Construction completed on Australia’s largest recycled water project

Late in 2008, after two and a half years of construction, purification centres were switched on, pumps were activated and water flowed through 200km of large-diameter pipeline marking completion of construction for the $2.5bn Western Corridor Recycled Water Project.
Producing up to 232ML of water a day, the project is the largest in the Southern Hemisphere and the third largest in the world. It provides purified recycled water - a climate and rainfall resilient source of pure water to three power stations at Tarong and Swanbank. In future, it will supply water to industry and potentially agricultural users, and should the regions drinking water supplies fall below 40%, the Wivenhoe Dam.
The project includes a network of more than 200km of large-diameter underground pipes, three advanced water treatment plants, nine storage tanks and 12 pumping stations. It also provides significant environmental benefits by removing nutrients from water that is released to waterways flowing to environmentally sensitive Moreton Bay.
The Western Corridor Recycled Water Project is now owned by a Queensland government statutory authority known as WaterSecure, which also owns the Gold Coast Desalination Plant. WaterSecure provides a safe and sustainable source of pure water for South East Queensland, with the capacity to produce up to 365ML of pure water each day, providing water security for the region.
Project overview
Three advanced water treatment plants located at Luggage Point, Gibson Island and Bundamba, are central to the projects successful operation. They use world-class, multi-barrier treatment processes to produce purified recycled water. Each uses technologies that have been used to successfully purify water in Singapore, Europe and the US, but the combinations of technologies used in Queensland is unique and provides the most stringent safeguards to public health.
More than 200km of pipelines, pump stations and balance tanks link the system. The pipeline starts at Luggage Point and Gibson Island advanced water treatment plants at the mouth of the Brisbane River, travels through Brisbanes eastern and southern suburbs and meets the Bundamba advanced water treatment plant at Ipswich.
Purified recycled water pipelines travel in multiple directions from Bundamba. One pipeline leads to the Swanbank power station. A second pipeline continues north to Caboonbah at the top of Wivenhoe Dam, where it taps into an existing pipeline and takes water to power stations at Tarong.
 

Producing purified recycled water
Testing has demonstrated that water produced by the Project meets the Australian Drinking Water Guidelines. Water undergoes the worlds most rigorous purification processes, including real-time water quality monitoring, and testing for more than 400 parameters.
The projects advanced water treatment plants contribute three essential barriers of the advanced water treatment process, microfiltration, reverse osmosis and advanced oxidation.
    Microfiltration forces treated water under pressure through tiny straw-like filters that remove suspended material and micro-organisms including some viruses;
    Reverse osmosis pushes water under high pressure through a semi-permeable membrane, removing viruses, organic compounds and inorganic compounds such as salt; and
    Advanced oxidation is the final step of the advanced water treatment process. It uses hydrogen peroxide and ultraviolet light to destroy any remaining compounds. The outcome is a pure, safe and secure source of water.
Keith Davies, CEO of the Western Corridor project and WaterSecure, says the advanced water treatment processes are second to none.
The project is exceptional because it combines the best technologies known to humanity to produce one of the purest sources of water in the world. No other water project uses the same level of advanced water treatment processes that we use in Queensland. This is the first time that microfiltration, reverse osmosis and advanced oxidation have been combined within individual purification centres.
The projects quality has not gone unnoticed. Our work has been hailed around the world and was recognised by 11 international and national awards, including the 2008 Water Reuse Project of the Year at the Global Water Awards and the 2008 International Project of the Year from the Construction Management Association of America.
International delegations have praised the project and the environmental considerations we have made, as well as our best practice examples in design, construction and water treatment technologies.
By using global experts throughout all stages of design and construction, weve ensured the best outcomes. Weve already provided more than 15 billion litres of pure water to Swanbank and Tarong power stations. This water is safe and satisfies stringent requirements of the Australian Drinking Water Guidelines.
