Sub-slab Depressurization System (SSDS).

The image provided depicts the initial layout of a network comprising PVC pipes with a diameter of four inches. This network is designed for the implementation of a sub-slab depressurization system (SSDS) at a designated "e" site in New York City. The intended location for these pipes is beneath a proposed eight-story residential building. SSDS systems are recommended for sites grappling with soil vapor-related challenges. The primary goal of this SSDS installation is to alleviate the accumulation of soil vapors underneath the site. Such vapors could potentially pose a substantial threat to both human health and the environment.

In the case of this particular site, an active SSDS is deemed necessary due to the identification of heightened levels of perchloroethylene (PERC - Tetrachloroethylene) in soil vapor samples taken post-excavation. The network of pipes will be finalized at the roof line, where a six-inch goose neck pipe will be installed to prevent rainwater infiltration. These pipes will be interconnected with a centrifugal blower, responsible for creating negative pressure that effectively expels accumulated soil vapors from beneath the foundation of the building.