The BIOGEST® storm screen ensures high performance screening during periods of heavy rainfall. The solid retention system is installed at overflow weirs and can easy be retrofitted in existing structures. The waste water flows through the perforated screen basket, which is arranged as a semicircle section. The screen basket is fully automatically cleaned during operation. The system retains floating matter and sediments efficient and protects the environment from pollution.

The BIOGEST® Storm Screen Type SAS is installed at the overflow weir, before the weir. It consists of a perforated semicircle filtering basket, with holes of 6 mm (5,6 or 8 mm) diameter, a rotating screw conveyor and a zone of calm for the discharge of the collected screenings. It is kept clean by a rotating screw conveyor and the screened water can be release toward the forwarding water flow.


The screen is controlled by a level measurement installed before the weir. As the water level rises to a critical overflow point the screw conveyor starts to rotate. It keeps the holes clean from any debris and transports the screening debris in axial direction toward the discharge zone.
The gear motor placed at one end of the machine is compact in size and is sized based on the length and diameter of the machine.


  • Ideal solid retention by means of two-dimensional screening
  • Forwarding of extracted screening material to the WWTP
  • Efficient and continuous automatic cleaning of screen surface
  • Easy retrofitting through existing manhole and on existing overflow weirs
  • Fully automatic operation by the integrated control and monitoring of the water level
  • Robust stainless-steel construction with minimal maintenance
  • Screen basket size DN 300 – 1000
  • Capacity up to 10 m³/sec.
  • Perforation 6 mm (other sizes on request)