Adelaide Desalination Plant

Adelaide Desalination Plant
Desalination plant
Location Lonsdale, South Australia
Daily capacity 300 megalitres per day
Annual capacity 100 gigalitres per annum
Cost A$1.83 billion
Energy generation offset Renewable (TBA)
Technology Reverse Osmosis
Percent of water supply 50% of Adelaide
Completion date December 2012
Website www.sawater.com.au

The Adelaide Desalination plant, formerly known as the Port Stanvac Desalination Plant, is a SWRO (sea water reverse osmosis) desalination plant located in Lonsdale, South Australia which has the capacity to provide the city of Adelaide with up to 50% of its drinking water needs. On 11 September 2007, South Australian Premier Mike Rann announced that the State Government would fund and build a desalination plant to guarantee Adelaide's water supply. He said the plant, to be totally powered by renewable energy, would be 'a necessary insurance policy against future droughts'.[1]

In February 2008, the State Government appointed SA Water as the lead agency responsible for the delivery of the project and also appointed a Steering Committee of Chief Executive of key Agencies to provide strategic oversight and review of all key decision prior to approval by the SA Water Board and or the Government and Parliament; this Steering Committee had an Independent Chair (Mr. Kevin Osborn).

On 13 May 2009, following negotiations between the Premier and Prime Minister Kevin Rudd, it was announced that the Adelaide Desalination plant would be doubled in size following extra Federal funding.[2]

The plant was completed on time and within the original budget ($1.83 billion). It has an estimated operating cost of $130 million per year ($2.5 million per week), when operating at full capacity of 100 GL per annum.

It was officially opened on 26 March 2013.[3]

The capital cost of A$1.824 billion for the Adelaide Desalination Project includes:

  1. The desalination plant and associated marine works
  2. A pumping station and 12 km transfer pipeline to take the desalinated water to the Happy Valley Reservoir Treatment Plant (Treated Water tanks) where it is blended with treated catchment rainwater and delivered into the SA Water distribution system
  3. SA Power Networks electricity supply sub-station
  4. Preliminary site works, land and other interconnection works with SA Water's existing facilities

The Adelaide Desalination Project is (and remains) the largest infrastructure project that the State of South Australia has funded, owns and has completed successfully - to date.

Background and Project Challenges

South Australia, as the "driest state in the driest (inhabited) continent",[4] has experienced severe water shortages during periods of drought. As drought conditions worsened during 2006-7, reduced inflows into the River Murray lead to the introduction of progressively harsher water restrictions and the future of Adelaide's water supply came to the fore as a political issue.[5]

Although there had been some prior consideration at state government level for a desalination plant to supply metropolitan Adelaide, in the leadup to the November 2007 federal election campaign Prime Minister John Howard promised that, if re-elected, his Coalition government would contribute towards the capital cost of a desalination plant to reduce the city's dependence on the River Murray. Opposition leader (then) Kevin Rudd made similar pledges.[6]

Awards & Recognition

The Adelaide Desalination Project is recognised by professional organisations, industry bodies and independent judges from around the world. Awards include:

Location

The site for the main desalination plant was purchased by SA Water from ExxonMobil in December 2008.[7] Construction commenced in March 2009.

The plant is located on the eastern shore of Gulf St Vincent just north of ExxonMobil's disused Port Stanvac Oil Refinery. It lies within the industrial suburb of Lonsdale in the City of Onkaparinga. The residential area just north of the plant lies within the suburb of Hallett Cove (part of the City of Marion).

Construction

Initially the desalination plant was to have a capacity of 50GL per year (supplying up to 25% of Adelaide's needs) with an indicative estimated cost of $1.295 billion (in Nominal dollars or dollars at completion) and construction completion by end June 2012. Subsequently, with deteriorating drought in South Australia, the project was fast-tracked to compress the planning and procurement program and target early First Water (or 10% of plant output) up to 12 months earlier followed by progressive completion of the remaining 50 GL per year plant. Government approved the fast-track of the First Water milestone within the overall approved amount of $1.374 billion (Nominal cost or cost at completion) for the 50 GL/a plant.[8][9][10]

In February 2008, the SA government approved an initial funding of $9.5M for the design, construction, operation and maintenance of a small Temporary Pilot Desalination Plant with a capacity of 100,000 litres per day.[9] Construction of this temporary pilot plant commenced in June 2008, and was completed on 4 August 2008.[11] The pilot plant was operated for 2 years through to October 2010 and provided valuable information to further optimise the design of the main plant.

