Trichloroethylene (TCE)

Treatment Technologies

The preliminary assessment of remediation technologies feasible for reclamation of subsurface environmental media contaminated with TCE must involve consideration of the compound's physical and chemical properties (i.e., distribution coefficients, reactivity, solubility, etc.). These properties are directly responsible for behavior, transport, and fate of the chemical in the subsurface environment. Knowledge of a compound's physico-chemical tendencies can be used to alter behavior and fate of that compound in the environment.

TCE contamination frequently is addressed with pump-and-treat systems for remediation and containment of the dissolved-phase plume, but some innovative technologies have demonstrated a capacity for fairly rapid removal of mass from DNAPL source zones, and others have treated dissolved-phase contamination successfully. Approaches applied to the remediation of TCE and other DNAPLs include bioremediation, electrokinetics, flushing technologies (cosolvent/alcohol flooding, surfactant flushing), in situ oxidation, monitored natural attenuation, phytoremediation, (steam injection, electrical heating, in situ vitrification), volatilization technologies (soil vapor extraction, air sparging, in-well stripping), and treatment walls. Additional information, including site-specific reports, is available at Technology Focus.

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Survey Publications/Presentations

Archive of Seminar on In Situ Treatment of Groundwater Contaminated with Non-Aqueous Phase Liquid Contamination: Fundamentals and Case Studies

Chlorinated Solvent Source Zone Remediation
Kueper, B.H., H.F. Stroo, C.M. Vogel, and C.H. Ward (eds.)
Springer, New York , ISBN 978-1-4614-6922-3. SERDP-ESTCP Environmental Remediation Technology, Vol. 7, 713 pp, 2014

This peer-reviewed volume begins with an overview of current practice. The second chapter summarizes the challenges involved in source zone remediation. Subsequent chapters discuss source-zone characterization issues and techniques, responses of downgradient plumes to source remediation, remediation modeling, the use of mass flux and mass discharge information, hydraulic displacement and recovery, in situ chemical oxidation, in situ chemical reduction, enhanced flushing with cosolvents and surfactants, in situ bioremediation, monitored natural attenuation, combined remedies, and costs of source zone treatment. Additional information: Table of contents and chapter abstracts.

Contaminants in the Subsurface: Source Zone Assessment and Remediation
National Research Council, Committee on Source Removal of Contaminants in the Subsurface.
National Academies Press, Washington, DC. ISBN: 030909447X, 383 pp, 2004

After discussing the definition of 'source zone' and the characterization thereof, this report reviews the suite of technologies available for source remediation and their ability to reach a variety of cleanup goals, from meeting regulatory standards for ground water to reducing costs. The report proposes elements of a protocol for accomplishing source remediation that should enable project managers to decide whether and how to pursue source remediation at their sites.

Comparison of EHC, EOS, and Solid Potassium Permanganate Pilot Studies for Reducing Residual TCE Contaminant Mass
Marks, C.
E2S2: Environment, Energy Security and Sustainability Symposium and Exhibition, 9-12 May 2011, New Orleans, Louisiana. Presentation 12621, 30 slides, 2011

At the Defense Distribution Depot San Joaquin-Sharpe (DDJC-Sharpe) site, Lathrop, CA, three treatment technologies were evaluated for their potential to increase TCE mass removal in the saturated zone. Introduction of emulsified oil (EOS) in the North Balloon began in April 2008, injection of solid potassium permanganate in the South Balloon began in May 2008, and injection of a redox compound (EHC, complex organic carbon plus ZVI) in the Central Area began in August 2008. Where the amendment was able to contact the contaminant, all three amendments reduced TCE concentrations to <5 ug/L (the cleanup level). All three amendments continued to distribute/diffuse horizontally after injection and had secondary water quality impacts. Solid potassium permanganate was selected as the preferred amendment because it distributed/diffused significantly more in fine-grained soils than the other two amendments, destroyed TCE more quickly without formation of daughter products, and was cost effective because multiple injections were not necessary. The pilot study results also showed that hydraulic fracturing increased the distribution of the amendment in fine-grained soils when compared to gravity-fed injection wells. Additional information: Longer Abstract; DDJC-Sharpe 2009 5-Year Review

Decision Guide: A Guide for Selecting Remedies for Subsurface Releases of Chlorinated Solvents
Sale, T. and C. Newell.
ESTCP Project ER-200530, 145 pp, 2011

The document is intended to provide current knowledge in support of sound decisions. The section on "Understanding the Problem" describes the behavior of chlorinated solvents in subsurface environments. Other sections discuss formulating objectives, determining what can be attained, developing packages of remedial measures, and assessing limitations. This guide is not intended to foster or discourage efforts to clean up subsurface releases, but to help practitioners who are faced with difficult decisions and to lay the groundwork for developing realistic expectations regarding the outcome of such treatments. The authors assume that the reader has a general understanding of hydrogeology, the movement of chemicals in porous media, remediation technologies, and the overall remedy selection process.

Dense Non-Aqueous Phase Liquids (DNAPLs): Review of Emerging Characterization and Remediation Technologies
Interstate Technology & Regulatory Council (ITRC). DNAPLs-1, 81 pp, 2000.

Reviews three general types of emerging DNAPL characterization technologies and two categories of emerging DNAPL remediation technologies: thermal enhanced extraction and in situ chemical oxidation.

Development of Assessment Tools for Evaluation of the Benefits of DNAPL Source Zone Treatment
L.M. Abriola, P. Goovaerts, K.D. Pennell, and F.E. Loeffler.
SERDP Project ER-1293, 173 pp, 2008

This report details the results of work that has enhanced the understanding of significant mechanisms controlling DNAPL source zone behavior and describes lessons learned that can provide improved DNAPL site management strategies. It discusses 4 important concepts: (1) partial source-zone mass removal can result in substantial local concentration and mass flux reductions; (2) potential remediation efficiency is closely linked to source-zone architecture (ganglia-to-pool ratios); (3) biostimulation and bioaugmentation approaches are feasible for treatment of DNAPL source zones; and (4) the uncertainty in mass discharge ([M/T]) estimates can be quantified through application of geostatistical methods to field measurements.

The DNAPL Remediation Challenge: Is There a Case for Source Depletion?
EPA 600-R-03-143, 2003

Releases of Dense Non-Aqueous Phase Liquids (DNAPLs) at a large number of public and private sector sites in the United States pose signifi cant challenges in site remediation and long-term site management. Extensive contamination of groundwater occurs as a result of signifi cant dissolved plumes generated from these DNAPL source zones that vary in size and complexity depending on site characteristics and DNAPL properties and distribution. Risk and liability management, consistent with regulatory compliance requirements, could involve remediation of the source zone as well as management of the dissolved plume.

DNAPL Remediation: Selected Projects Where Regulatory Closure Goals Have Been Achieved
EPA 542-R-09-008, 2009

The purpose of this paper is to highlight sites where dense nonaqueous phase liquid (DNAPL) source reduction has been demonstrated as an aid in meeting regulatory cleanup goals. The presence of DNAPL in the subsurface can serve as a long-term source of dissolved contaminant plumes in groundwater, making it more difficult to reach regulatory closure. However, once the DNAPL source is addressed, residual groundwater plumes may be more amenable to treatment, including less aggressive techniques such as monitored natural attenuation (MNA) or bioremediation. This paper updates the document, DNAPL Remediation: Selected Projects Approaching Regulatory Closure, prepared in 2004 by providing more recent information on technologies and on five additional selected sites at which DNAPL source reduction technologies were applied.

DNAPL Source Reduction: Facing the Challenge
Interstate Technology & Regulatory Council (ITRC). DNAPLs-2, 42 pp, 2002.

Description of some aggressive in situ technologies to eliminate or reduce DNAPL source zones.

Enhanced Attenuation: Approaches to Increase the Natural Treatment Capacity of a System
Tom Early, et al.
WSRC-TR-2005-00198, 161 pp, 2006

This guide covers the following EA approaches: (1) hydraulic manipulation to reduce contaminant infiltration using low-permeability barriers, diffusion barriers, covers, encapsulation, and diversion of electron acceptors; (2) passive residual source reduction (e.g., bioventing); (3) increase in system attenuation capacity via biological processes, such as bioaugmentation, biostimulation, and wetlands development and other plant-based methods; (4) abiotic and biologically mediated abiotic attenuation methods; and (5) reactive barriers.

Enhanced Attenuation: Chlorinated Organics
Interstate Technology and Regulatory Council (ITRC) Enhanced Attenuation: Chlorinated Organics Team. EACO-1, 109 pp., Apr 2008.

This report was produced by the Interstate Technology and Regulatory Council (ITRC). Many sites with chlorinated organic contamination in groundwater have gone through extensive remedial evaluations and actions. The remedial alternatives for many of these sites include high-energy treatments such as pump-and-treat systems. After years of operation, the effectiveness of these high-energy processes has begun to diminish without remedial objectives being met. Other more effective remedial alternatives need to be implemented; however, there is a lack of guidance available to regulators and the environmental community regarding how and when to transition these sites to lower-energy remedial alternatives and eventually to monitored natural attenuation (MNA). To answer this need, the ITRC Enhanced Attenuation: Chlorinated Organics (EACO) Team developed this guidance, which includes a protocol to assist in a smooth transition (or a bridge) between aggressive remedial actions and MNA.

Enhancements to Natural Attenuation: Selected Case Studies
T.O. Early (ed.). WSRC-STI-2007-00250, 132 pp, 2007

Presents case studies of engineered covers; biostimulation and bioaugmentation to address trichloroethene (TCE) contamination at Cape Canaveral, FL; a ZVI PRB for TCE and chromate at the U.S. Coast Guard Support Center, Elizabeth City, NC; a full-scale mulch biowall for TCE at Offutt Air Force Base, NE; and a wetland enhancement/reactive mat for TCE, carbon tetrachloride, chloroform, and 1,1,2,2-tetrachloroethane at Aberdeen Proving Ground.

Estimating Cleanup Times Associated with Combining Source-Area Remediation with Monitored Natural Attenuation
M. Widdowson, F. Chapelle, C. Casey, and M. Kram.
NFESC TR-2288-ENV, 192 pp, 2008

ESTCP Cost & Performance Report

U.S. EPA guidance specifically requires a reasonable time frame for MNA to achieve site-specific cleanup objectives; thus, it is necessary to provide estimates of cleanup times whenever MNA is proposed as part of a cleanup strategy. The U.S. Navy, USGS, and Virginia Tech have developed Natural Attenuation Software (NAS) as a screening tool designed for estimating time of remediation for MNA with varying degrees of source area remediation. This report describes the software and the results of its use at 8 sites contaminated primarily with chlorinated ethenes.

Impacts of DNAPL Source Treatment: Experimental and Modeling Assessment of the Benefits of Partial DNAPL Source Removal
A.L. Wood, M.D. Annable, J.W. Jawitz, R.W. Falta, M.C. Brooks, C.G. Enfield, P.S.C. Rao, and M.N. Goltz.
EPA 600-R-09-096, SERDP Project ER-1295, 172 pp, Sep 2009

When it is not practical or economically feasible to achieve complete DNAPL mass depletion using aggressive remediation techniques, it must be determined if the aggregate benefits of partial DNAPL mass depletion are sufficient to reduce risks to an acceptable level and if the costs associated with this partial depletion are justified by the benefits received. This report summarizes field, lab, and modeling research conducted to address these issues, with the primary objective being the development of a scientifically defensible approach for assessing the long-term environmental impacts (benefits) of DNAPL removal from source zones.

Improved Monitoring Methods for Performance Assessment During Remediation of DNAPL Source Zones
R. Siegrist, R. Oesterreich, L. Woods, and M. Crimi.
Strategic Environmental Research and Development Program (SERDP), Project ER-1490, 116 pp, 2010

Investigators evaluated (1) the effects that sampling methods can have on the accuracy of measurements made for chlorinated solvents in samples of porous media collected from intact cores, and (2) the effects that remediation agents can have on the ability to infer CVOC mass levels in the subsurface based on groundwater concentration data. The accuracy of VOC measurements was investigated using an experimental apparatus packed with sandy porous media and contaminated with known levels of VOCs (PCE, TCE, TCA) sampled using different methods under variable, but controlled, conditions. Five sampling methods were examined representing different degrees of porous media disaggregation and duration of atmospheric exposure that can occur during sample acquisition and preservation in the field. CVOCs were studied at dissolved, sorbed, and nonaqueous phases. Five porous media temperatures were examined ranging from 5 to 80 degrees C to represent ambient or thermal remediation conditions, and two water saturation levels were used to mimic vadose zone and groundwater zone conditions. Results show that sampling method attributes can impact the accuracy of VOC measurements in porous media by causing negative bias in VOC concentration data ranging from near 0 to 90% or more. In situ remediation technologies, such as thermal treatment, ISCO, and flushing, have the potential to alter subsurface properties, which can affect the behavior of CVOCs, including DNAPLs.

In Situ Remediation of Chlorinated Solvent Plumes
Stroo, H.F. and C.H. Ward, eds.
Springer, New York, ISBN: 978-1-4419-1400-2, 690 pp, 2010

Following a general overview of groundwater contamination and challenges associated with chlorinated solvent-contaminated sites, the authors describe the current state of the science with a focus on the chemistry and key microbial and abiotic processes responsible for degradation of chlorinated solvents, plus how source zone architecture impacts their characterization and remediation. Analyses are provided of the advantages, performance, and relative costs of a range of remedial technologies, with case studies of several template sites and analyses of the capital costs, as well as costs for laboratory testing, pilot-scale demonstration, design, system operation, monitoring and maintenance during operations, and demolition and restoration after remediation. Table of contents with abstracts

Frequently Asked Questions Regarding Management of Chlorinated Solvents in Soils and Groundwater
T. Sale, C. Newell, H. Stroo, R. Hinchee, and P. Johnson.
Environmental Security Technology Certification Program (ESTCP), Project ER-0530, 38 pp, 2008

This brief document addresses 25 key questions, providing a concise overview of current knowledge regarding the management of subsurface chlorinated solvent releases. Source zone areas are defined and discussed, with summaries of the benefits and limitations of various source characterization and remediation technologies. The document addresses current technical and practical limitations, as well as the changes that have occurred over time at many chlorinated solvent sites. Although the document is meant neither to foster nor discourage source zone treatment, it takes a hard look at the costs and performance of the most commonly used source zone treatment technologies and compares source treatment to alternative containment approaches.

Independent Technical Review of the X-740 Groundwater Remedy, Portsmouth, Ohio: Technical Evaluation and Recommendations
B.B. Looney, D.G. Jackson, B.D. Riha, R. Ramirez, L. Whitehurst, and C.A. Eddy-Dilek.
SRNL-STI-2010-00176, 53 pp, 2010

Two technologies implemented at this site—phytoremediation using a stand of hybrid poplar trees from 1999-2007 and ISCO using modified Fenton's Reagent from 2008-2009—have proven ineffective in achieving remedial action objectives. The contaminated aquifer zone (the Gallia) is currently dominated by slow release of TCE from formations above, below, and within the Gallia itself. The review has indicated that the slow release of TCE from clay and sandstone into the Gallia represents a long-term source of TCE that can re-contaminate the Gallia in the future; hence, otherwise effective technologies that do not leave residual treatment capacity in the system are unlikely to achieve the cleanup goals. The review team classified 3 technologies as potentially viable: (1) enhanced anaerobic bioremediation using long-lived electron donor and low-pressure liquid deployment; PRBs; and passive upgradient drains to divert water around the contaminant source zone and plume.

Pilot Project to Optimize Ground Water Remediation Systems at RCRA Corrective Action Facilities: Summary Report and Lessons Learned
U.S. EPA, Office of Solid Waste and Office of Superfund Remediation and Technology Innovation.
EPA 542-R-04-018, 26 pp., 2004.

This document summarizes information derived from Remedial Site Evaluations (RSEs) performed at five RCRA sites during 2003 and 2004. The primary contaminants of concern at all five sites are chlorinated solvents, such as TCE, and four of the five sites involve contamination that is present in fractured rock.

PREMChlor: Probabilistic Remediation Evaluation Model for Chlorinated Solvents: User's Guide
Liang, H., R. Falta, C. Newell, S. Farhat, P.S.C. Rao, and N. Basu.
ESTCP Project ER-0704, 76 pp, Mar 2010

PREMChlor has been developed for simultaneously evaluating the effectiveness of source and plume remediation, considering the uncertainties in all major parameters. The technical foundation of PREMChlor is U.S. EPA's REMChlor model. PREMChlor is developed by linking the analytical model REMChlor to a Monte Carlo modeling package GoldSim via a FORTRAN dynamic link library application. Cost analysis of common technologies for DNAPL source removal and dissolved plume treatment are included. PREMChlor gives users a single platform where cost, source treatment, plume management, monitored natural attenuation, and risk assessment can all be evaluated together, and where uncertainty can be incorporated into the site decision-making process. A license-free file containing the user-friendly graphical user interface has been generated to make PREMChlor available for use by others: PREMChlorModelFiles.zip; Decision & Management Tools for DNAPL Sites: Optimization; ESTCP Cost and Performance Report (2011)

Proven Technologies and Remedies Guidance: Remediation of Chlorinated Volatile Organic Compounds in Vadose Zone Soil
Berscheid, M., K. Burger, N. Hutchison, H. Muniz-Ghazi, B. Renzi, P. Ruttan, and S. Sterling.
California Department of Toxic Substances Control, 154 pp, 2010

Presents an option for expediting and encouraging cleanup of sites with chlorinated VOCs in vadose zone soil by streamlining the cleanup process. This approach limits the number of evaluated technologies to excavation/disposal and SVE and provides resources to facilitate the design and implementation of both remedies. Considerations for operation and maintenance of SVE systems, including zone of capture assessment, operational assessment, and shutdown and cleanup confirmation are included.

SERDP/ESTCP Expert Panel Workshop on Research and Development Needs for Cleanup of Chlorinated Solvent Sites
Environmental Security Technology Certification Program (ESTCP), 87 pp, 2001.

Strategies for Monitoring the Performance of DNAPL Source Zone Remedies
Interstate Technology and Regulatory Council (ITRC) Dense Nonaqueous-Phase Liquids Team. DNAPLs-5, 206 pp., Aug 2004.

This document is intended for regulators and others interested in learning about approaches to performance monitoring while implementing various in situ technologies for the treatment of DNAPLs. In this document, we present a number of ways in which the success or failure in treating a DNAPL source zone has been measured. Because the vast majority of experience in DNAPL source zone remediation has been in unconsolidated geologies, such as sands and silts, many of the conclusions, recommendations, and lessons learned presented in this document do not necessarily transfer to performance assessment in fractured bedrock, karst, or other consolidated geologies.