Davies says each advanced water treatment plant must undergo a comprehensive validation and verification process. Validation involves confirming that the advanced water treatment plant is operating as designed and according to design specifications. Verification ensures the advanced water treatment plant is consistently producing water that complies with water quality standards.
Davies says the quality of water is further guaranteed by the Water Supply (Safety and Reliability) Act 2008.
All water produced by the project must meet strict water quality and health standards outlined within this new regulatory framework, This act exists to protect public health and ensure the project can continue to operate and protect public water supplies. Under it, we are required to produce a recycled water management plan that identifies risks and details actions to minimise these risks.
The Queensland Water Commission has also established a panel of international experts to provide the highest quality, independent technical advice. This panel includes world leaders in ecotoxicology, environmental science, public health, environmental microbiology, limnology and advanced water treatment.
Improving outcomes for Moreton Bay
Davies says the project will leave a positive environmental legacy that will last for generations. Firstly, the amount of water is equivalent to a large dam. By providing this water from another source, we are preventing the need for at least one extra dam to be built in the future, he says.
In the immediate term, the project is improving water quality in the Brisbane and Bremer rivers, which flow to Moreton Bay, an environmentally sensitive and internationally recognised wetland. Nutrients that would otherwise be released to these rivers are removed in the treatment process.
For example, treated wastewater is no longer released to the Bremer River at Bundamba. This reduces levels of phosphorus and nitrogen in the river, meaning we can expect an improvement in aquatic ecosystems including plant life, fish stocks and invertebrates.
Where reverse osmosis concentrate is released to the Brisbane River, nutrient levels have been greatly reduced.
Davies says innovative construction procedures have allowed the Project to provide positive environmental outcomes. In constructing more than 200km of pipeline, the project passed through many sensitive creek and estuarine habitats. To minimise negative impacts of construction, we undertook a comprehensive environmental and social impact assessment and used innovative construction practices.
Horizontal directional drilling is a great example of sustainable infrastructure practices. It replaced traditional trench crossings at a number of locations, including the Brisbane River, Aquarium Passage and the lower reaches of Bulimba Creek. HDD minimised the impacts on sensitive environments and critical infrastructure.
2.5 years of construction
Because of its size and complexity, the project was delivered in stages known as 1A, 1B, 2A and 2B. Western Corridor Recycled Water Pty Ltd successfully met the construction deadlines for all project stages.
Stage 1A was designed to take immediate pressure off the Wivenhoe Dam by supplying Swanbank power station with up to 20ML a day. It comprised construction of the first stage of the Bundamba advanced water treatment plant and associated pipelines, and was completed after just 10 months of construction.
Stage 1B upgraded the capacity of the Bundamba centre to 66ML a day and began supplying water to Tarong and Tarong North power stations. It included construction of almost 100km of pipeline and was completed in June 2008, just nine months after water first flowed to Swanbank.
Stage 2A entailed construction of the Luggage Point (66ML a day capacity) and Gibson Island (50ML a day capacity) advanced water treatment plants, and more than 80km of underground pipeline. This pipeline was built through some of South East Queenslands most developed regions and posed considerable challenges. Stage 2A was completed on October 31, 2008 and marked the first time the entire 200km system was linked together as a completed whole.
Stage 2B, completed in December 2008, upgraded the Gibson Island advanced water treatment plant, increasing its capacity to 100ML a day.
While construction of core project elements is now complete, further drought contingency works are underway to upgrade the systems yield and ensure the pipeline can efficiently transport increased volumes of water.
Keith Davies says the project has set industry benchmarks and will remain a key element of South East Queenslands water supply strategy for generations.
The project alliances have toiled night and day to bring the project in on time and under budget, but most importantly theyve done it safely, with a lost-time injury rate well below industry standards, he says.
Alliances
The Project was delivered by Western Corridor Recycled Water, with assistance from Veolia Water Australia, the alliances and a workforce of more than 1800 people.
