Sub-slab Depressurization System Installation

• Sub-slab depressurization system to mitigate vapor intrusion
• extraction trench and vapor recovery fans

Global Treatment Solutions was contracted to design and install an active sub-slab depressurization system (SSDS) in an approximately 2,100-square-foot residential/commercial building located in Southeast Michigan. As a result of a Phase II Environmental Site Investigation, soil and groundwater samples collected from the site documented concentrations of petroleum VOCs exceeding EGLE’s Volatilization to Indoor Air Pathway (VIAP) Screening Levels. Global installed an SSDS, which included a total of two VOC extraction fans, four vertical extraction points, and two 15-foot runs of vapor collection material to mitigate potential vapors from entering the basement of the building. Additionally, Global installed eight sub-slab soil gas points to monitor the SSDS performance and has proposed routine monitoring to document system performance.