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

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

In Situ Chemical Reduction

Additional Resources

Technology Innovation News Survey

The Technology Innovation News Survey contains market/commercialization information; reports on demonstrations, feasibility studies and research; and other news relevant to the hazardous waste community interested in technology development. This report is updated every two weeks.

Adobe PDF LogoFundamental Study of the Delivery of Nanoiron to DNAPL Source Zones in Naturally Heterogeneous Field Systems
Lowry, G., T. Phenrat, F. Fagerlund, T. Illangasekare, P. Tratnyek, and R.L. Johnson.
SERDP Project ER-1485, 144 pp, 2012

Although results indicate that emplaced NZVI can decrease the flux of contaminants emanating from entrapped DNAPL, they also suggest that NZVI available commercially today must be optimized to work as an effective reactive barrier. This optimization will require mobility of a greater fraction of the injected iron than was found in the combinations of nanoiron types and polymeric surface modifiers used in the study.

Reductive Dechlorination for Remediation of Polychlorinated Biphenyls
Wu, B.Z., H.Y. Chen, S.J. Wang, C.M. Wai, W. Liao, and K. Chiu.
Chemosphere 88(7):757-768(2012)

This review references 108 papers on reductive treatment for PCBs published within the last decade. The treatments reviewed fall into one of three categories: (1) catalytic hydrodechlorination with H2, (2) Fe-based reductive dechlorination, and (3) other reductive dechlorination methods (e.g., hydrogen-transfer dechlorination, base-catalyzed dechlorination, and sodium dispersion). The advantages of each remediation technology are discussed. Longer abstract

Adobe PDF LogoBest Practices for Injection and Distribution of Amendments
Rosansky, S., W. Condit, and R. Sirabian.
TR-NAVFAC-EXWC-EV-1303, 81 pp, 2013

Although there are many reasons for the sub-optimal performance of an in situ technology (e.g., chemical oxidation, chemical reduction, and enhanced bioremediation), a common underlying factor appears to be the inability to achieve adequate distribution and contact between the reagents, substrates, and target contaminants. This document presents current best practices for introducing liquid- and solid-phase amendments into aquifers to improve the likelihood of adequate amendment distribution. Lessons learned from three Navy case studies are provided.

Adobe PDF LogoIn Situ Chemical Reduction using Zero Valent Iron Injection: A Technique for the Remediation of Source Zones
CityChlor, 104 pp, 2013

This document contains a technical summary of the state of the art in the use of injections of ZVI at nano- or micro-scale for treating soil and groundwater contaminated with chlorinated solvents. Given that practical experience within the European market with respect to this technique was rather limited at the time the document was written, the text is based upon an extensive literature review, a survey of soil remediation companies and suppliers, and experiences from the CityChlor pilot test in Herk-de-Stad. This document will enable the reader to evaluate the practicality of this technique and also provide a guideline for its usage. [Note: CityChlor is an INTERREG IVB-NWE project between partners from Flanders, Germany, France, and the Netherlands who work on innovative solutions for cleanup of contaminated sites.]

A Risk/Benefit Appraisal for the Application of Nano-Scale Zero Valent Iron (NZVI) for the Remediation of Contaminated Sites
Bardos, P., B. Bone, P. Daly, D. Elliott, S. Jones, G. Lowry, and C. Merly.
NanoRem Issues Paper, 89 pp, 2014

This report discusses the relative risks and benefits of NZVI usage for in situ remediation (i.e., the potential for the NZVI treatment agent itself to present human health or environmental risks) and its sustainability as a technique; identifies the areas where further investigation might be required; and provides an overview of NZVI use in full-scale, pilot, and lab studies to date. This paper is intended to help stakeholders by identifying key issues and providing a basis for evidence-based decisions.

Adobe PDF LogoBiogeochemical Transformation Handbook
Darlington , R. and H. Rectanus.
TR-NAVFAC EXWC-EV-1601, 41 pp, 2015

In situ biogeochemical transformation (ISBGT) processes result in the degradation of contaminants through combined biological, mineral, and chemical pathways. This handbook can serve as a key resource in evaluating, selecting, and implementing the ISBGT technology. The handbook presents the fundamentals of ISBGT in a question and answer format; explores the mechanisms that contribute to ISBGT processes; discusses contaminants that can be degraded by ISBGT; identifies key considerations for enhancing, monitoring, and evaluating ISGBT processes; and emphasizes the importance of site characterization in recognizing and accounting for the contributions of ISBGT to natural attenuation.

Superfund Remedy Report, 17th Edition
EPA 542-R-23-001, 2020

EPA prepares the Superfund Remedy Report to provide information and analyses on remedies EPA selected to address contamination at Superfund National Priorities List and Superfund Alternative Approach sites. This report is the latest in a series, prepared since 1991, on Superfund remedy selection. The latest edition focuses on the analysis of Superfund remedial actions selected in fiscal years 2018, 2019, and 2020.

The data that forms the basis of the analyses contained in SRR 17th Edition can be found at Superfund Data and Reports by downloading Contaminant of Concern Data for Decision Documents by Media and Remedy Component Data for Decision Documents by Media.

Adobe PDF LogoHorizontal 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

Optimizing Injection Strategies and In Situ Remediation Performance
The Interstate Technology & Regulatory Council Optimizing Injection Strategies and In Situ Remediation Performance Team. Report No. OIS-ISRP-1, 180 pp, 2020

This guidance describes how treatment ineffectiveness can be avoided through effective upfront characterization and design. It also provides the state of the practice based on firsthand knowledge and experiences for a broad audience, including environmental consultants, responsible parties, federal and state regulators, and community and tribal stakeholders. The document is divided into sections including remedial design characterization; amendment, dose and delivery design; implementation and feedback optimization, regulatory perspectives, community and tribal stakeholder considerations, and case studies.