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

Activated Carbon-Based Technology for In Situ Remediation Focus Area

Posted: August 14, 2018

Activated carbon (AC)-based technology involves emplacement of AC-based amendments for in situ remediation of soil and groundwater. Besides AC, amendments typically include other reactive products commonly used with in situ remediation technologies, such as in situ chemical reduction (ISCR), in situ chemical oxidation (ISCO), and bioremediation. The technology is commonly referred to as "carbon-based injectate" (CBI), especially for remediation of petroleum hydrocarbons. AC-based amendments remove contaminant via two processes: adsorption by AC and degradation by reactive amendments. The coupling of adsorption and degradation makes this technology a promising remedial option for addressing persistent plumes emanating from contaminants sorbed on soil, residual non-aqueous phase liquid (NAPL), or mass stored in low-permeability zones. The technology might also be applicable near or at the source area, especially when combined with other source treatment remedies, to limit contaminant mass flux out of source zones to downgradient plumes.

Remedial Technology Fact Sheet — Activated Carbon-Based Technology for In Situ Subsurface Remediation

Posted: August 7, 2018

This fact sheet concerns an emerging remedial technology that applies a combination of activated carbon (AC) and chemical and/or biological amendments for in situ remediation of soil and groundwater contaminated by organic contaminants, primarily petroleum hydrocarbons and chlorinated solvents. The technology typically is designed to carry out two contaminant removal processes: adsorption by AC and destruction by chemical and/or biological amendments. With the development of several commercially available AC-based products, this remedial technology has been applied with increasing frequency at contaminated sites across the country, including numerous leaking underground storage tank (LUST) and dry cleaner sites. It also has been recently applied at several Superfund sites, and federal facility sites that are not on the National Priorities List. This fact sheet provides information to practitioners and regulators for a better understanding of the science and current practice of AC-based remedial technologies for in situ applications.

Superfund Research Program Multiproject Center Grants (P42)

Posted: July 5, 2018

The National Institute of Environmental Health Sciences (NIEHS) is announcing the continuation of the Superfund Research Program (SRP) Centers. This program supports coordinated, multiproject, multi- and interdisciplinary Centers that address the broad, complex health and environmental issues that arise from hazardous waste sites. SRP Center grants support problem-based, solution-oriented research Centers that consist of multiple, integrated projects representing the biomedical and environmental science and engineering disciplines. The Center cores also are tasked with administrative, community engagement, research translation, research support, and training functions. Per NIEHS legislative authority, only Higher Education Institutions may apply. Letters of intent are due by November 19, 2018, and applications are due by December 19, 2018.

ITRC Seeks 2019 Team Projects

Posted: July 3, 2018

The Interstate Technology & Regulatory Council (ITRC) requests proposals for 2019 ITRC remediation and non-remediation projects. All applicable topics will be considered, but scoring evaluation criteria will give greater weight to proposals that address the needs identified in the recent State survey fact sheet, or proposals which update ITRC documents that are outdated. Proposals are due by July 13, 2018.

EPA's 2018-2019 Small Business Innovation Research (SBIR) Phase I Solicitation

Posted: July 3, 2018

EPA is calling for small businesses to apply for Phase I awards up to $100,000 to demonstrate proof of concept in the following topic areas: clean and safe water, air quality, land revitalization, homeland security, manufacturing, sustainable materials management and safer chemicals. Successful Phase I companies are eligible to apply for Phase II funding, which awards up to $300,000 for two years with a commercialization option of up to $100,000, to further develop and commercialize their technologies. Applications are due by July 31, 2018.

Registration Now Open! 2018 Environmental Measurement Symposium, New Orleans, LA, August 6-10, 2018

Posted: June 28, 2018

The Environmental Measurement Symposium is the combined meeting of the Forum on Laboratory Accreditation and the National Environmental Monitoring Conference (NEMC) and is the largest conference focused on environmental measurements in North America. The NELAC Institute (TNI) and the U.S. EPA are co-sponsors. The theme of this year's symposium is "The Future Landscape of Science." The deadline for early registration is Monday, July 16.

