OXLEY CREEK STP INLET SCREEN UPGRADE AND CENTRIFUGE REPLACEMENT

Project Start Date

December 2016

Project Completion Date

June 2018

Client

Queensland Urban Utilities

Comdain's Role

Principal Contractor

Value Range Category

$5m - $10m

Location

Queensland

Capabilities

Treatment Infrastructure

Inlet Screen Upgrade

Dec 2016 – Oct 2018

Investigation, design, procurement, fabrication, construction, commissioning and performance testing of the Oxley Creek STP Inlet Screen Upgrade works.

  • Remove three existing mechanical 5 mm aperture Meva Monoscreens
  • Install three new Aqseptence 2,200 l/s centre-flo band screens
  • Install three actuated penstocks and three manual penstocks upstream of screens
  • Install three manual double penstocks downstream of screens
  • Upgrade control software to initiate a grit flush sequence by increasing the velocity through the screen channels
  • Install four manual double penstocks at grit chambers
  • Decommission and make good four stop boards and slots at grit chambers
  • Repair two grit paddles, replace two drives and clean two grit chambers
  • Install two new Screw Wash Presses
  • Inlet area platform replacement

Centrifuge Replacement

June 2017 – June 2018

Replace Centrifuge No. 2 at Oxley Creek STP and provide performance proving.

  • Decommissioning, removal and cleaning/washdown of the existing Centrifuge at Oxley Creek STP, which is the Alfa Laval centrifuge .
  • Design, supply, installation and commissioning of a new centrifuge and ancillary equipment .
  • Design, supply, installation and commissioning of any piping modifications .
  • Design, supply and installation of all modifications to the existing platforms, handrails and stairs
  • Design, supply, install and commission new variable speed drives (VSD) for the new centrifuge.

Highlights and Innovations:

  • Replacement of Washpactor, and ancillary equipment with two Screw Wash Presses with only one day’s downtime. The work area was a tight footprint that required a 27 stage step process with partial demolition and construction steps. The whole change over process occurred without environmental incident.
  • Installation of new double penstock gates in the only inlet works for the 310,000 EP STP. The Client required double isolation to work in the channels for the installation. A 4-8 hour window was provided in the middle of the night to work under double isolation. Temporary black mild steel 6 mm plates were fabricated and drilled into the concrete walls to provide the necessary double isolations within the 4-8 hour windows.
  • The new 10.3 tonne centrifuge was larger than the redundant one being removed. The centrifuge was lifted in by two cranes doing a coordinated dual lift. The centrifuge was installed without incident, even though the tolerance was only 15 mm.

Watch the video here: