Presentation Overview:

Remediation of groundwater contamination using ISCO (in situ chemical oxidation) involves

injecting oxidants directly into the source zone and downgradient plume. The oxidant

chemicals that are commonly used include permanganate (sodium and potassium), hydrogen

peroxide, and ozone. The oxidant chemicals react with the contaminant, producing innocuous

substances such as carbon dioxide (C02), water (H20), and inorganic chloride. However, the

full spectrum of reaction intermediates and products is not fully understood at this time for all

contaminants. Examples of potential contaminants that are amenable to treatment by ISCO

include BTEX (benzene, toluene, ethylbenzene, and xylenes), tetrachloroethylene (PCE),

trichloroethylene (TCE), dichloroethylenes, vinyl chloride (VC), MTBE (methyl- tert-butylether), PAH (polyaromatic hydrocarbons) compounds, and many other organic contaminants.

The purpose of this training is to familiarize you with the recently released ITRC In Situ

Chemical Oxidation Technical and Regulatory Guidance document. It provides technical and

regulatory information to help you understand, evaluate and make informed decisions on ISCO

proposals. Included is a description of the various chemical oxidants, regulatory

considerations, stakeholder concerns, case studies, and technical references.

**********************************

ITRC – Interstate Technology and Regulatory Council (www.itrcweb.org)

EPA-TIO – Environmental Protection Agency – Technology Innovation Office (www.cluin.org)

ITRC Course Moderator:

Mary Yelken (Western Governors’ Association/ITRC – myelken@westgov.org)

1

Welcome to ITRC’s

Internet Training

Thank you for joining us.

Today’s presentation is focused on the ITRC technical and

regulatory guidance document entitled:

“In Situ Chemical Oxidation of Contaminated Soil and

Groundwater”

Sponsored by ITRC and EPA-TIO
2

 ITRC – Shaping the Future of Regulatory

Acceptance

È Natural Attenuation

È EISB (Enhanced In Situ

Bioremediation)

È Permeable Reactive Barriers (basic

and advanced)

È Diffusion Samplers

È Phytotechnologies

È ISCO (In Situ Chemical Oxidation)

È Constructed Treatment Wetlands

È Small Arms Firing Range

Characterization and Remediation

È Systematic Approach to In Situ

Bioremediation

ITRC Member State

Federal 

Partners

Sponsors

Industry, Academia, Consultants,

Citizen Stakeholders

ITRC Membership

States

www.itrcweb.org

ITRC Internet Training Courses

The bulleted items are a list of ITRC Internet Training topics – go to www.itrcweb.org and

click on “internet training” for details.

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. ITRC consists of 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 streamline the regulation 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 6,000 people from all aspects of the environmental community,

ITRC is a unique catalyst for dialogue between regulators and the regulated community.

ITRC originated in 1995 from a previous initiative by the Western Governors’ Association

(WGA). In January 1999, it affiliated with the Environmental Research Institute of the States,

ERIS is a 501(c)3 nonprofit educational subsidiary of the Environmental Council of States

(ECOS). ITRC receives regional support from WGA and the Southern States Energy Board

(SSEB) and financial support from the U.S. Department of Energy, the U.S. Department of

Defense, and the U.S. Environmental Protection Agency.

To access a list of ITRC State Point of Contacts (POCs) and general ITRC information go to

www.itrcweb.org.
3

In Situ Chemical Oxidation

ISCO Presentation Overview

 ̧ Overview of ISCO

 ̧ Oxidants & Safety

 ̧ Pilot Studies

 ̧ Questions and answers

 ̧ Oxidants & Safety (cont.)

 ̧ ISCO Design

 ̧ Monitoring

 ̧ Regulatory Issues

 ̧ Questions and answers

 ̧ Links to additional resources

 ̧ Your feedback

Logistical Reminders

 ̧ Phone Audience

l Keep phone on mute

l * 6 to mute your phone

and again to un-mute

l Do NOT put call on hold

 ̧ Simulcast Audience

l Use at top of each

slide to submit questions

No Associated Notes
4

Today’s Presenters

È Thomas L. Stafford

l La. Dept. of Environ. Quality

l P.O. Box 82178

l Baton Rouge, LA 70884-2178

l T 225-765-0462

l F 225-765-0435

l tstafford@deq.state.la.us

È Wilson Clayton, Ph.D., P.E., P.G.

l Aquifer Solutions, Inc.

l 28599 Buchanan Drive

l Evergreen, CO 80439

l T 303-679-3143

l F 303-679-3269

l wclayton@aquifersolutions.com

Both were members of the ITRC ISCO team. Other team members are listed

in the ISCO document, available for download from the ITRC web site.