In June 2009, after start of construction of the first 50 GL plant, the South Australian Government announced that the plant's annual output was to be doubled to 100Gl, bringing the total cost of the project to $1.824 billion, with "first water" (from the first 50 GL/a plant) still targeted as early as possible (end December 2010) and final capacity (100 GL) milestone being end December 2012.[12] This increase in capacity was assisted with a grant of $228 million from the federal government, with the stated aim of reducing Adelaide's dependence on water drawn from the River Murray.[13]

Construction challenges and doubling of the plant capacity pushed the (accelerated) first water from the 50 GL plant to 31 July 2011.[14]

Capacity

In June 2009, and after start of construction for the first 50 GL plant, and following a third consecutive year unprecedented drought in the State, the South Australian Government announced that the plant's annual output would be doubled from 50Gl (gigalitres) to 100Gl, approximately 270Ml (megalitres) per day,[15] providing up to 50% of Adelaide's domestic water supply.[12]

The plant sources all its electricity from 100% GreenPower accredited Renewable Energy sources. SA Water contracted with AGL to provide this green power under a 20-year contract at an annual cost estimated at over $75 million per year;[16] In December 2010 it was confirmed that the total operating cost of the desalination plant was around $130 million per year for the full 100 GL plant (in 2015/16 dollars).

By 20 October 2015, the Adelaide Desalination Project had produced 126.3 billion litres of water for domestic supply.[17]

Workplace safety

The health and safety of all workers and stakeholders associated with the project is the principal concern for SA Water and the AdelaideAqua consortia. A "home without harm" safety culture was established from day one across the project, and was embraced by the entire workforce as part of a rigorous Health and Safety program that included:

Despite rigorous occupational health and safety systems, a fatality occurred onsite in July 2010. SafeWork SA investigated and no charges were laid on SA Water or the principal Contractor, AdelaideAqua.

Nearly 9 million hours were worked on the project site with a lost time injury frequency rate (LTIFR) approximately ten times lower than the construction industry average in Australia. It also resulted in the creating of unique and innovative employee safety and wellbeing initiatives such as the Daily Start Card and Just Culture.

Energy sources

The desalination plant is powered by 100% accredited renewable green energy sources within South Australia. The plant sources its electricity from renewable energy sources provided by AGL Energy under a 20-year contract at an annual cost initially estimated at over $75 million per year (for the first 50 GL plant);.[16] Energy supply cost is part of the overall operating cost of the facility which was confirmed by SA Water in December 2010 at $130 million per year (for double the capacity or 100 GL plant). SA Water advised that the $130 million per year would result in one of the lowest operating cost per unit of desalinated drinking water of any desalination plant in Australia. This was possible because of energy efficient technologies and innovations throughout the plant.

The plant's buildings have been designed to maximise natural light during the day and a selection of high thermal materials (e.g. solid precast concrete walls and insulation) to improve thermal properties, thereby minimising energy consumption. More specifically, Solar Photo Voltaic cells have been placed on the reverse osmosis buildings for localised power generation. Each reverse osmosis building has an approximately 100 kW solar cell array providing a site capacity of approximately 200 kW at peak sun hours. The high pressure pumps feeding the reverse-osmosis membranes are the largest consumers of energy in the plant. Energy recovery devices are installed to harness the pressure in the saline concentrate stream and use it to pressurise some of the feed water. As a result, the high pressure pumps are only needed to deliver half of the water feeding the reverse osmosis system, reducing energy consumption in the plant by up to 40 per cent. Likewise, two turbine generators in the outfall tunnel take advantage of the plant elevation 50 meters above sea level. This mini-hydroelectric system is capable of producing 1290 kW of renewable electricity which is fed back into the plant, reducing energy consumption by approximately 2.5%.

Effects on marine life

The lack of tidal movement for up to 2–3 days during dodge tides, which occur twice a month in Gulf St Vincent, reduces mixing of the water column. This has raised concerns in the early phase of the project planning about the potential effects of brines saline concentrate discharged from the desalination plant on benthic flora and fauna.[18][19]

Dodge tides and other local conditions have been taken into account in the design of the outfall system. Discharge to the sea is via a 1,080 m undersea tunnel, with dispersal through one of 6 specially designed diffusers. Each diffuser has a head consisting of 4 duck bill valves that assist in maintaining high discharge velocity for optimum mixing, independent of plant operating conditions.

Marine monitoring buoys placed at 100 m radius from the outfall structures allow real time data monitoring via the plant control system, to assess performance against EPA discharge licence conditions. Monitoring of the surrounding marine environment started before construction of the plant began and will continue into the future to ensure no adverse environmental impact.