2018 Brownfields Utilization, Investment and Local Development (BUILD) Act Comment Solicitation

Posted: June 28, 2018

The BUILD Act was enacted on March 23, 2018 as part of the Consolidated Appropriations Act, 2018. The BUILD Act reauthorized EPA's Brownfields Program, and made amendments to the 2002 Small Business Liability Relief and Brownfields Revitalization Act. Authorized changes affect brownfields grants, ownership and liability provisions, and state and tribal response programs. EPA is developing policy guidance to implement the BUILD Act. As part of this process, the EPA is soliciting comment on three provisions in the BUILD Act: the authority to increase the per-site cleanup grant amounts to $500,000; the new multi-purpose grant authority; and the new small community assistance grant authority. To help frame comments, EPA published questions related to these provisions in the Federal Register. Comments will be accepted through July 10, 2018.

2018 Brownfields Utilization, Investment and Local Development (BUILD) Act Comment Solicitation

Posted: June 28, 2018

The BUILD Act was enacted on March 23, 2018 as part of the Consolidated Appropriations Act, 2018. The BUILD Act reauthorized EPA's Brownfields Program, and made amendments to the 2002 Small Business Liability Relief and Brownfields Revitalization Act. Authorized changes affect brownfields grants, ownership and liability provisions, and state and tribal response programs. EPA is developing policy guidance to implement the BUILD Act. As part of this process, the EPA is soliciting comment on three provisions in the BUILD Act: the authority to increase the per-site cleanup grant amounts to $500,000; the new multi-purpose grant authority; and the new small community assistance grant authority. To help frame comments, EPA published questions related to these provisions in the Federal Register. Comments will be accepted through July 10, 2018.

Construction Completion Report, Seaboard Chemical Corporation and Riverdale Drive Landfill Site

Posted: June 22, 2018

The cleanup area and joint remediation effort encompasses the City of High Point's landfill site adjacent to Seaboard Chemical's closed treatment, storage, and disposal facility. The landfill is now capped and maintained under an approved post closure plan. The site is affected by chlorinated and non-chlorinated organics, DNAPL (ethenes, ethanes, and others), and 1,4-dioxane in the shallow and deep groundwater and landfill leachate. The most effective long-term method to accomplish the hydraulic containment of the plumes and treatment of the groundwater and leachate collected at the site was determined to be shallow and deep groundwater extraction in conjunction with leachate recovery and treatment in physical and natural systems. The main physical treatment area encompasses the AOP unit, settling vat effluent filters, water chemistry lab, and effluent storage tanks. Prior to being pumped to the cap of the landfill for phytoremediation, the leachate and groundwater from the extraction wells go through the clarifier (for solids to settle), aeration/filtration treatment removes metals, and an air stripper reduces the organics concentration. A 33-acre stand of mainly pine tree species is maturing on the landfill cap.

Screening-Level Feasibility Assessment and Design Tool in Support of 1,4-Dioxane Remediation by Extreme Soil Vapor Extraction (Xsve)

Posted: June 22, 2018

XSVE, or extreme soil vapor extraction, is an enhanced form of soil vapor extraction (SVE) for remediation of 1,4-dioxane in vadose soils. XSVE is enhanced by focused extraction and heated air injection to facilitate 1,4-dioxane removal. HypeVent XSVE for 1,4-Dioxane (HypeVent XSVE) is a spreadsheet-based tool that runs in Microsoft Excel®. The tool was developed in anticipation of remediation professionals' need for a screening-level feasibility assessment and design tool for XSVE applications. HypeVent XSVE facilitates quick exploration of the best-case performance for 1,4-dioxane removal from soils using the XSVE technology.

Demonstration and Validation of Enhanced Monitored Natural Recovery at DOD Sites: ESTCP Cost and Performance Report

Posted: June 22, 2018

Enhanced monitored natural recovery (EMNR) involves the placement of a thin layer (commonly < 30 cm) of clean sand or clean sediment over contaminated sediment, coupled with ongoing natural recovery processes and a monitoring program to achieve ecological recovery and risk reduction at contaminated sediment sites. In some cases, dredged sediment may be preferable to quarried sand because it has natural organic matter to support benthic life. In general, thin-layer capping (TLC) is not designed to provide complete chemical isolation but to provide a reasonable degree of physical isolation and reduction toward lower chemical concentrations targeting site-specific remedial action objectives and goals. EMNR also reduces potential resuspension or transport of contaminated sediment particles. The demonstration was implemented at Site 99, the Quantico Embayment site, Quantico, Virginia. TLC grain sizes were selected in the final design to be stable during both normal river flows and during periods of flood flows and storm-generated waves. For the Quantico Embayment site, the clean sand EMNR remedy was shown to be effective in reducing exposure in surface sediments as measured by bulk sediment total DDX concentrations, porewater DDX concentrations, and direct measurement of bioaccumulation in two site-exposed benthic organisms.

