Analysis of Selected Enhancements for Soil Vapor Extraction
EPA 542-R-97-007, 246 pp, 1997.

This report provides an engineering analysis of, and status report on, selected enhancements for the following soil vapor extraction (SVE) treatment technologies: air sparging, dual-phase extraction, directional drilling, pneumatic and hydraulic fracturing, and thermal enhancement. It also offers an evaluation of each technology's applicability to various site conditions, cost and performance information, a list of vendors specializing in the technologies, a discussion of relative strengths and limitations of the technologies, recommendations to keep in mind when considering the enhancements, and extensive references.

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 (including steam flushing, conductive heating, and electrical resistance heating) 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 a site.

Critical Evaluation of State-of-the-Art In Situ Thermal Treatment Technologies for DNAPL Source Zone Treatment
J.T. Kingston, P.R. Dahlen, P.C. Johnson, E. Foote, and S. Williams.
ESTCP Project ER-0314, 1,272 pp, 2010

The performance of thermal technologies for DNAPL source zone remediation was assessed with particular emphasis on post-treatment groundwater quality and mass discharge (i.e., mass flux). Documents from 182 applications were collected and reviewed—87 electrical resistance heating, 46 steam-based heating, 26 conductive heating, and 23 other heating technology applications—conducted between 1988 and 2007, with attention to the site geologic settings, chemicals treated, design parameters, operating conditions, and performance metrics. The results of the study are summarized in a set of spreadsheet-based summary tables linking this information to five generalized geologic scenarios. The Summary Tables identify generalized scenarios that can be used to anticipate the likely performance of thermal-based DNAPL treatment technologies at a site. Another product of this work, 'State-of-the-Practice Overview of the Use of In Situ Thermal Technologies for NAPL Source Zone Cleanup,' condenses the 1,000-plus pages of this report into an 86-page primer prepared for a program manager audience. State-of-the-Practice Overview; ESTCP Cost & Performance Report

Environmental Quality Design: In Situ Thermal Remediation
U.S. Army Corps of Engineers. EM 200-1-21, 243 pp, 2014

This document provides guidance and background for the appropriate screening and selection of the following technologies: steam-enhanced extraction, electrical resistivity heating, and thermal conductive heating.

Feasibility Study: Preliminary Documented Safety Analysis for In Situ Thermal Desorption in the Subsurface Disposal Area
D.G. Abbott, Idaho Completion Project, Idaho Falls.
INEEL/EXT-03-00962, 50 pp, 2003

Green Remediation Best Management Practices: Implementing In Situ Thermal Technologies
EPA 542-F-12-029, 2012

Over recent years, the use of in situ thermal technologies such as electrical resistance heating, thermal conductive heating, and steam enhanced extraction to remediate contaminated sites has notably increased. The U.S. EPA's latest (13th) green remediation "BMP fact sheet" describes processes, equipment, and analytical tools that can be used to reduce the environmental footprint of applying these technologies, which typically involves significant energy consumption. The best management practices (BMPs) address other core elements of a greener cleanup: reducing air pollutants and greenhouse gas emissions, reducing water use and negative impacts on water resources, improving materials management and waste reduction efforts, and protecting ecosystem services. The BMPS may be used during design, construction, operation and maintenance, and/or monitoring of an in situ thermal project.

Groundwater Issue Paper In Situ Thermal Remediation
Davis, E.L. EPA/600/R-23/062, 46 pp, 2023

In situ thermal remediation technologies rely on adding energy to the subsurface to change the phase distribution and other physical properties of volatile and semivolatile organic contaminants to mobilize them and aid in their recovery. The most used in situ thermal remediation technologies today are Steam Enhanced Extraction (SEE), electrical resistance heating (ERH), and thermal conductive heating (TCH; sometimes called in situ thermal desorption, ISTD).  These three technologies are applicable to and have been proven for a wide variety of organic contaminants and in a wide variety of hydrogeologic settings, both above and below the water table. Thermal remediation technologies are very aggressive and are most applicable for contaminated sites (or portions of sites) where contaminant concentrations are the greatest, generally areas where nonaqueous phase liquids (NAPLs) are present.  This paper briefly describes these commonly used in situ thermal remediation technologies and how they are deployed to remediate VOC and SVOC contaminated sites. Advice based on experience gained from sites where these technologies have been implemented is provided on soliciting thermal remediation services, how to determine the area/volume to be treated, and when to terminate the heating portion of the remediation.  This paper includes both information gathered from other published papers and knowledge gained from the author’s extensive experience of technical support for thermal remediation.