Synthesis Report on Five Dense, Nonaqueous-Phase Liquid (DNAPL) Remediation Projects
U.S. EPA, National Risk Management Research Laboratory, Cincinnati, OH.
EPA 600-R-07-066, 94 pp, 2007

Summarizes the performance and results of demonstration projects for the remediation of DNAPL contamination at five sites: (1) thermally enhanced remediation with resistive heating and with steam injection/extraction for TCE DNAPL at Launch Complex 34, Cape Canaveral, FL; (2) cosolvent flushing, surfactant flushing, cosolvent DNAPL mobilization, complex sugar flushing, and AS/SVE for PCE at Dover AFB, DE; (3) surfactant-enhanced aquifer remediation for chlorinated solvent contamination (primarily TCE) at Hill AFB, UT; (4) thermally enhanced remediation of fractured bedrock with steam injection for multiple contaminants, primarily PCE and TCE in the quarry site at Loring AFB, Limestone, ME; and (5) cosolvent flushing and enhanced bioremediation for PCE at Sages Drycleaners in Jacksonville, FL.

TCE Removal from Contaminated Soil and Ground Water: Ground Water Issue
H.H. Russell, J.E. Matthews, and G.W. Sewell.
EPA 540-S-92-002, 10 pp, 1992.

Technology Evaluation Report: Technologies for Dense Nonaqueous Phase Liquid Source Zone Remediation
John C. Fountain.
Ground-Water Remediation Technologies Analysis Center, TE-98-02, 70 pp, 1998.

The Use of Molecular and Genomic Techniques Applied to Microbial Diversity, Community Structure, and Activities at DNAPL and Metal-Contaminated Sites: Environmental Research Brief
Azadpour-Keeley, A., M.J. Barcelona, K. Duncan, and J.M. Suflita.
EPA 600-R-09-103, 19 pp, Sep 2009

Subsurface microbial communities will respond both to the presence of contaminants, which can be detected during characterization, and to the engineered manipulation of subsurface conditions, which can be monitored during remediation. This Brief provides a background on classic molecular and genomic sciences and discusses the results and interpretation of their application to field-scale subsurface remediation activities.

Bioremediation

Bioaugmentation for Remediation of Chlorinated Solvents: Technology Development, Status, and Research Needs
Environmental Security Technology Certification Program (ESTCP). 126 pp, Oct 2005

This white paper reviews the state of bioaugmentation science at the present time, summarizes the current status of this rapidly evolving innovative technology, identifies the key issues confronting the science, and evaluates the lessons learned from current practical applications. This technology 'snapshot' may be useful to remedial project managers faced with selecting, designing, and implementing a bioaugmentation strategy.

Bioenhanced In-Well Vapor Stripping (BEHIVS) to Treat Trichloroethylene
Strategic Environmental Research and Development Program (SERDP). 75 pp, 2003.

An in-well vapor stripper and two biotreatment wells were installed near a TCE-contaminated "hot spot" zone at Edwards AFB for an August-December 2001 technology demonstration. In-well vapor stripping and in situ aerobic cometabolic bioremediation were combined to address a TCE source area without bringing contaminated ground water to the surface.

Bioremediation Systems at Beale Growing, Getting Better
Centerviews, Vol 14 No 1, p 6-7, Spring 2008

Additional Information (67KB/17pp/PDF)

Beale AFB, CA, has enhanced in situ bioremediation (EISB) systems in 2 areas to address groundwater contaminated with TCE. The systems combine in situ biostimulation using food-grade injectants and bioaugmentation using Dehalococcoides bacteria in KB-1. One system is achieving successful reductions in contaminant levels, and the other system is new. These combined bioremediation processes can take several years to achieve the cleanup goal, depending on groundwater conditions, distribution of the electron donor, and initial solvent concentrations.

Case Study: In Situ Accelerated Anaerobic Bioremediation
A. Bloom, B. Lyon, and L. Stenberg.
E2S2 2010: Environment, Energy Security, and Sustainability Symposium and Exhibition, 14-17 June 2010, Denver, Colorado. National Defense Industrial Association (NDIA), Abstract 9778, 34 slides, 2010

Accelerated anaerobic bioremediation (AAB) was applied at Dover AFB to a large, multi-source plume of chlorinated ethenes and some ethanes. The Area 6 plume is ~1 mile in length and over 1,000 feet wide and originates from at least 5 separate source areas that commingle in the subsurface. Remediation involved targeted direct AAB injection of a substrate mixture of sodium lactate, emulsified vegetable oil (EVO), and nutrients in source areas. After 3 years of treatment, plume-wide degradation is being observed. PCE and TCE concentrations within the AAB treatment areas have declined by over 80% in many wells, and the presence of ethene is increasing in areal extent over time. See longer abstract

Comparative Demonstration of Active and Semi-Passive In Situ Bioremediation Approaches for Perchlorate Impacted Groundwater: Active In Situ Bioremediation Demonstration (Aerojet Facility)
Cox, E. and T. Krug.
ESTCP Project ER-200219, 848 pp, 2012

During the demonstration of active enhanced in situ bioremediation at the inactive Rancho Cordova test site in California, groundwater containing perchlorate and TCE was extracted from the shallow aquifer, amended with ethanol, and recharged to the shallow aquifer. The active biobarrier provided treatment and containment of a 600-ft wide section of the plume in the shallow aquifer using two groundwater extraction wells and a single groundwater recharge well. Indigenous bacteria were able to biodegrade perchlorate concentrations as high as 4,300 µg/L to less than 4 µg/L within 50 ft of the recharge well. TCE dechlorination followed bioaugmentation of the shallow aquifer with KB-1 to introduce dehalorespiring bacteria.

DCE/VC Stall Tool
U.S. Navy, Naval Facilities Engineering Command, Environmental Restoration Technology Transfer, Multimedia Training Tools Website, 19 pages, 2011

At some sites, conditions for complete reductive dechlorination of PCE or TCE to ethene are not present, and degradation stalls at DCE and/or VC. Three basic requirements must be met to form a complete reductive dechlorination pathway: sufficient electron donor (a fermentable carbon source), appropriate redox potential (strongly reducing conditions) in the aquifer, and microbial communities capable of complete dechlorination of PCE to ethene. This tool provides RPMs with the information necessary to recognize DCE and/or VC stall and explores its biological and/or environmental causes, along with potential solutions.

Demonstration of Bioaugmentation at Kelly AFB, TX
2004. B. Alleman, M. Place, and D. Major. AFRL-ML-TY-TR-2004-4530, 155 pp.

This report describes an application of the KB-1 culture to remediate TCE contamination at Kelly AFB.

Demonstration of Bioaugmentation at Kelly AFB, Texas: ESTCP Cost And Performance Report
Environmental Security Technology Certification Program (ESTCP), Project ER-9914, 42 pp, 2007

After augmentation of the aquifer with KB-1™ (a prepared culture of halorespiring bacteria) to address PCE, TCE, and their degradation products, complete dechlorination of PCE to ethene was observed.

Demonstration of Biodegradation of Dense, Nonaqueous-Phase Liquids (DNAPL) Through Biostimulation and Bioaugmentation at Launch Complex 34 in Cape Canaveral Air Force Station, Florida: Final Innovative Technology Evaluation Report
A. Gavaskar, W-S. Yoon, M. Gaberell, E. Drescher, L. Cumming, J. Sminchak, J. Hicks, B. Buxton, M. Morara, T. Wilk, and R. Copley.
EPA 540-R-07-007, 103 pp, 2004

The demonstration to evaluate the technical and cost performance of the bioremediation technologies when applied to a TCE DNAPL source zone began in June 2002 and ended in February 2003. Sequential application of biostimulation (ethanol as electron donor) and bioaugmentation (the KB-1 consortium) was evaluated in the same small test plot beneath a building. The treatments significantly decreased total TCE and DNAPL mass in the target treatment zone.

Development and Validation of a Quantitative Framework and Management Expectation Tool for the Selection of Bioremediation Approaches at Chlorinated Ethene Sites
Lebron, C., T. Wiedemeier, J. Wilson, F. Loeffler, R. Hinchee, and M. Singletary.
ESTCP Project ER-201129, 178 pp, 2015

The overarching project objective was to develop and validate a framework for making bioremediation decisions based on site-specific physical and biogeochemical characteristics and constraints. The key deliverable is called BioPIC, an easy-to-use decision tool for estimating and integrating the impact of quantifiable parameters on NA and microbial remedies to achieve detoxification of chlorinated ethenes. The quantitative framework and BioPIC were beta-tested for chlorinated ethenes (mainly PCE, TCE, and daughter products) degradation at four sites. Additional information: BioPIC tool and other reports

Development of a Design Tool for Planning Aqueous Amendment Injection Systems: User's Guide
R.C. Borden, et al.
ESTCP Project ER-0626

A simple spreadsheet-based tool developed to assist in the design of injection-only systems for distributing emulsions or soluble substrate allows quick comparison of the relative costs and performance of different injection alternatives and identification of the design best suited to site-specific conditions. Emulsion Design Tool (2008); Soluble Substrate Design Tool (2012) .

Edible Oil Barriers for Treatment of Chlorinated Solvent Contaminated Groundwater
M.T. Lieberman and R.C. Borden.
ESTCP Project ER-0221, 228 pp, 2009

The Effect of Concentrated Electron Donors on the Solubility of Trichloroethene
E. Hood, D. Major, and G. Driedger.
Ground Water Monitoring & Remediation, Vol 27 No 4, p 93-98, 2007

Although recent vendor claims suggest that the addition of highly concentrated electron donor solutions to increase the aqueous solubility of TCE during enhanced in situ bioremediation is a significant mechanism of contaminant mass removal, the results of experimental measurements of the solubility of TCE in aqueous solution with 8 typical electron donors suggest that due to the small changes in TCE solubility in comparison to the high electron donor concentrations employed, it is difficult to envision circumstances justifying the use of a high electron donor concentration to enhance TCE solubility as part of a bioremediation strategy, though the use of more concentrated (e.g., 50 to 95%) ethanol solutions would be appropriate for cosolvent flooding.

Engineered Approaches to In Situ Bioremediation of Chlorinated Solvents: Fundamentals and Field Applications
U.S. EPA, Technology Innovation Office.
EPA 542-R-00-008, 144 pp, July 2000.
Contact: Linda Fiedler, fiedler.linda@epa.gov

Enhanced Amendment Delivery to Low Permeability Zones for Chlorinated Solvent Source Area Bioremediation
Adamson, D., C. Newell, M. Truex, and L. Zhong.
ESTCP Project ER-200913, 202 pp, 2014

A demonstration of the use of shear-thinning fluid based technology to improve treatment within low-permeability (low-k) zones of heterogeneous subsurface environments was conducted in a test cell within the Area D TCE plume at Joint Base Lewis-McChord. Low-k zones, which can serve as a long-term secondary source of contamination when transport is diffusion-controlled, are difficult to target using standard injection-based treatment approaches. A shear-thinning fluid can be used to distribute a bioremediation amendment (e.g., lactate) around an injection well such that the solution achieves better penetration and delivers the amendments to zones of both high and low permeability. When injected at a relatively high velocity compared to natural groundwater flow velocities, the shear-thinning nature of the solution allows it to flow more readily, promoting cross-flow from high- to low-permeability zones. During the demonstration, the shear-thinning fluid improved amendment distribution by ~41% with enhanced persistence and treatment effectiveness within the lower-k zones of the heterogeneous aquifer. Permeability contrasts of 1-2 orders of magnitude may be amenable to this technology (e.g., improving distribution to silt layers within a sand matrix, but not clay layers). Field work began in August 2013, and performance monitoring events were completed in February and May 2014. Additional Information: ESTCP Cost and Performance Report

Enhanced Attenuation of Unsaturated Chlorinated Solvent Source Zones Using Direct Hydrogen Delivery
Newell, C.J., A. Seyedabbasi, D.T. Adamson, T.M. McGuire, B. Looney, P.J. Evans, J.B. Hughes, M.A. Simon, and C.G. Coyle.
ESTCP Project ER-201027, 532 pp, 2013

Over a 6-month test period, a total of 830,000 standard cubic feet of gas—10% hydrogen, 79% nitrogen, 10% propane, and 1% carbon dioxide—was injected into a fine-grained vadose zone at a former missile silo site in Nebraska . The hydrogen gas was designed to stimulate biodegradation of TCE and its breakdown products that persisted after three years of SVE. Although the system was successful at converting TCE, a "cis-DCE stall" condition occurred. ESTCP Cost & Performance Report

Enhanced In-Situ Anaerobic Bioremediation of Chlorinated Solvents at LF-08, Whiteman Air Force Base, Missouri
Federal Remediation Technologies Roundtable Cost and Performance Database, 2007

Evaluation of Performance And Costs Associated With Anaerobic Dechlorination Techniques. Phase I Site Survey
Environmental Security Technology Certification Program (ESTCP). Rev. 2, 135 pp, 2002.

The objective of this report is to summarize relevant performance and cost data on various engineered approaches to stimulate in situ anaerobic dechlorination (biologically-driven reductive degradation) of chlorinated compounds, such as TCE.

A pilot test was conducted between 2003 and 2007 at Charleston Naval Weapons Station, SC, to evaluate the effectiveness of EOS®, a commercially available emulsified oil substrate, for enhancing the biodegradation of dissolved-phase chlorinated VOCs in groundwater and aquifer material in a treatment cell. The cell contained 4,000 cubic ft of contaminated aquifer material with up to 16,000 µg/kg TCE in soil and >20,000 µg/L TCE in groundwater. Phase I involved site characterization, baseline sampling, EOS injection, and monitoring for 28 months. Phase II involved a bench-scale treatability study, development and injection of a newly formulated pH-buffered substrate to overcome a pH problem, and an additional 11 months of monitoring to measure the effect of the second substrate. The buffered EOS raised the pH and alkalinity of the aquifer, which allowed the native dehalorespiring populations to re-initiate their metabolism of TCE and DCE and biodegrade TCE throughout the test cell. Over the entire 41-month monitoring period in Phases I and II, the total chlorinated VOC concentration decreased from 198 µM to 17 µM, a decline of 91%. See also the ESTCP Cost and Performance Report.

Field Evidence for Co-Metabolism of Trichloroethene Stimulated by Addition of Electron Donor to Groundwater
Conrad, M.E., E.L. Brodie, C.W. Radtke, M. Bill, M.E. Delwiche, M.H. Lee, D.L. Swift, and F.S. Colwell.
LBNL-3683E, 40 pp, 2010

Following favorable results from the 1999 pilot test, electron donor has been injected into the Snake River aquifer beneath the Test Area North site at Idaho National Laboratory for more than 10 years to stimulate microbial reductive dechlorination of TCE in groundwater. Significant TCE removal from the source area of the contaminant plume and elevated dissolved methane in the groundwater extending 250 m from the injection well are evident, indicating that electron donor amendment designed to stimulate reductive dechlorination of TCE can also stimulate cometabolism of TCE. [NOTE: this is the manuscript version of the paper in Environmental Science & Technology 44(12):4697-4704(2010)]

Field Push-Pull Test Protocol for Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons
Y. Kim, M. Azizian, J. Istok, and L. Semprini. Environmental Security Technology Certification Program, 83 pp, 2005

This protocol describes a newly developed field technology--the single-well push-pull test--for evaluating the feasibility of using in situ aerobic cometabolic processes to treat ground water contaminated with chlorinated solvent mixtures.

Final Report for the Enhanced Anaerobic Bioremediation Pilot Test, Bountiful/Woods Cross Superfund Site, Bountiful, Utah
Bureau of Reclamation, Denver, CO. 66 pp, 2006

Fluidized-Bed Adsorption Bioreactor for the Treatment of Groundwater Contaminated with Solvents at Low Concentration
Paul H. Miyares, Cynthia V. Teeter, and C. James Martel.
Special Report 99-1, 20 pp, 1999.

This biostimulation/bioaugmentation pilot study to address TCE contamination involved a side-by-side comparison in 3 test cells of 3 different bioremediation substrates: sodium lactate, chitin, and emulsified soybean oil. Following the first round of substrate injection and sampling, all 3 test cells were inoculated with a commercially available dechlorinating culture containing Dehalococcoides ethenogenes. Based on the results of the pilot test, full-scale enhanced anaerobic bioremediation was selected for the site's 2006 Record of Decision. Emulsified oil is recommended as the electron donor.

Groundwater Remediation Startup Report, Site Monitoring & Performance Evaluation Report, Revision 1.0: Chemical Injections & Attenuation Monitoring, 2nd & Kirby Site, Hutchinson, Kansas
Kansas Department of Health & Environment (KDHE), Topeka. 235 pp, 2015

Dissolved-phase TCE and related contaminants have been found in the site groundwater at this truck transportation facility. The site contractor used direct-push injections to introduce emulsified vegetable oil (EVO) to provide the electron donor needed to produce the reducing and anaerobic conditions that stimulate contaminant biodegradation. A total of ~9,000 gal of EVO-water solution (900 gal EVO product, specifically SRS^®-FRL) was injected throughout the course of the project. The presence of cDCE as a degradation product of TCE indicates some degree of ongoing reductive dechlorination. This report details the specific measures applied to accelerate the chemical and biological degradation of TCE in the site groundwater.

Impact of Landfill Closure Designs on Long-Term Natural Attenuation of Chlorinated Hydrocarbons: ESTCP Cost and Performance Report
Environmental Security Technology Certification Program (ESTCP), Project ER-0019, 47 pp, 2008

A 24-month pilot-scale field demonstration of a recirculation bioreactor at Landfill 3, Altus AFB, OK, was undertaken to show that a combination of organic material addition and accelerated leaching can rapidly reduce source area concentrations of CAHs (TCE) in groundwater at unlined, closed landfills. A 30-ft x 30-ft x 11-ft-deep portion of the landfill near the suspected TCE source area was excavated and backfilled with a mixture of mulch and sand. A groundwater extraction trench was excavated into the shallow aquifer downgradient of the reactor cell and backfilled with gravel. Groundwater from the trench was extracted and distributed within the bioreactor cell using a drip irrigation system. The bioreactor removal efficiencies for TCE and total chlorinated ethenes from recirculated groundwater ranged from 97 to 100% and 76 to 96%, respectively. Because of a continuing TCE source upgradient of the bioreactor and the accumulation of daughter products in the aquifer beneath and adjacent to the bioreactor, the objective of reducing CAH concentrations by 90% was not achieved. The cost analysis indicates that because the mulch bioreactor technology has the potential for high costs to be incurred, depending on the size of the source area and the type of waste encountered, this treatment approach may be appropriate for well-defined, small, isolated source areas marked by shallow groundwater but not for large landfills with multiple source areas.