Trends in Methyl Tert-Butyl Ether Concentrations in Private Wells in Southeast New Hampshire: 2005 to 2015

Posted: June 22, 2018

In southeast New Hampshire, where reformulated gasoline was used from the 1990s to 2007, MTBE concentrations ≥ 0.2 µg/L were found in water from 26.7% of 195 domestic wells sampled in 2005. In 2015 (8 yr after MTBE was banned), 10.3% continued to have MTBE. Most wells (140 of 195) had no MTBE detections (concentrations < 0.2 µg/L) in 2005 and 2015. On average, MTBE concentrations decreased 65% among 47 wells, whereas MTBE concentrations increased 17% among 4 wells between 2005 and 2015. The percent change in detection frequency from 2005 to 2015 (the decontamination rate) was lowest in areas of high population density and in wells completed in the Berwick Formation geologic units. The decontamination rate was highest where population densities were low and wells were completed in bedrock composed of granite, metamorphic, and mafic rocks. Wells in the Berwick Formation are characteristically deeper and have lower yields than wells in other rock types and have shallower overburden cover, which may allow for more rapid transport of MTBE from land-surface releases. Slide presentation:

1,4-Dioxane Remediation by Extreme Soil Vapor Extraction (Xsve)

Posted: July 5, 2018

Although 1,4-dioxane's vapor pressure is in the range of TCE or benzene, 1,4-dioxane is totally water soluble and hence becomes sequestered in vadose zone pore water, which serves as a long-term source of groundwater contamination. Conventional soil vapor extraction (SVE) is able to remove some 1,4-dioxane, but a substantial residual source can remain. Extreme soil vapor extraction (XSVE) specifically addresses 1,4-dioxane-contaminated soil by incorporating enhancements such as decreased infiltration, increased air flow, focused vapor extraction, and injection of heated air. The former McClellan AFB near Sacramento provided an XSVE demonstration site adjacent to an SVE well with high 1,4-dioxane concentrations. The XSVE system consisted of four 2-in steel-cased injection wells forming a 20-ft square with a central 4-in steel-cased extraction well (38-68 ft bgs screened interval each). The system operated for ~13 months with about 98% uptime at injection temperatures maintained in the 100-130°C range (mid-screen). Post-demonstration, treatment zone decreases of ~94% 1,4-dioxane and 45% soil moisture were observed. Downward migration of 1,4-dioxane due to condensation was not observed. A screening-level mass and energy balance model, HypeVent XSVE, was developed to simulate the remediation of 1,4-dioxane by XSVE.

Long-Term Performance Assessment at a Highly Characterized and Instrumented DNAPL Source Area Following Bioaugmentation

Posted: July 5, 2018

In a study of long-term behavior in chlorinated ethene DNAPL source areas following in situ bioaugmentation in heterogeneous media, monitoring was performed up to 3.7 years following active TCE bioremediation using a high-density monitoring network. Soil sampling, passive flux meters, and push-pull tracer testing was performed. Results 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 that 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 study results suggest biological processes have the potential to persist to treat TCE years after cessation of active bioremediation, thereby serving as an important component of remedial design and long-term attenuation. Reliance on ethene generation alone as an indicator of complete dechlorination significantly underestimated the extent of complete dechlorination, as CSIA analysis provided a more reliable estimate, thus highlighting the importance of utilizing isotopic data to determine dechlorination rates in complex systems. Results also emphasized the importance of high-resolution characterization and monitoring in facilitating improved design and performance monitoring.

