Eleven years after releasing an initial draft, EPA has finally
issued for public comment its proposed vapor intrusion guidance
documents: the "Final Guidance for Assessing and Mitigating
the Vapor Intrusion Pathway from Subsurface Sources to Indoor
Air" (VI Guidance) and the "Guidance for Addressing
Petroleum Vapor Intrusion at Leaking Underground Storage Tank
Sites" (Petroleum VI guidance). While providing more certainty
as to how to investigate and assess vapor intrusion, the guidance
could significantly increase remediation costs, add more
uncertainty to business transactions and cause regulators to reopen
sites where cleanup had previously been declared closed.
VI Guidance. The 196-page VI Guidance will be
applicable to Comprehensive Environmental Response, Compensation
and Liability Act (CERCLA), Resource Conservation and Recovery Act
(RCRA) and brownfield grant sites. As the guidance is meant to
comply with the National Oil and Hazardous Substances