Tom Stafford has been working in the fields of environmental

remediation, restoration, monitoring, and investigation as an Environmental

Scientist for the Remedial Services Division of the Louisiana Department of

Environmental Quality for fifteen years. His responsibilities include

design of sampling plans, remedial actions, monitoring, oversight of others

conducting these activities in the field, inspecting laboratories that are

providing data for these activities, and review of work plans for performing

these activities submitted by others. Tom leads the ITRC In Situ Chemical

Oxidation team.

Wilson S. Clayton, Ph.D., P.E., P.G., is a co-founder and Vice President of

Aquifer Solutions, Inc., a small woman-owned business specializing in vadose

zone and groundwater hydrology and in-situ remediation. Dr. Clayton was

previously employed with Groundwater Technology Inc., and then by

acquisition with Fluor Daniel GTI, and IT Corporation. Dr. Clayton held

positions including Territory Manager, Treatability Laboratory Director, and

National Practice Leader for in-situ chemical oxidation. Dr. Clayton holds a

Ph.D. in Geological Engineering from Colorado School of Mines. He has

published several technical papers related to in-situ chemical oxidation,

dealing with oxidant reaction kinetics, subsurface oxidant transport, and other

implementation-related topics.
5

Key “ISCO” Tech. & Reg. Issues

Most Common Concerns

l UIC (Underground Injection Control) - ISCO doc. p. 12

ÿ Constituents in the injected fluid exceed a primary or

secondary drinking water standard

ÿ Formation of toxic intermediate products

ÿ Unknown toxicity of a constituent of the oxidant/catalyst

ÿ Formation/mobilization of colloids due to breakdown of

NOM

ÿ Migration of contaminants away from the plume or

source area

l Effect on Natural Biota

l Health and safety

ÿ Chemical Mixing and Handling

ÿ Atmospheric Venting

ÿ Chemical Transport

Each of these concerns will be addressed in our discussion today and are

covered in the Guidance Document. There are two problems specific to

permanganate that were not discussed in the document: 1. Manganese ore

contains chrome. There are are traces of chrome in Na and KMnO4. All of

this chrome would be Cr6+. 2. Naturally occurring potassium contains a

significant concentration of 40K. Potassium forty is radioactive. Both of these

issues can cause problems in some states. In some cases the problems would

preclude use of one or both permanganate salts. In others it would increase the

suite of chemicals that must be quantified by monitoring.

NOM – natural organic matter

Refer to page 12 of the ITRC ISCO Technical and Regulatory Document for

additional information. Document can be downloaded at no-cost at:

www.itrcweb.org
6

Goals of Today’s Session

È Introduce the ITRC Document on ISCO

l “In Situ Chemical Oxidation of Contaminated Soil and

Groundwater”

È Discuss the Basics of ISCO

l Oxidation with Permanganate, Hydrogen Peroxide

(Fenton’s Reagent), and Ozone

È Provide Case Study Examples

È Discuss Potential Regulatory Issues

È Provide Guidance to Address Stakeholder Concerns

È Provide References for Additional Study

No Notes
7

What is In Situ Chemical Oxidation?

È Definition: A technique whereby an oxidant is

introduced into the subsurface to chemically oxidize

organic contaminants changing them to harmless

substances.

l Rapidly Emerging Technology

l Still Subject of Academic Research as Well as Applied

Routinely as a Commercialized Process

l Several Options for Selection of Oxidant Chemicals

l Requires Good Understanding of Contaminant

Characteristics to Ensure Effective Treatment

ISCO is being evaluated as an alternative and applied at an increasing number

of sites.

The number of oxidants increases the applicability of the technique.

Taking short cuts during site investigation may lead to inappropriate

application and be very costly.
8

Oxidation Chemistry Is Not New

In-Situ Application is New

È Chemical Oxidation: 1772 by Antoine Lavoisier

È Ozone: Discovered in 1785 by van Marum.

l Hydrocarbon oxidation in 1855 by Schonbein.

l Water treatment by ozonation in France in 1907.

È Hydrogen Peroxide: Discovered in 1818 by

Thenard.

È Fenton’s Reagent: Discovered in 1876 by Fenton

È Permanganate: Alkene oxidation in 1895 by

Wagner.

As you can see, the concept of chemical oxidation is not new, and in fact has

been established for >225 years. The new part is the application of oxidant

chemicals to contaminants in situ.
9

Where has ISCO Been Used?

ISCO Applied in

These States

ISCO has been used in all the states colored red, and likely has been used in

others also.
10

When is ISCO Applicable?

È Organic Contaminants

l PAHs, Pesticides, Chlorinated Solvents, Petroleum

Hydrocarbons, others

È Some Contaminants Require More Aggressive

Oxidant Chemicals

È Screening Level Evaluation Needed to Assess Site

Feasibility and Appropriate Oxidant Chemicals.

ISCO is applicable to a wide variety of chemicals.

