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

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

Recent Additions

Summer 2015 Technology News and Trends

Posted: October 13, 2015

This issue highlights investigation and mitigation of vapor intrusion at or near contaminated sites, with a focus on summarizing how vapor intrusion was addressed at three sites where response actions are underway. Vapor intrusion is the general term given to migration of hazardous vapors from any subsurface vapor source, such as contaminated soil or groundwater, through the soil and into an overlying building or structure. A wide variety of chemical contaminants can give off vapors, which can migrate towards and enter buildings or other enclosed spaces. These vapors can enter buildings through cracks in basements and foundations, as well as through conduits and other openings in the building envelope. Vapor intrusion is a potential human exposure pathway. Depending upon building- and site-specific circumstances, indoor concentrations of chemical vapors arising from the vapor intrusion pathway may threaten human health or safety.

Stabilization and Solidification of Contaminated Soil and Waste: A Manual of Practice

Posted: September 30, 2015

This document has been designed as a practical reference for regulators, site owners, engineering firms, and others involved in selecting, designing, bidding, and providing oversight for the remediation of hazardous waste sites using S/S. This book provides guidance on applicable contaminants, site characteristics, project planning, equipment capabilities, production rates, performance specifications and the quality assurance of S/S treated materials. Included are references to numerous case studies and an extensive reference list of completed projects that successfully employed S/S.

Use of MNA for Inorganic Contaminants in Ground Water at Superfund Sites

Posted: September 30, 2015

This new monitored natural attenuation (MNA) policy document for inorganic contaminants expands on and is designed to be a companion to the 1999 MNA guidance. Together, these two policy documents provide guidance on the consideration of MNA for a broad range of contaminants at Superfund sites. This 2015 MNA guidance, consistent with the 1999 MNA guidance, indicates that multiple "lines of evidence" should be obtained to evaluate whether MNA should be considered as part of the site's selected response action. As a related matter, the 1999 MNA guidance also recommends use of a tiered analysis approach for considering MNA, which typically involves a detailed analysis of site characteristics that control and sustain attenuation. The 2015 MNA guidance builds on this tiered approach and recommends a phased analytical approach tailored specifically for inorganic contaminants.

Ow-5/55r Area In-Situ Geochemical Stabilization Remediation Pilot Test, Former Koppers Company, Inc. Site, Nashua, New Hampshire

Posted: September 4, 2015

In situ geochemical stabilization (ISGS) technology comprises the injection of an enhanced permanganate-based reagent (RemOx® EC) into NAPL-impacted zones to achieve containment/stabilization and solute flux reduction. Silica-based precipitates are deposited around NAPL ganglia and droplets following reagent injection, which leaves a mineral shell that reduces overall permeability in the treated area, thereby reducing the volumetric flux of upgradient groundwater into and through the impacted area. The oxidation of dissolved-phase constituents also "hardens" or chemically weathers the NAPL as it loses its more labile SVOCs. This report describes the results of an ISGS pilot test conducted November 11-13, 2014, to isolate creosote NAPL in a treatment area ~45 ft by 75 ft.

Israp: Interactive Sediment Remedy Assessment Portal

Posted: September 4, 2015

ISRAP is an online interactive portal designed to help users understand monitoring requirements and monitoring tools associated with sediment remediation. The website can also be useful in understanding data needs during the RI/FS, especially as they pertain to remedies themselves, and post-remedy monitoring. The main feature of the site is the sediment monitoring tools matrix, a database of sediment monitoring tool information that was developed to facilitate the design and optimization of sediment monitoring programs. The matrix can be browsed in a step-by-step mode, if desired. For first-time users, a Frequently Asked Questions (FAQ) link is provided. A tutorial offers a functional overview of the matrix design and navigation in addition to a short primer about sediment remediation monitoring needs and tools.

Chester River Hospital Center Pilot Test Evaluation Report and Proposed 2015 Action Plan

Posted: September 18, 2015

The Chester River Hospital Center (CRHC) Technical Team implemented a pilot study in August 2014 to demonstrate the viability and effectiveness of the Ivey-sol® surfactant flushing push-pull process to safely liberate sorbed residual hydrocarbons from soils. CRHC had used pump and treat (P&T) for over 20 years to remove liquid petroleum hydrocarbons (free product) and remediate the groundwater. Based on the evidence of monitoring results, the project moved into a closure status/process during 2012/2013; however, subsequent monitoring data led to the restart of P&T, and investigations revealed that a seasonal high water table contacted sorbed residual hydrocarbons in a smear zone in soils near the original spill. In July 2014, MDE approved the proposed Ivey-sol® pilot study under a set of specific conditions. The push-pull flushing process was completed successfully, and CRHC proposed its use at full scale to complete the cleanup. [MDE approved the revised action plan (with modifications) in July 2015.]

