Vapor Intrusion On-Demand Webinar Links

The Geosyntec Vapor Intrusion Webinar Series provides a thorough synthesis of the state of knowledge on the characterization and remediation of PFAS-impacted sites.

The password for each webinar is geosyntecVI

Vapor Intrusion Webinars

Optimizing Vapor Intrusion Pathway Assessment

Efficient and effective vapor intrusion (VI) pathway investigations come from a strong understanding of VI fundamentals and from a diverse toolbox for field and office applications. This webinar will give an overview of VI conceptual site models (CSMs) and introduce advanced techniques to fill data gaps and revise the VI-CSM. Temporal variability in indoor air analytical data, spatial variability in sub-slab soil gas analytical data, background sources of common volatile contaminants and preferential pathways can make the answers to common questions posed during VI investigations seem complex: (i) Do I have to sample indoor air? (ii) Do I need to collect multiple rounds of indoor air samples? (iii) How many sub-slab soil gas samples do I need to collect? And (iv) which preferential pathways are most important? The speakers will address these questions in the context of current research and the array of tools available to today’s VI practitioner.

  • Kelly Pennell, Ph.D., University of Kentucky
  • Chase Holton, Ph.D., P.E. (CO, OK), Geosyntec Consultants
  • Todd Creamer, P.G., Geosyntec Consultants

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VI Mitigation Systems for New Buildings: One Size Doesn't Fit All

The design and installation of successful and cost-efficient vapor intrusion (VI) mitigation systems in new buildings requires an understanding of the VI pathway at the site (the VI Conceptual Site Model [CSM]) and how the mitigation approach would prevent VI from occurring in the future building (the mitigation CSM). Based on this understanding, we will consider three common stakeholder questions: 1) should we design an active or passive system, 2) what type and thickness of vapor barrier is needed, and 3) what negative pressures or vacuum levels are needed for active depressurization systems? Key factors addressing all three of these questions include how the mitigation approach would control VI, how you can demonstrate successful performance, and how you can show continued performance in the future. Other stakeholder priorities that can effect these decisions include effects of the system on building design and construction, installation costs, and long-term operating, maintenance, and monitoring costs.

  • Matthew Williams, Michigan Department of Environment, Great Lakes, and Energy
  • David Folkes, P.E. (CO), Geosyntec Consultants
  • Eric Lovenduski, Geosyntec Consultants

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When Due Diligence Goes Wrong - Assessing the VI Pathway to Support Successful Property Transactions

When it comes to vapor intrusion (VI), there are state-specific guidance documents and property-specific considerations that apply to environmental due diligence. Therefore, a one-size-fits all approach is not applicable when assessing the VI pathway. This presentation will discuss things to consider and pitfalls to avoid that might affect successfully completing a property transfer.

  • Nicholas Targ, Holland & Knight
  • Kaitlyn Rhonehouse, P.E. (FL, NC), Geosyntec Consultants

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More Information

For consultation regarding regulatory or compliance issues, contact us at This email address is being protected from spambots. You need JavaScript enabled to view it. or visit www.geosyntec.com/vi.