Downstream Defender® An advanced vortex separator with an outlet pipe that can be orientated to suit actual site conditions. Inlet Product Profile The Downstream Defender® is the most advanced hydrodynamic vortex separator available for the removal of sediment, oil and floatables from stormwater runoff. The Downstream Defender® is proven to be more efficient than other structural treatment devices with a much reduced footprint and is the only separator with internal components proven to prevent pollutant re-entrainment (or washout). Outlet Advantages • • • • • • • • • High removal efficiency over a wide range of flows. Proven to prevent pollutant re-entrainment. Able to incorporate a change in pipe direction from 90 to 270 degrees. Low system headloss. Internal bypass with high flow capacity. No moving parts and no power requirement. Consolidates maintenance to a single location. Independently tested and verified performance. Approved by regulatory agencies throughout the world. Applications • • • • • Control of sediment, floatables and petroleum products. Highway runoff. SuDS schemes. Wetland schemes. Basin and pond protection. • • • • • Park & Ride schemes. Watercourse protection. Industrial and commercial areas. Vehicle maintenance washdown yards. Quarry settlement ponds. Physical Properties / Performance Diameter of Unit DN (mm) Treatment Flow Rate Hydraulic Capacity * of Chamber + l/s l/s Inlet / Outlet Pipe Diameter mm Oil Storage Capacity litres Sediment Storage Capacity m3 1200 21 120 300 270 0.7 1800 51 300 450 1350 1.7 2550 115 600 600 2500 3.8 3000 160 750 750 4650 4.4 * The table above shows the Treatment Flow Rates at which typical removal efficiencies of greater than 80% are achieved for oil and sand. + The hydraulic capacity of the chamber is the maximum flow that can pass through the chamber without surcharge to upstream network. A major portion of the pollutant materials tend to be included in the first flush of the runoff during a storm event, as flow rates build up. Therefore with a correctly sized unit, the vast majority of solids and hydrocarbons can be removed and retained within the unit. Headloss at Treatment Flow is typically less than 150 mm. www.hydro-int.com Stormwater® Hotline: 01275 337977

How it Works The Downstream Defender® internal components are designed to enhance the separation process by minimising headloss, increasing efficiency and preventing re-entrainment of captured pollutants. Advanced hydrodynamic separation is achieved by extending and stabilising the flow path, whilst isolating the captured pollutants in dedicated storage zones. Contaminated stormwater entering the unit is directed downwards and around the periphery of the chamber (green arrows). Inlet Oils, litter and floatable material are initially captured at the inlet and transferred to the oil storage zone...