disposal - RCRA characteristics, smelting other. Ecological - Transfer from soil/water to plants - will this effect the bugs and bunniesToxicity to plantsSoil to air water is this acceptable?Fate and transport issuesHealth and safety issues may change during each phase of remediation.

Health & Safety50

Problems Possible Solutions Dusts Moisten soil, mist sprayers Volatiles released Air samplers and alarms, PPE Migration of soil amendments, fertilizers, etc Mist sprayers (powders & sprays), runoff control

(liquids) Bites, stings, and other natural dangers Fencing, traps, repellents, etc. Contacting with contaminant in the plants Fencing, traps, repellents, etc. Possible irritants produced by the plants Inventory the species and note susceptibilities Dermal contact with the contaminated media PPE (protective clothing, environmental suits) Altered contaminant transport characteristics Modeling, monitoring and contingency plans Weeds affecting surrounding vegetation Maint. Plan including weed control, pesticide. Root damage to foundations, underground utilities, etc

Maintenance plan including inspections,

Obstructed vision due to limbs, overgrowth, Maint. Plan for pruning, trimming, mowing, Fire due to the accumul of dry plant matter Maintenance plan to clear and contain or remove Trespassers Institutional controls and security measures

Health and safety issues must be constantly evaluated. The table lists many of the problems encountered with some of the phytotechnologies.

Regulatory, Stakeholder or Policy Issues

51

MonitoringProjected and measured effectivenessWhen is the project done and post closure careFollow fate of parent compoundDetermine composition of transformation productsFollow the fate of by-productsFollow the fate of the parent compound into the plant

tissuesMake quantitative mass balance in the soil-water-plant

system

Not all of these are unique to phytoremediation. What type of parameters will be measured to gauge the effectiveness. (these are displayed on the next slides)What is the endpoint what type of monitoring is needed. Evaluating continuity of cap, draw down of tree standsIs it being mobilized moving down instead of into the plant?Ditto for byproductsWhere is the contamination going roots shoots leaves?

Monitoring52

Agronomic ConditionsField ParametersOrganic Compounds and Degradation ProductsTranspiration GasesMicrobial AnalysisFrequency

Initial characterizationPre-planting & after germinationRegular intervals after each growing season

More monitoring issues for plantsFertilizer soil moisture ….What is needed to optimize growth How often during the O&M does this have to be done.

Monitoring“Typical Analytical Methods”

54

Parameter to be Monitored

Analytical Methods

Dissolved Oxygen Standard Method # 421 or equivalent pH SW-846, Method 9040 Ammonia-N Standard Method # 417 or equivalent Nitrate-N Standard Method # 418 or equivalent Kjeldahl-N Standard Method # 420 or equivalent Available Phosphorus Check w/ Dept. of Agriculture Total Phosphorus Standard Method # 424 or equivalent Temperature Standard Method # 212 or equivalent Metals such as Fe, Mg, Ca and other elements

Standard Method # 300 series or equivalent

Conductivity SW-846, Method 9050A

53

Listed here are some of the parameters that may have to be monitored to ensure the optimal operation of a plant based remediation system. The methods would not be found on most remedial work plans. The analytical are mostly standard methods -not SW 846.

Monitoring“Typical Analytical Methods”

54

Parameter to beMonitored

Analytical Methods

Water table Field inst. i.e. inter-phase probeMicrobes Standard Method # 900 series or

equivToxicity Tests for Microbes Standard Method # 800 series or

equivalentCarbon dioxide Standard Method # 406 or SW-846,

Method 9060Total Organic Carbon Standard Method # 505 or equivalentTotal Organic Halogen Standard Method # 506 or equivalentBiochemical Oxygen Demand Standard Method # 507 or equivalentRedox Potential Eh measurementsContaminant of concern Applicable U.S. EPA methods

54

The rest of the list. This table is included at Table 8 in the tech and reg document.

Operation & Maintenance

55

Operations Parameter Maintenance RequirementSoil Conditions Maintain soil amendments, soil pH, fertilizer and chelating agents. Irrigation System Irrigation system may be needed to start and during drought conditions. Plant Maintenance Plants may need to be thinned, pruned, mowed and treated to control weeds. Fencing Fencing may need to be installed to keep people and animals out. Replanting Replanting will be required for annual plants or .failed growth Vector Control Control plan for mice, rats, starlings and other vectors may be needed. Monitoring Well Maint Monitoring wells will be needed and require some maintenance. Disposal of Plant Material Plant material may need to be treated as a hazardous waste Storm water Runoff Ensure best management practices are used to control storm water runoff Mech Support Systems Maintenance is required for mech systems during dormancy (pumps for

pump-and-treat systems). Chelating Agents When chelating agents will need to be added on a routine basis. Wetlands Systems Pond maintenance, plant harvesting, influent and effluent monitoring, and

sediment control.

