Active Vapor intrusion mitigation systems are installed to reduce health risks in buildings where chemical vapors from contaminated soil may be inhaled by indoor occupants. Active vapor intrusion mitigation systems provide the added benefits of reducing radon, and moisture inside the buildings where they are installed. Active and passive systems may also be installed in buildings where contamination might occur in the future. Active systems run continually and should be monitored on a regular basis for proper operation.
What is Vapor Intrusion?
Vapor intrusion is the movement of chemical vapors from contaminated soil and groundwater into nearby buildings. Vapors primarily enter through openings in the building foundation or basement walls – such as cracks in the concrete slab, gaps around utility lines, and sumps. It also is possible for vapors to pass through concrete, which is naturally porous. Once inside the home or workplace, vapors may be inhaled posing immediate or long-term health risks for the occupants. Risks will depend on the types of chemical vapors and their concentrations, how much time people spend in the building, and the building’s ventilation. Vapor concentrations will be higher indoors when windows and doors remain closed. Mitigation methods, which lessen the effects of vapor intrusion, may be needed until contaminated soil or groundwater is cleaned up.
What are Vapor Mitigation Methods?
Vapor mitigation methods can be either passive or active. Passive methods prevent the entry of chemical vapors into the building and are generally installed during building construction, although passive mitigation can sometimes be used on existing structures. Active methods change the pressure difference between the sub-slab and the inside of the building to keep vapors out. The goal with an active vapor mitigation system is to create a negative pressure below the concrete floors of buildings with basements and slab on grade buildings, the systems are similar in style to active radon mitigation systems. For homes built over a crawl space with open soil floors a vapor barrier can be installed along with other components of an active vapor mitigation system.
Protect Environmental can install a vapor mitigation system to meet your application; we have installed systems for single family homes, apartment communities, and commercial buildings of all sizes. Let us put our experience to work for you. Contact us for more information.