Improving Effectiveness of Bioremediation at DNAPL Source Zone Sites by Applying Partitioning Electron Donors (PEDS)
Lebron, C.A ., D. Major, M. McMaster, and C. Repta.
ESTCP Project ER-200716, CR-NAVFAC-EXWC-EV-1402, 3,859 pp, 2014

Partitioning electron donors (PEDs) are water-soluble electron donors that partition directly into a target DNAPL to effect enhanced in situ bioremediation. A PED technology field demonstration was conducted at a TCE source zone at NASA Launch Complex 34 using n-butyl acetate (nBA), a colorless liquid that volatilizes to form dense vapors that have the potential to form an explosive mixture with air. Introduced to the source area using direct-push injection equipment, nBA was able to promote biodegradation and achieved sustained production of dechlorination products, even in the presence of co-contaminant 1,1,2-trichloro-1,2,2-trifluoroethane (CFC113). This project showed that nBA can (1) achieve high rates of biologically enhanced DNAPL dissolution; (2) be easily and effectively delivered; and (3) sustain donor supply at an effective concentration at the DNAPL:water interface to promote the growth and activity of the dechlorinating biomass. [Note: See the first 112 pages of the PDF file for the main report; the subsequent appendices contain lab forms, boring logs, and other field data.] Additional information: ESTCP Cost and Performance Report.

In Situ Bioremediation: Interim Remedial Action Report, Test Area North, Operable Unit 1-07B
U.S. DOE, Idaho Operations Office.
DOE/NE-ID-11221, Rev 2, 48 pp, June 2009

This Interim Remedial Action Report is for the in situ bioremediation (ISB) remedial component of Operable Unit 1-07B at Test Area North at the Idaho National Laboratory. ISB is the final hot-spot remedial component of the overall OU 1-07B groundwater remedial action. The ISB system injects amendment into the aquifer to enhance the growth of indigenous subsurface microorganisms that naturally dechlorinate trichloroethene, tetrachloroethene, dichloroethene, and vinyl chloride to nonhazardous ethene, ethane, chloride, carbon dioxide, and water. Working in conjunction with naturally occurring organisms, the ISB system creates a biologically reduced zone that encompasses the plume's hot spot by injection of an electron donor, which stimulates biological activity in the aquifer. The injection system has been used to deliver both sodium lactate and whey powder as electron donors. Routine operations for the ISB system include amendment injection, sampling, and field laboratory procedures. This interim report provides a chronology of events and a description of the remedial action facilities, systems, components, and operating documents that lead to a declaration that the system is operational and functional. The report also summarizes project costs and lessons learned.

In Situ Bioremediation of Chlorinated Ethene: DNAPL Source Zones
Interstate Technology & Regulatory Council (ITRC), Bioremediation of DNAPLs Team. BioDNAPL-3, 138 pp, June 2008

This publication systematically lays out the technical and related regulatory considerations for in situ bioremediation (ISB) of chlorinated ethene dense DNAPL source zones, providing information related to site characterization requirements, treatment system application and design criteria, process monitoring, and process optimization. The ability of ISB technology to enhance the dissolution and desorption of nonaqueous-phase contaminants to the aqueous phase, where they can be degraded by the microbial population, depends on the spatial distribution of DNAPL mass in the subsurface (e.g., pool/ganglia ratio) and the ability to deliver amendments throughout this architecture.

In Situ Bioremediation of Chlorinated Ethene DNAPL Source Zones: Case Studies
2007

This report was published by the Interstate Technology and Regulatory Council (ITRC). As part of its strategic approach, the ITRC BioDNAPL's Team determined that an independent evaluation of the status of bioremediation was needed, that review of a .data rich. set of case studies would be the best evaluation approach, and that a forum would be an appropriate setting for the process. The team gathered and evaluated a number of proposed case studies and selected a group of six that would demonstrate bioremediation of DNAPLs in a wide range of conditions. The selected case studies can be classified as demonstrations, pilot-scale tests, those in design, and full-scale cleanups.

In-Situ Bioremediation of Chlorinated Hydrocarbons: an Assessment of Projects in California
California Department of Toxic Substances Control, Office of Pollution Prevention and Technology Development.
OPPTD Document No. 1217, 163 pp, 2006.

In Situ Bioremediation of Chlorinated Solvent Source Areas with Enhanced Mass Transfer
T. Macbeth, and K. Sorenson.
Environmental Security Technology Certification Program (ESTCP), Project ER-0218, 396 pp, 2008

A demonstration of enhanced mass transfer of chloroethenes from DNAPL to groundwater during in situ bioremediation of TCE was conducted at the Fort Lewis Logistics Center East Gate Disposal Yard (EGDY) using the Bioavailability Enhancement Technology?, or B.E.T.(tm). For the first time at the field scale, this demonstration provided rigorous documentation of the electron donor (whey) concentration-dependence of enhanced mass transfer of chlorinated solvents in a source area. In 2 hydraulically isolated treatment cells, each consisting of a network of monitoring wells, an injection well, and an extraction well, anaerobic reductive dechlorination occurred concurrently with enhanced mass transfer and resulted in rapid source strength reduction. The rapid effect on downgradient contaminant flux observed at the Ft. Lewis site might be a best-case scenario owing to the high ambient groundwater flow rates. See also the ESTCP Cost and Performance Report.

During an evaluation of the performance of in situ bioremediation (ISB) systems at 5 sites in California, the reviewers observed several recurring issues. The project case studies illustrate the reviewers' recommendations for avoiding common ISB problems.

In Situ Bioremediation of DNAPL Source Zones
37 pp, Aug 2005

This document was prepared by Lisa Moretti, a National Network of Environmental Management studies grantee, under a fellowship from the U.S. Environmental Protection Agency. The objective of this report is to provide an overview of in situ bioremediation of DNAPL source areas. This report discusses the integral steps when implementing bioremediation, such as site characterization, design considerations, and post-treatment monitoring. In addition, this report also examines the use of bioremediation as a polishing treatment for the source zone. Case studies are included as examples of the use of bioremediation as a stand-alone and a polishing treatment for DNAPL source areas.

In Situ Bioremediation of Perchlorate in Groundwater
P. Hatzinger and J. Diebold.
ESTCP Project ER-0224, 536 pp, 2009

A field demonstration was conducted from September 2004 (beginning with a 6-week tracer test) until December 2006 to evaluate the in situ biological reduction of perchlorate and co-contaminant TCE using a horizontal flow treatment well (HFTW) system to mix electron donor into perchlorate-contaminated groundwater by recirculating the groundwater. The HFTW technology consists of two dual-screened treatment wells, one pumping contaminated groundwater from a deep aquifer region and injecting it into a shallower zone, and the other pumping contaminated groundwater from the shallower aquifer region and injecting it into the deeper zone. Electron donor (citric acid) was added and mixed with contaminated groundwater at each well, creating an anaerobic, bioactive zone between and downgradient of the HFTWs during system operation. After evaluation of initial performance, the electron donor concentration was increased, and the system was augmented with a commercial culture containing Dehalococcoides spp. Under active/passive operation, the treatment of perchlorate, as well as TCE, was equivalent to or better than that observed during the continuous-pumping phases, while biofouling was more readily controlled.

In-Situ Substrate Addition to Create Reactive Zones for Treatment of Chlorinated Aliphatic Hydrocarbons: ESTCP Cost and Performance Report
Environmental Security Technology Certification Program (ESTCP), CU-9920, 93 pp, Mar 2007

Demonstrations of enhanced reductive dechlorination (ERD) were conducted at two Air Force bases--Vandeberg and Hanscom--to show the ability of this bioremediation approach to dechlorinate TCE plumes in the subsurface over a relatively short time period and to gather information for estimating long-term treatment effectiveness, life span, and costs.

In-Situ Substrate Addition to Create Reactive Zones for Treatment of Chlorinated Aliphatic Hydrocarbons: Hanscom Air Force Base
C.C. Lutes, V. D'Amato, A. Frizzell, M. Hansen, G. Gordon, P. Palmer, and S. Suthersan.
Environmental Security Technology Certification Program (ESTCP), 431 pp, 2003.

The active treatment phase of the demonstration took place from October 2000 to October 2002, during which time 47 injections conducted in a single injection well delivered 1,250 gallons of raw blackstrap molasses, 11,250 gallons of dilution water, 7,575 gallons of push water, and 4,732 grams of potassium bromide. Monitoring was conducted during the demonstration to gauge technology effectiveness, describe changes in biogeochemical conditions, and gather process monitoring feedback.

In-Situ Substrate Addition to Create Reactive Zones for Treatment of Chlorinated Aliphatic Hydrocarbons: Vandenberg Air Force Base
C.C. Lutes, A. Frizzell, B. Molnaa, and P. Palmer.
Environmental Security Technology Certification Program (ESTCP). 335 pp, 2004.

This report documents an evaluation of the efficacy of the In-Situ Reactive Zone/Enhanced Reductive Dechlorination (IRZ/ERD) technology in removing TCE from impacted ground water in a range of geologic conditions and TCE concentrations. Active molasses-based treatment from February 2001 to April 2003 provided an opportunity to evaluate IRZ at a site that was initially highly aerobic, with minimal evidence of natural attenuation of TCE.

In Situ Treatment of a Dilute Chlorinated Solvent Plume in an Acidic Aerobic Aquifer
Alexander, M. | Remediation 30(2): 25-35(2020)

In situ bioremediation was selected to remediate a 29‐acre dilute, acidic and aerobic, chlorinated solvent plume (mainly TCE and 1,1,-DCE) at the Monitor Devices Inc./Intercircuits Inc. Superfund site in New Jersey. Remediation began in late 2010 and continued over 9 years. The amendments injected included electron donor and bicarbonate buffer solution and, once anaerobic aquifer conditions became established, a bioaugmentation culture. Amendments were injected in multilevel injection wells (IWs), to maintain control over the vertical interval of amendment delivery. The areal coverage of the plume has been reduced by 59% based on the 10µg/L TCE isocontour and the contaminant mass has been reduced by 79%. Lessons learned from this project include the need for bioaugmentation in the acidic aquifer and an efficient and effective manner of well construction and amendment injection using multiscreen single casing IWs and packer systems. Also, there were differences in longevity of the electron donor amendment versus the bicarbonate neutralization additive, and varied amendment delivery techniques (IWs, direct injection, horizontal well installation) were needed in selected lower permeable zones to attain treatment.

Limited-Access Bioremediation in a Factory Setting
Farnsworth, D.R., W.A. Murray, and D.L. Bronson.
Proceedings of the Annual International Conference on Soils, Sediments, Water and Energy, Vol 15 Article 2, 7 pp, 2010

At a factory in New Hampshire, TCE released through a storm-water outfall pipe contaminated the groundwater. Tight soils, shallow water table, access limitations, and a pending property sale complicated the cleanup. Due to the low permeability of the soil, effective introduction of the Hydrogen Release Compound (HRC) required many injection points and applications. After the start of HRC application, VOC levels at the outfall dropped to below the state regulatory standard. The treatment has not interfered with site activities or the sale of the property, and site closure is expected to be completed in a reasonable timeframe.

Loading Rates and Impacts of Substrate Delivery for Enhanced Anaerobic Bioremediation
B. Henry.
ESTCP Project ER-0627, 476 pp, 2010

The author evaluated 15 case studies of different substrates used to stimulate biodegradation of chlorinated compounds: Hydrogen Release Compounds (HRC and HRC-X), vegetable oil (neat and emulsified), whey, molasses, ethanol and lactate, and mulch in permeable biowalls. This report discusses the factors that limit enhanced in situ bioremediation and describes (in Appendix B) a Substrate Design Tool developed in Microsoft Excel to assist the practitioner in evaluating a site for an application of enhanced in situ bioremediation. Substrate Design Tool; ESTCP Cost & Performance Report; 2010 Addendum

Long-Term Performance Assessment at a Highly Characterized and Instrumented DNAPL Source Area Following Bioaugmentation
Schaefer, C., G. Lavorgna, M. Annable, and A. Haluska.
ESTCP Project ER-201428, 167 pp, 2018

In a study of long-term behavior in a TCE DNAPL source area following in situ bioaugmentation in heterogeneous media, monitoring performed up to 3.7 years following active bioremediation showed that biogeochemical conditions remained favorable for reductive dechlorination of chlorinated ethenes despite the absence of lactate, lactate fermentation transformation products, or hydrogen. While ethene levels suggested relatively low dechlorination of the parent TCE and daughter products, CSIA showed the extent of complete dechlorination was much greater than indicated by ethene generation. Results of push-pull tracer testing confirmed that DNAPL remained in a portion of the source area, consistent with soil and groundwater data. Overall results suggest biological processes have the potential to persist to treat chlorinated ethenes for years after active bioremediation ends. Additional information: ESTCP Cost & Performance Report; Conceptual site model paper

A Low-Cost, Passive Approach for Bacterial Growth and Distribution for Large-Scale Implementation of Bioaugmentation
Trotsky, J., R.A. Wymore, M.R. Lamar, and K.S. Sorenson.
ESTCP Project ER-200513, TR-2354-ENV, 585 pp, 2010

The relative pros and cons of active recirculation and low-cost, passive inject-and-drift strategies for large-scale bioaugmentation of TCE in groundwater were evaluated in a side-by-side comparison at the Seal Beach Naval Weapons Station, Seal Beach Site 70, CA. The active and passive approaches were compared in a full-scale TCE source area application. Electron donor was added weekly for the active cell and monthly for the passive cell. After several months of pre-conditioning, a commercially available culture was added. Overall, bacterial growth and dechlorination performance was similar using both approaches, but the active system was more costly. ESTCP Cost and Performance Report

Operation and Analysis of the BEHIVS System at Edwards Air Force Base
P.L. McCarty, S.M. Gorelick, M.N. Goltz, G.D. Hopkins, and F.-J. Eisenberg.
Strategic Environmental Research and Development Program (SERDP). 109 pp, 2003.

This report summarizes the results of operation of the bioenhanced in-well vapor stripping (BEHIVS) system at Edwards AFB in 2001, numerical modeling analysis of the results, study conclusions, and recommendations for application of the BEHIVS system at other sites.

Overview of In Situ Bioremediation of Chlorinated Ethene DNAPL Source Zones
The Interstate Technology & Regulatory Council (ITRC) Bioremediation of DNAPLs Team.
BioDNAPL-1, 89 pp, 2005.

Performance of Full-Scale Enhanced Reductive Dechlorination in Clay Till
Damgaard, I. , P.L. Bjerg, C.S. Jacobsen, A. Tsitonaki, H. Kerrn-Jespersen, and M.M. Broholm.
Ground Water Monitoring & Remediation 33(1):48-61(2013)

Enhanced reductive dechlorination was implemented by direct-push injection of molasses and dechlorinating bacteria at a low-permeability clay till site contaminated with chlorinated ethenes (Gl. Kongevej, Denmark ). After 4 years of remediation, the formation of degradation products, the presence of Dehalococcoides spp., and the isotope fractionation of TCE, cis-DCE, and VC demonstrated the degradation of chlorinated ethenes in the clay till matrix as well as in sand lenses, sand stringers, and fractures. Bioactive sections of up to 1.8 m had developed in the clay till matrix, while sections where degradation was restricted to narrow zones around sand lenses and stringers were also observed. An average mass reduction of 24% was estimated after 4 years of remediation. Model simulation scenarios indicate that a mass reduction of 85% can be obtained within ~50 years without further increase in the narrow reaction zones if no donor limitations occur at the site. Additional information: I. Damgaard Ph.D. thesis (2012); Broholm et al. (2012); Design Tool

Pilot-Scale Demonstration of a Two-Stage Methanotrophic Bioreactor for Biodegradation of Trichloroethene in Groundwater: Emerging Technology Summary
U.S. EPA, Superfund Innovative Technology Evaluation (SITE) Program.
EPA 540-S-93-505, 5 pp, 1993.

Post-Remediation Evaluation of EVO Treatment: How Can We Improve Performance?
Borden, R.C.
ESTCP Project ER-201581, 151 pp, 2017

Field, lab, and design evaluations of emulsified vegetable oil (EVO) use for enhanced reductive dechlorination (ERD) of TCE contamination at two sites at the former Naval Training Center Orlando are presented. Although the remediation systems at both sites initially achieved substantial reductions in TCE concentrations, concentrations of cDCE and VC increased in some wells due to TCE degradation and remain elevated. Results from the project evaluations were used to identify the reasons for the ERD systems' failure to meet cleanup goals and to develop new approaches and procedures to improve performance. Additional information: Excel Spreadsheet Design Tool

Project SABRE: Source Area BioRemediation
CL:AIRE (Contaminated Land: Applications in Real Environments), London, UK. SABRE Bulletins 1-6, Sep 2010

Project SABRE began in October 2004 and ran through 2009 at a former chemical manufacturing plant in the East Midlands. A multidisciplinary team from the UK, USA, and Canada undertook the 5-year collaborative project to demonstrate that in situ enhanced anaerobic bioremediation can result in effective treatment of chlorinated solvent DNAPL source areas—in this case, TCE. The project team also sought to improve related site investigation tools and understanding of subsurface processes. Enhanced bioremediation was implemented through introduction of DNAPL-partitioning soya oil emulsion (SRS(tm), a commercial product provided by Terra Systems Inc.) to the source zone as a source of electron donor at the DNAPL:water interface. As one of the most highly instrumented field-scale groundwater test facilities constructed anywhere in the world, the SABRE test cell provided effective containment of groundwater in the sandy gravel aquifer enclosed within the cell, which enabled the field trials to be conducted with a constrained flow field, controlled residence times, and relatively accurate quantification of mass fluxes.

Push-Pull Tests for Evaluating the Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons: ESTCP Cost and Performance Report
Environmental Security Technology Certification Program, NTIS: ADA468544, 46 pp, 2006

Single-well push/pull test methods were demonstrated at Fort Lewis Logistics Center (using toluene as a cometabolic growth substrate) and McClellan AFB (during cometabolic air sparging with propane as a growth substrate) to determine (1) the transport characteristics of nutrients, substrates, and CAHs and their transformation products; (2) the capability of indigenous microorganisms to utilize selected substrates and transform targeted contaminants and surrogate compounds; (3) the rates of substrate utilization and contaminant transformation; and (4) the combinations of injected nutrients and substrates that maximize rates of contaminant transformation.

Principles and Practices of Enhanced Anaerobic Bioremediation of Chlorinated Solvents
2004. Air Force Center for Environmental Excellence (AFCEE), 457 pp.

