October 21, 2019

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Helen Dawson and Todd McAlary Wrote a Series of Vapor Intrusion Fact Sheets for the U.S. Department of Defense

Helen Dawson, Ph.D. (Washington D.C.) and Todd McAlary, Ph.D., P.Eng., P.G. (Ontario) recently completed a series of vapor intrusion (VI) fact sheets to supplement the U.S. Department of Defense (DoD) Vapor Intrusion Handbook.

Helen is a Senior Principal Civil and Environmental Consultant based in Washington, D.C. with more than 30 years of experience focused on private practice, academia, and public service. Her practice spans a wide range of technical disciplines including vapor intrusion, groundwater characterization, and contaminant fate and transport modeling related to the spread of dense non-aqueous phase liquids, chlorinated solvents, and metals in the environment.

Todd is a Senior Principal Engineer with more than 30 years of international consulting experience focused on the evaluation of contaminant fate and transport in soil and groundwater. Todd specializes in assessing and mitigating the migration of volatile organic compound (VOC) vapor from the sub-surface environment into buildings and in the assessment of human health risks associated with inhalation exposure.

The DoD Vapor Intrusion Handbook was issued a decade ago and the DoD has sponsored considerable applied research on VI through the Strategic Environmental Research and Development Program (SERDP)/Environmental Security Technology Certification Program (ESTCP) program since then.  The fact sheets are intended to provide an overview of these advancements and provide a supplement to the DoD Handbook.  Helen and Todd were retained for this effort by the U.S. Navy because of their deep knowledge of the subject matter and their demonstrated written communication skills. Several of the new technologies described in the fact sheets were pioneered by Geosyntec professionals, including passive sampling, high volume sampling, building pressure cycling and forensic methods to differentiate VI from background sources.

More Information

Learn more about the fact sheets: https://www.denix.osd.mil/irp/vaporintrusion/
Learn more about the DoD: https://www.defense.gov/
For consultation regarding vapor intrusion, contact Helen at This email address is being protected from spambots. You need JavaScript enabled to view it. or Todd at This email address is being protected from spambots. You need JavaScript enabled to view it.
Learn more about Helen: https://www.geosyntec.com/people/helen-dawson
Learn more about Todd: https://www.geosyntec.com/people/todd-mcalary