Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/1056083
December 2018 Water.desalination+reuse In Site 27 NEW SOUTH WALES • Sydney Desalination Plant ca- pacity up to 246,600 m3/d • Plant suffered severe storm damage in 2015 • Sydney and surrounds forecast to add 1.5 million more people by 2035 New South Wales was o - cially listed as 100 per cent in drought in August, but a wet- ter-than-usual October saw res- ervoir levels stabilise at around 63 per cent full. This is just three percentage points above the trigger level at which Sydney's $1.89 billion desalination plant would be switched on. The privately-leased plant at Kurnell was originally com- missioned by the former Labor government in 2007 during the Millennium Drought, which saw Sydney's dams fall to a third of capacity. However, only a few short months aŠ er it began operating, higher-than-expected rainfall meant that the Syndey Desali- nation Plant (SDP) was put into hibernation mode, a state it has e' ectively remained in ever since. Matters were complicated when a severe storm, which was mooted a possible tornado, in December 2015 ripped through the facility causing major struc- tural damage. Following the incident, SDP faced calls for closure as it continued to rack up hundreds of millions of dollars in mainte- nance fees, since water authority Sydney Water was locked into a 50-year water supply agree- ment with investment company Sydney Desalination Plant Ltd, which holds even when the plant is idle. AŠ er the comple- tion of storm repairs to the facil- ity in October 2018, the plant is now ready to be switched back on when Sydney's dam storage levels drop below 60 per cent capacity. A statement from Sydney De- sal Ltd states that once switched on, the plant can begin produce drinking water within three to four months; and that it takes six to eight months to reach maximum capacity, or 250,000 m3/d, which represents about 15 per cent of Sydney's total drink- ing water demand. With the populations of Sydney, Illawarra and Blue Mountains forecast to add 1.5 million more people by 2035, SDP still has the potential to deliver some value, potential- ly becoming part of the region's base load water supply. SA WATER CONSULTS PUBLIC ON DESALINATION PLANS South Australia Water (SA Water) has kicked off a public consultation on an $80 million desalination plant project at Sleaford Bay on the Eyre Peninsula. The plant was originally mooted a decade ago, and in July 2018 SA Water completed the purchase of 60 hectares of land at Sleaford Bay for the project. Construction is slated to begin in 2020. The desalinated product water will be used to supplement groundwater from Uley South Basin, and is expected to help reduce the natural hardness of the water. A desalination plant was identifi ed in 2009 as the preferred option to supplement future supply, in a long-term plan developed with the local community and National Resources Management Board. SA Water is committed to continue working with community groups throughout the planning and design of the new desalination plant.Sleaford Bay was identifi ed as the preferred location based on factors such as proximity to the water supply network, strong ocean currents, and site accessibility. Study of SDP brine outfall shows limited marine impacts A study into the marine ecological impacts of Sydney Desalination Plant, which claims to be the fi rst major research of its type in the world, found only limited evidence of toxicity. The six-year study was commissioned by the plant's original owner, Sydney Water, and carried out by the University of New South Wales, NSW Fisheries Research, and Southern Cross University. It examined the eff ects on marine invertebrate recruitment of pumping and diff using high-concentration salt water into the ocean. Impacts were monitored at six locations, each about 25 metres underwater, over a six-year period covering when the plant was under construction, during operation, and idle. The main eff ects occurred over an area within 100 metres of the outfall, where changes to water fl ow meant that some invertebrates, including barnacles, increased in number, while others reduced in quantity or did not recover a er shutdown of the outfl ow. Negative impacts were observed on species with slow swimming larvae, such as tubeworms, lace corals, and sponges. Beyond 100 metres, saline concentration was found to be almost at background levels, which researchers put down to the eff ective design of high- pressure diff users. "Our comprehensive study shows the hyper-saline outfl ow from this modern plant is not having a major impact on the New South Wales coast. The potential marine ecology impacts from a well-designed and well-located desalination plant should not immediately prevent us from considering desalination in a period of severe, prolonged drought," says the paper's senior author, professor Emma Johnston, Dean of Science at University of New South Wales • First large-scale ecological impact study of desalination outfall reveals trade-off s in eff ects of hyper-salinity and hydrodynamics was published in peer review journal Water Research, in September 2018. Potential marine ecology impacts should not immediately prevent us from considering desalination. Emma Johnston, University of New South Wales The proposed plant is to be set back from the bay by two kilometres supply network, strong ocean currents, and site accessibility. of toxicity. The six-year study was commissioned by the plant's original owner, Sydney Water, and carried out by the University of New South Wales, NSW Fisheries Research, and Southern Cross University. It examined the eff ects on marine invertebrate recruitment of pumping and diff using high-concentration salt water into the ocean. Impacts were monitored at six locations, each about 25 metres underwater, over a six-year period covering when the plant was under construction, during operation, and idle. The main eff ects occurred over an area within 100 metres of the outfall, where changes to water fl ow meant that some invertebrates, including barnacles, increased The proposed plant is to be