Stormwater Management
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Stormwater Quality Systems
Space-Saving Stormwater Separator for Reliable Compliance
Stormwater Management
/
Stormwater Quality Systems
Space-Saving Stormwater Separator for Reliable Compliance

First Defense® is a compact stormwater separator engineered for space-constrained sites. Certified by NJDEP and NJCAT, it delivers proven removal of sediment, trash, and floatables while integrating easily into new or retrofit stormwater systems.
Space-Saving Stormwater Separator
Nexterra’s First Defense® Compact Stormwater Separator is engineered to capture sediment, trash, and floatables in a space-saving, high-performance system. Its small footprint makes it an excellent solution for tight or difficult site conditions, allowing you to stay compliant without sacrificing valuable land.
Available in multiple configurations, including a high-capacity model with independently verified flow rates, First Defense adapts to a wide range of regulatory requirements. The system can be seamlessly integrated into treatment trains, making it a versatile choice for managing runoff from streets, parking lots, and other impermeable surfaces while maintaining reliable water quality performance.
Key Benefits of First Defense
- Compact and Flexible Fits into space-constrained sites without reducing performance.
- Proven Treatment Independently tested to capture sediment, trash, and floatables.
- Multiple Configurations Includes a high-capacity model for enhanced flow.
- Integration ReadyWorks effectively within treatment trains for comprehensive stormwater management.
Keep Your Stormwater Projects Efficient and Compliant with First Defense
Nexterra makes it simple to protect your site and meet stormwater regulations with compact, cost-effective solutions. Connect with our team today to learn how First Defense can help you maximize space, reduce maintenance, and safeguard water quality for the long term.
Certified Performance in a Compact Package
When stormwater systems are judged on results, First Defense stands on solid ground with certifications from NJDEP, NJCAT, and RIDEM. These approvals confirm that it consistently captures fine solids, oils, and debris before they can damage downstream assets, and real-world testing shows it performs just as well outside the lab. That proven record comes through in the details.
- Certified by NJDEP and RIDEM for 50 percent removal of total suspended solids, with NJCAT verification confirming consistent performance
- Field studies demonstrate reliable operation during real storm events, capturing sediment and floating material without washout
- High Capacity models validated for exceptional flow rates, giving engineers confidence on sites with heavy runoff
- Internal bypass system conveys peak flows safely, protecting captured pollutants and maintaining effectiveness even in extreme weather




Engineered for Volume and Flow Challenges
Not every site faces the same storm conditions, which is why First Defense is built to handle both routine events and extreme surges. Its hydrodynamic separation process works in tandem with internal safeguards to keep pollutants in place, even when water volumes spike. That design shows its value in a few key ways.
- Among the highest approved flow rates in the United States, allowing treatment of large volumes without external bypass structures
- Integrated bypass system that prevents washout of pollutants during peak storm events
- Vortex separation process that settles solids and traps floatables, reducing long-term maintenance needs
Flexibility for Complex Sites
From tight urban corridors to retrofit projects with shallow cover, First Defense makes integration straightforward. It can fit into standard manholes or vaults, and its modular design adjusts easily to unusual layouts without compromising performance. That adaptability comes through in its core features.
- Modular design that allows configuration for different pipe sizes, inlet layouts, and depth constraints
- Practical for both retrofits and new installations where excavation or slope is limited
- Preassembled components that reduce installation time and simplify deployment




Applications Where It Counts
Stormwater projects vary widely, but First Defense proves effective across them all. It can serve as pretreatment before other systems, or as a stand-alone option when space or budget calls for simplicity. Its versatility makes it a practical choice in scenarios like these.
- Pretreatment before infiltration, filtration, or storage systems
- Retrofit installations within existing stormwater networks
- Sites requiring reliable trash capture and oil separation
- Urban redevelopment or constrained layouts where excavation is limited
- High-flow projects needing compliance and long-term reliability