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

Small Business Innovation Research (SBIR) Phase I

Posted: September 1, 2016

The U.S. Environmental Protection Agency announces the release of its Small Business Innovation Research (SBIR) Phase I Solicitation to support the development and commercialization of innovative environmental technologies. The solicitation is posted on FedConnect, and all applications must be submitted through this electronic system. EPA is one of 11 federal agencies that participates in the SBIR Program as a result of the Small Business Innovation Development Act of 1982. 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: air and climate, manufacturing, toxic chemicals, water, water and homeland security, and greener buildings. See the full solicitation for specific subtopics under each topic area and for details on how to apply. Successful Phase I companies are eligible to apply for Phase II funding, up to $300,000 for two years with a commercialization option of up to $100,000, to further develop and commercialize their technologies. Proposals are due October 20.

Consideration of Greener Cleanup Activities in the Superfund Cleanup Process

Posted: August 18, 2016

EPA recently issued a guidance memorandum recommending approaches for regional Superfund programs to consider when evaluating greener cleanup activities through the CERCLA process. The memorandum also encourages regions to consider conducting an environmental footprint analysis to help identify best practices that may help minimize the footprint on a site-specific basis. Relevant parts of the CERCLA process include site characterization; remedial investigation and feasibility study or engineering evaluation/cost analysis; development of decision documents; and enforcement mechanisms. The memorandum supplements the Agency's fact sheets and policy statements addressing greener cleanup activities, tools and considerations and is intended as guidance for Fund-lead, federal facility-lead, and potentially responsible party-lead cleanups.

Bioremediation of Source Zone and Migrated Plumes

Posted: August 22, 2016

The former Unocal distribution facility in Wichita, Kansas, blended and packaged bulk chemicals for industrial customers. During historical operations, PCE was released to the site groundwater. Remedial technologies implemented at the site since 1989 to treat chlorinated VOCs in the groundwater include soil vapor extraction, pump and treat, excavation, bioremediation, and phytoremediation. Despite these measures, contaminated groundwater has migrated a quarter mile from the primary source area to adjacent properties. During annual groundwater monitoring conducted in 2013, PCE and its daughter products were present at concentrations over 10,000 µg/L. Monitoring data indicated that reductive dechlorination was ongoing, but little to no biodegradation was apparent in many off-site portions of the plume. A phased treatment approach is being implemented at the site. Based on results from a 2013 Bio-Trap® treatability study, EHC® and EHC® Liquid were selected to stimulate both biodegradation and chemical reduction. Baseline monitoring was conducted in June 2014, and the first round of injections began in July 2014. A total of ~29,500 lb EHC (as 30% slurry) and 1,850 gal EHC Liquid (diluted to make a 5% solution) were injected among six barriers and one injection grid through 165 injection points over a one-month period. Performance monitoring results (Nov 2014 and Mar 2015) indicate the amendments are conditioning the aquifer to promote reductive dechlorination. Additional information: Interim Measure Injection Completion Report, Former Unocal Chemical Distribution Facility (2015) at

Impact of Clay-DNAPL Interactions On Transport and Storage of Chlorinated Solvents in Low Permeability Zones

Posted: August 22, 2016

The objective of this research was to examine clay-DNAPL waste interactions as a contributor to the accumulation of chlorinated compound contamination in subsurface clay lenses and layers. Results showed that contact between DNAPL waste and Na-smectitic clay materials caused a contraction of the clay's basal space, producing cracking, in a time frame on the order of weeks. The hypothesized mechanism is syneresis, involving the sorption of the surfactants from the waste onto the clay surface and the solvation of the surfactants' aggregates. Numerical simulations suggest that even a small amount of cracking, and the time-variable dissolution of the DNAPL stored in the cracks into the surrounding clay matrix, extends the remediation time by decades.

