The EPA has released two technical guides to support assessment and mitigation activities at sites where vapor intrusion is an actual or potential concern.
Vapor intrusion is a potential concern at any building — existing or planned — located near soil or groundwater contaminated with vapor-forming toxic chemicals.
The Technical Guide for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Vapor Sources to Indoor Air applies to all sites being evaluated under federal land cleanup statutes by the EPA, other federal agencies, state and tribal governments and brownfield grantees. A companion document, the Technical Guide for Addressing Petroleum Vapor Intrusion at Leaking Underground Storage Tank Sites addresses any sites where vapor intrusion related to petroleum contamination from underground storage tanks is a potential concern.
Both guides are applicable to residential and non-residential settings.
The guides present EPA’s current recommendations for identifying, evaluating and managing vapor intrusion while providing flexible technical approaches to accommodate site-specific conditions and circumstances.
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 very manageable, resulting in long-term benefits including improved public health and less costly response actions. These benefits are especially likely when actions are undertaken early.