Prefabricated packaged Inlet Works for Bolton Upon Dearne Wastewater Treatment Plant - UK

  • Europe News
  • Grit Handling

SPIRAC was contracted by Tier One Contractor Galliford Try to provide a prefabricated packaged treatment plant for the Bolton Upon Dearne Preliminary Treatment Area (PTA). The Inlet Works sits on a reinforced concrete slab built by civils contractor CPC civils and is supported by a galvanised steel support structure elevated approximately 5m above ground level, to enable flows to gravitate through the downstream process units.


SPIRAC designed, supplied, delivered and installed the following equipment on site. 

Three FINEGUARDTM screens, each capable of passing a maximum flow of 566 l/sec of sewage at a design water depth of 1.0 metres downstream. The FINEGUARDTM Screen consists of a band of perforated screen panels which are  secured to drive chains on either side of the panels. On reaching the discharge section of the screen, the screen panels are cleaned of debris by means of a self-adjusting brush mechanism and water spray jets ensuring that clean panels are always presented to the oncoming flow. The screen panels are secured in such a way that replacement of individual  panels can be achieved with a minimum of effort and down time. 


The screenings are transferred from the screens via a launder trough system. The SPIROWASH® units wash out the organic material, reduce the volume and weight of the screenings by compaction before delivering them to a skip via a press tube. 

A Grit Vortex unit removes suspended grit from the sewage flow, this consists of a  pre-fabricated Grit Vortex Chamber – capable of handling up to a maximum 628 l/sec of screened raw sewage flow. The grit is extracted by means of a grit pump  and is fed to a  SANDSEP® grit separator unit capable of handling up to 20l/sec of grit slurry. The SANDSEP® unit will dewater and discharge grit into a skip.


1. Three FINEGUARDTM  screens 
2. Two SPIROWASH® MW-Q280 screenings washer
3. Grit Vortex VG40
4. SANDSEP® SA-320 grit classifier