This document was published by the Air Force, Navy and the DoD Environmental Security Technology Certification Program (ESTCP). The objective of this Principles and Practices document is to describe the state of the practice of enhanced anaerobic bioremediation. The scientific basis of enhanced anaerobic bioremediation is explained, and relevant site selection, design, and performance criteria for various engineered approaches in current practice are discussed. 2010 Addendum: Loading Rates and Impacts of Substrate Delivery for Enhanced Anaerobic Bioremediation

Protocol for Enhanced In Situ Bioremediation Using Emulsified Edible Oil
Robert Borden, Solutions-IES.
Environmental Security Technology Certification Program, 100 pp, May 2006

Remedial Action Completion Report (CDRL A001B) and Preliminary Closeout Report, Former Air Force Plant PJKS, Waterton Canyon, Colorado
Air Force Center for Engineering and the Environment, 44 pp, 2013

A pilot study conducted at PJKS in 2004-2005 to evaluate the effectiveness of in situ anaerobic reductive dechlorination (ARD) of TCE and NDMA in bedrock source areas showed a decline in TCE contamination, which in 2006 led to the expansion of an interim corrective measure to stimulate ARD in the D-1 area groundwater plume. Horizontal and vertical injection wells delivered sodium lactate, emulsified edible oil (EEO), nutrients, and Dehalococcoides (dhc) to the Fountain Formation aquifer. In 2008, two full-scale biobarriers were constructed via injection of EEO, sodium lactate, and dhc into direct-push boreholes to target the alluvial transition groundwater areas, provide a barrier to plume migration, and further deplete TCE contamination in the downgradient plume. A technical impracticability waiver is recorded in the ROD for NDMA in the crystalline bedrock due to geological and technological limitations, although the VOCs in the bedrock are expected to meet MCLs. Additional information: PJKS EE/CA (2005); Focused Feasibility Study (2010); Case Study Slides (2012)

A Review of Biofouling Controls for Enhanced In Situ Bioremediation of Groundwater
Environmental Security & Technology Certification Program (ESTCP), Project ER-0429, 62 pp, 2005

Solar-Powered Remediation and pH Control: ESTCP Cost and Performance Report
ESTCP Project ER-201033, 73 pp, 2017

The primary project goal was to demonstrate a solar-powered technology—Proton Reduction Technology (PRT)—to generate hydrogen in situ and reduce aquifer acidity to promote reductive dechlorination. During operation, PRT uses a low voltage potential applied across electrodes installed within an aquifer to impress a direct current in the subsurface. PRT was tested on a plume of dissolved-phase TCE and cis-DCE in a low-pH aquifer at Joint Base McGuire-Dix-Lakehurst, New Jersey. The demonstration used electrodes inserted into PVC wells within the contaminated low-pH aquifer for 507 days of operation coupled with aquifer bioaugmentation to ensure the presence of dechlorinating bacteria to support biodegradation. Solar panels and deep-cycle 12-volt batteries provided electricity to operate the system. PRT resulted in partial reductive dechlorination of CVOCs in the low-pH aquifer, but TCE dechlorination was incomplete under the demonstration conditions, which was attributed to the borderline pH and reducing conditions achieved.

Successful Enhanced Bioremediation and Bioaugmentation of a Carbon Tetrachloride and TCE Groundwater Plume
Zawtocki, C. and M. Bramblett.
In Situ and On-Site Bioremediation 2009: Proceedings of the 10th International In Situ and On-Site Bioremediation Symposium, 5-8 May, Baltimore, Maryland. Battelle Press, ISBN: 9780981973012, 2009

Groundwater at a former specialty chemical facility in the South Carolina Piedmont is contaminated with carbon tetrachloride, TCE, and benzene. In 2007, two pilot tests were conducted to evaluate the use of emulsified oils and a bioaugmentation culture to stimulate anaerobic biodegradation of the carbon tetrachloride and TCE.
View longer abstract.

Technical and Regulatory Requirements for Enhanced In Situ Bioremediation of Chlorinated Solvents in Groundwater
Interstate Technology and Regulatory Council (ITRC). ISB-6, 122 pp, 1998.

Technical Protocol for Using Soluble Carbohydrates to Enhance Reductive Dechlorination of Chlorinated Aliphatic Hydrocarbons
S.S. Suthersan, C.C. Lutes, P.L. Palmer, F. Lenzo, F.C. Payne, D.S. Liles, and J. Burdick.
Environmental Security Technology Certification Program (ESTCP). 173 pp, 2002.

This protocol provides guidance for successful site selection and application of enhanced reductive dechlorination (ERD) technology for remediation of chlorinated hydrocarbons through stimulation by soluble carbohydrates. The ERD technology (patented by ARCADIS) stimulates indigenous microbiological organisms through the engineered addition of electron donors (e.g., molasses, whey, high-fructose corn syrup, lactate, butyrate, benzoate) that contain degradable organic carbon sources.

Use of In-Situ Bioremediation of Trichloroethene to Reduce Long-Term Monitoring and Life Cycle Costs
P. Srivastav, G. Jones, R. Mayer, S. Watson, A. Willmore, and A.S. Reed.
E2S2 2010: Environment, Energy Security, and Sustainability Symposium and Exhibition, 14-17 June 2010, Denver, Colorado. National Defense Industrial Association (NDIA), Abstract 10045, 26 slides, 2010

At Spill Site 32 on Columbus AFB, Columbus, MS, the TCE plume is ~0.5 miles wide by 1 mile long and lies partially under an active flight training runway. A remedial design for in situ enhanced bioremediation was developed to reduce TCE concentrations in 2 hot spots to prevent further migration and reduce the cleanup timeframe. An easily fermentable carbon source (EVO/lactate mixture) and an elevated concentration of actively dechlorinating culture was applied at full scale in the field using direct-push injection of nutrients, culture, and a pH buffer at 442 points. In the first year, TCE was reduced over 90% within the treatment areas, and the estimated cleanup time to reach the MCL throughout the plume was reduced from over 60 years for natural attenuation to less than 10 years using enhanced bioremediation in the hot spots. See longer abstract

Workplan for Enhanced In-Situ Bioremediation Pilot Test for Former Intel Facility, 365 Middlefield Road, Mountain View, California
Weiss Associates. Northeast Mountain View Advisory Council, 240 pp, 2005

In a feasibility study that investigated the remediation potential of in situ bioremediation with Hydrogen Release Compound (HRC), in situ bioremediation with Newman Zone emulsified edible oil, in situ chemical oxidation using permanganate, expansion of the existing ground water extraction and treatment system, and excavation of impacted saturated soils, in situ bioremediation with emulsified oil was identified as the most appropriate remedial option for reducing chlorinated hydrocarbons in the ground water of the Intel facility site.

Electrokinetics

Electrokinetics: Technology Overview Report
Liesbet Van Cauwenberghe.
Ground-Water Remediation Technologies Analysis Center, TO-97-03, 21 pp, 1997.

Innovative Technology Summary Report: Lasagna™ Soil Remediation
U.S. DOE, 19 pp, 1996.

Use of Large-Scale Electrokinetic and ZVI Treatment for Chlorinated Solvent Remediation at an Active Industrial Facility
Athmer, C.J.
Remediation Journal 24(4):41-51(2014)

A Lasagna™ system, which combines electrokinetic and ZVI technologies, uses a direct current electrical field to mobilize contaminants via electroosmosis and soil heating. The contaminants are intercepted and reduced in situ using treatment zones containing ZVI. Lasagna™ was implemented for soils contaminated with chlorinated solvents, including DNAPL, at an active industrial site in Ohio . The remediation systems were placed in tight clay soils beneath traffic areas without interruption to facility production. In the moderately contaminated soils around the actively treated source areas, a grid of ZVI-filled boreholes was installed for passive treatment of residual contamination. The active systems removed 80% of the TCE mass, while the passive ZVI borings continue to reduce the TCE. Cleanup goals have been met, and the site is now in monitoring-only mode to track contaminant attenuation. Additional information: 35 slides

Flushing Technologies (Cosolvent/Alcohol Flooding, Surfactant Flushing)

AATDF Technology Practices Manual for Surfactants and Cosolvents
Advanced Applied Technology Demonstration Facility for Environmental Technology (AATDF) Program, TR-97-2, 1997.

Cyclodextrin-Enhanced In Situ Removal of Organic Contaminants From Groundwater at Department of Defense Sites. Cost and Performance Report
2004. Environmental Security Technology Certification Program (ESTCP) Project CU-0113, 101 pp.

In-Situ Decontamination of Sand and Gravel Aquifers by Chemically Enhanced Solubilization of Multiple-Compound DNAPLs with Surfactant Solutions: Phase 1 - Laboratory and Pilot Field-Scale Testing and Phase 2�Solubilization Test and Partitioning and Interwell Tracer Tests
U.S. DOE, Washington, DC. DOE/MC/29111-01, 625 pp, 1997.

Manual of Subsurface Restoration: Contaminant Flushing With Surfactants and Cosolvents
Donald M. Lowe, (ed.).
Ann Arbor Press, ISBN: 1575041081, 1998.

Surfactant-Enhanced Aquifer Remediation (SEAR) Design Manual
Naval Facilities Engineering Service Center. NFESC Technical Report TR-2206-ENV, 110 pp, 2002.

Surfactant-Enhanced Aquifer Remediation (SEAR) Implementation Manual
Naval Facilities Engineering Service Center. NFESC Technical Report TR-2219-ENV54, 54 pp, 2003.

Surfactant-Enhanced DNAPL Remediation: Surfactant Selection, Hydraulic Efficiency, and Economic Factors
D.A. Sabatini, R.C. Knox, J.H. Harwell.
EPA 600-S-96-002, 15 pp, 1996.

Surfactants and Cosolvents for NAPL Remediation: a Technology Practices Manual
D.F. Lowe, C.L. Oubre, C.H. Ward (eds.).
Lewis Publications, Boca Raton, FL. ISBN: 0-8493-4117-5. 448 pp, 1999.

Technical and Regulatory Guidance for Surfactant/Cosolvent Flushing of DNAPL Source Zones
Interstate Technology & Regulatory Council (ITRC). DNAPLs-3, 151 pp, 2003.

Technology Overview Report: In Situ Flushing
Diane S. Roote.
Ground-Water Remediation Technologies Analysis Center (GWRTAC). TO-97-02, 24 pp, 1997.

Technology Status Report: In Situ Flushing
Diane S. Roote.
Ground-Water Remediation Technologies Analysis Center (GWRTAC). TS-98-01, 212 pp, 1998

Well Injection Depth Extraction (Wide) Soil Flushing. Innovative Technology Summary Report
U.S. DOE, Ohio Field Office, Ashtabula Environmental Management Project, Ashtabula, OH.
DOE/EM-0577, 30 pp, 2001.

In Situ Chemical Oxidation

Case Study Comparison of Multiple Activation Methods for Sodium Persulfate ISCO Treatment
G. Cronk.
Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 19-22, 2008, Monterey, California. Battelle Press, Columbus, OH. 8 pp, 200

Six brief in situ chemical oxidation (ISCO) case studies (full and pilot scale) from sites in California illustrate the use of different methods--hydrogen peroxide, ferrous or chelated iron, alkaline conditions (high pH)--for persulfate activation. Good to excellent contaminant reductions (generally >85%) were achieved in all 6 cases for contaminants such as 1,4-dioxane and chlorinated solvents (2), a mixed chlorinated solvent plume (1), methylene chloride DNAPL (1), gasoline-range hydrocarbons (1), and benzene (1).

Controlled Vadose Zone Saturation and Remediation (CVSR) Using Chemical Oxidation
Cronk, G., S. Koenigsberg, B. Coughlin, M. Travers, and D. Schlott.
The 7th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 24-27, 2010. Battelle Press, Columbus, OH. 8 pp, 2010

CVSR was implemented with ISCO at an active industrial site in Illinois to address PCE, TCE, methylene chloride, ethylbenzene, toluene, and total xylenes in the soil. Alkaline-activated sodium persulfate using sodium hydroxide was applied to shallow soils to a depth of 15 ft. The vadose zone soils were saturated using a combination of vertical injection wells, an infiltration gallery, and horizontal injection wells installed beneath two small buildings. Due to the presence of low permeability silts and clays, the ROI of each vertical injection well was ~10 ft. About 4,700 gallons of sodium hydroxide (25% concentration) and 11,500 lbs of sodium persulfate were injected over a 27-day period in November/December 2008. A second injection of activated persulfate was performed in Area 1 in August 2009. The concentrations of the compounds of concern all decreased by 88 to 99% within 180 days after treatment.

Cooperative Technology Demonstration: Polymer-Enhanced Subsurface Delivery and Distribution of Permanganate
Crimi, M., J.A.K. Silva, and T. Palaia.
ESTCP Project ER-200912, 322 pp, Feb 2013

The use of a water-soluble polymer with permanganate for in ISCO of organic contaminants was demonstrated to improve the sweep efficiency of permanganate through heterogeneous media. In two injection wells at Marine Corps Base Camp Lejeune's TCE-contaminated Site 88, permanganate only was delivered to the control well, while permanganate and the polymers xanthan gum (for improved sweep) and sodium hexametaphosphate (for manganese dioxide by-product control) were delivered to the second well. The sweep efficiency doubled from 37% in the permanganate-only plot to 67% in the permanganate + polymer plot with one pore volume of amendment delivered. With polymer, preferential flow was reduced with no negative impact to injection pressure. Total costs of polymer-amended ISCO above traditional ISCO are estimated at ~$58 per cubic meter of treated media. Additional benefits of implementation can include lower injection volume, less field time, and lower probability of contaminant rebound. Additional information: Project ER-200912 Final Debrief; ESTCP Cost & Performance Report

Engineering Evaluation/Cost Analysis: Properties Immediately Adjacent to Marina Cliffs/Northwestern Barrel Site South Milwaukee, Wisconsin
U.S. EPA Region 5, 136 pp, 2006

This report contains information on the implementation and results of a full-scale in situ chemical oxidation (ISCO) pilot study conducted using the BIOX(r) technology in three areas affected by benzene, PCE, TCE, vinyl chloride, and xylenes.

Engineering Issue Paper: In Situ Chemical Oxidation
EPA 600-R-06-072, 2006

This issue paper was produced by the EPA Risk Management Research Laboratory and the Engineering Forum. It provides an up-to-date overview of ISCO remediation technology and fundamentals, and is developed based on peer-reviewed literature, EPA reports, web sources, current research, conference proceedings, and other pertinent information.

Expediting Cleanup of a Pump and Treat Site by Use of Chemical Oxidation Technology
G. Cronk and L. Stevens.
Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 19-22, 2008. Battelle Press, Columbus, OH. 11 pp, 2008

At the U.S. Gypsum Company site in La Mirada, CA, a pump-and-treat system has operated for over 10 years (1996 to 2006), successfully reducing the size of two co-mingled contaminant plumes, one with benzene and one with dissolved-phase TCE. To expedite this cleanup, two ISCO technologies were implemented. For the TCE plume, a pilot test using potassium permanganate achieved TCE reductions ranging from 85 to 100% in 120 days, and a full-scale permanganate treatment is planned to address the remaining TCE plume. For the benzene plume, injections of catalyzed hydrogen peroxide and activated sodium persulfate resulted in a reduction in benzene concentrations from a pre-ISCO maximum of 5,500 µg/L to 98 µg/L, a 98% reduction. Other wells have shown benzene reductions from 96 to 99.9%.

Focused In-Situ Chemical Oxidation of Chlorinated VOCs and 1,4-Dioxane Using Sodium Persulfate in Fine-Grained Soils
K.S. Houston, J. Horst, and G. Wroblewski.
Pollution Engineering, 8 pp, Mar 2009

At a former machining and metal working site where the groundwater is affected by PCE, TCE, 1,1-DCE, and 1,4-dioxane, focused ISCO using sodium persulfate was considered for discrete source mass treatment to expedite mass removal and decrease the operational timeframe, but lab treatability tests indicated that strategic oxidant dosing would achieve the remediation goal. In a field pilot test, effective 1,4-dioxane and VOC treatment was achieved, likely the result of naturally occurring reduced metals (e.g., ferrous iron) that facilitated sulfate radical formation, which also showed that oxidant field loading based solely on lab-determined total oxidant demand of site soil and groundwater slurries can overstate the mass of oxidant required to achieve effective treatment.

Improved Understanding of Fenton-Like Reactions for the In Situ Remediation of Contaminated Groundwater, Including Treatment of Sorbed Contaminants and Destruction of DNAPLs
R.J. Watts, F.J. Loge, and A.L. Teel.
Strategic Environmental Research and Development Program (SERDP), 276 pp, 2006

Investigation of the processes and mechanisms associated with the use of catalyzed hydrogen peroxide propagations (CHP, or modified Fenton's reagent) for ISCO shows that superoxide has a major role in the degradation of highly oxidized contaminants, the destruction of DNAPLs, and the enhanced desorption of hydrophobic contaminants from soils and subsurface solids. The suite of reactive oxygen species generated in CHP reactions, including hydroxyl radical, superoxide, and the strong nucleophile hydroperoxide, provide a near-universal treatment matrix for chemical contaminants. This report discusses the applicability of modified Fenton's to the destruction of carbon tetrachloride, chloroform, benzo[a]pyrene, hexadecane, 1,1,1-TCA, 1,2-DCA, PCE, and TCE.

Independent Review of the X-701B Groundwater Remedy, Portsmouth, Ohio: Technical Evaluation and Recommendations
B.B. Looney, C. Eddy-Dilek, J. Costanza, J. Rossabi, T. Early, K. Skubal, and C. Magnuson.
SRNL-STI-2008-00424, 83 pp, 2008

The review team (1) assessed the performance of an ongoing oxidant-based treatment technology that uses lances to inject catalyzed hydrogen peroxide, (2) provided specific recommendations for DOE and Ohio EPA to consider if oxidant injections are to be continued, and (3) recommended alternatives to the current remediation strategy for the X-701B TCE plume.

Innovative Technology Summary Report: In Situ Chemical Oxidation Using Potassium Permanganate
U.S. DOE. DOE/EM-0496, 35 pp, 1999.

In-Situ Chemical Oxidation to Address Residual VOC Plumes on the Savannah River Site
Seaman, J.C., B. Kramer, J. Kupar, M. Malin, and P.C. Knapp.
Proceedings of the 2011 Georgia Water Resources Conference, April 11-13, 2011, University of Georgia. Abstract only, 2011

A field-scale demonstration was conducted to evaluate ISCO for residual TCE on DOE's Savannah River site. TCE concentrations in the plume ranged from 10 to 40 mg/L. Catalyzed persulfate was injected intermittently over a 10-day period as 10 oxidant batches (~230 g sodium persulfate/L) totaling 4,800 gallons (18,168 L). Quantifiable concentrations of persulfate were detected in observation well 1 (OW1) ~2 weeks after injection, peaking at ~150 mg/L and then slowly decreasing over 295 days of monitoring. Subsequent lab experiments confirmed the somewhat limited mobility of persulfate in the SRS subsurface environment due to sorption in Fe-oxide rich materials. Batch results confirmed the continued effectiveness of persulfate in degrading VOCs in the absence of an activating agent at the relatively low persulfate concentrations (< or = 192 mg/L) observed in OW1. Additional information: 21 slides about this project Laboratory and Modeling Efforts

In Situ Chemical Oxidation Multimedia Training Tool
U.S. Navy, Naval Facilities Engineering Command, Environmental Restoration Technology Transfer, Multimedia Training Tools website, 23 pp.

A variety of toxic organics, including dense nonaqueous-phase liquid (DNAPL), are amenable to destruction or at least partial degradation through chemical oxidation processes initiated by the application of compounds such as potassium permanganate or Fenton's reagent. The most recent advances in the understanding of the application of in situ chemical oxidation (ISCO) for ground-water remediation are presented through this multimedia training tool.