However not all oxidants are applicable to all chemicals in all cases.

Bench scale testing is necessary to pair oxidant with the contaminant and

geochemistry of the site.

Ozone is also much more applicable to the vadose zone because it is a gas.

Pilot scale application growing to full application is often the best method
11

Oxidation Chemistry Primer

È Oxidation involves breaking apart the chemical

bonds and removing electrons

È The “Oxidant” is the “Electron Acceptor”, and is

Chemically Reduced by the Reaction

È Chemicals with Double Bonds are Most Readily

Oxidized

È Strong Oxidants Attack a Wider Range of Bonds

No Notes
12

Elements of an ISCO Project

Safety is always the number 1 concern at an ISCO project.
13

The Technical Goals of ISCO

Can Be Varied

È Source Zone Treatment

l Non-Aqueous Phase Liquid (NAPL) Treatment

l Soil Contamination Treatment

l Mass Reduction vs. Numerical Concentration Goal

È Groundwater Plume Treatment

l Groundwater Attenuation After Source Zone Oxidation

l Oxidation of Dissolved Groundwater Plume

No Notes
14

Technical Caveats

È ISCO is Often Not a Sole Solution! – Other

Remediation Processes are Often Combined.

È ISCO Performance is Site-Specific.

È Match Monitoring Parameters to Performance

Goals.

È Nothing is Effective in All Situations – A Project

Failure is Not a Technology Failure.

È “Rules of Thumb” are Meant to Be Broken.

No Notes
15

Advantages and Disadvantages of

ISCO

È Advantages

l Fast Treatment (weeks

to months)

l Temporary Facilities

l Treatment to Low Levels

(ND in some cases)

l Effective on Some Hardto-Treat Compounds

È Disadvantages

l Requires Spending

“Today’s” Money to Get

Fast Cleanup

l Involves Handling

Powerful Oxidants, and

Carries Special Safety

Requirements

These Lists Assume Appropriate 

Technology Selection and Application

No Notes
16

Importance of Site Goals &

Conditions for Success / Failure

È Success Factors

l Oxidation Reactions

l Oxidant Dose

l Oxidant Delivery

È Failure Factors

l Oxidation Reactions

l Oxidant Dose

l Oxidant Delivery

No Notes
17

Oxidant Selection Criteria – How Do

You Pick an Oxidant??

È Target Contaminant Reactivity with Oxidant

È Target Treatment Zone

l Vadose Zone – Ozone Gas Injection

l Saturated Zone – Peroxide or Permanganate Liquid

È Size of Treatment Zone

l Permanganate is More Long-Lived and Can Be

Delivered over a Larger Area in the Subsurface

È Cost

No Notes
18

And the Oxidants Are...

Fenton’s Reagent, Ozone, and Permanganate

(Also - Recent Development: Persulfate)

Oxidant Oxidation Potential (volts)

stronger

Hydroxyl Radical (.OH) -2.87

Ozone (O3) -2.07

Hydrogen peroxide (H2O2) -1.77

Permanganate Ion (MnO4

-

) -1.695

moderate

Persulfate and Peroxone may be addressed in a future update of the ISCO

document.
19

Oxidation Technology Selection

ßRequires Continuous

Injection Process.

ßDifficult Delivery into

Groundwater (Sparging).

ßStrong gaseous oxidant.

ßCan produce free radicals.

ßGas well suited to vadose zone

injection.

Ozone

(O3, SOP = -2.07 V)

ßNot strong enough oxidizer

for some compounds (i.e.

TCA, DCA, pesticides,

PCBs, others)

ßImpurities in Permanganate

significant at very large dose.

ßHighly persistent solution can

be delivered over large areas in

subsurface.

ßDilute solutions relatively safe

to handle

Permanganate

(MnO4

 -, SOP = -1.7 V)

ßRequires pH reduction,

HCO3

- Buffering Problematic

ßPeroxide instability

ßRelease of heat and gas

may mobilize contaminants

ßProduces Strong Oxidant,

hydroxyl radical (OH•).

ßRelease of heat and gas

enhances volatilization and

mixing

Fenton’s Reagent

(OH•, SOP = -2.87 V)

 Oxidant Pros Cons

Each oxidant has positive and negative aspects to consider. The oxidant must

be selected based on the individual site needs.
20

Safety – All Oxidants

È Chemical Handling Safety

l Follow All Chemical-Specific Handling and Mixing

Precautions.

l Dilute Oxidants Pose Less Hazard

È Monitor Oxidant Concentrations in Subsurface and at

Adjacent Receptors.

