Action Item: Vapor intrusion has been a primary concern of state and federal environmental agencies for the past decade, and, accordingly, remedial actions have included vapor migration and intrusion as an exposure pathway. Now, the direction and methods by which to evaluate vapor intrusion have been formalized and enhanced by the EPA's issuance of new vapor intrusion guidance documents. The EPA's issuance of these guidance documents will likely increase transactional due diligence costs and litigation costs as well, and states are sure to follow the EPA's lead in developing formal vapor intrusion investigation guidelines.
On June 11, 2015, the
U.S. Environmental Protection Agency ("EPA") released two technical guidance documents that address assessment and mitigation activities at residential and non-residential sites where vapor intrusion is an actual or potential concern, including sites being investigated under
CERCLA and
RCRA.
Vapor intrusion refers to the migration of vapors from contaminated subsurface sources, such as groundwater, through soil and into overlying building and structures. Vapor intrusion may be a potential concern at any building located near soil or groundwater contaminated with vapor-forming hazardous materials.
The EPA's focus on vapor intrusion has grown significantly over the last decade, as has the focus of state regulatory agencies involved in reviewing and directing remedial actions to address releases of hazardous materials. The new guidance documents incorporate the EPA's current recommendations for identifying, evaluating, and managing vapor intrusion, while providing some flexible technical approaches to accommodate site-specific conditions and circumstances. These guidance documents were intended to promote national consistency in assessing and addressing the vapor intrusion human exposure pathway at contaminated sites. Indeed, many states have been awaiting the publication of these guidance documents before releasing their own state vapor intrusion guidance documents. The two new vapor intrusion guidance documents, which have not yet been published in the
Federal Register, supersede and replace the EPA's 2002 Draft Vapor Intrusion Guidance.
At sites where vapor intrusion poses a potential or actual hazard to occupants' health or safety, exposures usually can be prevented or reduced through relatively simple actions, such as changing building pressure and ventilation. In most cases, costs associated with addressing vapor intrusion can be manageable, resulting in what the EPA believes to be long-term benefits, including improved public health and less costly response actions. The EPA believes that these benefits are especially likely when actions are undertaken early.
The new guidance documents, which the EPA will rely upon in connection with response and enforcement, will result in several impacts. First, the EPA's focus on vapor intrusion will likely increase remedial obligations under CERCLA and other statutes requiring remediation, such as RCRA. Second, due diligence costs associated with transactions that involve the sale, purchase, or leasing of real property are likely to increase as parties involved in those transactions determine that the risks associated with potential vapor intrusion issues warrant investigation and mitigation, which could even include sites where remedial actions have already been implemented and received a "no further action" status if those sites were not previously investigated with "vapor intrusion" as a pathway for exposure. Third, the additional inquiry into the potential for vapor intrusion as set forth in the new guidance documents may result in private party litigation serving to provide plaintiffs with another cause of action by which to claim exposure to vapors from hazardous materials and contaminants, and damages resulting from that exposure. In cases involving properties that have received remedial action approval without any focus on a vapor intrusion pathway, the ability to defend against such litigation may prove difficult.
The new guidance documents and supporting tools can be found by clicking on the following:
