Behavior of Perfluoroalkyl Chemicals in Contaminated Groundwater
ER-2126
Objective
The recent publication of provisional health advisory levels for some perfluoroalkyl chemicals (PFCs) in drinking water has raised concerns about the risk PFC surfactants pose to human health. Aqueous film-forming foams (AFFF) of various formulations have been used by the Department of Defense (DoD) to combat fuel fires for many years. In addition, AFFF products have been used during fire-training exercises at many DoD sites. Many AFFF formulations contain PFC or PFC-based surfactants, and thus PFCs have often been released in the presence of co-contaminants such as fuel-derived hydrocarbons and chlorinated solvents. Serious data gaps exist with respect to understanding the behavior of PFCs in groundwater systems, particularly in the presence of co-contaminants. Moreover, very little is known about how PFC fate and transport will be affected when sites are subject to in situ remediation aimed at attenuating the co-contaminants also present.
The objective of this project is to evaluate the relative importance of key physicochemical and biological parameters in determining the fate and transport of PFCs in groundwater in the presence of co-contaminants and during remediation of co-contaminants.
Technical Approach
Controlled experiments will be conducted under laboratory conditions to carefully evaluate a range of factors that affect PFC transport, including the presence of co-contaminants such as chlorinated solvents and fuel-derived nonaqueous phase liquids (NAPLs). In particular, the importance of co-contaminant concentration, composition, interfacial area, and extent of remediation on the retardation of PFCs will be examined. This research will also help elucidate the extent to which current in situ technologies widely used for co-contaminant remediation may also alter the fate and transport of PFCs present in groundwater. Monitored natural attenuation (MNA), enhanced reductive dechlorination (ERD), and in situ chemical oxidation (ISCO) impacts on PFC fate and transport will be explored. Batch tests and flow-through experiments in 1-D columns and 2-D cells will be completed to examine the complex interactions between hydrological, biogeochemical, and remedial conditions on PFC behavior. The data from various scales will be analyzed to determine the key variables impacting PFC behavior in contaminated groundwater during ambient and remediation-induced conditions.
Benefits
This research will provide a fundamental understanding of PFC transport in contaminated groundwater, particularly in the presence of co-contaminants. Additional benefits to DoD include reduced uncertainty about how co-contaminant remediation technologies will affect PFC fate and transport. This reduced uncertainty will lead to greater confidence in remedial decisions at AFFF-impacted sites. (Anticipated Project Completion - 2014)
Points of Contact
Principal Investigator
Dr. Christopher Higgins
Colorado School of Mines
Phone: 303-384-2002
Fax: 303-273-3413
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.