È Subsurface Energetic Reactions

l Mainly an issue with Fenton’s / hydrogen peroxide.

l Monitor Subsurface Reactions and Temp. and Ramp Up

Injection Slowly

Safety first is the rule with ISCO!
21

Safety – Specifics

È Fenton’s Reagent - Hydrogen Peroxide (H2O2)

l Liquid – very strong oxidizer

l Hydrogen Peroxide Delivered in Tanker Trucks or Drums

l Generally Injected with Iron Catalyst

È Ozone (O3)

l Gas – very strong oxidizer

l Ozone Gas Generated on-site Using Electrical Equipment

È Permanganate (K or Na) (KMnO4 or NaMnO4)

l Liquid Solutions – very strong oxidizers, but less aggressive than

peroxide or ozone

l KMnO4 sold as crystalline solid

l NaMnO4 sold as 40% liquid solution

No Notes
22

Some Common Questions About

ISCO?

È Is the Oxidation Reaction Complete, Are By- Products

Present and What Is Their Fate?

È Will I Oxidize/Mobilize Metals?

È Will Oxidation Kill-Off Subsurface Microbes and Halt

Natural Attenuation Processes?

È Are There Any Short-term Hazards During Treatment?

È How Much Oxidant Do I Need?

È Is It Expensive?

The Answers to These Questions Are Not Universal. Up-Front

Evaluation and Design Work Is Needed to Answer These

Questions for a Site.

No Notes
23

Is the Oxidation Reaction Complete, Are By- Products

Present and What Is Their Fate?

È Same Fundamental Question for All Destructive

Treatment Mechanisms

l Bioremediation

l Natural Attenuation

l Chemical Reduction Treatment

l Chemical Oxidation Treatment

È Important Site Specific Factors

l What Dose of Treatment is Applied?

l What is Site Geochemistry?

l How Will Chemical/Biological Processes Interact?

No Notes
24

Will I Oxidize/Mobilize Metals?

È All Oxidation Technologies Can Potentially Oxidize

Redox Sensitive Metals to a More Mobile Valence

State

l Chromium, Uranium, Selenium, Arsenic

È Occurs with Naturally Occurring Metals as Well as

Contaminants

È In Most Cases Documented, Metals Naturally

Revert Back to the Reduced State After Oxidation

Treatment is Complete

È Site-Specific Bench and Field Testing Required

No Notes
25

Will Oxidation Kill-Off Subsurface Microbes and

Halt Natural Attenuation Processes?

È Subsurface Microbes are Very Robust and Difficult

to Eliminate

È Difficult to Deliver Enough Oxidant to Completely

Contact All Microbes

È Generally, Microbial Populations Decline

Temporarily and then Rebound After Treatment

No Notes
26

ISCO Design Criteria

A primary design concern is the proper oxidant concentration and dose. The

concentration and dose are determined by the oxidant demand and reaction

kinetics. Other variables include the horizontal and vertical spacing of

injections, which are largely determined by the site geology.
27

Oxidant Reaction Kinetics Control

Transport

Oxidant

Half Lives:

One Hour

One Day

One Week

Analytical Model Based on 1st Order Kinetics

Injection Scenario: 5 gpm of 2.5% permanganate

Into 5 foot layer in Saturated Zone

The lateral distance that the oxidant will travel from the point of injection is

dependent on the reaction kinetics. The oxidant is consumed by the reaction,

and can only travel as far as the reaction kinetics allow
28

Oxidant Demand –

Primary Design Factor

È Soil Matrix (TOC) is Generally Dominant

È Groundwater Constituents Relatively Unimportant

È Matrix Demand May Exceed Contaminant Demand

È Bench Scale Testing Critical

Q: When is Oxidant Demand Too Great?

A: 1. Cost

2. Can’t Deliver The Oxidant Volume

3. If Groundwater or Soil Quality Is 

Impacted by Oxidant

No Notes
29

Design Basis –

Bench and Field Testing

È Bench Testing

l Proof of Concept for New Applications

l Measurement of Oxidant Consumption in Soil

l Measurement of Treatment Under “Ideal” Conditions

l Sophisticated Bench Tests

ÿ Research Tool

ÿ For Most Projects, Site Specific Field Pilot Testing is

More Valuable than Detailed Column Tests, etc.

