The Continuous Deflective Separation (CDS) units are mainly used to manage stormwater, but they also have wastewater, water supply, and industrial applications. The compact design is well suited for space constrained and urban sites, where the installation of a larger stormwater treatment is impractical. Depending on state regulations, these devices are either used by themselves, or as a pretreatment system in conjunction with other stormwater treatments.

The CDS unit is a hydrodynamic separator that uses vortex settling to remove sediment, trap debris and trash, and separate floatables such as oil and grease. A CDS unit can be made from precast or in situ cast concrete, stainless steel, or fiberglass. It is composed of a sophisticated insert with a filter screen with openings that can be sized during manufacture. The insert is mounted internally in a four-foot diameter concrete manhole. This prefabricated system is on-line with an internal bypass.

This treatment’s insert can obstruct cleaning. Maintenance requirements are similar to other hydrodynamic separators, and include periodic removal of solids by a vacuum truck.