Environmental · Defined
Vapor encroachment condition (VEC)
A condition involving the presence or likely presence of contaminant vapors in the subsurface of a property due to a release from contaminated soil or groundwater.
Why it matters
Vapor encroachment screening is not the same as proving vapor intrusion into a building. The distinction affects which investigation or mitigation questions follow.
In practice
A project example
A subsurface vapor concern is identified, but the available evidence does not yet establish entry into indoor space.
Technical references
General educational guidance from KOW Building Consultants. Examples are illustrative, not project records. The applicable contract, standard, program, and jurisdiction control the requirements for a specific assignment.