È Field Pilot Testing

l Often Pilot Test Achieves Treatment of a Target Zone

l Designed to Provide Full-Scale Design Parameters

l Need Close Monitoring

No Notes
30

Bench Testing

È Groundwater-Only Systems

l Don’t Account for Soil Interactions

l Can provide very preliminary information

È Soil – Groundwater Slurry Systems

l Allows Measurement of Soil Interactions

l Provides Soil Matrix Demand

l Allows Measurement of Metals Solubility and

Attenuation

È Flow Through Column Tests

l Useful for Kinetic-Transport Studies & Research

l Not Commonly Conducted on ISCO Projects

No Notes
31

Example Bench Test – Slurry

Ozonation of PAHs and PCP

Ozone Gas

Stirring

Shaft

 Gas Effluent

0

200

400

600

Treatment Time

(hrs)

0 12.5 30.6 50

PAH (g/l)

Ozonation

Nitrogen Control

0

2

4

6

Treatment Time (hrs)

0 12.5 30.6 50

PCP (g/l)

Ozonation

Nitrogen Control

2 liter slurry

vessel

Credit: IT Corporation

No Notes
32

Field Pilot Testing

È Site the Pilot Test in a Representative Area

È Conduct Sufficient Background and Pre-Test

Monitoring to Assess changes in Site Conditions

È Allow Sufficient Duration for All Oxidation Reactions

to Go to Completion

È Some Common Observations:

l Increase of Dissolved Contaminants at Early Time.

l Rapid Decrease in Dissolved Levels at Later Time.

l Post-Treatment Rebound in dissolved levels.

È Need to Monitor/Sample Soils to Assess Level of

Mass Reduction

Results from a pilot test will often modify the design.
33

Example Field Pilot Test –

Cape Canaveral Demonstration

20% TCE Treatment

& Extent of KMnO4

30% TCE Treatment

Fluoride Tracer Influence

40% TCE Treatment

25 Feet

> 5,000 ppm TCE

> 1,000 ppm TCE

> 100 ppm TCE

Injection

Point

Credit: IT Corporation

No Notes
34

Question & Answers

Effective Depth of

Application?

Cost?

Will it work on free

product ?

Horizontal Well

Spacing?

At this time we will consider any questions you may have.
35

Fenton’s Reagent

È Process:

l Hydrogen Peroxide and Iron Catalyst React to Produce

Hydroxyl Radicals (OH•).

È Basic Reaction:

l H2O2 + Fe+2‡ Fe+3 + OH- + OH•

l Hydroxyl Radicals are non-Specific Oxidizing Agents

l Contaminants converted to H2O, CO2, & Halides (Cl-)

No Notes
36

Fenton’s Reagent Treatment

Mechanisms

È Advanced Oxidation Via Hydroxyl Radicals

l Amended Catalyst

l Soil Mineral Catalyst

È Direct Oxidation by Hydrogen Peroxide

È Contaminant Boiling and Volatilization

l Hydrogen Peroxide Decomposition is Exothermic

È Assess the Degree of Treatment by Oxidation Vs.

Volatilization Through Subsurface Monitoring

l Temperature

l Vapor Concentrations

l CO2 Production

Injection at concentrations greater than 11 percent peroxide can cause

the ground water to boil

Each pound of hydrogen peroxide can release 1,200 BTUs of heat

energy and up to six cubic feet of oxygen gas
37

Safety - Hydrogen Peroxide

È Chemical Handling, Transportation, and Storage

l Hydrogen Peroxide Is Highly Reactive and Must Be Handled by

Trained Personnel in Accordance with Appropriate Procedures

È Subsurface Application Hazards

l Heat

l Off-Gas

l Vapor Migration

È Well-Head Pressurization and Blow-Offs are Common

to Some Peroxide Applications.

È Peroxide Injection into Free Product Must Be Closely

Monitored to Prevent Fire or Explosion.

È Subsurface Peroxide Injection Should Be Closely

Monitored, and Reactions Ramped-Up Slowly.

No Notes
38

Applying Fenton’s Reagent

È Mixture of 35% H2O2 and Ferrous Sulfate is Typical

l Lower concentrations may be used to reduce heat and

gas generation

È Delivered at Depth Using:

l Lance Permeation

l Soil Mixing Techniques

l Injected Water Amendments

No Notes
39

Fenton’s Design Considerations

È What Hydrogen Peroxide Dose is Required?

l Based on Contaminant Mass and Oxidation SideReactions

È How Much Catalyst is Needed

È What Hydrogen Peroxide Concentration is

Appropriate?

l Higher Concentrations More Aggressive

l Higher Concentrations Lead to Peroxide

Decomposition and Heat and Off-Gas Generation

È How Persistent is the Peroxide in the Surface and

How Far Will it Flow From the Injection Point?

