Southern Seawater Desalination Plant, Australia

The new plant is located at Taranto Road, north of Binningup, approximately 150km south of Perth. It is being built in two stages, each with a maximum capacity of 50 gigalitres (GL) a year.

The first stage of the plant was officially opened in September 2011. It was completed three months ahead of schedule and required an investment of A$955m ($943.5m). It is expected to reach its full capacity of 50GL/year within a year.

The second stage of the project was announced in August 2011. It will involve expansion of the plant's capacity from 50GL/year to 100GL/year. The expansion is estimated to cost A$450m ($444.6m) and is anticipated to be completed by December 2012. The state government has already approved a funding of A$300m ($296.4m) towards the expansion.

The plant is owned by Water Corporation which is the main provider of water, wastewater and drainage services in Western Australia.

In addition to the state capital, the new plant will supply water to the nearby city of Bunbury, located 175km south of Perth's central business district (CBD).

Components of the Southern Seawater Desalination Plant project

The first stage of the project involved construction of a seawater reverse osmosis (SWRO)-based, 50GL/year capacity desalination plant that can be expanded to 100GL/year. It also included pre-treatment and post-treatment facilities.

The second component of the project is the 28km long underground pipeline from Binningup to a storage facility comprised of four summit tanks located northeast of Harvey. The pipeline will facilitate the transfer of potable water from the plant to the integrated water supply scheme (IWSS).

Other components of the project include seawater pump station, a seawater intake pipeline to feed seawater into the seawater pump station and a 2km pipeline to deliver the water from the storage facility in Harvey into the Stirling-Harvey Trunk main.

Project background

The proposal for the SSDP was announced by the Premier of Western Australia in May 2007. Following the announcement, Water Corporation engaged consultants to conduct various studies to assist with the project design and meet the statutory requirements of the Federal Department of Environment and Water Resources (DEW) and Western Australia's Department of Environment and Conservation (DEC).

Water Corporation received conditional environmental approval for the plant in June 2009. Construction on the new plant commenced in July 2009 after getting full project approval from the Federal Government.

Key players with a role in Water Corporation's Australian plant

Environmental management consultancy 360 Environmental was commissioned in July 2007 to conduct flora and fauna investigations at the plant and pipeline locations.

KBR was engaged to undertake oceanographic survey, preliminary diffuser design, marine hydrodynamic modelling, coastal processes, sediment characterisation, water characteristics, biomonitoring and benthic habitat studies.

Noise survey was completed by Herring Storer Acoustics. Social impact assessment and sustainability statement were completed by GHD.

Brad Goode and Associates was commissioned in January 2008 to conduct a Site Identification Aboriginal Heritage Survey. WorleyParsons had undertaken comparison of the three shortlisted sites.

The Southern SeaWater Alliance (SSWA) was awarded the design, build and operate (DBO) contract for the desalination plant in late June 2009. The SSWA consortium is headed by two multidiscipline construction companies Tecnicas Reunidas (38%) and Valoriza Agua (38). Engineering consultancy firm WorleyParsons (5%) and construction company AJ Lucas (19%) are the partners.

The DBO contract entitles SSWA to operate the plant for 25 years.

Purpose of the new desalination plant

The SSDP is part of Water Corporation's strategic approach for long-term water sustainability. The desalination plant was ordered in response to the reduced rainfall in the state, population growth and subsequent increase in water consumption.

Western Australia has witnessed a 12% decline in rainfall over the last ten years. This has lowered the flows of stream into the dams by up to 50%. It has been estimated that the state's capital will require an additional 150 billion litres of water by 2031. In order to address these needs, the South Australian Government commissioned the Southern Seawater desalination project.

The new plant has the potential to deliver 30% of the state's water supply from climate independent water sources. It is expected to deliver total potable water savings of up to 1,200GL a year.