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

FY 2018 SERDP Solicitations Released

Posted: October 31, 2016

The Department of Defense's Strategic Environmental Research and Development Program (SERDP) is seeking environmental research and development proposals for funding beginning in FY 2018. The Core Solicitation provides funding opportunities for basic and applied research and advanced technology development. Core projects vary in cost and duration consistent with the scope of the work proposed. The Statements of Need (SON) referenced by this solicitation request proposals related to the SERDP program areas of Environmental Restoration (ER), Munitions Response (MR), Resource Conservation and Climate Change (RC), and Weapons Systems and Platforms (WP). The SERDP Exploratory Development (SEED) Solicitation provides funding opportunities for work that will investigate innovative environmental approaches that entail high technical risk or require supporting data to provide proof of concept. Funding is limited to not more than $200,000 and projects are approximately one year in duration. This year, SERDP is requesting SEED proposals for the Munitions Response program area. All Core pre-proposals were due January 5, 2017. SEED proposals are due March 7, 2017.

Integrated Stable Isotope-Reactive Transport Model Approach for Assessment of Chlorinated Solvent Degradation

Posted: November 3, 2016

This demonstration project was funded by ESTCP with the main goal of demonstrating the utility of combining compound-specific isotope analysis (CSIA) and reactive transport modeling (RTM) to quantify and strengthen support for monitored natural attenuation remedies for groundwater contaminated with chlorinated ethene constituents. The demonstration followed two main tracks: development and initial calibration of the modeling software and a demonstration of the combined CSIA/RTM approach through an assessment of a contaminated site (the Shallow TCE & PCE Plume and the Deep TCE Plume at Hill AFB, Operable Unit 10). The success of the technology demonstration was defined in terms of producing results that are useful for development/improvement of the conceptual site model and are superior to those obtained by CSIA alone.

A Tree-Based Remediation System for Treatment and Hydraulic Control of a Hydrocarbon Plume in a 20 Foot Deep Aquifer at a Former Refinery in Central Oklahoma

Posted: November 3, 2016

The 15-20 ft deep groundwater at the former refinery occurs mainly in a sandy aquifer overlain by 20 ft of dense clay. A detailed groundwater model of the aquifer and petroleum hydrocarbon contaminant plume indicated that a tree-based remediation system using 400 trees, each pumping 50 gal/d/yr, could control the plume's off-site migration. A TreeMediation® system using patented TreeWell® technology was identified as the best approach for insuring that the tree-based system would use groundwater at the required rates. Four non-irrigated pilot study areas were established in 2012, each consisting of 72 trees (hybrid poplar, weeping willow, and London plane) planted in cased holes 3 ft in diameter to force root development to the water table and insure that contaminated groundwater was the primary water source. The pilots evaluated tree growth and development under the effects of extreme climate conditions and up-to-LNAPL levels of groundwater contamination. Following successful demonstration of the phytotechnology option, the selected solutions for the site included treating LNAPL pockets with oxygen sparging, and reducing the hydraulic gradient with a tree-based pump-and-treat system to create an opportunity for monitored natural attenuation to control off-site migration of the contaminant plume. Based on the pilot results, half of a full-scale phytoremediation installation was completed in spring 2015.

Soil Dioxin Relative Bioavailability Assay Evaluation Framework

Posted: November 18, 2016

Until standard procedures for estimating the relative bioavailability (RBA) of PCDD/F in soil are established, there is a need for a consistent approach to evaluate the strengths and weaknesses of assays designs proposed or implemented to support risk assessments. This report offers a framework for making such evaluations. Specific design parameters that should be subject to evaluation are identified and relevant scientific literature is cited where more in-depth discussion can be found. Whenever possible, minimal requirements for study designs are proposed. This report also identifies issues that have yet to be resolved regarding how RBA assays should be designed and which could be objectives of further research to develop RBA assays for soil PCDD/F and applications to risk assessment.

State Vapor Intrusion Guidance Updates

Posted: November 18, 2016

  • The Kansas Dept. of Health and Environment updated its 2007 VI guide with Kansas Vapor Intrusion Guidance (25 pp, 2016).