No Notes
40

Fenton’s Reagent; Specific Data Needs

& Limiting Factors

È Additional Data Needs

l VOCs

l LEL

l CO2, O2

l Fe in Soil & Groundwater

l Alkalinity of Soil and Groundwater

È Limiting Factors

l High TOC Levels

l Low Soil Permeability

l Highly Alkaline Soils

No Notes
41

Fenton’s Reagent Process Options

È Several Proprietary Process Options are

Commercialized

È Variations Between Processes Generally Relate to

l Hydrogen Peroxide Concentration

l Iron Catalyst Formulation and Delivery

l Injection Equipment

l Injection Pressure and Flow

È Some Fenton’s Processes Involve Aggressive,

Energetic Treatment, Others Involve More

Controlled Treatment

No Notes
42

Hydrogen Peroxide Injection

Credit: SECOR

Oxidants can be injected via driven lances or wellheads.
43

Fenton’s “Slurry Oxidation” in Open

Trench

Credit: SECOR

Oxidant may be applied directly to contaminated soil.
44

Ozone Oxidation

È Ozone (O3) is a Gas that is Generated On-Site

È Ozone is a Very Powerful Oxidizer

È Applicable Contaminants

l Chlorinated Solvents

l PAHS, Chlorinated Phenols

l PCBs, Pesticides

È Ozone is Generated From Oxygen, and Degrades

to Oxygen

È Since Ozone is a Gas it is most Ideal for Vadose

Zone Treatment, Compared to Liquid Oxidants

No Notes
45

Ozone Safety

È Subsurface Ozone Reactions are Non-Energetic

È Catalyst Beds Can Be Used for Ozone Gas Destruction in

SVE off-gas.

È Ozone Generators Produce up to 50,000 ppm 03, while the

IDLH is 10 ppm and the TLV is 0.1 ppm

È Confined Spaces with Ozone Generators Need Continuous

Air Monitoring.

È All Equipment in Contact with Ozone Must Be Stainless

Steel or Teflon and Oil-Free.

È Ozone Injection System Leak Testing is Critical.

l Pressure Testing May Not Find All Leaks.

l Use Potassium Iodide solution (ozone colorimetric detector)

on a paper towel to detect small leaks.

No Notes
46

Ozone Implementation

È Gas Injection Above Water Table (Vadose Zone)

l Ozone Gas Applicable to Source Zone Treatment in

Vadose Zone

l Gas Flow Easier to Control than Injection of Liquid

Solutions

È Gas Sparging Below Water Table (Saturated Zone)

l Ozone Sparging More Difficult to Ensure Uniform

Delivery Compared to Liquid Solutions

l Applicable to Source Zone Treatment of “Reactive

Barrier” Implementation

È Both Approaches Usually Combined with Soil Vapor

Extraction to Control Ozone Off-Gas

No Notes
47

Ozone Gas Mass Transfer

Ozone Rich,

Contaminant Lean Gas Stream

Ozone and

Contaminant

Diffusion

Soil Particle

Contaminant Oxidation

Ozone Depleted,

Contaminant Rich Gas Stream

Gas Flow

Fingers

NAPL & Sorbed 

PAHs

No Notes
48

Ozone Oxidation Mechanisms

COOH

COOH

Biodegradation

Ozonation

Ozonation

Step 1:

Add O3 Step 2A - 

Chemical 

Oxidation

Step 2B - “Chem-Bio”

CO2 

H2O

Biodegradation

Ozonation

No Notes
49

Ozone Oxidation Implementation and

Logistics

È Ozone Generation systems

l Continuous Pressure and Flow

l Continuous Ozone Output

È Injection systems

l Continuous Injection

l Multi-Level Wells Help Ozone Distribution

È Proprietary Systems

l C-Sparge, involves Ozone Sparging and Recirculation

Well

No Notes
50

Ozone Oxidation Design Specifics

È Ozone Treatment is a “Continuous Injection”

Process

È Ozone Generators Produce a Fixed # of lbs O3 per

day

È Time For Treatment = lbs O3 required / lbs O3 per

day

È For example, if 1,000 lbs contaminant are present,

and ozone consumption is 7 lbs O3 per lb contam.,

then 7,000 lbs O3 is Required. To Achieve

Treatment in 1 Year, Requires ~ 20 lbs O3 per day.

No Notes
51

Ozone Monitoring Specifics

È Subsurface

l Contaminants in Soil and Aqueous Phases

l Ozone Gas Distribution

l Dissolved Ozone Distribution

l Vadose Zone Soil Moisture Monitoring

È Work Space Air Monitoring – Safety

l Time-Weighted Ozone Monitoring in Breathing Space

l Confined Spaces with Ozone Generators Require

Continuous Monitoring

No Notes
52

Example of Ozone Treatment System

Clayton, 2000

00.0 5.00 10.00 15.00 20.00 25.00

-25.00

-20.00

-15.00

-5.00

Ozone Generator

-10.00

00.0

Reference: Clayton, 2000, “Injection of Gas-Phase Oxidants: Ozone Gas” in

Vadose Zone Science and Technology Solutions V. II, eds. Looney and Falta.

