Environment
Font Size  Make text larger   Make text smaller

Case study: Outfall pipeline in Western Australia

ERM Power and Smithbridge jointly received a prestigious national 2008 Earth Award for their work to protect Cockburn Sound during the construction of NewGen Kwinana's outfall pipe.

The award, given by the Civil Contractors' Federation, recognises environmental excellence in construction.

The following activities led to the successful environmental outcome, and were applauded by the CCF in its commentary on the awards:

  • A substantial temporary bridge was used along the full length of the pipeline to provide safe, all-weather access for cranes and other construction equipment, delivery vehicles, and people. This minimised the footprint of the works on the existing seabed and local marine life.

    It is estimated that this innovation restricted the area of disturbance to the seabed to less than 20 per cent of what it would normally be using an open trench and rock armour protection.

Kwinana Power Station temporary bridge

  • An innovative method of “leapfrogging” a short length of cofferdam along the length of the pipeline was successfully used. All excavation, pipe-laying, and backfilling operations were carried out within the confines of the cofferdam. This contained all plumes associated with the works. This was particularly important for the neighbouring Perth Seawater Desalination Project.

  • ERM and Smithbridge re-used many materials and components from the construction works. For example, the sheet-pile waling system was purchased second-hand from the Perth Metro rail project and then sold to the Alkimos project north of Perth.

  • The methodology in the original environmental management plan was not changed during construction, giving the project stakeholders and community groups' confidence in the ability of ERM and Smithbridge.

  • The concerns of beach users were considered when designing the outfall, and it was designed so as not to leave any obstacles to beach access. Also, no permanent works protruded above existing levels, leaving the beach as a safe place for beach users.

Click here to find out more about the NewGen Kwinana Power Station.