55

This is a partial list of operational parameters and the maintenance requirements needed for a phyto-system. Regulators site managers and PRPs should look for discussions of these issues within any proposal using phytotechnology. The lists are self explanatory and discussed in the Tech and reg document (Table 9).

Regulatory, Stakeholder or Policy Issues

56

Additional Phytotechnology Concerns

Is this a low-tech way of doing nothing?

Harvesting of plants by the public

Because of the lack of abundant success stories there may be the perception that this is a way to stall or give the appearance of doing something when all one is doing is planting trees.

Example of local population that ate mustard greens and may attempt to harvest them when planted at a brownfields application.

Regulatory, Stakeholder or Policy Issues

57

Emerging IssuesLand treatment of contaminated ground

water - i.e. RCRA 3020(b)Use of genetically engineered plantsUse of non-native plantsRCRA approval for vegetative covers for

landfills

If contaminated ground water is used for irrigation in a phytoremediation situation what type of permitting if any would be necessary, A RCRA 3020(b) would not seem appropriate but without alternatives may be imposed . ITRC has and will continue to discuss issues like this and develop solutions for the member states.

The use of transgenic species must be evaluated and their appropriate use discussed among several agencies and stakeholders.

Alternative covers are appropriate in a number of situations.

In Closing

Phytotechnologies are cost effectiveHabitat friendlyBroad applicationLimitations like any other techniqueNo unique regulatory issues for PhytoStates are concurring and using the

“Phytotechnologies Tech & Reg Guidance” as a tool to evaluate the appropriateness of proposals containing phytotechnologies (States already concurring: AL, CO, IL, KS, LA, MO, ND, NJ, NY, OK, OR, SC, TN, VA, VT, WV)

58

What is the ITRC state concurrence process?State concurrence is the formal review and documented acceptance of the willingness to use/test ITRC Technical and Regulatory Guidance Documents. It does not mean that your state concurs on the technology, but that your state is concurring on the use of the document as a decision-making tool to evaluate the appropriateness of the use of the technology at sites in your state. The Point of Contact (POC) in each ITRC state is responsible for having the appropriate personnel in their state agency review the ITRC Technical and Regulatory Guidance Documents and to provide their state's level of concurrence on each document. The POC will then send a letter to the ITRC State Engagement Coordinator indicating their state's level of concurrence on the specific document. This information is maintained and updated in a concurrence matrix. The intent is to provide concurrence information to document users via the website.

Why is the concurrence process important?The concurrence process serves as a formal mechanism to gain state commitment to use the ITRC products and services. In addition, concurrence on ITRC Technical and Regulatory Guidance Documents provides predictability for parties wanting to use an innovative technology in an ITRC state.

Questions & Answers

Questions

and

Answers

For more information on ITRC training opportunities visit: www.itrcweb.org

Thank you for attending this ITRC training course.

59

No Associated Notes

Thank You!

Links to Additional Resources

rtdf.orgbibliography

itrcweb.orgclu-in.orgITRC Decision Tree

60

The link to additional resources is http://www.clu-in.org/conf/itrc/phyto/resource.htm click on “links to additional resources”Information on ITRC at: http://www.itrcweb.orgYour feedback is important – please fill out the form at: http://www.clu-in.org/conf/itrc/phyto/feedback.cfmThe benefits that ITRC offers to state regulators and technology developers, vendors, and consultants include:•helping regulators build their knowledge base and raise their confidence about new environmental technologies•helping regulators save time and money when evaluating environmental technologies•guiding technology developers in the collection of performance data to satisfy the requirements of multiple states•helping technology vendors avoid the time and expense of conducting duplicative and costly demonstrations•providing a reliable network among members of the environmental community to focus on innovative environmental technologiesHow you can get involved in ITRC:•Join a team – with just 10% of your time you can have a positive impact on the regulatory process•Sponsor ITRC’s technical teams and other activities•Be an official state member by appointing a POC (Point of Contact) to the State Engagement Team•Use our products and attend our training courses•Submit proposals for new technical teams and projects•Be part of our annual conference where you can learn the most up-to-date information about regulatory issues surrounding innovative technologies