Battelle Press.
53

Ozone Injection Research and

Demonstration Plot

Credit: IT Corporation

Manifold system and injection points are visible in the foreground.
54

Permanganate Oxidation

È Permanganate is the Most Stable But Least

Aggressive Oxidant (compared to ozone and

peroxide)

È Permanganate is available as either KMnO4 or

NaMnO4

È Application Methods Employed To Date:

l Batch Injection of Liquid Solution

l Recirculation of Liquid Solution

l Fracture Emplacement of Liquid Solution

l Fracture Emplacement of Crystalline Solids

Two Forms of Permanganate Commercially Available

Namn04 at 40% (by Wt) Concentration in Solutions

Kmno4 Solid Crystals, With Aqueous Solubility of 4% to 7%, Depending on

Chemistry and Temp. Of Mix Water.

Contact Carus Chemical, Perus, Il for Further Information, Including Msds.

KMnO4

Solid Crystals Commonly Mixed to Create Aqueous Solutions.

Process May Involve Manual or Automated Mixing Systems.

Lower Solubility of Kmno4 Limits Possibility for Energetic Reactions.

NaMno4

Liquid Product Facilitates Mixing Compared to Solid Crystals.

Diluted Namno4 Is Safer to Handle Than Full-strength 40% Solution.

40% Namno4 Is a Strong Oxidizing Solution, That Can React Energetically. Never

Neutralize Concentrated Namno4 Liquid Solution.
55

Safety - Permanganate

È Subsurface Reactions Generally Non-Energetic

È Proper Oxidant Handling is Needed.

l Crystalline Solids Represent Dust Hazard

l Concentrated NaMnO4 must be diluted before

neutralization

È While Permanganate is the Least Aggressive

Oxidant – It Can Still React Energetically During

Handling

l Accident Occurred in Piketon Ohio Resulting in

Thermal Burns From Explosion of Concentrated

NaMno4 During Handling.

Safety first with ISCO! Worker safety training is a must.
56

Permanganate Oxidation

È Applicable Contaminants

l Chlorinated Ethenes (TCE, DCE, etc)

l PAHs

l Other Double-Bonded Organics

È Non-Applicable Contaminants

l PCBs, Pesticides

l Chlorinated Ethanes (TCA, DCA, etc.)

È Frequently Asked Questions:

l What About MnO2 Precipitation?

l What About Manganese Residual in Soil or

Groundwater?

No Notes
57

KMnO4 Reactions with Chlorinated

Solvents

È Perchloroethene (PCE)

 4KMnO4 + 3C2Cl4 + 4H2O ‡ 6CO2 + 4MnO2 + 4K+ + 12Cl- + 8H+

È Trichloroethene (TCE)

 2KMnO4 + C2HCl3 ‡ 2CO2 + 2MnO2 + 3Cl- + H+ + 2K+

È Dichloroethene (DCE)

8 KMnO4 + 3C2H2Cl2 + 2H+ ‡ 6CO2 + 8MnO2 + 8K+ + 6Cl- + 2H2O

È Vinyl Chloride (VC)

10KMnO4 + 3C2H3Cl ‡ 6CO2 + 10MnO2 + 10K+ + 3Cl- + 7OH- + H2O

This slide shows the reactions of potassium permanganate with common

chlorinated solvent contaminants.
58

TCE-Permanganate Reactants,

Intermediates, and Products

TCE

C2HCl3

Cyclic Ester

MnO4C2HCl3

Permanganate Ion

MnO4

-

Carboxylic Acids

HaCbOcOHd

HMnO3

HCl

CO2 H2O

H2O

ClMnO2

Yan and Schwartz, 1998

Intermediate products are produced during the reaction. (Ref. Yan and

Schwartz, 1998, in Physical, Chemical, and Thermal Technologies,

Battelle Press, Columbus, OH)
59

Permanganate Oxidation

Design Basics

È Selecting K vs. Na

È Determining Oxidant Dose and Concentration

È Mixing systems

È Injection systems

l Fracture-Based

l Batch Injection

l Continuous Injection

l Using Existing Wells Common

No Notes
60

KMnO4 Mixing Operations

Credit: IT Corporation

Batches of permanganate are mixed on site prior to injection.
61

Permanganate Oxidation Design

Specifics

È Permanganate Solutions Can Be Readily Mixed

from less than 0.5% solution up to 40% (NaMnO4)

È The Ability to Vary the Concentration Allows

Flexibility in Designing Dose (Oxidant Mass) vs.

Solution Volume (Dictated by Geology)

È Injection of Higher Concentrations Decreases the

Chemical Usage “Efficiency”

È Batch Injection Common For Permanganate

Because of Its Persistence

No Notes
62

Permanganate Monitoring Specifics

È Permanganate can Persist in the Subsurface for

Several Months – Monitoring Should Extend Over

This Full Period to Capture The Treatment

Effectiveness

È Soil Core Sampling Needed to Assess Mass

Reduction

È Purple Color of Permanganate Solution Allows

Qualitative Detection – However visual detection

cannot differentiate 100 ppm vs. 100,000 ppm

Permanganate leaves a distinctive purple stain.
63

Monitoring Issues –

All Oxidation Technologies

È Treatment and Process Monitoring

È Closure Monitoring

È Post-Closure Monitoring

No Notes
64

Treatment Monitoring

È Oxidation is a “Destructive” Technology

l No Ability to Measure/Track Extracted Contaminant

Mass

l Documentation of Treatment Effectiveness Requires

“Before and After” Contaminant Delineation

l Sampling and Analysis of all Phases (especially soils)

Required to Characterize Contaminant Mass

Destruction.

