Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/724419
18 On Site September 2016 Water. desalination + reuse ...TECHNOLOGY: Wonthaggi on the Bass Coast was ultimately chosen as the best location because it has ready access to high quality, high activity ocean water for the supply of seawater, and rapid dispersal of saline concentrate. The site terrain was consid- ered highly appropriate for the construction of a desalination plant, and it offered ease of access to Melbourne's existing water network. The city's water system flows from north and east, to west and south, with pipe sizes that reduce from east to west, making an east-side connection the most practical. VDP continuously monitors seawater concentrate before it reaches outlets in the ocean. Salinity loggers inside and out- side the discharge zone, which is licensed by the Environment Protection Authority Victoria, ensure that seawater concentrate is diluted back to the appropri- ate levels in a defined mixing zone. Data collected by moni- toring the marine environment during the five years before the plant was commissioned has provided an excellent source of knowledge about the dynamics of the local water. The commissioning process took seven months, with the first RO train taking six weeks, the second, four weeks, and the third, two weeks. Since then, the plant has been maintained in standby mode ready to be brought back into operation as required, and can be started from zero to full production in less than three months. PPP covers finance, build, operate and transfer THE faCTs • The deal set a new benchmark for public-private partnerships (PPPs) • Water orders are placed annually and must be confirmed to Aqua Sure by the state by April 1 • Prices are set in the contract by volume, in increments up to 150 gigalitres • The contract is managed on behalf the Victorian government by the department of environment, land, water, and planning • The project generated $1.3 billion of supply contracts, of which 75 per cent went to Australian companies THE fiGurEs • Orders can be for 0, 50, 75, 100, 125, or 150 gigalitres • Contract runs for 30 years to 2039, at which point ownership will be transferred to Victoria state • The capital cost of the project was set a $3.5 billion as part of the contract and was not exceeded Business model • Annual payments by government without water supplies were report- edly $607 million in 2016-17 One of the largest PPPs procured worldwide in the past decade, VDP was a milestone for PPPs, especially given the difficult eco- nomic times during which it was brought forward, and the scale and complexity of the project. The plant was originally mooted in the 2007 Victorian state water plan, "Our water, our future". AquaSure, a joint venture of Dégremont and Thiess, won a 30-year contract to finance, build, operate, and maintain the desalination plant from the Victorian state p remier, John Brumby, in 2009. One other consortium was shortlisted, BassWater, comprising John Hol- land Group and Veolia. The PPP was funded by $3.7 billion of debt from financial institutions in Australia, Europe and Asia. This was refinanced by AquaSure in 2013 with help from Macquarie Capital. The debt is being repaid by contract payments that are made by the Victorian state government, and funded by utility Melborne Wa- ter. The payment in 2016-17 was $607 million, not including the amount due for the water, which was reportedly $27 million. AquaSure subcontracted the design and construction to Dégremont and Thiess (now Ventia), and Watersure was Watersure's onsite team of 52 engineers, operators, maintenance and other staff keeps VDP in top condition so that it can begin producing desalinated water at three months' notice. Teams of operators and coordinators work 24 hours a day, seven days a week, to keep the plant running smoothly. Watersure brings together expertise from Suez in design and operation of water treatment facilities, and experience from Ventia (formerly Thiess Services) in delivering water services. rEvErsE OsmOsis • Each membrane in the VDP has a surface area of 40.9 m2. • The membrane material is wrapped up in cylinders like a closed umbrella. • The site includes zones to enable future plant expansion to a capacity of 200 gigalitres. signed up to provide ongoing operations and maintenance services. The capital cost for construction was fixed in the contract at $3.5 billion. "Water- sure combines Suez's expertise in design and operation, and Ventia's skills in delivery. Both are leaders in their fields," says Brassington. VDP can be brought into water production mode as required within three months. Each year, the Victorian govern- ment is required to issue a water order by April 1, with production starting in July. Orders are for a set number of gigalitres, and by giving a full year for delivery of the water, the unit cost is kept down. The price of water for each of the options was set in the contract between Victoria state and AquaSure in 2009. The contract stipulates that AquaSure is to hand over owner- ship of the plant, in full working order, to the government at no additional cost in 2039. "The capital cost of $3.5 billion to construct the VDP was fixed in the contract with AquaSure and there has been no increase in cost to the state government or water custom- ers. Having pledged to deliver, operate and maintain the most technically advanced , environ- mentally sensitive and energy efficient desalination facility in Australia, we are doing just that," said Brassington.