Vapor intrusion is the movement of chemical vapors from soil and groundwater contaminated with petroleum or chlorinated solvents into overlying or nearby buildings. Vapor can enter through openings or cracks in the building foundation or through the naturally occurring pores in concrete. Once inside, vapors can accumulate and pose short- and long-term health risks.
To mitigate these risks in new and existing developments, WithersRavenel evaluates building architecture, identifies preferential routes of vapor migration into buildings, and recommends a mitigation strategy that complements the building design. Solutions include HVAC retrofits, installation of engineered barriers, and construction of sub-slab depressurization/exhaust systems. We have successfully designed, constructed, and operated these systems for both private companies and state projects authorized through the Dry-Cleaning Solvent Cleanup Act Program managed by the North Carolina Department of Environmental Quality. Coupled with our use of the latest air monitoring techniques for soil gas, sub-slab vapor, and indoor air, these strategies create interior spaces that are safer for living and conducting business.