When volatile chemicals have the potential to migrate from contaminated groundwater or soil into an overlying building—i.e., vapor intrusion (VI)—a whole new layer of complexity is added to environmental remediation projects. In Washington State over the last several years, vapor intrusion has been under increasing regulatory scrutiny. An understanding of vapor intrusion typically revolves around a few core questions:

• How to accurately evaluate it?
• How to keep abreast of what’s required, given that the regulatory guidance is constantly evolving?
• How to protect human health during and after site cleanup?

During Aspect’s monthly technical exchange series, Eric Marhofer, Dave Heffner, Carla Brock, Eric Geissinger, and Kirsi Longley of our environmental team gave a roundtable presentation of their collective experience at assessing vapor intrusion at well over 100 sites.