Vapor Intrusion & Mitigation


Golars has conducted Vapor Intrusion (VI) investigation and mitigation services at residential, commercial and industrial properties, to address volatile chemical intrusion from petroleum hydrocarbon and solvent releases. Vapors from contaminated soil and groundwater can encroach and intrude into buildings, causing human exposure. Golars has multiple projects that have vapor intrusion issues which are being investigated and mitigated.

Vapor intrusion investigation is conducted in accordance with USEPA Region 5 Superfund division Vapor Intrusion guidelines. A site inspection (building survey) is conducted, prior to air sampling, to identify and inventory potential indoor sources, unrelated to the subsurface vapor intrusion, that could potentially contribute to indoor air conditions. The visual inspection of the building is also conducted to identify potential penetration points and pathways for vapors to enter into the building. During the investigation, sub-slab, indoor air and outdoor air samples are collected from the property. Golars follows the “multiple lines of evidence” approach to support decision making regarding the VI issue – i.e., groundwater sampling data, soil gas sampling data, sub-slab sampling data, indoor and outdoor air sampling data, background internal and external source data, building use data, site geology and site history. The data collected from multiple lines is evaluated and interpreted to arrive at a conclusion. Remedial actions are generally initiated if the site presents a human exposure risk from the constituents above the ATSDR risk levels depending on the type of property.