Traditionally South Australia has always relied on the River Murray for much of its water. On average 40% of Adelaide’s water supply comes from the River Murray, but in a drought year as much as 90% of the supply may come from this one finite resource. With further population growth, a secure water supply was under serious threat. In 2009, the South Australian Government launched the Water for Good plan . A key component of this plan was a $1.824 billion construction of a desalination plant to secure long-term and climate independent sustainable water supplies for South Australia, and to reduce the State’s reliance on the River Murray and other rain-dependent sources.
Many conditions were attached to the final development approval which required strict environmental management and monitoring to ensure the construction and operational phases of the project meet the strict environmental performance expectations from the client and EPA. In February of 2009, South Australia Water awarded the design, build, maintain and operate contract for the project to the Adelaide Aqua consortia involving McConnell Dowell.
The project’s major components included:
- Design, construction and commissioning of a reverse osmosis desalination plant
- Operation and maintenance the desalination plant for 20 years
- A capacity to produce 100 gigalitres of drinking water each year (which is sufficient to fulfil 50% of metropolitan Adelaide’s current water needs)
- Design, construction and commissioning of a pump station and transfer pipeline system that pumps desalinated water from the plant through a water treatment process and then pumped into the existing water supply network
- Associated complex High Voltage electrical works.
The 100GL P/A reverse osmosis plant brought McConnell Dowell’s multidiscipline capability to the fore with earthworks, civil structures, marine tunnelling, mechanical, electrical and building works. The highly efficient reverse osmosis design has set benchmarks for energy savings and minimal physical footprint. The innovative pre-treatment process has provided high levels of reliability using less energy and reducing chemical dosing requirements.
The construction team established industry leading approaches in protecting the local environment by developing a customised floating detention and sedimentation system to minimise the impact of construction works on the local marine ecology.
Following a successful construction handover, the Adelaide Aqua O&M team continue to exceed the expectations of the client by reducing operating costs, environmental impacts and energy use.