Centralized treatment options are the standard in stormwater quality management, but there are a number of different ways to accomplish this treatment model. Whether you use an in-line system and treat the entire flow or an off-line system and only treat the first flush has a lot to do with what standard of treatment you are trying to uphold and what your expectations of short term and long term costs are. Our approach at Construction EcoServices is to look at the site in its entirety and find out what design strategy best fits the end user. Questions like “How long do you anticipate owning the property” and “How many outfalls and inlets will the property have” are critical in determining what the best course of action is. Where a client, such as Halliburton, FMC Technologies or Phillips 66, might plan on owning a facility for over 10 years, an inline system might better fit their needs as maintenance intervals are longer and cost of ownership is less. If you are a retail developer that are looking to build and sell the property, an off line system might make more sense because the upfront construction costs are less. Either way, Construction EcoServices has the expertise and products to fit your client’s needs.

Nutrient Separating Baffle Box® (NSBB™)

Advanced Stormwater Runoff Treatment System

Why Do We Recommend This Product?

“As a product specialist, I always want to use the most efficient and effective products, which is why I always use The Nutrient Separating Baffle Box® (NSBB™). They’re easy to install, maintain long-term, and are designed to maximize available site space without compromising performance.”

Eli Gonzalez
Stormwater Quality Product Specialist, Stormwater Systems

The Nutrient Separating Baffle Box® (NSBB™) is an advanced multi stage stormwater runoff treatment system. The patented screen system is designed to capture and store debris in a dry state to minimize nutrient leaching, allowing for easier maintenance. The triple chamber design enables a high level removal of TSS over a range of particle sizes and is effective in capturing both nutrients and hydrocarbons. A patented deflector system ensures no sediment scouring occurs during high flows, allowing for online installation without needing separate diversion structures. With the addition of a SkimBoss® MAX or Floating Skimmer, the NSBB™ can further amplify the effects of the already included Hydro-Variant Technology®, bolstering pollutant capture potential, detention time and balancing conveyance with flow rate. The NSBB™ is a widely accepted treatment solution among civil engineers, developers ​and municipalities.

  • Filtering is provided by the screen system basket, suspended above static water level, which has a capacity of several cubic yards depending on the model. The function of the screen basket is to capture gross solids like trash, foliage and debris.
  • Sediment separation is facilitated by three settling chambers with a capacity of several cubic yards each depending on the model. These chambers collect smaller sediments and particulate metals.
  • ​StormBooms™ attached to the influent side of the skimmer remove floating and emulsified hydrocarbons from the water.


  • Fits within existing easements
  • Retrofits existing watersheds
  • Patented screens maximize storage and prevent debris loss
  • Rainwater harvesting and wet or dry detention
  • Dry state storage separates debris from water and sediment
  • Water will not turn septic
  • Easy vacuum truck servicing
  • Full capture for trash TMDL’s


NSBB Sizing Chart

NSBB Model #Pipe SizeInterior WidthInterior LengthBaffle HeightInterior Height
2-4-604″ to 12″12″ to 15″2′4′24″5′
3-6-728″ to 18″18″ to 24″3′6′36″6′
4-8-8412″ to 18″18″ to 30″4′8′36″7′
5-10-8412″ to 30″30″ to 42″5′10′36″7′
6-12-8418″ to 36″36″ to 48″6′12′36″7′
8-12-8430″ to 48″48″ to 60″8′12′36″7′
8-14-10036″ to 54″48″ to 60″8′14′40″8′ 4″
10-14-9642″ to 60″60″ to 72″10′14′40″8′ 4″
10-16-12548″ to 60″60″ to 72″10′16′46″10′ 5″
12-20-13254″ to 72″12′20′48″11′

First Defense® High Capacity

Versatile Stormwater Separator

Capture and retain stormwater sediment, trash and floatables in a unit that saves site space and adapts to smaller or logistically difficult site locations.

First Defense® is a versatile stormwater separator with the highest approved flow rates in the United States, enabling engineers and contractors to save site space and projects costs by using the smallest possible footprint. It also works with single and multiple inlet pipes and inlet grates.  It is easily maintained from the surface by standard vacuum tanker.

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® works easily with single or multiple inlet pipes and inlet grates, and is independently tested, verified and approved.

Targeted Pollutants

  • Coarse particles
  • Fine particles
  • Trash
  • Floatables


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 systems 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.


Cuts Footprint Size and Cuts Costs
The First Defense® provides space-saving, easy-to-install surface water treatment in standard sized chambers/manholes.


Adapts to Site Limitations
Variable configurations will help you effectively slip First Defense® into a tight spot. It also works well with large pipes, multiple inlet pipes and inlet grates.

Prevents Washout
The First Defense® retains the pollutants it captures. The low-energy vortex separation of the First Defense® eliminates excessive agitation of captured pollutants ensuring that these pollutants are not washed out during subsequent rainfall events.


Saves Installation Time
Every First Defense® unit is delivered to site pre-assembled and ready for installation – so installation is as easy as fitting any chamber/manhole.


Downstream Defender®

Advanced Hydrodynamic Vortex Separator

Capture and retain sediment, oils and floatables from stormwater runoff over a wide range of flows in a small footprint.

The Downstream Defender® is an advanced hydrodynamic vortex separator that provides impressive and reliable removal of fine and coarse particles, hydrocarbons and floatable debris from surface water runoff, delivering high levels of stormwater treatment over a wide range of flow rates.

A compact, low-maintenance stormwater treatment BMP, the Downstream Defender® enables engineers to deliver effective pollutant removal at a single point in the drainage system.

Available in a range of sizes, it can function as either pretreatment or as a stand-alone device, providing engineers and contractors with a flexible, cost-effective stormwater management option.

Targeted Pollutants:

  • Fine and coarse particles / total suspended solids (TSS)
  • Floatable trash and debris – now available with 5mm screen to meet 100% trash capture TMDL
  • Liquid- and sediment-bound oils and hydrocarbons
  • Sediment-bound heavy metals
  • Sediment-bound nutrients


The Downstream Defender® reliably treats surface water runoff from impermeable surfaces including highways, car parks, industrial areas and urban developments

  • As part of green infrastructure, LID or LEED systems
  • Areas where high solids and trash capture are a must
  • Control of silting upstream of wetlands, ponds and basins
  • Industrial stormwater pollution control


The Downstream Defender® can accommodate a change in outlet pipe direction to suit site-specific requirements.


Cuts Headloss
Low headloss means more site flexibility and provides engineers with design options for shallower sites.

Saves Space and Money
Downstream Defender® can treat high peak flows in as little as half of the footprint of other structural BMP systems. A smaller footprint means an easier install that’s less expensive and requires less work.

The Downstream Defender® is proven to prevent washout of captured pollutants. Carefully designed internal components isolate the pollution storage areas, ensuring that what is captured is retained, even during high flows.