Treatment process

The Adelaide Desalination plant removes salt from, or desalinates, seawater using the process of reverse osmosis. There are also additional steps before and after the desalination process. Stage 1: Pre-treatment – to remove particulate (non-dissolved) material from the seawater.

Pre-treatment at the plant is achieved in three steps. Band screens remove coarse solids greater than 3mm from the water before it is pumped into the plant. Disc filters filter the water further, removing material larger than 0.1 mm (100 micron). Ultra-filtration membranes then remove material larger than 0.04 micron, including bacteria and most viruses. Stage 2: Reverse-osmosis – to remove dissolved salts from the water.

The water is pumped through a full 2 pass reverse osmosis system (i.e. all water passes through 2 separate reverse osmosis membranes) where dissolved salts are progressively removed. Approximately 48.5% of the feed water is converted to low salinity water, termed permeate, while the remainder is returned to the sea as saline concentrate. Stage 3: Post-treatment – to prepare the water for distribution.

The permeate from the reverse osmosis system is stabilised and then chlorinated and fluoridated ready for distribution. It is stored in 50 megalitre tanks onsite before it is transferred to the Happy Valley Water Treatment Plant through the Transfer Pump Station.

Controversy

As of January 2016, the desalination plant continues to run despite having sufficient reservoir capacity and water allocation from the Murray River. The cost to maintain the plant is estimated at A$1 million per day.[20][21]

Gallery

Transfer Pump Station 

See also

References

  1. ↑ ABC News, Sept 11,2007 (reporter Nick Harmsen
  2. ↑ SA Govt New Release, 13 May 2009 "Adelaide to double size of its Desal plant", www.sawater.com.au/
  3. ↑ http://www.premier.sa.gov.au/images/news_releases/13_03Mar/desal.pdf
  4. ↑ Griffin, T. & McCaskill, M. (1986): Atlas of South Australia, South Australian Government Printing Division. p 60.
  5. ↑ Libs' user-pays water plan Michael Owen, AdelaideNow, 29 August 2007. Retrieved 26 August 2011.
  6. ↑ Howard's desal plan to wean city off Murray Pia Akerman and Siobhain Ryan, The Australian, 23 October 2007. Retrieved 26 August 2011.
  7. ↑ State Government secures desal plant site from Mobil AdelaideNow, 23 December 2008. Retrieved 25 August 2011.
  8. ↑ Adelaide go-ahead for $1bn desal plant John Wiseman, The Australian, 5 December 2007. Retrieved 25 August 2011.
  9. 1 2 Work begins on pilot desal plant Jeremy Roberts, The Australian, 21 January 2008. Retrieved 25 August 2011.
  10. ↑ Desal plant open by 2011 Nick Henderson, AdelaideNow, 11 January 2008. Retrieved 26 August 2011.
  11. ↑ Port Stanvac desalination pilot plant up and running AdelaideNow, 4 July 2008. Retrieved 25 August 2011.
  12. 1 2 100Gl desalination expansion in Public Works today Department of Premier & Cabinet, News release 9 June 2009. Retrieved 25 August 2011.
  13. ↑ $228m Desalination plant to be doubled in size AdelaideNow, 12 May 2009. Retrieved 26 August 2011.
  14. ↑ Water begins to flow from Adelaide's new desalination plant AdelaideNow, 31 July 2011. Retrieved 25 August 2011.
  15. ↑ Acciona back to expand Adelaide desalination ABC News, 28 June 2009. Retrieved 25 August 2011.
  16. 1 2 Concern over desal energy cost ABC News, 8 September 2009. Retrieved 25 August 2011.
  17. ↑ "Californian drought delegation tours South Australia". ABC News. Retrieved 2015-12-17.
  18. ↑ Desalination (Port Stanvac) Sixty-third report of the Environment, Resources and Development Committee, Parliament of South Australia
  19. ↑ Study uncovers desal plant shock for Gulf's health Michael Owen, The Advertiser, 19 December 2008 (AdelaideNow online edition dated 18 December 2008 11:30pm) accessed 4 April 2011
  20. ↑ http://www.abc.net.au/news/2014-12-29/adelaide-desal-plant-to-keep-running/5991256
  21. ↑ http://www.abc.net.au/news/2016-01-18/water-usage-across-adelaide-increases/7094710

External links

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Coordinates: 35°5′48.7″S 138°29′2.6″E / 35.096861°S 138.484056°E / -35.096861; 138.484056

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