Blog posts tagged with 'gas sampling'

Sub-slab soil gas sampling is one of the most important lines of evidence in vapor intrusion investigations. When volatile chemicals are present in soil or groundwater, vapors can migrate through the subsurface and enter buildings through cracks, joints, utility penetrations, and other openings in the slab. The Environmental Protection Agency (EPA) describes vapor intrusion as the migration of vapor-forming chemicals from subsurface sources into overlying buildings, and its guidance treats sub-slab data as a key part of evaluating whether the pathway is complete and whether occupants may be at risk.