Understanding Dioxin-Like Compounds in Indoor Dust

Posted: September 18, 2015

A study was funded by a grant from EPA's Environmental Justice Small Grant Program to a community organization, Protect Gainesville's Citizens Inc., to evaluate the concentrations and patterns of dioxins and dioxin-like compounds in indoor dust from homes near the former Koppers wood treating Superfund site in Gainesville, Florida. In 2012 EPA collected the initial samples from 30 homes, 17 of them adjacent to the Koppers site. Potential dioxin-like contributions from flame retardant chemicals present in foam furniture or electronics in the homes were also investigated. No dust sample had a concentration above 100 ppt. Indoor dioxin data were evaluated before and after the Koppers surface soil remediation.

Use of Monitored Natural Attenuation for Inorganic Contaminants in Ground Water at Superfund Sites

Posted: September 18, 2015

This new monitored natural attenuation (MNA) directive for inorganic contaminants expands upon and is designed to be a companion to the 1999 MNA guidance. Together, these two policy documents provide guidance on the consideration of MNA for a broad range of contaminants at Superfund sites. Both directives say that multiple lines of evidence should be obtained to evaluate the feasibility of including MNA in the site's selected response action. This 2015 guidance builds upon the approach indicated in the 1999 directive for tiered analysis of site characteristics that control and sustain attenuation, and recommends a phased analytical approach tailored specifically for inorganic contaminants. Both guidance documents are available at

Compilation of Information Relating to Early/Interim Actions at Superfund Sites and the TCE IRIS Assessment

Posted: September 18, 2015

In response to requests from U.S. EPA Regional offices, this memorandum compiles information regarding existing EPA guidance on early or interim actions at Superfund sites. The memo also provides current information about the toxicity of TCE. The information referenced in this document may be used to support Superfund decision-making at sites with actual or potential inhalation exposures to TCE.

Soil and Groundwater Remediation Technologies for Former Gasworks and Gasholder Sites

Posted: October 4, 2015

This report describes key issues, contaminants, and types of site that gas distribution networks are currently facing. It also covers the main soil and groundwater in situ, ex situ, and conventional civil engineering technologies currently available to treat contaminants commonly associated with manufactured gas plants (MGPs). The report discusses soil and groundwater remediation in the UK and internationally so that lessons can be learned from other jurisdictions on how different stakeholders remediate their former MGP and gasholder facilities.

Risk-Based Management of Mercury-Impacted Sites

Posted: October 4, 2015

Hg typically is found as a principal pollutant for only a few specific industries, such as chlor-alkali plants, where the majority of the Hg impacts identified in surrounding soils typically comprise the original elemental form of Hg, often at relatively high concentrations (e.g., 100-1000 mg/kg). Mercury also has been used as a key reactant in the production of organic compounds, such as the synthesis of vinyl chloride and acetaldehyde from acetylene. Hg may be present at other industrial sites as a secondary pollutant at relatively low concentrations, such as 1-10 mg/kg Hg levels in coal-tar contaminated soil at gas and coking works. This report was prepared to share current information, eight brief case studies, and best practices for characterization and management of Hg-contaminated soil and groundwater at industrial sites.

Guidance for Design, Installation and Operation of In Situ Air Sparging Systems

Posted: October 4, 2015

In situ air sparging is a process in which a gaseous medium (commonly air) is injected into groundwater through a system of wells. As the injected air rises to the water table, it can strip VOCs from groundwater and the capillary fringe. The process also oxygenates groundwater, enhancing the potential for biodegradation at sites with contaminants that degrade aerobically. The Wisconsin DNR developed this guidance for environmental professionals who investigate contaminated sites and design remedial systems. A working knowledge of geology, hydrogeology, and basic engineering is required to design an effective system. Given that each site is unique with respect to contaminants, access constraints, size, hydrogeology, and other characteristics, designers may deviate from the guidance depending upon site-specific circumstances.

Navfac Technical Memorandum On Vapor Intrusion Passive Sampling

Posted: October 4, 2015

This technical memorandum was prepared for NAVFAC Remedial Project Managers, contractors, and other stakeholders to provide an overview of the use of passive samplers for vapor intrusion applications. It describes the basics of passive sampler theory and design, the available types of passive samplers, the advantages and limitations of passive samplers, and important considerations when implementing a passive sampling program. Results from two vapor intrusion case studies at DoD sites are highlighted.

U.S. EPA Proceedings of National Conference On Mining-Influenced Waters: Approaches for Characterization, Source Control and Treatment

Posted: October 4, 2015

In 2014, EPA's Office of Research and Development sponsored a conference in Albuquerque, New Mexico, on August 12-14 to provide a forum for the exchange of scientific information on current and emerging approaches to characterization, monitoring, source control, treatment, and remediation of mining-influenced waters. The conference was aimed at mining remediation researchers and practitioners; federal, state, local, and tribal decision-makers; the mining industry; and others interested in the management, remediation, and restoration of waters affected by hardrock mining. This publication contains the presentation abstracts and speaker biographies.