Integrated Field-Scale, Lab-Scale, and Modeling Studies for Improving Our Ability to Assess the Groundwater to Indoor Air Pathway at Chlorinated Solvent-Impacted Groundwater Sites

Posted: August 22, 2016

This project was conducted primarily at a house overlying a dilute chlorinated hydrocarbon (TCE) groundwater plume. The house was outfitted with sensors and automated systems to facilitate monitoring of indoor air and ambient and building conditions as well as groundwater and soil gas. Monitoring was conducted under both natural and controlled building conditions, and both TCE and radon were quantified in indoor air and soil gas. Sampling was conducted under natural conditions for about 2.5 yr. Two recurring behaviors were observed with the indoor air data. The temporal behavior prevalent in fall, winter, and spring involved time-varying impacts intermixed with sporadic periods of inactivity. In summer, VI had long periods of inactivity combined with sporadic VI impacts. Subsurface concentrations were less temporally variable than indoor air, and the variability increased in moving from the source to indoor air.

Exceptionally Long MTBE Plumes of the Past Have Greatly Diminished

Posted: August 22, 2016

Studies published in the late 1990s and early 2000s identified the presence of exceptionally long MTBE plumes (>2,000 ft) in groundwater, cited in technical literature as characteristic of MTBE plumes. To investigate the subsequent behavior and fate of these MTBE plumes over the past decade, reviewers compiled recent groundwater monitoring records for nine historical MTBE groundwater plumes whose lengths formerly ranged from 2,700 ft to 10,500 ft in length. Groundwater monitoring data compiled in this review show that these large MTBE plumes decreased in length over the past decade, with five of the nine plumes exhibiting decreases of 75% or more compared to their historical maximum lengths. MTBE concentrations within these plumes declined by 93-100%, with two of the nine sites showing such significant decreases (98% and 99%) that the regulatory authority found the sites require no further action. This paper is Open Access at

Integrating Passive Sampling Methods Into Management of Contaminated Sediment Sites: a Guide for Department of Defense Remedial Project Managers

Posted: August 22, 2016

This document discusses how to integrate passive sampling methods into the management of contaminated sediment sites, with a focus on the passive sampling devices most commonly used to measure non-polar organic chemicals, such as PCBs and PAHs.

Field Demonstration of Propane Biosparging for In Situ Remediation of N-Nitrosodimethylamine (Ndma) in Groundwater

Posted: September 20, 2016

Propane gas and oxygen were added to groundwater via sparging to stimulate native microbes to biodegrade NDMA in situ at the Aerojet Superfund site in Rancho Cordova, Calif. Groundwater NDMA concentrations at the test site ranged from ~2,000 to >30,000 ng/L. The biosparging system was operated for a period of 374 days, and full rounds of sampling were conducted on 12 occasions. Data from this field test indicate that propane biosparging can be an effective approach to reduce the concentrations of NDMA in a groundwater aquifer by 3 to 4 orders of magnitude, and that concentrations in the low ng/L range can be achieved with continuous treatment. The groundwater in this region currently is captured by a groundwater extraction and treatment system, and NDMA is removed by UV irradiation. Based on a cost analysis for treatment of a shallow groundwater plume (~10-40 ft bgs) ~400 ft in width, a propane biosparge barrier was estimated to be more cost-effective for NDMA removal than pump and treat with either UV or a fluidized bed bioreactor.

Coupling Between Overlying Hydrodynamics, Bioturbation, and Biogeochemical Processes Controls Metal Mobility, Bioavailability, and Toxicity in Sediments

Posted: September 20, 2016

In lab experiments performed to determine the coupled effects of hydrodynamics, bioturbation, and biogeochemical processes on the transformation, mobility, bioavailability, and toxicity of metals in contaminated sediments, oxidation of surficial sediments liberated metal species that were then mobilized to both porewater and overlying water. Liberation of metals generally increased with hydrodynamic shear on the sediment-water interface, even in some low-permeability sediments. Sediment resuspension transitorily mobilized particulate metals but did not significantly mobilize dissolved metals or increase contaminant bioavailability or toxicity. Bioturbation and bioirrigation by burrowing worms, however, greatly increased sediment heterogeneity, oxygen delivery into sediments, and efflux of metals to both porewater and overlying water. Bioturbation also destabilized sediments, resulting in greater particle resuspension and metals efflux following flow perturbations. Based on these findings, the authors recommend including measurements of the effects of flow forcing and sediment resuspension in concert with biological perturbations during assessments of metals bioavailability and toxicity in contaminated sediments.