Designed with site flexibility in mind, the First Defense^® stormwater separator provides versatile capture of sediments, trash and floatables that allows engineers to maximize available site space without compromising stormwater treatment level.

First Defense^® is available in different configurations to comply with stormwater regulations defined by various jurisdictions. 

Targeted Pollutants 

• Coarse particles
• Fine particles
• Trash (screened version for full trash capture now available)
• Floatables

Approvals, Verifications and Certifications

• New Jersey Corporation for Advanced Technology (NJCAT) - First Defense Optimum
• New Jersey Department of Environmental Protection (NJDEP) - First Defense Optimum
• New Jersey Corporation for Advanced Technology (NJCAT) - First Defense High Capacity
• New Jersey Department of Environmental Protection (NJDEP) - First Defense High Capacity 
• ISO 14034 verification for Canadian OGS
• City of Indianapolis - First Defense High Capacity
• City of Indianapolis - First Defense Optimum
• Virginia Department of Ecology BMP Clearinghouse
• Ohio Department of Transportation 
• Virginia Department of Transportation
• California Water Boards Full Trash Capture

Applications

The First Defense^® reliably treats runoff from impermeable surfaces across a broad range of catchments.

First Defense also operates successfully as part of a management train alongside other proprietary or natural drainage features, for example as treatment before infiltration.

• As part of LID or LEED and Sustainable Drainage Systems (SuDS)
• Stormwater treatment at the point of entry into the drainage line
• Sites constrained by space, topography or drainage profiles with limited slope and depth of cover
• Retrofit installations where stormwater treatment is placed on or tied into an existing storm drain system
• Pretreatment for filters, infiltration and storage

Watch the animation below for an overview of how the First Defense^® works.

1. Contaminated stormwater runoff enters the inlet chute from a surface grate and/or inlet pipe. The inlet chute introduces flow into the chamber tangentially to create a low energy vortex flow regime that directs sediment into the sump while oils, floating litter and debris rise to the surface.
2. Treated stormwater exits through a submerged outlet chute located opposite to the direction of the rotating flow. Enhanced vortex separation is provided by forcing the rotating flow within the vessel to follow the longest path possible rather than directly from inlet to outlet.
3. Higher flows bypass the treatment chamber to prevent turbulence and washout of captured pollutants. An integral bypass chute conveys infrequent peak flows directly to the outlet chute, eliminating the expense of external bypass control structures.
4. Floatables are diverted away from the bypass chute into the treatment chamber through the floatables draw off port.