Other Recent Additions
Recent Additions
2014 ITRC Projects in the Remediation Area
Posted: May 15, 2013
The Interstate Technology & Regulatory Council (ITRC) requests proposals for 2014 ITRC projects in the remediation area only. ITRC would like to focus proposals on the following topical areas: site characterization, sampling, and monitoring; soil and groundwater contamination, specifically groundwater or contaminant fate and transport modeling; and long term stewardship, land use controls, and institutional controls. Proposals on other topics will be considered, but preference will be given to those that address one of the areas above. Proposals are due by 5:00 pm Eastern time on Friday, June 14, 2013.
Draft Final Vapor Intrusion Guidance Documents
Posted: April 17, 2013
EPA has prepared external review drafts of two guidance documents about vapor intrusion: a general guidance for all compounds and one focused on petroleum hydrocarbons released from underground storage tanks. When final, these guidance documents will help ensure vapor intrusion exposure assessment and mitigation actions to protect human health are undertaken in a technically, scientifically and nationally consistent manner. The public may provide input by May 24, 2013.
Superfund Risk Assessment and How You Can Help
Posted: April 11, 2013
EPA developed the 40-minute video "Superfund Risk Assessment and How You Can Help" to help explain in plain terms the Superfund human health risk assessment process and how communities can be involved. The video lays the groundwork for in-depth discussion on human health risk assessment, how it relates to cleanup, and how people can be involved. The community interviews in the video enhance the message that early community involvement is important to the Superfund cleanup program. A presenter’s manual is available, designed to support EPA Superfund staff during public presentation of the 40-minute video.
The 10-minute introductory video contains information extracted from the 40-minute video. This video could be shown to a community to assess whether they want to know more about human health risk assessment.
To request a copy of a transcript for this video, please contact Jean Balent at balent.jean@epa.gov.
Also available is a 19-minute video "Superfund Radiation Risk Assessment and How You Can Help: An Overview" which explains in plain terms the Superfund human health risk assessment process for radioactive contaminants and how communities can be involved.
The 10-minute introductory video contains information extracted from the 40-minute video. This video could be shown to a community to assess whether they want to know more about human health risk assessment.
To request a copy of a transcript for this video, please contact Jean Balent at balent.jean@epa.gov.
Also available is a 19-minute video "Superfund Radiation Risk Assessment and How You Can Help: An Overview" which explains in plain terms the Superfund human health risk assessment process for radioactive contaminants and how communities can be involved.
Geochemical Characterization and Longevity Estimates of a Permeable Reactive Barrier System Remediating a 90Sr Plume
Posted: May 7, 2013
In 1998, a "wall and curtain" permeable reactive barrier (PRB) containing clinoptilolite as a reactive material was installed at the Chalk River Laboratories in Chalk River, Ontario, to prevent discharge of a strontium-90 plume into a nearby swamp. After nearly 14 years of operation, refined estimates of the PRB's efficiency and longevity indicate the system is highly efficient in treating an average mass flux of >17,000 Bq/m2/day and could continue to function for 80 to 100 years.
In Situ 'Deliverability' Trials Using Calcium Polysulphide to Treat Chromium Contamination at Shawfield, Glasgow
Posted: May 7, 2013
Calcium polysulfide (CaSx) reduces highly soluble Cr(VI) compounds to much less soluble and comparatively harmless Cr(III) compounds. Following earlier field trials that indicated the effectiveness of CaSx application in reducing Cr(VI) associated with chromite ore processing residue, another field trial was conducted in 2009 to identify the most effective mechanism for delivering CaSx into the subsurface. The CaSx delivery methods investigated were (1) a groundwater recirculation system (which also achieved in situ flushing of contaminated soil); (2) direct-push injection using close grid spacing; and (3) soil mixing. All three trials provided evidence of total Cr mobilization as a combination of chemical-physical action. [NOTE: The bulletin is available without charge on the CL:AIRE website to registered users (also free) at
Engineered Phytoremediation of Benzene, GROs, DROs and Other VOCs in Groundwater
Posted: May 7, 2013
Two phytoremediation pilots were installed in 2007 at sites in central Michigan to assess the potential for engineered phytoremediation to (1) gain hydraulic control of the local groundwater units and (2) remediate groundwater containing elevated concentrations of dichloropropane, benzene, gasoline range organics (GROs), diesel range organics (DROs), and other VOCs. The Root_Sleeve™ liner of the TreeWell® engineered phytoremediation system is designed to treat the groundwater via a bioreactor effect before the groundwater contacts the root system. This bioreactor effect is demonstrated in the sampling data as well as by the absence of phytotoxic effects of the elevated contaminant concentrations on the trees, most of which realized aggressive and healthy growth. The few occurrences of phytotoxicity were attributed to elevated chloride levels. Hydraulic data show increasing hydraulic effects with each growing season. Groundwater in the pilot study area has shown progressive reductions in contaminant concentrations (~20% cumulatively) over the 5-year term of the study.
