The objective of this topic area was to seek demonstration projects of methodologies, protocols, or decision-making tools that can improve our ability to more accurately and cost effectively assess vapor intrusion from subsurface volatile organic compounds. Vapor intrusion from chlorinated solvents is of particular interest. The ultimate goal of these efforts is to provide better and more cost-effective protection of human health. The following issues must be considered:

• Improve the fundamental understanding of the mechanisms involved in fate and transport processes in groundwater under varying natural and engineered conditions.
• Determine the impact of co-contaminants on fate and transport processes.
• Improve the understanding of the behavior of perfluoroalkyl contaminants under typical remedial technologies for co-contaminants. For example, perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) may be present at sites contaminated with petroleum hydrocarbons and possibly chlorinated solvents (e.g. historical fire training sites); therefore, understanding the fate of PFOS and PFOA during monitored natural attenuation or enhanced anaerobic dichlorination is critical.
• Develop remedial strategies for perfluoroalkyl contaminants, including consideration of the necessity for treatment train approaches to facilitate treatment of co-contaminants.

The projects listed below were selected to address the objectives of this topic area. Additional information on individual projects can be found by clicking the project title.

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  • Lead Investigator: Dr. Paul Johnson, Colorado School of Mines
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  • Dr. Eric Suuberg, Brown University, Department of Engineering
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  • Dr. Helen Dawson, Geosyntec Consultants, Inc., Principal Civil and Environmental Engineer
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  • Dr. Alan Rossner, Clarkson University, Institute for a Sustainable Environment
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  • Dr. Thomas McHugh, GSI Environmental Inc., Principal Environmental Toxicologist

Research should lead to developing a greater understanding of vapor pathways through the subsurface around residential and industrial buildings. The research that will be developed through this topic area will demonstrate methodologies, protocols, or decision-making tools that can improve our ability to more accurately and cost effectively assess vapor intrusion from subsurface volatile organic compounds. Issues that were considered when developing methods and technologies include the impact of temporal and spatial variability of contaminant measurements, the impact of preferential vapor pathways, identification of the required lines of evidence, and determination and management of the uncertainties associated with samples collected in the short term and their extrapolation over the long term.