In 2004, John Young (Kelvinhaugh), which is now part of Abergeldie Complex Infrastructure, formed a joint venture with CH2MHill to design and construct a 2 ML/day membrane bioreactor with sodium hypochlorite post dosing to achieve high quality recycled water at Sydney’s North Head STP to replace the potable water previously being used.

Scope included process design, design of the concrete tank, design of the aeration system to achieve the required oxygen transfer for the high suspended solids in the reaction tank, and design of the membrane filter system to achieve the required quality, with due regard to the membrane flux for maximizing the life of the membranes and reducing the maintenance costs and associated downtime.

Complex Challenges:

The design (basic MLE) recognized that, for the given height allowed for the tank structure by the client, reducing the size of the aeration tank to the optimum SRT would reduce the floor area available for the diffusers and thus compromise an optimum aeration design.

Comprehensive commissioning was carried out following construction. Data was recorded over the 150 day proving period. Parameter tolerances included transmembrane pressures, thermotolerant coliforms, DO, ph, chemical usage, suspended solids, ammonia and plant power consumption. All were well within the specified technical parameters. At the time of its commissioning, the new facility was the largest MBR operating in Australia.

Division: Water Client: Sydney Water Corporation Current Status: Complete Start Date: August 2004 Construction Period: 60 Weeks Contract Type: Lump Sum Value: $ 3 million Consultants/designers: Abergeldie Young Process Engineering Pty Ltd

Business unit:



Sydney Water Corporation

Current status:


Start date:

August 2004

Completion period:

October 2005

Contract type:

Lump sum


$3 million