Stormwater Separator

Stormwater Separator


StormTrooper® — The Premier Stormwater Hydrodynamic Separator

Patented Technology

ParkUSA hydrodynamic separators utilize advanced and patented technologies to enhance the removal of pollutants from stormwater efficiently and effectively.

Coalescing Plate Separation

Specialized treatment includes coalescing plate technology that enables small oil droplets accumulate and merge to form larger clusters which allow for easier removal and collection.

High-Flow Bypass

Built-in high-flow bypass prevents resuspension of captured pollutants during high flow events, such as heavy rainfall, and ensures that the separator continues to function effectively.

Easy Installation

StormTrooper® is designed for simple installation, typically requiring only excavation, placement, and connection to the existing stormwater infrastructure.

Low Maintenance

System requires minimal intervention to maintain optimal performance. Regular inspection and removal of accumulated debris are typically the primary maintenance tasks.


Available in various sizes and capacities, making them suitable for a wide range of applications, from small parking lots to large industrial sites.


The ParkUSA StormTrooper® is the most advanced hydrodynamic separator available in the industry. Its state-of-the-art system employs patented technology to effectively remove sediments, trash, and oil from stormwater runoff, ensuring responsible environmentally practices and compliance with EPA Clean Water Act.

The StormTrooper® features proven technology and has been successful in thousands of installations across the Nation. Hydrodynamic separators are a versatile component of a stormwater management and can be tailored to many applications including applications specifically developed for aquifers and sensitive watersheds. The StormTrooper® AQ was originally developed to protect the Edwards Aquifer in Texas and is now available for sensitive watersheds everywhere. Our separators can also capture hazardous materials from gas stations and other high-risk sites that are particularly vulnerable to stormwater contamination. The StormTrooper® HMI captures free oil, grease, TSS, debris, and other hydrocarbons, with minimal operating costs and no filter cartridges needed.

The ParkUSA StormTrooper® is easy to install, maintain, and operate, with durable precast concrete construction improves the quality of stormwater discharges and protect the environment.

How It Works

The StormTrooper® system features a patented design with coalescing plate technology and is specifically engineered to capture free oil and sediment from stormwater runoff and retain these pollutants for periodic removal. The system targets the “first-flush” flow, which occurs during the initial phase of a storm event and carries most pollutants from catchment areas.

Designed to handle varied flow rates, from low to very high, the StormTrooper® provides optimal treatment of stormwater runoff. To accommodate excessive flow, our hydrodynamic separator incorporates a bypass mechanism that allows only the design flow to pass through the interceptor while diverting high flows directly to the storm sewer system. This prevents scouring and the resuspension of captured pollutants from previous storm events.

Maintaining any stormwater quality treatment system is critical to its long-term performance. The StormTrooper® design makes inspections and maintenance easy as all inspections are conducted at grade. In the event of an oil, fuel, or chemical spill, an immediate inspection is necessary. Any accumulated oil and sediment should be removed by a licensed waste management company and disposed of correctly. StormTrooper® maintenance is quick and affordable, and it can be performed using a standard vacuum truck.


About the Precast Interceptor

The StormTrooper® is a patented stormwater treatment system featuring a patented design with coalescing plate technology, specifically engineered to capture free oil and sediment from stormwater runoff and retain these pollutants for periodic removal. The StormTrooper® SWST-C system consists of a precast concrete control manhole and a rectangular separator unit with internal baffles, piping, and patented coalescing plates. This model is designed for direct burial and includes heavy-duty access covers for cleaning and maintenance. Model SWC features a cylindrical shape separator unit.

See it in Action



This hydrodynamic separator can be used as a pre-treatment system before other stormwater management practices, such as infiltration systems or bioretention areas.

Standalone Treatment

The system can be used as a standalone treatment system for stormwater runoff and can be installed in-line with the stormwater conveyance system or in a separate treatment train.

Upstream/Downstream of Detention Pond

Installed upstream of a detention pond, a separator can remove pollutants from the runoff before it enters the detention pond to increase the pond effectiveness. Downstream, the separator can remove sediment and other pollutants that were not captured.

Aquifer Recharge Zone Treatment

The StormTrooper® AQ is designed specifically for use in an aquifer recharge zone, where pollutants carried by stormwater runoff can seep into the ground and contaminate the aquifer.

Gas Stations

Gasoline stations and auto repair shops are a common source of pollution, with the risk of oil and other hydrocarbons being spilled into the stormwater system.

Landfills and Waste Management

Landfills and waste management facilities are a significant source of pollution, with the risk of hazardous materials entering the stormwater system.

Spill Prevention

By incorporating the StormTrooper system into spill prevention plans, industries and businesses can effectively reduce the risk of environmental damage and associated cleanup costs.


Hydrodynamic separators can be retrofitted into existing stormwater management systems to improve pollutant removal and reduce maintenance requirements.

Combination with Other Stormwater Management

Hydrodynamic separators can be combined with other stormwater management practices, such as rain gardens or green roofs, to improve their overall effectiveness.

Specs & Docs


StormTrooper AQ Flyer


StormTrooper HMI Flyer


Stormwater Interceptor (StormTrooper Model SWST-10 to SWST-150)


Stormwater Interceptor – Cylindrical (StormTrooper Model SWST-05C thru SWST-60C)


Stormwater Interceptor (Model SWAQ-05 thru SWAQ-110)


StormTrooper (Model SWAQ-05 thru SWAQ-110 with Bypass)


Hazardous Material Interceptor – StormTrooper (Models HMI-100 to HMI-400)

Municipal Resources

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