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Downstream Defender®

The Rocla Downstream Defender® separator is an advanced hydrodynamic vortex separator. Rotary and shear forces are generated to augment gravitational forces and remove settleable solids using a much smaller area than sedimentation basins. An oil and floatables trap within the vessel provides a compact solution for non point source pollution.

Testing at Coventry University (UK) has indicated that the Downstream Defender® separator can remove 68% to 99% of settleable solids, including large proportions of fine particles (less than 100 microns), 80% to 97% of free oils and floating gross pollutants.

Installing a Downstream Defender® separator is as simple as installing a standard access chamber. The Downstream Defender® separator is delivered to site completely fabricated, ready to be installed in the excavated hole and connected to the drainage system.


  • new developments
  • car parks
  • streets and roadways
  • industrial sites
  • construction sites
  • shopping centres
  • agricultural run-off
  • mine sites
  • service stations
  • wetland protection