Sixteen of the worlds leading construction, engineering, project management and water services companies formed five alliances to build the project, along the way employing thousands of specialists from more than 40 countries and clocking up almost seven million work hours.
The alliance approach involved significant collaboration between the Queensland Government and private companies, with common alliance themes being a risk-sharing and reward-sharing culture with unanimous decision making.
Bundamba Alliance
Bundamba Alliance completed construction of the Bundamba advanced water treatment plant, which produces up to 66ML of purified recycled water a day. The Thiess-Black and Veatch joint venture completed Stage 1A of the centre in August 2007, less than 10 months after construction started. In winning the 2008 International Water Reuse Project of the Year Award, judges described Bundamba 1A as a technical masterpiece.
Despite work continuing for up to 24 hours a day, six days a week, excellent standards were maintained with 1.7m workforce hours completed without a lost time injury. International delegations have praised the design and fast-track nature of procurement and construction activities of the centre, as well as the safe working operation of the site.
Gibson Island Alliance MWH, Worley Parsons, Baulderstone Hornibrook and United Group Infrastructure
Gibson Island Alliance is responsible for building the Gibson Island advanced water treatment plant, which produces up to 100ML of purified recycled water a day. The Alliance built the projects largest centre on the smallest site, and subsequently embraced a culture of innovation to ensure results are delivered and objectives achieved. More than 30 innovations were delivered during construction, with a number of these being implemented following suggestions from the construction workforce. At present, further drought contingency works are underway.
Luggage Point Alliance CH2M Hill, Laing ORourke, Connell Wagner, Hatch
Luggage Point Alliance constructed the Luggage Point advanced water treatment plant, which produces up to 66ML of water a day. The Luggage Point Alliance initially constructed a pilot centre to simulate a full-scale advanced water treatment plant. This pilot centre tested different membrane technologies to establish the best combinations that would ensure the highest quality and consistency of water produced. At present, further drought contingency works are underway.
Eastern Pipeline Alliance - AJ Lucas, Transfield Services, GHD
Eastern Pipeline links Luggage Point and Gibson Island to the Bundamba advanced water treatment plant. Eastern Pipeline Alliance constructed 104km of underground pipelines, 10 pumping stations and seven balance tanks and managed around 50 crossings of roads, railways and major waterways, including the Brisbane River. Pipeline construction occurred through a heavily built up area and was complete in October 2008. At present, further drought contingency works are underway.
Western Pipeline Alliance - McConnell Dowell, Abigroup and GHD
Western Pipeline comprises the pipeline that transports water west of the Bundamba advanced water treatment plant. The Western Pipeline Alliance built more than 80km of large-diameter pipeline, two pumping stations at Bundamba and Lowood and two balance tanks at Esk and Lowood. Pipeline construction was completed in June 2008.
Starting at the Bundamba advanced water treatment plant, the pipeline travels north-west for 32km to a 5ML balance tank and pump station at Lowood. The pipeline then splits into two, with one pipeline heading 48.5km north to Caboonbah, via the Esk balance tank, where it links with pipelines supplying water to the Tarong power stations. The second pipeline heads 16.4km to Coominya, where water will be released into Wivenhoe Dam once combined dam levels fall below 40%.
The Alliance was recognised for its speed of pipeline construction, with more than 50% of the pipeline being built in just six months and, on one day, a massive 1.52km of pipe was laid.
Davies says WaterSecure will provide the water required to ensure a positive future for South East Queensland. Water is the fundamental element that we simply cant do without. And in a region increasingly affected by climate change, extreme drought and substantial population growth, access to fresh water is more important than ever. WaterSecure is the outcome of two years of innovation, excellence and plain hard work.
Weve looked to the best examples overseas and throughout Australia to provide reliable answers to Queenslands water supply requirements. Weve combined two climate-independent water sources to produce a pure source of water that will directly assist South East Queenslands population growth, economic growth and water supply certainty for generations to come. Were immensely proud of our efforts and those of our alliance partners.