Expedited installation of horizontal sub-slab soil vapor extraction wells provides a quick solution to an emergency vapor intrusion scenario.
By: Kyle Carlton, PG, Senior Geologist
Recently, a property owner of an office building was facing loss of tenants and fines from the state if the emergency indoor air quality situation was not immediately addressed.
Vapor intrusion resulting from a former dry-cleaning operation resulted in dangerous concentrations of chlorinated solvent vapors within the building.
Directional Technologies, Inc. (DTI) was contracted to provide a time-sensitive and non-intrusive solution.
DTI quickly mobilized to the site and installed three sub-slab horizontal soil vapor extraction (SVE) wells ranging in lengths from 70 feet to 85 feet at an approximate depth of 4-feet below the building foundation. The horizontal SVE wells intercept rising vapors and provide an external pathway for extraction of the vapors before they accumulate and enter the building at harmful concentrations.
This approach allowed all businesses to remain open and operate therefore preventing loss of business for the tenants or a loss of tenants.
Advantages of Horizontal SVE wells for vapor intrusion sites:
- Non-intrusive to building occupants and activities
- Extended well screen lengths to intercept vapors resulting in no gaps in influence
- Provides contaminate source remediation as well as vapor intrusion mitigation