Integrated Forensics Approach to Fingerprint PCB Sources in Sediments Using Rapid Sediment Characterization (RSC) and Advanced Chemical Fingerprinting (ACF)
Posted: May 7, 2013
To identify PCB sources to sediments, this project demonstrated an integrated approach to fingerprinting PCB contamination that combines sediment screening technologies on a large number of field samples followed by detailed PCB congener analysis in conjunction with advanced chemical fingerprinting data interpretation on a subset of selected laboratory samples. Sites with extensive preexisting data sets were selected for the demonstration: the South Basin at Hunters Point Shipyard, located south of San Francisco, and the Ashtabula River Dredge site, located east of Cleveland. All the techniques discussed in this report are commercially available from multiple sources.
Comparative Demonstration of Active and Semi-Passive in Situ Bioremediation Approaches for Perchlorate Impacted Groundwater: Active in Situ Bioremediation Demonstration (Aerojet Facility)
Posted: May 7, 2013
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 to promote in situ biodegradation of the contaminants. 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. Results demonstrate that the site's indigenous bacteria are capable of biodegrading perchlorate using ethanol as an electron donor. Perchlorate concentrations as high as 4,300 µg/L were reduced to less than 4 µg/L within 50 ft of the recharge well. TCE dechlorination was observed at the downgradient monitor well following bioaugmentation of the shallow aquifer with KB-1 to introduce dehalorespiring bacteria.
Combining Low-Energy Electrical Resistance Heating With Biotic and Abiotic Reactions for Treatment of Chlorinated Solvent DNAPL Source Areas
Posted: May 7, 2013
Project ER-0719 demonstrated the combination of low-temperature subsurface heating with in situ remedies to enhance remediation performance through both increased degradation reaction rates and contaminant dissolution. Dechlorination was induced in two test cells for zero-valent iron (ZVI) and in situ bioremediation (ISB) using emulsified oil and whey powder. For the ZVI test, temperature elevated from 10°C to between 35-45°C increased dechlorination by a factor of 4 to 8. For the ISB test, a similar temperature increase accelerated overall contaminant dechlorination by a factor of 2-4 at hotspot locations close to residual contaminant mass. Field test results demonstrated that 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 treatment maintained low aqueous TCE concentrations. The heating infrastructure was limited to subsurface electrodes and a power control unit. Results indicate the combined methods may be cost-effective in source zones with moderate contaminant mass.
Vapor Intrusion Public Participation Advisory
Posted: May 7, 2013
This Advisory describes public participation approaches designed to facilitate effective communication and coordination with communities and stakeholders affected by or concerned with vapor intrusion at sites that have a potentially complete indoor air exposure pathway.
Mercury Contaminated Sites: Summary Report, NICOLE Technical Meeting
Posted: May 7, 2013
Across the European Union, mercury is listed as a priority hazardous substance, and its use is being largely phased out. The technical workshop on mercury-contaminated sites of 4 December 2012, in Brussels, Belgium, was held to identify and disseminate state-of-the-art strategies, techniques, and technologies that support the management of Hg-contaminated sites while minimizing risk and maximizing sustainability. This report summarizes the workshop presentations and discussions.
