Prefabricated package treatment plant

The plant was designed such that it can be supported on galvanised steel support beams elevated approximately 5m above ground level, to enable flows to gravitate through downstream process units.

The grit pump, grit classifier and screenings washer/compactor are installed on a concrete slab at ground level. The PTA assembly is prefabricated and transported to site in such a manner that minimises installation and requires bolted connections only.


1. Shafltess Screenings Conveyor
2. SPIRAC Grit Vortex
3. SANDWASH® Grit Washer
4. SPIROWASH® Screening Washer

The two drumscreen work in a duty/standby configuration to remove solids larger than 2.0 mm in two dimensions from the incoming flow and are connected  to  SPIRAC screenings conveyor system, for reliable and maintenance-free solids transport. The screenings conveyors transport screenings to the screenings washer/compactor via a drop chute. The SPIROWASH® washes out the organics from the screenings and reduces the volume and the weight of the screening and compacts them. The screenings washer/compactor wash and compact the screenings before depositing them into a combined screenings and grit bin.

Screened sewage passes from the fine screen channels to the SPIRAC GRIT VORTEX tank. SPIRAC Grit Vortex unit is designed for separating high density grit particles from lower density organics.The installed grit pump withdraws grit slurry from the grit tank and pumps it to the SANDWASH® grit washer which washes and separates the grit, and transfers it to the combined screenings and grit bin. The SPIRAC Grit Washer makes sure that all visible organics on the grit is removed.

Projected Outcomes

  • Improved quality of effluent being released to the environment.
  • Increased system capacity to cater for expected growth and development in the area.
  • The new system provides significant improvements and is more reliable.
  • New site has less impact on the Sarina township.

The new treatment plant is built to cater to a population of 7000 people. The design also allows for further expansion.