Addressing Vapor Intrusion at Remediation and Redevelopment Sites in Wisconsin

Posted: July 5, 2018

This guide identifies the conditions where assessment of the vapor intrusion pathway is necessary at contaminated sites; sets out the criteria for evaluating health risk; identifies appropriate responses; explains long-term stewardship; and clarifies when sites with a complete or potential vapor migration pathway may achieve closure. The guide is applicable to contaminated sites where volatilization of subsurface contaminants has migrated or has the potential to migrate to current or future occupied buildings.

Treatment of Perfluorinated Alkyl Substances in Wash Water Using Granular Activated Carbon and Mixed-Media

Posted: July 17, 2018

This report summarizes the results from testing conducted to evaluate the treatment of large volumes of water containing perfluorinated alkyl substances (PFASs), specifically treatment for water contaminated by aqueous film forming foam (AFFF) used in firefighting. The AFFF selected for this study was a product widely used historically, and it contained PFOA and PFOS. Treatment of the AFFF-contaminated water was investigated using Calgon Filtrasorb® 600 granular activated carbon (GAC) and Ziltek RemBind™ mixed media. The contaminated water was pumped through treatment media and then emptied into bladder tanks. The goal was to assess the respective performance of the two products to reduce the PFAS concentration before disposal of the water (e.g., in a sewer).

Superfund X-Ray Fluorescence Field Operations Guide

Posted: July 17, 2018

This guide was developed for consideration by Region 4 On-Scene Coordinators (OSCs) and Remedial Project Managers (RPMs) to provide the OSCs/RPMs with a methodology to collect defensible XRF data for lead and arsenic (and possibly other metals) in soil samples. The technical information provided for measuring concentrations of contaminants in soil in a practical, cost-effective, and timely manner does not constitute rulemaking by the Agency; the purpose of the guide is to aid in the collection of high-quality soil data for select contaminants that can be used in risk assessments.

Standard Operating Procedure for An in Vitro Bioaccessibility Assay for Lead and Arsenic in Soil

Posted: July 17, 2018

The purpose of this standard operating procedure (SOP) is to define the proper analytical procedure for the validated in vitro bioaccessibility (IVBA) assay for lead and arsenic in soil, to describe the typical working range and limits of the assay and quality assurance factors, and to indicate potential interferences. The method has been validated only for lead and arsenic in soil, not other contaminants or matrices (e.g., water, air, amended soils, dust, food, etc.). This SOP is intended to be used as a reference for developing site-specific quality assurance project plans and sampling and analysis plans.

Validation Assessment of in Vitro Arsenic Bioaccessibility Assay for Predicting Relative Bioavailability of Arsenic in Soils and Soil-Like Materials at Superfund Sites

Posted: July 17, 2018

This report summarizes the basis for EPA's determination that the in vitro bioaccessibility (IVBA) method for arsenic has satisfied the validation and regulatory acceptance criteria for application of the method in an appropriate regulatory context. The arsenic method estimates site-specific relative bioavailability (RBA) of arsenic in soils quickly and inexpensively relative to in vivo methods and is well suited for regulatory use in arsenic risk assessment.

Bisc Semi-Annual Monitoring and Performance Report, Rev. 1: July 1 to December 31, 2017, Perchlorate Bioremediation System, Henderson, Nevada

Posted: August 2, 2018

This monitoring and performance report for the perchlorate treatment system at Henderson, Nevada, documents groundwater monitoring and fluidized bed reactor (FBR) remediation system data collected July 1 through December 31, 2017, as well as results of the annual monitoring well sampling event. Groundwater treatment system operation is based at a 9,000 ft2 building located within a 1.77-acre site in Henderson. The FBR system began operation in late September 2012 and is designed to remove perchlorate from groundwater extracted from the Valley Auto Mall area (near the source area close to the former PEPCON facility) as well as the shallow groundwater bearing zone before it enters the Las Vegas Wash. The treatment system comprises 14 extraction wells, a water handling and FBR treatment plant, and a discharge system. The FBR plant consists of two first-stage FBRs that contain sand while a second-stage FBR contains granular activated carbon. Microorganisms growing as a film on the media utilize metabolic pathways to reduce perchlorate, chlorate, nitrate, and oxygen in redox reactions that result in nitrogen, CO2, water, and minerals. Ethanol is added as an electron donor along with nutrients (di-ammonium phosphate/urea mixture) and other trace elements. The pH is adjusted through the addition of a 50% (by weight) solution of sodium hydroxide.