Vapor intrusion sometimes occurs where chemicals were spilled, leaked, or dumped and not cleaned up.
For example, properties such as gas stations, dry cleaners, or businesses operating metal parts degreasers use chemicals like gasoline or solvents that can cause vapor intrusion. If these chemicals get into the ground, they can move through the soil and dissolve into groundwater.
Although the chemicals are often released as liquid, they easily evaporate, becoming a vapor under the ground that you often cannot see or smell. At some point, the vapors may come in contact with buildings – usually around basements or floors.
These vapors may get into buildings through openings such as cracks, or other openings around pipes and sumps. This is a concern because people may breathe in these harmful vapors without knowing. The vapors, also known as soil gas, are assessed with soil gas wells or vapor pins that allow the vapors to be sampled and analyzed in a lab.
Vapor intrusion is addressed in the available informational pamphlet titled: “What is vapor intrusion and how is it investigated” by EGLE and the Michigan Department of Human Health and Services (DHHS).