Brownfield Redevelopment Sub-Slab Depressurization Systems
Contamination of soil and groundwater from the release of hazardous materials resulting from various spills, prior disposal methods, or unfortunate accidents can result in indoor air conditions that potentially can cause harm to a building's occupants. Harmful vapors from volatile organic compounds (VOCs) that rise up from the contaminated soil can enter a structure through a multitude of ways. This is commonly referred to as vapor intrusion. Fortunately vapor intrusion does not need to be a barrier to the redevelopment of brownfield sites. The EPA has developed methods to test brownfield sites for vapor intrusion, and techniques such as sub-slab depressurization or sub-membrane depressurization have been proven to reduce or eliminate contaminants inside of a structure.
The most commonly used method to prevent further vapor intrusion in a structure is to have a sub-slab depressurization (SSD) system installed. A sub-slab depressurization system works by drawing air from underneath the slab with the use of PVC piping and an in-line fan unit. As the system continuously pulls air from under the slab, the toxic vapors are either deterred from entering the structure, or drawn into the piping to be vented into a safer area. Depending on the building type, the sub-slab depressurization system will either be pulling air from a dug out collection pit, or from a drain-tile system for maximum depressurization. If the building doesn’t have a slab, or only has a partial slab, a vapor barrier will need to be placed and sealed down to continue with the SSD process. Lifetime Environmental Solutions has been in business for over 22 years and specialize in designing and installing sub-slab depressurization systems. If you are planning to redevelop a brownfield site and need vapor mitigation performed, give us a call! We can provide you with a detailed estimate fast and easy!
Brownfield Redevelopments and Vapor Intrusion
Redeveloping a structure with possible air contamination issues can be a challenging endeavor. Many times, contaminants in the air cannot be seen, smelled, or tasted, so it is hard to discern whether or not an issue is present without the proper testing. There are many different factors that go into how a building can have a vapor intrusion issue including what type of business previously used the building. If the previous building was used as a gas station, dry cleaner, or metal fabrication company, there is a high potential of VOC’s in the soil beneath. Foundation issues may also be a factor in how much vapor is allowed into the structure.
Once proper testing has been completed, and an issue has been identified, a sub-slab depressurization can help divert the dangerous vapors rising up from the soil, to a safer area. If the building does not have a slab, or a partial slab, a technique called sub-membrane depressurization may be used in tandem with a sub-slab depressurization system. This involves the placement of an air tight vapor barrier on the open soil to trap the rising contaminants. After the vapor barrier is in place, an active sub-slab depressurization system can be added to draw those trapped gasses out from under the barrier.
To learn more about the vapor intrusion solutions available for brownfield redevelopment sites, give us a call! Our certified commercial team is eager to help you through the process.
Vapor Exposure Risks
The inhalation of toxic soil vapors in humans can cause many different health issues depending on the type of contaminant. These health effects may take years of exposure before appearing, but in some cases can be immediate. For the most part, the compounds most associated with vapor intrusion are volatile organic compounds (VOCs). Volatile organic compounds are found in many fuels, cleaning materials, solvents, pesticides, and some types of dyes. When in vapor form, these can be inhaled into the lungs and get into the bloodstream. Depending on the toxicity of the vapors, this can cause death to the occupants inhaling these toxic vapors. Before redeveloping a brownfield site, actions should be taken to screen for vapor intrusion and prevent it with the installation of a sub-slab depressurization system. Give us a call today for an estimate!