Principles and Practices of In Situ Chemical Oxidation Using Permanganate
R.L. Siegrist, M.A. Urynowicz, O.R. West, M.L. Crimi, K.S. Lowe.
Battelle Press, Columbus, OH, ISBN:1-57477-102-7, 336 pp, 2001.

Record of Decision: Valmont TCE Superfund Site, Luzerne County, Pennsylvania
U.S. EPA Region 3, 151 pp, 2011

In situ treatment of the entire groundwater plume (TCE predominating) will be done by batch injection of a chemical oxidant (e.g., potassium or sodium permanganate) into the bedrock. EPA conducted a pilot study at the site between 2008 and 2010 to evaluate ISCO effectiveness as a stand-alone remedy by injecting a high volume (26,000 lbs) of potassium permanganate slurry into the fractured bedrock. Permanganate was injected as a slurry to increase oxidant residence time within the bedrock fractures and allow continued reaction with VOCs diffusing from the bedrock matrix. Delivery of the slurry was facilitated through pathways opened by hydraulic fracturing. The fracturing process dilated existing bedrock fractures and flushed fine-grained material from the fractures, thus allowing greater volumes of slurry to enter. Results indicated that the residence time of permanganate in the aquifer exceeded 6 months and achieved significant destruction of VOCs in the source area and in the plume. The radius of influence of slurry injection exceeded 160 ft. Additional information: Technology News & Trends, Dec 2010

Sodium Persulfate with Integrated Activator Destroys >99% Of Trichlorethylene in 5 Weeks at a Manufacturing Facility in the Netherlands
Mueller, M., H. Opdam, and J. van Doren.
AquaConSoil 2021, 15-17 June, virtual, abstract only, 2021

Klozur® CR was successfully applied at a former petrol station in northern Italy characterized by groundwater contamination, including hydrocarbons (C<12 ~2,000 µg/L), benzene (~500 µg/L), ethylbenzene (~ 380 µg/L) and MtBE (~ 13,000 µg/L). A total of 4,800 kg of Klozur CR (in a 25% aqueous solution) were injected in two events conducted 15 months apart. Following 18 months after the first application, contaminant concentrations were below the remediation goals in monitoring piezometers in the treatment area. TPH was reduced by >80%, while MtBE was reduced by >90 %. Monitoring data confirmed sustained elevation of oxidation-reduction potential and dissolved oxygen as necessary subsurface conditions to support treatment.

Technical and Regulatory Guidance for In Situ Chemical Oxidation of Contaminated Soil and Groundwater
Interstate Technology & Regulatory Council (ITRC). ISCO-1, 71 pp, 2001.

Technical Report: Subsurface Injection of In Situ Remedial Reagents (ISRRs) within the Los Angeles Regional Water Quality Control Board Jurisdiction
Wilson, S., D. Clexton, C. Sandefur, et al.
In Situ Remediation Reagents Injection Working Group, 46 pp, 2009

This compilation of general tools and best practices provides a reference manual for the planning, design, and field implementation phases of ISCO projects, with a strong emphasis on safety considerations. Specific attention is given to avoiding the visible surfacing of injected ISRR materials, minimizing impact to landscaping, and ensuring no surface pathway for potential ISRR runoff.

Technology Evaluation Report: In Situ Chemical Treatment
Yujun Yin and Herbert E. Allen.
Ground-Water Remediation Technologies Center (GWRTAC). TE-99-01, 82 pp, 1999.

Technology Status Review: In Situ Oxidation
Environmental Security Technology Certification Program (ESTCP), Arlington, VA. 50 pp, 1999.

In situ oxidation involves injection of strong oxidants such as hydrogen peroxide or potassium permanganate into the contaminated subsurface, in some cases with other chemicals that function as catalysts. The oxidants chemically break down CVOCs upon contact to inert materials such as carbon dioxide, chloride, and water.

Tucson International Airport Area Superfund Site
U.S. EPA Region 9 Fact Sheet, 2008

Results of the Analyses for 1,4-Dioxane of Groundwater Samples Collected in the Tucson Airport Remediation Project Area, South-Central Arizona, 2006-2009 (2009)

The site contains 7 major project areas: Air Force Plant 44 (AFP 44, operated by Raytheon Missile Systems Company), Tucson Airport Remediation Project (TARP), the Airport Property, the Arizona Air National Guard (AANG) 162nd facility, Texas Instruments, Inc. (formerly Burr-Brown Corporation), the former West-Cap property, and West Plume B. The groundwater COCs include TCE, DCE, chloroform, and chromium, and PCBs and metals have been found in some of the site soils. In 2002, 1,4-dioxane was discovered in several project areas. In July 2008, the Air Force installed an advanced oxidation process (AOP) treatment system for 1,4-dioxane. The AOP system injects hydrogen peroxide and ozone at multiple points into the mixing chamber with the contaminated water. The reaction of the water and chemicals together rids the contaminated water of both 1,4-dioxane and TCE. The addition of the new system will ensure TARP continues to meet its goal of no more than 3 ppb of 1,4-dioxane in drinking water. The TARP treatment plant has been in operation since 1994, using air stripping technology and carbon filtration to remove TCE from the groundwater. As of March 2008, 29.5 billion gallons of water have been cleaned and 3,557 pounds of TCE have been removed. This system provides clean drinking water to 50,000 residents of Tucson.

XPERT Design and Diagnostics' (XDD) In Situ Chemical Oxidation Process Using Potassium Permanganate (KMnO4): Innovative Technology Evaluation Report
U.S. EPA, National Risk Management Research Laboratory, Cincinnati, OH.
EPA 540-R-07-005, 96 pp, 2007

Describes an evaluation of the XDD ISCO process using potassium permanganate at a site in Hudson, NH, to address chlorinated volatile organics, including PCE, TCE, cDCE, 1,1,1-TCA, and 1,1-DCA.

In Situ Reduction

Case Studies: Closing Solvent Sites Using Activated Carbon Impregnated with Iron
Harp, T.A., LT Environmental, Inc, Arvada, CO.
Proceedings of the Annual International Conference on Soils, Sediments, Water and Energy 14(18):217-228(2009)

BOS 100(r), an innovative remediation product, is an activated carbon impregnated with an iron salt and pyrolized into nano-sized deposits of porous, metallic iron. The carbon catalyst adsorbs chlorinated contaminants, and the iron provides treatment via reductive dechlorination. This paper presents three case studies of application to sites with dissolved-phase CVOCs to document the effectiveness of the technology. (1) Full-scale treatment of TCE in 2005 with staggered injections of the product. (2) Full-scale cleanup of PCE at a former drycleaner in 2008 with staggered injections of the product. (3) Injection of the carbon slurry in 2007 as a PRB to intercept a PCE plume at an active drycleaner.

Cost and Performance Report: Nanoscale Zero-Valent Iron Technologies for Source Remediation
A. Gavaskar, L. Tatar, and W. Condit.
Naval Facilities Engineering Service Center, Port Hueneme, CA. CR-05-007-ENV, 54 pp, 2005.

This cost and performance report is the result of a comparative evaluation of the performance of zero-valent iron injection at three Navy sites: Hunters Point Shipyard (micron-scale particles), and Naval Air Station Jacksonville and Naval Air Engineering Station Lakehurst (nanoscale particles).

Demonstration of In Situ Dehalogenation of DNAPL Through Injection of Emulsified Zero-Valent Iron at Launch Complex 34 in Cape Canaveral Air Force Station, Florida: Innovative Technology Evaluation Report
A. Gavaskar, W.-S. Yoon, M. Gaberell, E. Drescher, L. Cumming, J. Sminchak, J. Hicks, B. Buxton, M. Morara, T. Wilk, and L. Bahn.
EPA 540-R-07-006, 223 pp, 2004

The field demonstration of emulsified zero-valent iron (EZVI) technology for treatment of a TCE DNAPL source zone began at Launch Complex 34 in June 2002 and ended in January 2003. Long-term ground-water monitoring results collected in December 2003 and March 2004 indicate that the EZVI treatment had a long-lasting effect on the chlorinated contaminants in the subsurface. TCE, cis-1,2-DCE, and (eventually) VC levels declined sharply in the one year following EZVI injection, and ethene levels increased substantially.

Field Application of a Reagent for In Situ Chemical Reduction and Enhanced Reductive Dichlorination Treatment of an Aquifer Contaminated with Tetrachloroethylene (PCE), Trichloroethylene, 1,1-Dichloroethylene, Dichloropropane and 1,1,2,2-Tetrachloroethane (R-130)
Leombruni, A., M. Mueller, A. Seech, and D. Leigh.
Environmental Engineering and Management Journal 19(10):1791-1796(2020)

Groundwater at an abandoned industrial area near Bergamo, Italy, was contaminated by PCE (>100 µg/L) and, to a lesser extent, TCE, DP, and 1,1,2,2-tetrachloroethane (R-130). EHC^® Liquid was selected to remediate the groundwater. The reagent was provided as EHC^® Liquid Mix (a soluble organo-iron salt) and ELS^® Microemulsion (a lecithin-based carbon substrate), designed to promote both in situ chemical reduction and enhanced reductive dechlorination. The two components were mixed with water and injected into the subsurface. Once in groundwater, EHC Liquid rapidly generated highly reduced conditions, favoring both biotic and abiotic dechlorination reactions. Less than 6 months after the injection of EHC Liquid in the main source area, concentrations of the target contaminants reached the site-specific remediation target values) in the main monitoring piezometers, demonstrating the effective establishment of enhanced biotic and abiotic reducing conditions and degradation of the target compounds.

Final Report Demonstration and Validation of the Horizontal Reactive Media Treatment Well (HRX Well^®) for Managing Contaminant Plumes in Complex Geologic Environments
Divine, C., M. Crimi, and J.F. Devlin. ESTCP Project ER-201631, 186 pp, 2020

The horizontal reactive media treatment well (HRX Well^®) was field-validated at Site 003 at Vandenberg Air Force Base in California. TCE was treated in the well abiotically with zero-valent iron. Total TCE mass discharge reduction was >99.99 % relative to the upgradient well. Significant biologically mediated treatment also occurred, facilitated by the residual guar-based biopolymer drilling fluid. After 436 days, decreases from 50-74% in TCE were observed at four downgradient monitoring wells, and the timing of the first arrival of treated water was consistent with model predictions. For this site, estimated lifecycle HRX Well costs were lower than costs for permeable reactive barrier and pump-and-treat alternatives.

Fracture-Emplacement and 3-D Mapping of a Microiron/Carbon Amendment in TCE-Impacted Sedimentary Bedrock
Bures, G.H., J.A. Skog, D. Swift, J. Rothermel, R. Starr, and J. Moreno.
Proceedings of the Seventh International Conference on Remediation of Chlorinated and Recalcitrant Compounds (Monterey, CA; May 2010). Battelle Press, ISBN: 978-0-9819730-2-9, Paper & presentation D-067, 9 pp + 23 slides, 2010

An in situ pilot remediation project was carried out on behalf of the U.S. Army Corps of Engineers (Omaha District) at the F.E. Warren AFB in Colorado. The pilot featured an innovative application of drilling, fracture emplacement, treatment, and geophysical technologies to mitigate impacts from chlorinated solvents. The former missile site complex is underlain by silty sandstone bedrock sediments affected by TCE >2,000 µg/L and associated VOCs. Pilot tests of biotic and abiotic in situ chemical reduction (ISCR) were conducted in the source area and dissolved plume to evaluate technology performance prior to developing the proposed remedy. The pilot involved the emplacement of over 100 tons of EHC^™, a micro-iron/complex-carbon treatment amendment, into deep bedrock sediments to attain optimal distribution throughout the contaminant plume, including beneath the former Launch and Service Building. The radius of fracture emplacement in the bedrock was up to 60 ft, with a typical fracture overlap of 30 to 50%. Following placement of the amendment, physical, chemical, and microbiological processes combined to create very strong reducing conditions that stimulated chemical and microbiological dehalogenation of the contaminants. View longer abstract. Additional information: Presentation Slides, Field Profile

Geophysical Imaging for Investigating the Delivery and Distribution of Amendments in the Heterogeneous Subsurface of the F.E. Warren AFB
Kelley, B., S. Hubbard, J. Ajo-Franklin, J. Peterson, Y. Wu, E. Gasperikova, B. Butler-Veytia, V. Shannon, and R. Coringrato.
ESTCP Project ER-200834, 80 pp, 2012

In 2009, a remedial action involving hydraulic fracturing and in situ bioremediation was conducted at Spill Site 7, the location of a TCE plume at F.E. Warren AFB. The June 2010 field demonstration involved an evaluation of the progress of in situ bioremediation (HRC[r]) via hydraulic fracturing and the use of geophysical imaging (time-lapse electrical resistivity tomography and seismic datasets) to monitor fracture emplacement and amendment distribution at the site. Additional information: ESTCP Cost & Performance Report

Innovative Injection Technique to Treat DNAPL in Granular and Fine Grained Matrices
Noland, S., R. Boyle, and T.A. Harp.
The Eighth International Conference for Remediation of Chlorinated and Recalcitrant Compounds, Monterey, CA, May 21-24, 2012. Battelle Press, Columbus, OH. 8 pp, 2012

High-energy, low-volume pulses of a water-based suspension of BOS 100^®, a granular activated carbon impregnated with metallic iron, were employed to remediate DNAPL at a large urban industrial facility, with injections facilitated using conventional hydraulic fracturing. Although large portions of the dissolved-phase plume responded to this technique, some areas were resistant, suggesting input from unknown sources. High-resolution sampling indicated the presence of localized thin seams of DNAPL-impacted soils at several locations in the vicinity of the former TCE underground storage tank. A modified "jetting" approach was developed that allowed extremely accurate placement and injectant/soil mixing over a relatively thick zone.

Jet-Assisted Injection of Nano-Scale, Zero-Valent Iron to Treat TCE in a Deep Alluvial Aquifer
Chang, P.R., A.D. Pantaleoni, and D.J. Shenk.
Proceedings of the Seventh International Conference on Remediation of Chlorinated and Recalcitrant Compounds (Monterey, CA; May 2010). Battelle Press, ISBN: 978-0-9819730-2-9, Paper & presentation D-098, 6 pp & 15 slides, 2010

An innovative injection approach was field-tested at a former aerospace manufacturing facility (Unidynamics, Goodyear, Arizona) to overcome significant challenges posed by the low permeability of the soil and depth of the contaminated groundwater. A 10,000-pound psi fracture lance injection tool was used to distribute nano-scale ZVI in a targeted injection interval between 108 to 118 ft bgs. Injection of 1,400 pounds of PolyMetallix(tm) was completed at two injection points spaced 15 ft apart over 3 days. Each injection point had a radius of 30 ft. Groundwater data showed a TCE mass removal efficiency of 82 to 96% within 2 weeks after completion of the injections.

Nanoscale Zero Valent Iron Training Tool
U.S. Navy, Naval Facilities Engineering Command, Environmental Restoration Technology Transfer, Multimedia Training Tools website, 32 pp.

Zero-valent iron (ZVI) is a strong reducing agent. Nanoscale iron particles typically have surface areas up to 30 times greater than larger-sized granular iron and are up to 1,000 times more reactive for the degradation of chlorinated organic compounds. NZVI is ideally suited for treating chlorinated organic compounds and dense nonaqueous-phase liquid (DNAPL) "hot spots" through injection directly into the source area of contamination. A slurry of NZVI can be distributed into the subsurface using a variety of carrying fluids that help the iron powders disperse into the subsurface and create contact between the contaminants and the iron particles. This training tool discusses injection methods, specific aspects of implementation, NZVI economics, advantages and limitations of the technology, and lessons learned.

Permeable Reactive Barrier Downgradient of the Southern Source Area, Former Tecumseh Products Company Site, Tecumseh, Michigan: Construction Documentation Report
U.S. EPA Region 5, 148 pp, 2012

The PRB was installed in May 2011. Site COCs include chlorinated VOCs (mainly TCE, TCA, and daughter products), SVOCs, 1,4-dioxane, metals, cyanide, and PCBs. Where the target treatment zone is relatively shallow, the design called for in situ soil blending to deliver DARAMEND(r) (a pelletized form of controlled-release carbon and ZVI) to the subsurface. The design included the use of injections to deliver ABC(r)+ (a patented mixture of ethyl lactate and glycerin, plus ZVI) to portions of the PRB farther beneath ground surface. ABC(r)+ also was used for shallow injections around an existing sewer pipe. Additional resources: Tecumseh website .

Rapid Source Zone Remediation of TCE in Fractured Bedrock Using High-Flow Injection
Pizarro, D. | DCHWS Design and Construction Spring 2022 Symposium, 30 March-1 April, Philadelphia, PA, 14 slides, 2022

Trap & Treat® BOS 100® was injected in shale fractured bedrock at a commercial site in New Jersey to remediate TCE in fractured bedrock. Efforts focused on treating groundwater in bedrock since chlorinated solvent impacts were not above limits for overburden soils. Transition zone injections were completed by installing Pre-Drill access points for Direct Push Technology injection using high-pressure and high-flow Wanner pumps. Wells were installed with air rotary/HSA, and the vertical interval of interest was left uncased for borehole geophysical tooling, discrete interval (18-inch) sampling via straddle packer, and straddle-packer injection. The custom bedrock injection unit was mobilized to the site to provide effective distribution of BOS 100 in secondary and primary porosities in the bedrock. The project objective for TCE and 1,1-DCE in groundwater was 1 µg/l. BOS 100 slurry was applied within the fracture network of three wells and ten pre-drilled points within the transition zone. Fracture Network Injections were conducted using a bedrock truck unit that provides high flow rates through a narrow (18-inch) straddle packer system. Transition Zone Injections were also conducted using the bedrock truck unit; injections were completed using high flow rates through 2.25" direct-push rods with a custom port injection tip. Injection flow rates of 70 to 100 gals/min were used throughout the project. Before transition and bedrock zone injections, the maximum baseline concentrations for the target contaminants in MW-2 were 73.1 µg/l for TCE and 3.3 µg/L for 1,1-DCE. All monitoring wells within the treatment footprint achieved the project objective of 1 µg/l for TCE and 1,1-DCE in less than 6 months of the injection event.

Remediation of Soil and Groundwater Contaminated with Organic Chemicals Using Stabilized Nanoparticles: Lessons From the Past Two Decades
Cai Z., X. Zhao, J. Duan, D. Zhao, Z. Dang, and Z. Lin.
Frontiers of Environmental Science & Engineering 14(5):84(2020)

This article overviews the fundamental principles on particle stabilization, and the evolution and some recent developments of stabilized nanoparticles for degradation of organic contaminants in soil and groundwater. This paper is Open Access at the Frontiers of Environmental Science & Engineering website.

The Effects of Hydraulic/Pneumatic Fracturing-Enhanced Remediation (FRAC-IN) at a Site Contaminated By Chlorinated Ethenes: A Case Study
Lhotsky, O., J. Kukacka, J. Slunsky, K. Markova, J. Nemecek, V. Knytl, and T. Cajthaml.
Journal of Hazardous Materials 417:125883(2021)

Direct-push pneumatic fracturing combined with the hydraulic delivery of a suspension of milled iron, sulfidated nZVI, and sand in guar gum solution was pilot tested in low-permeability, heterogeneous geology contaminated with PCE (present partially in the free phase in the unsaturated zone). A whey solution was subsequently injected into the fractures as a carbon source for bacteria. Long-term groundwater monitoring indicated that abiotic reduction of PCE and TCE was the dominant remediation process for several months after the injections. A complex microbial consortium developed that could effectively dechlorinate chlorinated ethenes (ClE). The average chlorine number in the groundwater decreased from 3.65 to 1.38 within 2.5 years after the injections, while the average ClE concentration increased from 13.5 to 31.5 mg/L due to substantial acceleration of the ClE mass transfer to the groundwater caused by the treatment.

Third Five-Year Review Report for Boomsnub/Airco Superfund Site, Hazel Dell, Washington
U.S. EPA Region 10, 141 pp, 2013

Cr(VI) and TCE were released to soil and groundwater at this Superfund site during historical commercial chrome plating (Boomsnub) and compressed gas production (Airco). In September 2006, a toe-of-plume pilot study was initiated for in situ reduction of residual contamination in an area believed to be located in the low-permeability silt layer at a depth of ~80-90 ft bgs. EHC-M™, a combination of controlled-release carbon and ZVI particles, was injected into the alluvial aquifer to stimulate reductive dechlorination of TCE and chemical reduction-precipitation of chromium. Post-remediation monitoring indicates EHC-M was effective at reducing TCE and chromium concentrations below cleanup levels. Additional information: Work plan for in situ treatment of areas of residual contamination

Treatment of Chlorinated Hydrocarbon Contaminated Groundwater with Injectable Nanoscale Bimetallic Particles: Lessons Learned
D.S. Liles.
ESTCP Project ER-0017, 8 pp, 2009

The reductive dechlorination of TCE by multiple types of nanoscale zero-valent iron (NZVI) was evaluated using particles obtained from multiple manufacturers. The manufacturing methods used to produce the NZVI particles tested result in particles that fall into two structural categories defined here as particles with amorphous atomic structures and those with crystalline atomic structures. These structural differences can lead to very different properties during the use of the NZVI for reductive dechlorination of TCE. The investigators learned that initial rates of reaction of different batches of iron provided by the same manufacture under the same brand name can differ dramatically, which likely reflects the continuing evolution of the manufacturing technology; each individual batch of iron should undergo kinetics testing as a quality control step before application in the field. Contrary to expectation, in almost all cases the TCE removal performance of NZVI particles was better in the non-palladized form compared to palladized particles. This brief report documents other lessons learned in the study and from the literature concerning NZVI reactivity, longevity, injectability, and potential for treatment of DNAPL.

Zero Valent Iron Injection Tool
U.S. Navy, Naval Facilities Engineering Command, Environmental Restoration Technology Transfer, Multimedia Training Tools Website, 61 pp, 2011

This Web tool focuses on ZVI injection for treating chlorinated solvents and is designed to assist RPMs in the development and implementation of effective ZVI injection applications. Users can learn about 1) the scientific concepts related to the use of ZVI and the types of ZVI media available for injection, 2) different injection methods used to deliver ZVI to the subsurface, 3) which factors influence the applicability of the ZVI technologies, and 4) lessons learned during ZVI implementation.

Monitored Natural Attenuation

Advancing the Science of Natural and Enhanced Attenuation for Chlorinated Solvents
B.B. Looney, et al.
WSRC-STI-2006-00377, 79 pp, 2006

This document describes the concept of using mass balance as a central framework for attenuation-based remedies and identifies technical contributions to support its use. References to both project documents and pertinent publications in the open literature are provided as sources of technical details.

Application of Monitored Natural Attenuation and Risk-Based Corrective Action at a Chlorinated-Hydrocarbon Contaminated Site for Risk Management
Dai W.C., T.T. Tsai, C.M. Kao, Y.M. Chang, and H.C. His.
Research Journal of Chemistry and Environment 16(3):87-97(2012)

This paper presents a case study of the feasibility of MNA for risk reduction of TCE and 1,1-DCE at a spill site. The objectives were to (1) evaluate the possible exposure routes and human health risks from the contaminated groundwater using tiered risk assessment approach; (2) apply the BIOCHLOR model to assess the effectiveness of natural attenuation for the contaminant plume; (3) apply probability and Monte Carlo analyses to develop more practical remediation goals; and (4) develop a realistic streamlined process and risk-based decision-making strategies for site management.

Characterization and Monitoring of Natural Attenuation of Chlorinated Solvents in Ground Water: A Systems Approach, Revision 1
Tyler Gilmore (PNNL); B.B. Looney (SRNL); et al.
WSRC-STI-2006-00084, 65 pp, Aug 2006

Commonly Asked Questions Regarding the Use of Natural Attenuation for Chlorinated Solvent Spills at Federal Facilities
U.S. EPA, Air Force, Army, Navy, and Coast Guard, [undated].

Compatibility of Alternative Chlorinated Solvent Source Treatment Strategies with Monitored Natural Attenuation
2004. Brian B. Looney and Karen M. Vangelas. WSRC-MS-2004-00236, 22 pp.

Draft Technical Protocol for Characterizing Natural Attenuation of Chlorinated Solvent Ground-Water Plumes Discharging into Wetlands
Environmental Security Technology Certification Program, ESTCP Project CU-9913, 53 pp, 2006

A Decision Flowchart for the Use of Monitored Natural Attenuation and Enhanced Attenuation at Sites with Chlorinated Organic Plumes
Interstate Technology & Regulatory Council (ITRC) Enhanced Attenuation/Chlorinated Organics Team. 13 pp, 2007

The flowchart provides a mechanism for transitioning sites through the remediation process, supports decision-making by regulators and site managers, and can be used to determine site remedial change from MNA to active remediation through enhanced attenuation (EA) technologies. EA is a plume remediation strategy to achieve ground-water restoration goals by providing a "bridge" between MNA and more aggressive methods.

Field-Scale Evaluation of Monitored Natural Attenuation for Dissolved Chlorinated Solvent Plumes
AFCEE, 455 pp, 2009

This report 1) presents a strategy and framework for quantitatively assessing the sustainability of MNA-based remedies for groundwater at chlorinated solvent-impacted sites, 2) provides case-study reviews using existing long-term monitoring data sets from multiple U.S. Air Force sites where chlorinated solvents exceed closure criteria, and 3) summarizes observations and recommendations that were developed when working through the case study examples. The 3 principal components of the sustainability assessment framework described in this report are analysis of plume stability, estimation of remediation timeframes, and estimation of the longevity of specific chlorinated aliphatic hydrocarbon degradation processes.

Framework for Site Characterization for Monitored Natural Attenuation of Volatile Organic Compounds in Ground Water
Pivetz, B.E., D. Abshire, W. Brandon, S. Mangion, B. Roberts, B. Stuart, L. Vanderpool, B. Wilson, and S.D. Acree.
EPA 600-R-12-712, 89 pp, 2012

Site characterization is essential to provide site-specific data and interpretations to determine if site remedial goals can be met with MNA in appropriate remedial time frames, and to provide site-specific data and interpretations to determine the necessary performance monitoring parameters, locations, and frequency for monitoring. A broad overview of technical issues includes development of a conceptual site model, characterization variables, sampling locations and frequencies, problematic issues encountered at MNA sites and approaches to overcome them, and the interpretations related to the MNA decision-making process.

Historical and Retrospective Survey of Monitored Natural Attenuation: Lines of Inquiry Supporting Monitored Natural Attenuation and Enhanced Passive Remediation of Chlorinated Solvents
2004. T.M. McGuire, C.J. Newell, B.B. Looney, and K.M. Vangelas. WSRC-TR-2003-00333, Rev. 1, 96 pp.

Natural and Enhanced Attenuation of Chlorinated Solvents Using RT3D
C.D. Johnson, M.J. Truex, and T.P. Clement.
PNNL-15937, 77 pp, 2006

This document describes the context for applying RT3D (Reactive Transport in 3 Dimensions) to monitored natural attenuation of chlorinated solvent contamination in ground water. It also discusses dechlorination reactions that may occur and the general approach for using RT3D reaction modules (including a summary of the RT3D reaction modules that are available) to model fate and transport of chlorinated solvents as part of MNA or for combinations of MNA and selected types of active remediation.

Natural Attenuation of Chlorinated Solvent Ground-Water Plumes Discharging into Wetlands
M.M. Lorah, D.R. Burris, and L.J. Dyer.
U.S. Geological Survey Scientific Investigations Report 2004-5220, 203 pp, 2005

Section 4 of this report introduces the "Draft Technical Protocol for Characterizing Natural Attenuation of Chlorinated Solvent Ground-Water Plumes Discharging into Wetlands" as an addendum to AFCEE's 1996 Chlorinated Solvent Natural Attenuation Protocol.

Natural Attenuation of Chlorinated Solvents in Groundwater: Principles and Practices
Interstate Technology and Regulatory Council (ITRC). ISB-3, 123 pp, 1999.

Proceedings of the Symposium on Natural Attenuation of Chlorinated Organics in Ground Water
EPA 540-R-97-504, 198 pp, 1997.

Providing Additional Support for MNA by Including Quantitative Lines of Evidence for Abiotic Degradation and Co-metabolic Oxidation of Chlorinated Ethylenes
Wiedemeier, T.H., J.T. Wilson, D.L. Freedman, and B. Lee.
ESTCP Project ER-201584, 632 pp, 2017

This report shows that an inexpensive downhole sonde (probe) can be used in existing 2- and 4-inch PVC groundwater monitoring wells to quantify magnetic susceptibility of aquifer material. Objectives are to (1) provide a method to readily and inexpensively acquire the magnetic susceptibility data required to evaluate the abiotic degradation of TCE by magnetite in aquifer materials using existing non-metallic groundwater monitoring wells, and (2) provide a method to readily and inexpensively acquire the data required to evaluate and quantify the rate constant for aerobic biological co-oxidation of TCE. Additional information: ESTCP Cost and Performance Report

Scenarios Evaluation Tool for Chlorinated Solvent MNA
M.J. Truex, C.J. Newell, B.B. Looney, and K.M. Vangelas.
WSRC-STI-2006-00096, Revision 2, 194 pp, 2007

This approach presents a framework that links the MNA evaluation and associated decision logic to key site characteristics and known NA phenomena. The tool consists of a user's guide and 13 scenarios built around general site and hydrogeologic conditions.

Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Groundwater
U.S. EPA, Office of Research and Development.
EPA 600-R-98-128, 248 pp, 1998.
Contact: John T. Wilson, wilson.johnt@epa.gov

Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites
EPA 9200.4-17P, 41 pp, 1999.
Contact: Hal White, white.hal@epa.gov

Using Advanced Analysis Approaches to Complete Long-Term Evaluations of Natural Attenuation Processes on the Remediation of Dissolved Chlorinated Solvent Contamination
J.S. Brauner, D.C. Downey, and R. Miller.
SERDP Project ER-1348, 462 pp, 2008

This report presents a strategy and framework for quantitatively assessing the sustainability of MNA-based remedies for groundwater at chlorinated solvent sites and summarizes observations and recommendations developed when working through the case studies. The case study reviews use existing long-term monitoring data sets from U.S. Air Force sites where chlorinated solvents exceed closure criteria. The described methods can also be used for the assessment of active remedies.

Permeable Reactive Barriers

Amendment Delivery Methodology for Permeable Reactive Barrier (PRB) Installation in Challenging Lithology at Shaw AFB
Simpson, G. | DCHWS East 2022 Spring Symposium, 30 March-1 April, Philadelphia, PA, 17 slides, 2022

The Shaw AFB, Environmental Restoration Program, has delivered several innovations, earning praise from the base leadership and the state regulatory agency. An innovative project was conducted when the leading edge of a TCE/PCE plume, that the main pump-treat-injection system could not contain, migrated 1.5 miles beyond the base boundary. A permeable reactive treatment barrier (PRB), 650 ft long, 20 ft wide, and ~30 ft thick, specifically designed to degrade chlorinated solvents, was installed about 100 feet below ground surface. The PRB was installed using the pre-drill technique GeoTap™, which used augers, air rotary or roto sonic techniques to total depth, a bentonite backfill, and direct push through the bentonite using direct push technology. Within the confines of the treatment barrier, BOS 100® aqueous slurries were injected into 130 temporary injection points, proactively intercepting and treating the plume's leading edge to prevent further uncontrolled impacts to downgradient parcels. The first semi-annual performance monitoring report recorded an average 38% reduction in TCE/PCE levels passing through the 20-year barrier.

A-Zone Aquifer ZVI Permeable Reactive Barrier Project, Hookston Station Site, Pleasant Hill, California: Final Construction Report
GeoSierra Environmental, Inc.
California Regional Water Quality Control Board, San Francisco Bay Region. 45 pp, Sep 2009

An iron PRB was installed in 2009 at an off-site location near the Hookston Station site to degrade TCE, cis-1,2-DCE, VC, and 1,1-DCE in site groundwater and limit their migration downgradient. Constructed using azimuth-controlled vertical hydrofracturing technology, the PRB consists of one continuous reactive zone of ZVI ~480 feet in length and ~32 feet in vertical height. Additional information: 2017 Status report ; CRWQCB Project Page

Artesian Treatment Vessels: A Sustainable In Situ Remediation System (Abstract)
Suthersan, S., M. Schnobrich, K. Mancini, C. McLaughlin, and S. Potter.
Ground Water Monitoring & Remediation 32(1):37-42(2012)

An innovative, sustainable remediation system was implemented to address historical TCE impacts in groundwater at the Fort Gordon Military Reservation near Augusta, GA. The TCE plume travels with ambient groundwater flow downhill toward a receiving stream. At the base of the hill, artesian groundwater conditions lift the plume toward the stream and surrounding flood zone. Remedy selection for the groundwater was challenged by the tight geologic formation and unique hydraulic conditions, as well as the sensitive ecology of the area, which limited site access. In August 2011, the contractor installed a novel artesian treatment vessel (ATV) system requiring no energy inputs or mechanical moving parts in a network of extraction wells along the floodplain of the receptor stream. The vessels are installed below land surface; the wells are screened in the core of the plume; and the differential upward pressure between the aquifer and the land surface conveys the groundwater through a bed of liquid-phase GAC within the vessel to remove the dissolved TCE. Treated groundwater is discharged and directed through a gravel diffusion bed. On the basis of the average influent TCE concentration of 100 µg/L, a flow rate of 3 gpm, and the total volume of carbon within each ATV (270 lbs), the maximum carbon life for each ATV is estimated to be ~6 years.

Attenuated Anaerobic Dechlorination of Groundwater Using HRC®. Mactec - Harding ESE: Demonstration Bulletin
U.S. EPA, Risk Management Research Laboratory, Cincinnati, OH.
EPA 540-R-08-003, 2 pp, 2008

An in situ PRB was designed that utilizes Hydrogen Release Compound (HRC®) to treat ground water contaminated with chlorinated compounds. A demonstration of this technology was conducted in 2000 near the Fisherville Mill brownfields site in South Grafton, MA, to determine its effectiveness in eliminating TCE and daughter products from the ground water. The cleanup criteria were not achieved at the downgradient monitoring wells over a period of 2 years despite extensive conversion of TCE to DCE.

Contamination Movement around a Permeable Reactive Barrier at Solid Waste Management Unit 12, Naval Weapons Station Charleston, North Charleston, South Carolina, 2009
Vroblesky, D.A., M.D. Petkewich, and K.J. Conlon.
U.S. Geological Survey Scientific Investigations Report 2010-5086, 84 pp, 2010

Chlorinated VOC (PCE, 1,1,1-TCA, TCE, cDCE, VC, 1,1-DCE, 1,2-DCA, and 1,1-DCA) groundwater contamination at SWMU 12 at the Naval Weapons Station Charleston, SC, is being addressed in part by a ZVI PRB 130 ft long and 3 ft wide installed in December 2002. In early 2004, groundwater contaminants began moving around the southern end of the PRB. USGS is monitoring and documenting the interaction of PRB and groundwater. Additional information: 2004-2006 Report 2006-2007 Report 2008 Report

Development of Permeable Reactive Barriers (PRB) Using Edible Oils
R.C. Borden.
SERDP Project ER-1205, 159 pp, 2008

A detailed field pilot test was conducted to evaluate the use of an emulsified oil biobarrier to enhance the in situ anaerobic biodegradation of perchlorate and chlorinated solvents in groundwater. The biobarrier was installed by injecting 380 L of commercially available soybean oil-in-water emulsion through 10 direct-push injection wells over a 2-day period. Field monitoring results over a 2.5 year period following emulsion injection indicates the oil injection generated strongly reducing conditions in the oil-treated zone with depletion of dissolved oxygen, nitrate, and sulfate, and increases in dissolved iron, manganese, and methane. Perchlorate at 3,100 to 20,000 µg/L was degraded to below detection (<4 µg/L) in the injection and nearby monitor wells within 5 days of injection. Two years after the single emulsion injection, perchlorate was less than 6 µg/L in every downgradient well compared to an average upgradient concentration of 13,100 µg/L. Emulsion injection stimulated reductive dechlorination of 1,1,1-TCA, PCE, and TCE during groundwater migration through the biobarrier but did not reduce them to target treatment levels.

Electrically Induced Redox Barriers for Treatment of Groundwater
T. Sale, M. Petersen, and D. Gilbert.
Environmental Security Technology Certification Program (ESTCP), CU-0112, NTIS: ADA438421, 187 pp, 2005

Closely spaced permeable electrodes can be installed through a ground-water contaminant plume in the format of a permeable reactive barrier, called an e-barrier. An e-barrier was installed at F.E. Warren Air Force Base in August 2002 in the path of a shallow alluvial TCE plume. This report documents results from a three-year collaboration between ESTCP and Colorado State University on the development and testing of this innovative electrolytic approach for managing redox-sensitive contaminants in ground water.

Electronically Induced Redox Barriers for Treatment of Groundwater at F.E. Warren Air Force Base, Wyoming (2007)
Federal Remediation Technology Roundtable, Cost & Performance Case Study Database.

Evaluating Long-Term Impacts of Soil-Mixing Source-Zone Treatment Using Cryogenic Core Collection
Olson, M., W. Clayton, T. Sale, S. De Long, M. Irianni-Renno, and R. Johnson.
ESTCP Project ER-201587, 232 pp, 2017

This project focused on DNAPL source zone remediation using soil mixing with ZVI and bentonite, a technology referred to as ZVI-clay soil mixing. In November 2012, the soil mixing technology was implemented in a TCE DNAPL source zone at Site 17, Naval Support Facility Indian Head, MD. Four years of remediation performance data indicate that TCE concentrations in soil and groundwater within the treated-soil zone had been reduced by up to four and five orders of magnitude, respectively. Groundwater concentrations in portions of the former-DNAPL source-zone approached MCLs within four years of soil-mixing completion. To assess post-remediation potential for TCE concentrations to rebound, as well as effects of remediation on natural fate and transport processes, high-resolution data representing both high-permeability and low-permeability soil strata were collected using cryogenic core collection.

