Reverse Current Screen and Grit System

The Or-Tec Blue Whale Reverse Current Grit System:
A grit removal system which automatically adjusts based on flow

The Or-Tec Blue Whale Reverse Current Screen & Grit System completely replaces a traditional headworks of a wastewater treatment plant and provides an easy to install, flange in/flange screening and grit system. Gone is the need for concrete channels for screens, concrete settling or vortex grit chambers. All that is needed to install the OR-TEC System is a level concrete pad and access to power and washwater. The Or-Tec Blue Whale unit is manufactured from stainless and has two distinct sections.

Screen Section

The screen section consists of a bar array with 3mm openings which provides very fine screening. The unit has rake scrapers whose penetrating teeth clean the screen face and ensure it remains open. No water is used in the screen as it is self-cleaning. The unit can also be provided with a Compactor Washer to wash and compact the screenings and discharge them at a convenient height above grade for disposal.

Grit Section

The grit section removes grit and sand and elevates it for disposal. It does this with its US patented, automatic variable weir. By varying the weir height based on high or low flow, the volume of the grit chamber changes. This change in volume helps keep the flow velocity at the ideal speed for settling grit of one foot per second thereby reducing BOD capture and increasing the grit system efficiency. Grit is discharged to the side of the unit at a convenient height above grade for disposal.


The Or-Tec Blue Whale Reverse Current Screen & Grit System features include:

  • Micro Bar Screen and Grit System in one unit
  • PLC controlled weir gate
  • Variable gate ensure constant flow
  • Up to 3,960gpm (5.7 mgd) flow rates
  • No wash water requirement
  • No rotating brush for cleaning
  • Stainless Steel Construction


  • WWTP Headworks
  • Food Processing and Packaging
  • Paper Mills
  • Industrial Materials