Passive Biobarrier for Treating Co-Mingled Perchlorate and Rdx in Groundwater at An Active Range

Posted: December 2, 2016

A field demonstration was undertaken to investigate the feasibility of using a passive emulsified oil biobarrier to remediate commingled perchlorate, RDX, and HMX in the naturally acidic groundwater at the Naval Surface Warfare Center, Dahlgren (Virginia). Microcosm studies indicated that a specific emulsified oil (EOS 550LS) plus a slow-release buffering agent (CoBupH) was the most effective substrate for promoting the biodegradation of all three target contaminants. Perchlorate degraded most quickly and HMX most slowly. After the second injection of emulsified oil, concentrations of RDX, HMX, and perchlorate fell by ≥92% in the centerline of monitoring wells extending 40 ft downgradient of the biobarrier. Accumulation of nitroso- degradation products from RDX was minimal. The biobarrier required no O&M other than injection/reinjection of oil substrate and had no impact on range activities.

Field Demonstration of Propane Biosparging for In Situ Remediation of N-Nitrosodimethylamine (Ndma) in Groundwater: ESTCP Cost and Performance Report

Posted: December 2, 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 sparging system, which consisted of three biosparging wells connected to an air compressor and propane gas feed, supplied ~1.8 lb of propane to the in situ test plot per day for a period of 374 days. NDMA concentrations declined by >99.7% in the treatment area. A full-scale propane biosparge system was estimated to be ~40% less expensive to build, install, and operate than a comparable UV system over a 30-yr time frame.

Bioaugmentation for Aerobic Bioremediation of Rdx-Contaminated Groundwater

Posted: December 2, 2016

RDX is mobile and persistent in aerobic groundwater and typically forms large, dilute plumes that are difficult and costly to remediate using conventional technologies, such as pump and treat or anaerobic biostimulation. This project demonstrated an innovative application of bioaugmentation to enhance RDX biodegradation in contaminated groundwater under aerobic conditions at the Umatilla Chemical Depot (UMCD) in Umatilla, Oregon. The principal demonstration objectives were to (1) select and optimize RDX-degrading microbial cultures for use in aerobic bioaugmentation at the site; (2) compare in situ RDX biodegradation rates for aerobic bioaugmentation to those for biostimulation; and (3) quantify and compare costs of RDX remediation. This report summarizes the demonstration activities and results.

Nanofiber-Enabled, Multi-Target Passive Sampling Device for Determination of the Freely-Dissolved Sediment Pore Water Concentrations of Organic Contaminants

Posted: December 2, 2016

A suite of electrospun nanofiber mats (ENMs) was fabricated as next-generation multi-target passive samplers to test their sorption capacities for a set of hydrophilic (aniline and nitrobenzene) and hydrophobic compounds (PCBs and dioxin). The average diameter of the ENMs ranged from 70 (PET) to 1,000 (EVA) nm, with a relative standard deviation of less than 50% for each material. In water the ENMs yielded a fast equilibration time (<3 days) for the tested compounds. The ENM-water partition coefficient (KENM-w) for the hydrophilic compounds ranged from 0.72 to 2.8 log units. The KENM-w for hydrophobic compounds ranged from 3.2 to 6.4 log units. Collectively, the rates and KENM-w measured for the best performing ENMs often exceeded partition coefficients achieved with commercially available passive sampling materials (e.g., low-density polyethylene and PDMS glass fiber), particularly for hydrophilic compounds.

Third-Generation (3g) Site Characterization: Cryogenic Core Collection and High-Throughput Core Analysis, An Addendum to Basic Research Addressing Contaminants in Low Permeability Zones: a State of the Science Review

Posted: December 2, 2016

Core samples frozen in situ before recovery can preserve pore fluids, volatile compounds, dissolved gases, redox conditions, mineralogy, microbial ecology, and pore structure. Furthermore, in situ freezing improves the quality of recovered core by preventing materials from dropping out of sample liners during recovery to ground surface. The steps followed for collecting frozen cores are referred to in this text as cryogenic core collection. Processing core in the lab simplifies field work and improves the resources (e.g., anaerobic chambers) that can be used when preparing samples for analysis, while allowing "production line" processing and analysis of large quantities of samples (i.e., high-throughput core analysis). In this project, the combination of cryogenic core collection and high-throughput sampling yielded high quality samples suitable for a wide range of chemical, physical, and biological analyses of chlorinated solvents and other persistent contaminants in groundwater in unconsolidated sediments. The protocols for sample collection and processing are sufficiently robust that they can now be used routinely at field sites.