No Notes
65

Subsurface Treatment Monitoring

È Pressure

È Temperature

È ORP, pH, other basic chemistry

È Contaminant Concentrations

l Vapor

l Dissolved

l Sorbed

l NAPL

È Metals

No Notes
66

Post-Treatment and Closure

Monitoring

È Allow Sufficient Time to Evaluate Conditions After

the Site Reaches a New, Post-treatment

Equilibrium

È All Oxidant Must Be Consumed Before Posttreatment Conditions Are Assessed

È Post-treatment Rebound (Increase) in Dissolved

Contaminants Can Be Observed Due to Desorption

and NAPL Dissolution

No Notes
67

ISCO Permitting

È Underground Injection Control (UIC)

l Usually Oxidation Treatment Viewed as Beneficial to

Aquifer Quality

l Common Concerns

ÿ Constituents in the injected fluid exceed a primary or

secondary drinking water standard

ÿ Formation of toxic intermediate products

ÿ Unknown toxicity of a constituent of the

oxidant/catalyst

ÿ Formation/mobilization of colloids due to breakdown

of NOM

ÿ Migration of contaminants away from the plume or

source area

There are few regulatory concerns specific ISCO. However, the oxidants will

oxidize metals making some of them more mobile. Pb, As, U, & Cr are some

that may trigger regulatory concern. Ozone and peroxide degrade to oxygen

and oxygen and hydrogen respectively. MnO4 degrades to MnO2. Manganese

dioxide is a brown black crystalline solid that is a regulatory concern due to

aesthetic considerations rather than health effects. (It stains anything but

glass.)

The injection well requirements that the injected solution stay in the targeted

zone, that the injectant does not mobilize secondary contaminants, that it does

not further degrade an aquifer, and other technical requirements still apply.

Additional details available in the ITRC ISCO Technical and Regulatory

Guidance Document – download at no-cost at: www.itrcweb.org
68

ISCO Permitting (continued)

È Federal Programs (RCRA & CERCLA)

l RCRA

l CERCLA

l EPCRA

l Other (TSCA, FIFRA)

È State Programs

l May Require a Permit, or May be Waived by Statute

l Refer to Regulatory Examples in Appendix A of ISCO

Document

Federal programs require that “substantive technical requirements” be

complied with, however, “administrative requirements” may be avoided in

some circumstances.

The administrative requirements such as; fees, public hearings, and other nontechnical requirements are waived. The public hearing process is often part of

the remedial process under CERCLA and RCRA.
69

Stakeholder & Tribal Issues

È Identify Stakeholders

l Local Officials

l Indian Tribes

l Neighborhood Organizations

l Individual Citizens

È Involve Stakeholders in the Process

l Problem Identification

l Site Investigation & Remedy Selection

l Timely Response to Inquiries

Stakeholder issues with ISCO are primarily the same as with any invasive

treatment technique. “Stakeholders” are any person or group that is interested

in the site. The best way to address their concerns is to include them at as

many steps of the process as possible.
70

In Closing

ÈISCO Technologies are an option for fast remediation

ÈOxidants and contaminants degrade to harmless substances

ÈLimitations like any other technique

ÈNo unique regulatory issues for ISCO

ÈSafe Handling of chemicals is essential

ÈITRC States are in the process of concurring on using the “ITRC

ISCO Tech & Reg Guidance” as a tool to evaluate the

appropriateness of proposals containing ISCO (States already

concurring: AL, IL, KS, LA, ND, NH, NY, OK, OR, SC, TN, VA,

VT)

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.
71

Question & Answers

Stakeholder

Issues?

RCRA 3020(b)?

How long does it

take?

Is it

proprietary?

Is it

safe?

For more information

on ITRC training

opportunities visit:

www.itrcweb.org

You may download a free copy of the ITRC document “Technical and

Regulatory Requirements for In Situ Chemical Oxidation” from the web site.
72

Thank You!

Links to Additional Resources

Additional resources for this ITRC internet training event are available at:

http://clu-in.org/conf/itrc/isco/resource.htm

Information on ITRC at: http://www.itrcweb.org

Your feedback is important – please fill out the form at: http://www.cluin.org/conf/itrc/isco/feedback.cfm

The 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 technologies

How 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