Tunnelling in heart of Brisbane CBD

The Challenge           

Brisbane Move, specifically the Adelaide Street tunnel, is a key part of the Brisbane Metro project for the Brisbane City Council.   A joint venture partnership led by construction company Acciona, the new 213 m tunnel built in the heart of Brisbane’s CBD, will provide a dedicated connection between the Inner Northern Busway and Southeast for metro and bus services. 

Aquatic Engineering was engaged to design and construct a water treatment plant (WTP) for the treating ground and construction water for discharge to stormwater. 

Due to the high-profile location next to the Brisbane Square Building the WTP had to ensure that-

• it be designed to fit in a narrow section of footpath on Adeliade street, with varying levels along the length of the street
• its operation did not affect neighbours as it was not located inside an acoustic building
• prefabricated to reducing placement & install times, so road closures where the minimum

Our Solution

A unique layout was developed in collaboration with the client and the WTP completely modelled in 3D CAD by our in-house expert.  Aquatic Engineering’s containerized units allow for modules to be stacked and locked together, that not only met the clients tight space requirements, but allowed for the placement of the entire water treatment plant in a single night shift, minimizing road closures and disruptions to the public.

Water was pumped from the tunnel to the WTP through coarse solids removal and into a Mudbug MBS50 silo.  The Mudbug MBS50 silo provided water storage and additional solids removal and was fitted with a rake to prevent accumulation of the settled material.

From the silo the water was:

• pH corrected
• flocculated and clarified in a Trident 4 lamella clarifier
• filtered through glass media and carbon
• Discharged to stormwater with continuous discharge monitoring

Settled solids from the Mudbug MBS50 silo and Trident 4 lamella clarifier were combined and processed through a Kraken KFP-800-50 automated chamber filter press.