Field Study of Enhanced TCE Reductive Dechlorination by a Full-Scale Whey PRB
Semkiw, E.S. and M.J. Barcelona.
Ground Water Monitoring & Remediation 31(1):68-78(2011)

At an industrial site located near Battle Creek, Michigan, a full-scale PRB 81 m wide was configured by injection of dairy whey in the downgradient region of a contaminant source zone to enhance the in situ biodegradation of high concentrations (102 to 103 �g/L) of chlorinated ethenes. Ten biannual whey injections were completed in a 3.5-year pilot phase and 1.5-year operational phase, achieving significantly improved and sustained dechlorination at extraction/injection and downgradient wells. The authors discuss carbon substrate cost comparisons and implications for efficient in situ treatment design. Longer abstract

Final Design Guidance for Application of Permeable Reactive Barriers for Groundwater Remediation
Gavaskar, A., N. Gupta, B. Sass, R. Janosy, and J. Hicks.
Environmental Security Technology Certification Program (ESTCP), Arlington, VA. 247 pp, 2000.

Geochemical and Isotope Study of Trichloroethene Degradation in a Zero-Valent Iron Permeable Reactive Barrier: A Twenty-Two-Year Performance Evaluation
Wilkin, R.T., T.R. Lee, M.R. Sexton, S.D. Acree, R.W. Puls, D.W. Blowes, C. Kalinowski, J.M. Tilton, and L.L. Woods.
Environmental Science & Technology 53(1):296-306(2019)

This study provides a 22-yr record of in situ degradation of chlorinated organics by a granular iron PRB. Groundwater concentrations of TCE entering the PRB were as high as 10670 µg/L. Treatment efficiency ranged from 81 to >99%, and TCE concentrations from <1 µg/L to 165 µg/L were detected within and hydraulically down-gradient of the PRB. After 18 years, effluent TCE concentrations remained above the MCL along segments of the PRB exhibiting upward trending influent TCE. Methanogenesis is a sink for inorganic carbon in ZVI PRBs that competes with carbonate mineralization, and this process is important for understanding pore-space clogging and longevity of iron-based PRBs.

In Situ Permeable Reactive Barrier for the Treatment of Hexavalent Chromium and Trichloroethylene in Ground Water:
Contact: David W. Blowes, blowes@sciborg.uwaterloo.ca
Volume 1. Design and Installation, EPA 600-R-99-095A, 128 pp., 1999
Volume 2. Performance Monitoring, EPA 600-R-99-095B, 240 pp., 1999
Volume 3. Multicomponent Reactive Transport Modeling, EPA 600-R-99-095C, 52 pp., 1999
D.W. Blowes, R.W. Gillham, C.J. Ptacek, R.W. Puls, T.A. Bennett.

Long-Term Evaluation of Mulch Biowall Performance to Treat Chlorinated Solvents
Walker Jr., K.L., T.M. McGuire, D.T. Adamson, R.H. Anderson.
Groundwater Monitoring & Remediation [Published online 9 January 2020 prior to print]

Seven mulch biowalls were installed Altus Air Force Base to degrade CVOCs in site groundwater and limit their migration downgradient. Microbial sampling indicated high reducing conditions within the biowalls and favorable conditions for CVOC destruction via microbial reductive dechlorination. High cellulose content of the mulch, elevated total organic carbon content in groundwater and elevated potentially bioavailable organic carbon (PBOC) measurements in soil samples further supports an ongoing, long-lived source of carbon for continued degradation. See longer abstract

Long-Term Performance Assessment of a Permeable Reactive Barrier at Former Naval Air Station Moffett Field
A. Gavaskar, W.S. Yoon, J. Sminchak, B. Sass, N. Gupta, J. Hicks, and V. Lal.
Naval Facilities Engineering Service Center, Port Hueneme, CA. CR-05-006-ENV, 37 pp, 2005.

A pilot-scale PRB filled with zero-valent iron was installed at former Naval Air Station Moffett Field in April 1996 to address chlorinated organics in the ground water. It was monitored periodically for the next 8 years. This report describes the results of the last round of monitoring conducted in July 2004, the relationship of the recent results to those of previous rounds, and implications for the longevity and hydraulic performance of the PRB.

Permeable Reactive Barrier Cost and Performance Report
Naval Facilities Engineering Service Center.
TR-NAVFAC-ESC-EV-1207, 85 pp, 2012

A cost and performance evaluation of three full-scale PRBs installed at Navy sites also considered the remedy footprint for each PRB, using SiteWise(tm) to assess energy consumption, water consumption, generation of criteria air pollutants, and other metrics. The PRBs represent a range of installation techniques, reactive media, and target contaminants: (1) Granular-scale ZVI trench placement at NWIRP Dallas, Texas, for TCE and Cr(VI); (2) Mulch/vegetable oil biowall rock trencher installation at NWIRP McGregor, Texas, for perchlorate and TCE; and (3) Micro-scale ZVI pneumatic fracturing injection at Hunters Point Naval Shipyard, San Francisco, for chloroform and TCE.

Regulatory Guidance for Permeable Barrier Walls Designed to Remediate Chlorinated Solvents, 2nd Edition
Interstate Technology Regulatory Cooperation Work Group (ITRC). PBW-1, 44 pp, 1999.

Report for Full-Scale Mulch Wall Treatment of Chlorinated Hydrocarbon-Impacted Groundwater
2004. Groundwater Services, Inc., Houston, TX. DTIC: ADA422621, 97 pp.

Technical Protocol for Enhanced Anaerobic Bioremediation Using Permeable Mulch Biowalls and Bioreactors
Air Force Center for Engineering and the Environment (AFCEE), 302 pp, 2008

Biowall substrates are typically low-cost materials (mulch, compost). The substrates are mixed with common construction materials (sand, gravel) to prevent compaction and maintain permeability. Amendments can be added to stimulate both biotic and abiotic degradation processes, based on the type of contaminant(s) present and the desired degradation pathway(s) to be stimulated. The technology can be applied in source areas or use groundwater recirculation to capture deeper plumes in an in situ bioreactor configuration. Appendix F provides three example case studies evaluating system performance for remediation of chlorinated solvent contamination in ground water: (1) a pilot-scale dual permeable mulch biowall system to address TCE, cis-DCE, and VC at Seneca Army Depot, NY; (2) a permeable mulch biowall to address TCE and cis-DCE at Altus AFB, OK; and (3) a pilot-scale recirculation bioreactor to address TCE, cis-DCE, and VC at Altus AFB.

Ten Year Performance Evaluation of a Field-Scale Zero-Valent Iron Permeable Reactive Barrier Installed to Remediate Trichloroethene Contaminated Groundwater
D.H. Phillips, T. Van Nooten, L. Bastiaens, M.I. Russell, K. Dickson, S. Plant, J.M.E. Ahad, T. Newton, T. Elliot, and R.M. Kalin.
Environmental Science & Technology 44(10):3861-3869(2010)

Cores from the reactive zone of the Monkstown ZVI PRB were collected in December 2006, 10 years after its installation to address dissolved-phase TCE. At that time, the PRB was still remediating the TCE to below detection limits. This paper describes the condition of the PRB as indicated by the cores and gives projections for its remaining life span.

Phytoremediation

Demonstration-Site Development and Phytoremediation Processes Associated with Trichloroethene (TCE) in Ground Water, Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas
2004. S.D. Shay and C.L. Braun. U.S. Geological Survey Fact Sheet 2004-3087, 4 pp.
Contact: Gregory Harvey, Gregory.Harvey@wpafb.af.mil

The objective of the demonstration project is to determine the effectiveness of eastern cottonwoods (Populus deltoides) in decreasing the mass of dissolved TCE in ground water through chemical, physical, and biological means.

Deployment of Phytotechnology in the 317/319 Area at Argonne National Laboratory-East: Innovative Technology Evaluation Report
U.S. EPA, National Risk Management Research Laboratory, Cincinnati, OH. EPA 540-R-05-011, 88 pp, 2003.
Contact: Steve Rock, rock.steven@epa.gov

In 1999, Argonne National Laboratory-East installed a vegetative cover system and approximately 800 hybrid poplars and willows to contain soil erosion and address chlorinated organics (e.g., PCE and TCE) and tritium in the ground water. The treatment period will continue for up to 20 years. This report presents results from from the first few years of site sampling, monitoring, and modeling.

Evaluation of Phytoremediation for Management of Chlorinated Solvents in Soil and Groundwater
EPA 542-R-05-001, 2005

This document is intended to aid regulators, site owners, consultants, neighbors, and other stakeholders in understanding the proper application of planted systems to remediate groundwater contaminated with halogenated solvents. It assumes a familiarity with environmental and regulatory processes, in general, but little knowledge of plant-based, or 'phytoremediation,' technologies. The document is not intended as regulatory guidance, but as an aid to understanding of the mechanisms of how plants detoxify certain compounds under certain conditions.

FY02 Final Report on Phytoremediation of Chlorinated Ethenes in Southern Sector Seepline Sediments of the Savannah River Site
R.L. Brigmon, F.M. Saunders, D. Altman, E. Wilde, C.J. Berry, M. Franck, P. McKinsey, S. Burdick, F. Loeffler, S. Harris. WSRC-TR-2002-00557, 171 pp., 2003.

This final report details the operations and results of a 3-year TCE Seepline Phytoremediation Project adjacent to Tims Branch in the Savannah River site A/M Area. Phytoreactor 1 was planted with loblolly pines, Phytoreactor 2 with hybrid poplars, Phytoreactor 3 was the non-vegetated control to evaluate natural attenuation progress, Phytoreactor 4 was planted with sterile Vetiver grass, and Phytoreactor 5 was set up as a wetland system.

In Situ Remediation of a TCE-Contaminated Aquifer Using a Short Rotation Woody Crop Groundwater Treatment System: ESTCP Cost And Performance Report (CU-9519)
Environmental Security Technology Certification Program (ESTCP), 81 pp, 2006

A field-scale demonstration was conducted to evaluate the capability of Eastern cottonwood trees to intercept and treat ground water contaminated with TCE and cDCE at the Carswell Golf Course, Fort Worth, TX (formerly Carswell Air Force Base).

Introduction to Phytoremediation
U.S. EPA, National Risk Management Research Laboratory, Cincinnati, OH.
EPA 600-R-99-107, 104 pp, 2000.

Measuring the Removal of Trichloroethylene from Phytoremediation Sites at Travis and Fairchild Air Force Bases
Klein, Heather A., Master's thesis, Utah State University, Logan. 113 pp, 2011

This thesis discusses the quantification of total TCE removal from phytoremediation demonstration plots at the Travis and Fairchild sites using tree coring and volatilization of TCE from leaves, tree trunks, and soil. The removal of TCE was estimated to be 18 g/yr at Fairchild and 839 g/yr at Travis, mainly from leaf and soil volatilization. Based on these estimates, phytoremediation removed 5% and 50% of the mass of TCE in the groundwater at the Fairchild and Travis Air Force sites, respectively.

Phytoremediation at Naval Air Station-Joint Reserve Base Fort Worth, Fort Worth, TX: Cost and Performance Report
U.S. EPA, Office of Superfund Remediation and Technology Innovation, 18 pp, 2005

Phytoremediation Field Studies Database for Chlorinated Solvents, Pesticides, Explosives, and Metals
2004

This document was prepared by Ana Hoffnagle and Cynthia Green, two undergraduate students under internships with United States Environmental Protection Agency (EPA). The paper briefly explains the concept of phytoremediation, details phytoremediation site considerations, and summarizes the successes and failures of field-scale sites where phytotechnologies have been applied or proposed.

Phytoremediation of Groundwater at Air Force Plant 4, Carswell, Texas. Innovative Technology Evaluation Report
2003. U.S. EPA, National Risk Management Research Laboratory, Cincinnati, OH. EPA 540-R-03-506, 100 pp.

Phytoremediation of TCE in Groundwater Using Populus
Chappell, Jonathan. White paper, 1997.

Phytoremediation of TCE-Contaminated Shallow Groundwater
U.S. EPA Website.

Phytotechnology Technical and Regulatory Guidance Document
Interstate Technology and Regulatory Council (ITRC). PHYTO-2, 124 pp, 2001.

Thermal Technologies (Steam Injection, Electrical Heating, In Situ Vitrification)

Application Guide for Thermal Desorption
Naval Facilities Engineering Services Center, Technical Report TR-2090-ENV, 256 pp, 1998.

Cost and Performance Review of Electrical Resistance Heating (ERH) for Source Treatment: Final Report
A. Gavaskar, M. Bhargava, and W. Condit.
Naval Facilities Engineering Service Center, TR-2279-ENV, 133 pp, 2007

The five projects examined in this review took place at four Navy sites and one NASA site, all affected primarily by one or more chlorinated solvent DNAPLs:

Naval Weapons Industrial Reserve Plant Bedford (primarily TCE, plus 1,1,1-TCA, PCE, and breakdown products);
Naval Complex Charleston (PCE and breakdown products);
Former Naval Air Station Alameda (vinyl chloride, DCA, 1,2-DCA, 1,1-DCE, trans-1,2-DCE, cis-1,2-DCE, 1,1,1-TCA, 1,1,2-TCA, TCE, and PCE);
Marine Corps Base Camp Lejeune (1,1,2,2-PCA and TCE); and
Cape Canaveral Air Station (TCE and PCE).
2008 Addendum: U.S. Naval Station Annapolis (TeCA, TCE, 1,1,2-TCA)

Dense Non Aqueous Phase Liquid (DNAPL) Removal from Fractured Rock Using Thermal Conductive Heating (TCH)
Lebron, C.A., D. Phelan, G. Heron, J. LaChance, S.G. Nielsen, B. Kueper, D. Rodriguez, A. Wemp, D. Baston, P. Lacombe, and F.H. Chapelle.
Contract Report CR-NAVFAC ESC-EV-1202, ESTCP Project ER-200715, 427 pp, Aug 2012

This project conducted (1) treatability studies to ascertain a treatment strategy (duration and temperature) for several rock types, (2) modeling to perform screening calculations and carry out mass estimates, and (3) field application of TCH at Naval Air Warfare Center Trenton, a fractured bedrock site. Treatability study results indicate that heating duration had a greater effect on the degree of PCE and TCE mass removal than heating temperature. In 97 days of continuous heating in the field, the average reduction in TCE concentrations was 41-69%; however, the rock matrix did not achieve the targeted temperature in all locations, due mostly to contaminated groundwater influx thru existing fractures. Additional information: ESTCP Cost and Performance Report

Demonstration of Resistive Heating Treatment of DNAPL Source Zone at Launch Complex 34 in Cape Canaveral Air Force Station, Florida: Final Innovative Technology Evaluation Report
Gavaskar, A., et al.
Report No: EPA 540-R-08-004, 133 pp + 241 pp of Appendices, Aug 2008

Effects of Thermal Treatments on the Chemical Reactivity of Trichloroethylene
J. Costanza, J. Mulholland, and K. Pennell.
EPA 600-R07-091, 117 pp, 2007

During experiments conducted to investigate abiotic degradation and reaction product formation of TCE when heated, the amounts of TCE degraded were very small at 120°C (0.01%) and 240°C (6.5%); however, a temperature of 420°C converted as much as 20% of the TCE to carbon dioxide and carbon monoxide.

Electric Resistive Heating at the Former Woodbriar and Westwood Dry Cleaning Facility Brookhill Azalea Shopping Center, Richmond, Virginia
Federal Remediation Technologies Roundtable Cost & Performance Database, 2010

Electrical Resistance Heating of Soils at C-Reactor at the Savannah River Site
M.R. Morgenstern, J.A. Amari, A.M. MacMurray, M.E. Farrar, T.P. Killeen, and R.F. Blundy.
WSRC-STI-2007-00488, 18 pp, 2007

An interim action was selected in 2004 to remove residual TCE source material by ERH technology coupled with SVE, with subsequent monitoring to determine the rate of decrease in the contaminant plume's concentration. A portable ERH/SVE system was deployed at multiple locations around the site. Extensive data were obtained from the first deployment, which heated the vadose zone down to 62 ft bgs over a 60-day period during the summer of 2006 and raised soil temperatures to over 200 degrees F. This treatment extracted 730 lbs of TCE, and subsequent sampling indicated a removal efficiency of 99.4%.

Groveland Wells Numbers 1 and 2 Superfund Site — Operable Unit 2: Final Remedial Action Report
U.S. EPA Region 1, 115 pp, 2011

Construction of an electro-thermal dynamic stripping process (ET-DSP(tm)) system, which combined ERH with SVE and multiphase extraction, was completed in four contiguous in situ thermal treatment areas in August 2010 and operated until February 2011 under EPA and Massachusetts DEP oversight. In total, the cleanup system operated for 192 days, removed 1,300 pounds of VOCS from the vadose and saturated zones, recovered over 18 gallons of pure TCE, pumped and treated over two million gallons of contaminated water and condensate, and extracted over 311 million cubic feet of gaseous vapors. Additional information: Superfund Site Progress Profile; FRTR Cost & Performance Report (2013)

How Heat Can Enhance In-Situ Soil and Aquifer Remediation: Important Chemical Properties and Guidance on Choosing the Appropriate Technique. EPA Ground Water Issue
E.L. Davis.
EPA 540-S-97-502, 18 pp, 1997.
Contact: Eva L. Davis, davis.eva@epa.gov

In Situ Soil and Groundwater Decontamination Using Electric Resistive Heating Technology (Six-Phase Heating)
CL:AIRE Technology Demonstration Project Bulletin 26 (TDP 26), 6 pp, 2008

This bulletin describes the UK's first use of six-phase heating to accomplish source removal of contaminants resulting from historic contamination of a former tools manufacturing site. Investigations at the 2-hectare site showed high levels of dissolved, adsorbed, and free-phase chlorinated hydrocarbons, primarily TCE and vinyl chloride in the soil and TCE in the groundwater. Post-remediation validation sampling results showed final reductions in adsorbed and dissolved-phase TCE concentrations in excess of 98 and 99%, respectively, at the end of 20 weeks. System redesign and continuous close monitoring and optimization throughout the project maintained elevated contaminant extraction rates and allowed considerable savings.

In Situ Thermal Treatment of Chlorinated Solvents: Fundamentals and Field Applications
EPA 542-R-04-010, 145 pp, 2004

This report addresses the use of in situ thermal treatment technologies to treat chlorinated solvents in source zones containing free-phase contamination or high concentrations of contaminants that are either sorbed to soil or dissolved in groundwater in the saturated or unsaturated zone. Information is provided about the following in situ thermal treatments: steam-enhanced extraction, electrical resistive heating, and thermal conductive heating.

New Advancements for In Situ Treatment Using Electrical Resistance Heating
T. Powell, G. Smith, J. Sturza, K. Lynch, and M. Truex.
Remediation, Vol 17 No 2, p 51-70, 2007

At the Fort Lewis, Washington, East Gate Disposal Yard, chlorinated solvents (primarily TCE) and petroleum products are being treated in situ in several contaminant source areas using electrical resistance heating (ERH) and multiphase extraction. This paper updates the progress of the project and discusses data that provide insights into the biotic and abiotic degradation processes observed throughout the range of operating temperatures.

Operational Risk Control & Adaptive Change Management During An Accelerated In-Situ Thermal Treatment Schedule
Geckeler, G. and P. Kakarla. | DCHWS 2021 Design and Construction at Hazardous Waste Sites Virtual Symposium, 29-30 March and 1 April, Virtual, 12 slides, 2021

This presentation highlights adaptive change management in the remedial design at a site with PCE and TCE concentrations as high as 20,000 mg/kg and 1,400 mg/kg, respectively, in the underlying glacial deposits. Site redevelopment plans drove the schedule for remediation. Thermal conduction heating was selected to remediate the contaminated soil, and the volatilized contaminants were extracted, condensed, and treated onsite. Challenges included the presence of subsurface utilities and utility restrictions.

Performance Evaluation of Technology Demonstration for Dynamic Underground Stripping with Hydrous Pyrolysis Oxidation (DUS/HPO) Using a Single Well at Beale Air Force Base
W.S. Yoon, A. Gavaskar, S. McCall, J. Sminchak, S. Carroll, G. Heron, and J. Hicks.
Environmental Security Technology Certification Program (ESTCP), Project ER-0014, 366 pp, Apr 2005

Evaluates a demonstration of DUS/HPO technology using a single well in a groundwater plume of dissolved-phase TCE and PCE at Beale Air Force Base, where contaminant levels showed declining trends—up to 85% in TCE levels and up to 91% in PCE levels—in the treatment zone monitoring wells.

Soil Vapor Extraction Using Radio Frequency Heating: Resource Manual And Technology Demonstration
Donald F. Lowe, Carroll L. Oubre, C.H. Ward (eds.).
CRC Press LLC, Boca Raton, FL. ISBN: 1566704642, 1999.

State of the Practice Worldwide: Complex Installation for In Situ Thermal Remediation Beneath an Active Manufacturing Facility
Heron, G., C. Thomas, C. Crownover, R. Glass, G. Crisp, B.S. Kennington, S. Tarmann, and L. Hidalgo. | Groundwater Monitoring & Remediation [Published online 7 June 2023 before print]
Abstract

This article presents major challenges and solutions for the design, construction, and operation of in situ thermal remediation (ISTR) to treat a vadose-zone TCE source at depths of 60 to 125 ft. below an occupied building at an active manufacturing facility. Innovative methods were required to install 135 steel casings from inside the building, including access limitations, space constraints that required angled borings and pre-modeling of rig mast positions, control measures to manage exhaust from up to four drill rigs operating simultaneously, adjustments to heater wiring to limit temperatures in shallow soils leading to indoor air heating and potential for vapor intrusion and ensure proper positioning and trajectory of closely spaced heaters. The installed heater casings were surveyed using a Devi-Flex™ tool to monitor heater placement in casings that ranged from 87-196 ft. at angles between 90° and 30° from horizontal and periodically needed to compensate for deflections caused by cobbles and boulders. Additional casings were installed to ensure adequate heater spacings in cases where deviations exceeded design parameters. ISTR was conducted using custom-built thermal conduction heaters designed to minimize heat output in the shallow vadose zone and inside the building. Temperatures in the lower vadose zone were maintained near boiling. Cables, vapor extraction pipes, and exhaust ducts were routed overhead and through the building roof to minimize disturbance to manufacturing operations. Three groups of heaters and vapor recovery wells were installed and operated in overlapping periods to expedite remediation.

Steam Enhanced Remediation Research for DNAPL in Fractured Rock: Loring Air Force Base, Limestone, Maine
E. Davis, N. Akladiss, R. Hoey, B. Brandon, M. Nalipinski, S. Carroll, G. Heron, K. Novakowski, and K. Udell.
EPA 540-R-05-010, 194 pp, 2005.
Contact: Eva L. Davis, davis.eva@epa.gov

Steam Injection for Soil and Aquifer Remediation. Ground Water Issue
E.L. Davis.
EPA 540-S-97-505, 16 pp, 1998.
Contact: Eva L. Davis, davis.eva@epa.gov

Technical Performance Evaluation for Phase I of the C-400 Interim Remedial Action at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky
U.S. DOE, Portsmouth/Paducah Project Office.
DOE/LX/07-1260&D1, 190 pp, Aug 2011

Phase I implementation of ERH was conducted as the C-400 IRA remedy to remove VOC contamination, mainly TCE, from subsurface soils. Full operation began at the end of March 2010, and heating ended at the end of October 2010, while SVE continued until all system operations ended on December 4, 2010. Post-operational sampling results show average percent reductions in contaminant concentrations of 95% for soil and 76% for groundwater in the east area, and 99% for both soil and groundwater in the southwest area. Target temperatures were not attained in the electrically resistive deep regional gravel aquifer due to groundwater flow velocity, formation resistivity, and heat loss by convective flow.

Technical Requirements for On-Site Low Temperature Thermal Desorption of Solid Media Contaminated with Hazardous Chlorinated Organics
Interstate Technology and Regulatory Council (ITRC). TD-2, 45 pp, 1997.

Technical Requirements for On-Site Low Temperature Thermal Desorption of Solid Media and Low Level Mixed Waste Contaminated with Mercury and/or Hazardous Chlorinated Organics
Interstate Technology and Regulatory Council (ITRC). TD-3, 68 pp, 1998.

Thermal Desorption Implementation Issues: Engineering Forum Issue Paper
John Blanchard and Robert Stamnes.
EPA 540-F-95-031, 9200.5-224FS, 8 pp, 1997.

This issue paper identifies issues and summarizes experiences with thermal desorption as a remedy for volatile organic compounds in soils. The issues presented reflect discussions with over 15 project managers and technical experts.

Treatment Using Electrical Resistance Heating (ERH) of Source Area CVOCs at a Former Manufacturing Facility, Newtown, CT
Taddeo, A.
In-Situ Thermal Remediation Workshop, 13-14 June 2012, Westford, MA. Northeast Waste Management Officials' Association (NEWMOA), 31 slides, 2012

The remedial strategy for chlorinated VOCs at a former metal tubing manufacturing facility located next to a railroad line in a suburban woodland/wetland area called for ERH in the source area and in situ bioremediation for the adjacent area and off-site plumes. ERH treatment was designed for a minimum duration of 4 months, with at least 30 days at 100 degrees C to reach 760 ppb or less TCE (reduction of 99.9% or greater) at an all-inclusive cost of $120/cy. Post-treatment residual TCE mass is very low, and the TCE mass flux has fallen below the TCE mass flux associated with the cleanup goal for the site. Additional information: ERH permitting concerns by the Connecticut DEEP

Use of Electrical Resistive Heating for the Remediation of CVOC and Petroleum Impacts in Soil and Groundwater, New York City, New York
Nichols, H.
In-Situ Thermal Remediation Workshop, 13-14 June 2012, Westford, MA. Northeast Waste Management Officials' Association (NEWMOA), 14 slides, 2012

ERH was implemented at a former industrial property located in New York City to address both petroleum and chlorinated VOC impacts. The targeted treatment depths varied between 25 and 40 ft below grade in an area of one-quarter acre, an estimated treatment volume of ~13,750 cubic yds. Shallow treatment was intended to address the area affected only by petroleum hydrocarbons, with intermediate treatment for the area affected by TCE and daughter products. During 283 days of ERH operation, the system removed over 3,200 lbs of VOCs from the site, including 2,800 lbs of TCE (equivalent to ~230 gallons of pure product). VOC groundwater concentrations were reduced over 99.99%.

White Paper on Thermal Remediation Technologies for Treatment of Chlorinated Solvents: Santa Susana Field Laboratory, Simi Valley, California
California Department of Toxic Substances Control, 69 pp, 2018

This paper summarizes the primary types of ISTR, discusses their effectiveness in reducing chlorinated VOC contamination in bedrock, and provides several specific examples of full-scale implementation.

Combined Remedies

Combining Low-Energy Electrical Resistance Heating With Biotic and Abiotic Reactions for Treatment of Chlorinated Solvent DNAPL Source Areas
Macbeth, T., M.J. Truex, T. Powell, and M. Michalsen.
ESTCP Project ER-200719, 383 pp, 2012

Low-temperature subsurface heating was combined with either ZVI or in situ bioremediation to enhance DNAPL remediation performance through both increased degradation reaction rates and contaminant dissolution. Moderate heating and minor operational costs enhanced efficiency and effectiveness of in situ treatment of TCE. Capture and treatment of contaminated vapor—a major cost element of standard thermal treatment—was not needed as the heating infrastructure was limited to subsurface electrodes and a power control unit. See also the 2015 ESTCP Cost & Performance Report

Fourth Five-Year Review Report for Outboard Marine Corporation Superfund Site, Waukegan, Lake County, Illinois
U.S. EPA Region 5, Chicago, IL. 71 pp, June 2012

The 2009 ROD for groundwater and DNAPL cleanup called for (1) soil mixing to incorporate ZVI and bentonite clay into the TCE DNAPL plume to accomplish in situ contaminant destruction; (2) injection of a soluble substrate (e.g., sodium lactate) into five VOC-contaminated source areas over multiple years to enhance in situ anaerobic bioremediation; (3) installation of an air sparge curtain to prevent off-site migration of dissolved chlorinated VOCs in groundwater; and (4) post-construction MNA and ICs until final cleanup levels are reached. EPA commenced air sparging in 2011, and Illinois EPA will take over system O&M in 2012. ZVI-bentonite mixing in the DNAPL plume area was completed in December 2011. Because of the location of one of the five identified VOC source areas, the in situ bioremediation remedy there was modified to a single ISCO injection (sodium permanganate) in May 2012. The other bioremediation injections will be conducted after evaluation of the effect of ISCO and any changes in groundwater flow following site building removal.

In Situ Bioremediation and Soil Vapor Extraction at the Former Beaches Laundry & Cleaners
Federal Remediation Technologies Roundtable Cost & Performance Database, 2010

The In Situ Treatment of TCE and PFAS in Groundwater Within a Silty Sand Aquifer
McGregor, R. and Y. Zhao | Remediation 31(2):7-17(2021)

At a former industrial site, shallow groundwater contained concentrations of TCE, cis-1,2-DCE, and VC as high as 985, 258, and 54 µg/L, respectively. Groundwater also contained maximum concentrations of the following PFAS: 12,800 ng/L perfluoropentanoic acid, 3,240 ng/L perfluorohexanoic acid, 795 ng/L perfluorobutanoic acid, 950 ng/L perfluorooctanoic acid, and 2,140 ng/L perfluorooctanesulfonic acid. A combination of remedial approaches was selected, with adsorption being used for PFAS and adsorption, chemical reduction, and anaerobic biodegradation used for the chlorinated ethenes. Two years of groundwater sampling indicated that the detected PFAS were treated to either their detection or below the analytical detection limit over the monitoring period. Post-injection results for the chlorinated ethenes indicated that the concentrations decreased by an order of magnitude within 4 months, with TCE decreasing to below the analytical detection limit over the 2-year monitoring period. Cis-1,2-DCE, and vinyl chloride concentrations decreased by over 99% within 8 months of injections, remaining at or below these concentrations during the 2-year monitoring period. Analyses of Dehalococcoides, ethene, and acetylene over time suggest that microbiological and reductive dechlorination were occurring in conjunction with adsorption within the aquifer.

Remediation of DNAPL through Sequential In Situ Chemical Oxidation and Bioaugmentation
D. Major.
ESTCP Project ER-0116, 92 pp, 2009

This project was conducted to assess the technical feasibility of sequential application of in situ chemical oxidation (ISCO) and in situ bioremediation (ISB) and to identify the optimal timing of the transition from ISCO to ISB. The field demonstration was conducted at Launch Complex 34, Kennedy Space Center, Florida, where an extensive TCE DNAPL source is present in the groundwater. In 1999, a demonstration of ISCO using potassium permanganate at LC-34 was completed in a 75 ft x 50 ft test plot. Construction of a groundwater recirculation treatment system was initiated and completed in 2003, and injections of ethanol (ISB, or biostimulation) and KB-1 (bioaugmentation) took place in 2004. The system was operated between June 2003 and August 2004. Electron donor addition (ISB) after ISCO resulted in partial biodegradation of TCE, with complete biodegradation observed after bioaugmentation. ESTCP Cost and Performance Report

Remediation System Evaluation: 10th Street Superfund Site, OU2, Columbus, Nebraska
U.S. EPA, Office of Superfund Remediation and Technology Innovation (OSRTI).
EPA 540-R-10-012, 77 pp, Feb 2010

Groundwater contamination at the 10th Street Superfund Site consists primarily of PCE, TCE, and cis-1,2-DCE. Three active components provide the groundwater remedy: 1) a groundwater extraction and treatment (GET) system; 2) an AS/SVE system located at the One Hour Martinizing (OHM) source area; and 3) ISCO treatment at the OHM source area and also at locations between OHM and the GET system. Optimization recommendations are provided in four primary categories: effectiveness, cost reduction, technical improvement, and sustainability.

Successful ISCR-Enhanced Bioremediation of a TCE DNAPL Source Utilizing EHC® and KB-1®
Peale, J.G.D., J. Mueller, and J. Molin.
Remediation Journal, Vol 20 No 3, p 63-81, 2010

Successful full-scale implementation of in situ chemical reduction (ISCR)-enhanced bioremediation of a TCE DNAPL source zone was conducted at an operating facility in Portland, OR. In the demonstration, concentrations of TCE were reduced rapidly to below the maximum contaminant level in less than 6 months following ISCR implementation using EHC® and bioaugmentation with the KB-1® consortium. EHC is a hydrophilic carbon/ZVI blend that promotes degradation of aliphatic hydrocarbons via microbial and abiotic pathways. The remedial action objective for the source area--TCE concentrations below 1% of the solubility limit, or 11,000 µg/L—was achieved in less than 12 months.

USA Defense Depot Memphis
U.S. EPA Region 4 Web site.

Simultaneous Thermal Treatment of Eight DNAPL Source Areas at Memphis Defense Depot (2009)

The most consistently detected VOC group of chemicals at concentrations above comparison criteria in the site media are CVOCs, such as TCE, PCE, 1,1,2,2-PCA, carbon tetrachloride, and chloroform. The final ROD (2004) for Dunn Field calls for excavation and off-site disposal of the contents of pits and burial trenches, SVE of principal-threat waste in the unsaturated subsurface soils, treatment of the groundwater CVOCs via injection of ZVI, and installation of a ZVI PRB to address high groundwater concentrations downgradient of Dunn Field. SVE operation began in the VOC-contaminated sand and gravel layer beneath source areas in July 2007. In situ thermal desorption (ISTD) began in the VOC-contaminated silty clay zone (top 30 ft) in May 2008. VOC removals for all remedies to date (soil and groundwater) totals ~9,000 pounds. A revised proposed plan and ROD amendment are planned for 2009 to document changes undertaken to achieve the remedial action objectives of the original ROD.

Volatilization Technologies (Soil Vapor Extraction, Air Sparging, In-Well Stripping)

Air Sparging Design Paradigm
Andrea Leeson, et al, Battelle, Columbus, OH.
Environmental Security Technology Certification Program (ESTCP), 150 pp, 2002.
Contact: Dr. Andrea Leeson, andrea.leeson@osd.mil

Air Sparging Guidance Document
K. Fields, et al., Battelle Memorial Inst.
Naval Facilities Environmental Service Center. NFESC TR-2193-ENV, 119 pp, 2002.

Environmental Quality: In Situ Air Sparging
U.S. Army Corps of Engineers. EM 200-1-19, 178 pp, 2013

Engineering and Design: Soil Vapor Extraction and Bioventing
U.S. Army Corps of Engineers.
EM 1110-1-4001, 424 pp, 2002.

Field Applications of In Situ Remediation Technologies: Ground-Water Circulation Wells
U.S. EPA, Technology Innovation Office.
EPA 542-R-98-009, 41 pp, 1998.
Contact: Kathy Yager, yager.kathleen@epa.gov

Groundwater Circulating Well Technology Assessment
Allmon, W.E., et al.
Environmental Security Technology Certification Program (ESTCP). NRL/PU/6115-99-384, 87 pp, 1999.

In-Situ Regeneration of Granular Activated Carbon (GAC) Using Fenton's Reagents
R.G. Arnold, W.P. Ela, A.E. Saez, and C.L. De Las Casas, Univ. of Arizona, Tucson.
Developed under a Cooperative Agreement with U.S. EPA, National Risk Management Research Laboratory, Subsurface Protection and Remediation Division, Ada, OK. 165 pp, 2006

In laboratory studies and a field pilot-scale demonstration, Fenton's reagents were cycled through spent GAC to degrade sorbed chlorinated hydrocarbons taken up during the treatment phase of soil vapor extraction. Little carbon adsorption capacity was lost in the process.

Roy F. Weston, Inc. and IEG Technologies Corporation Unterdruck-Verdampfer-Brunnen (UVB) Technology: Innovative Technology Evaluation Report
U.S. EPA, Superfund Innovative Technology Evaluation (SITE) Program.
EPA 540-R-95-500, 180 pp, 1999.

Soil Vapor Extraction Implementation Experiences. Engineering Forum Issue Paper
Robert Stamnes and John Blanchard.
EPA 540-F-95-030, 9200.5-223FS, 10 pp, 1997.

Technology Evaluation Report for the NoVOCs™ Technology Evaluation
U.S. EPA, Superfund Innovative Technology Evaluation (SITE) Program.
EPA 540-R-00-502A, 396 pp, 2000.

Site-Specific Information

CLU-IN Site Profile Databases

CLU-IN Site Profile Databases contain information on thousands of projects where innovative approaches have been used to deal with contamination problems.

Completed North America Innovative Technology Demonstration Projects

Lists field demonstrations of innovative remediation technologies sponsored by government agencies working in partnership with private technology developers.

Federal Remediation Technology Roundtable Technology Cost and Performance Reports

FRTR makes available over 130 reports of cleanup technologies for TCE-contaminated sites.

Literature References

Technology Focus: The Remediation Technology Information Center
An up-to-date compilation of the most relevant information sources on 17 remediation technologies ranging from the established (SVE) to the innovative (phytoremediation). New information added monthly.

Technology Innovation News Survey Archives
The Technology Innovation News Survey archive contains resources gathered from published material and gray literature relevant to the research, development, testing, and application of innovative technologies for the remediation of hazardous waste sites. The collected abstracts date from 1998 to the present, and the archive is updated twice each month.

U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

Trichloroethylene (TCE)

Treatment Technologies