Vapor Intrusion
Vapor Intrusion occurs when harmful soil contamination changes phase from liquid to vapor underground and moves upward through geologic layers and building foundations, accumulating within indoor air.
Vapor Intrusion occurs when harmful soil contamination changes phase from liquid to vapor underground and moves upward through geologic layers and building foundations, accumulating within indoor air.

Phase 2 Environmental Recommendation In some cases, there may be a Phase 2 Environmental recommendation for a property, resulting from a Phase 1 Environmental Site Assessment. Typically, this occurs when one or more Recognizable Environmental Conditions indicate the possibility of subsurface contamination. For instance, a property with an in-place underground storage tank (UST) can likely…

Liquefaction Liquefaction: Liquefaction is the process by which there is: (1) a sudden and significant decrease of shear resistance in a soil sample (cohesion-less); (2) a sudden (but temporary) increase of the pore-water pressure of a substance; and (3) a solid mass of soil that is transformed into a fluid state mass. In the event…

Triggered Creep In the field of geology, the term “Triggered Creep” refers to a type of creeping landslide, usually along a fault line, that is triggered by a source of seismic activity.

Reverse Fault Reverse Fault: In the field of geology, a reverse fault is a dip-slip fault in which the hanging wall moves upwards, relative to the footwall. The average dipping angle of a reverse fault ranges from 45 to 90 degrees. However, if less than 45 degrees, it becomes a “thrust fault.” Reverse faults are…

Underground Storage Tank Sizes & Volumes There are a variety of underground storage tank sizes and volumes. Usually, a UST size relates to the purpose, location, and content of the container. For instance, some underground diesel fuel tanks can have lengths up to 55 feet and hold as much as 30,000 gallons. Whereas waste oil…

What is a Vapor Barrier Membrane for Soil Gas Mitigation? A vapor barrier, or a sub-slab vapor membrane, is a layer of protective material that prevents toxic vapor intrusion into buildings. An impervious vapor barrier can be a combination of plastic film, fabric, and sheets. And there are also roll-on and spray-on applications. Contractors usually install…