The NJDEP has recently finalized its revamped Vapor Intrusion Technical Guidance Document to provide more in depth assistance in the evaluation of vapor intrusion concerns. Vapor intrusion concerns relate to the potential for the migration of volatile chemicals from the subsurface and to the overlying structures. The presence of volatile chemicals in the soil or groundwater offers the potential for chemical vapors to migrate through subsurface soils potentially impacting the indoor air (“IA”) quality of effected buildings. NJDEP’s initial Vapor Intrusion Technical Guidance Document was created in 2005, which governed how vapor intrusion investigations were performed on contaminated sites since that time. However, after much discussion amongst stakeholders, on January 13, 2012, NJDEP finalized its Vapor Intrusion Technical Guidance Document.

The new Vapor Intrusion Technical Guidance is designed to help assist the investigator to comply with the requirements of the NJDEP to properly assess the vapor intrusion pathway. The Vapor Intrusion Technical Guidance guides the investigators through the various stages of the process, including receptor evaluation, vapor intrusion investigation, mitigation, monitoring and ultimately termination of the system.