Guidelines: In Situ Thermal Treatment (ISTT) for Source Zone Remediation of Soil and Groundwater
Hiester, U., M. Mueller, H.-P. Koschitzky, O. Troetschler, U. Roland, and F. Holzer.
Centre of Competence for Soil, Groundwater and Site Revitalisation (TASK), 71 pp, 2013

This document illustrates the specific planning and implementation steps for in situ thermal treatment (ISTT) in different project phases in easy-to-understand, practice-based text. The guidelines are designed to assist in estimating and evaluating the site-specific remediation success of ISTT from the planning stage onward.

Horizontal Remediation Wells
Appendix A in How to Evaluate Alternative Cleanup Technologies for Underground Storage Tank Sites: A Guide for Corrective Action Plan Reviewers
EPA 510-B-17-003, 47 pp, 2017

Horizontal directional drilling can be used to install horizontal remediation wells (HRWs) at cleanup sites. The technology uses specialized equipment to produce either a curved surface-to-surface well or a blind well. HRWs are able to access locations beneath surface obstructions and to place long well screens in contact with the contaminated area. The wells can be thousands of feet long, with hundreds of feet of well screen. The potential for HRWs to complement a site remedy is described with reference to air sparging, bioremediation, chemical injection, soil vapor extraction, hot air or steam injection, LNAPL removal, plume containment, injection of treated water, and sampling. A detailed overview is provided of equipment and procedures for drilling a horizontal remediation well. Additional information: The complete UST CAP review manual

In Situ Treatment Performance Monitoring: Issues and Best Practices
EPA 542-F-18-002, 2018

The purpose of this issue paper is to describe how in situ treatment technologies may impact sampling and analysis results used to monitor treatment performance and provide best practices to identify and mitigate issues that may affect sampling or analysis. This paper discusses eight potential sampling or analytical issues associated with groundwater monitoring at sites where in situ treatment technologies are applied. These issues are grouped under three topic areas: Issues related to monitoring wells (Section 2); Representativeness of monitoring wells (Section 3); Post-sampling artifacts (Section 4).

In-Situ Thermal Treatment of Contaminated Soils and Groundwater
U.S. EPA, Environmental Response Team.
Videorecording (23 min.), 2002.

Three thermal methods for cleaning DNAPL-contaminated soils are discussed. Each heats the soils, contaminants, and groundwater and then removes the mobilized contaminants.

Issue Paper: How Heat Can Enhance In Situ Soil and Aquifer Remediation
Eva L. Davis.
EPA 540-S-97-502, 18 pp, 1997.

This issue paper contains in-depth information on the properties of some common organic contaminants that affect their movement in and recovery from the subsurface, as well as information on how these properties are affected by temperature.

Soil Vapor Extraction Using Radio Frequency Heating: Resource Manual and Technology Demonstration
D.F. Lowe, C.L. Oubre, and C.H. Ward.
CRC Press LLC, Boca Raton, FL. ISBN: 1566704642, 1999.

Addresses measurement procedures, engineering design, costs and economic analyses, and potential applications.

Steam Injection for Soil and Aquifer Remediation. Ground Water Issue
Eva L. Davis.
EPA 540-S-97-505, 16 pp, 1998.

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 presents ways in which success or failure in treating a DNAPL source zone has been measured.

The DNAPL Remediation Challenge: Is There a Case for Source Depletion?
Expert Panel on DNAPL Remediation.
EPA 600-R-03-143, 129 pp, 2003