The total project cost is $1.824 billion and the plant will deliver up to 100 billion liters (100GL) of water each year – this represents about half of metropolitan Adelaide’s annual water demand. A range of drinking water supply alternatives were considered, however – desalination was the only climate-independent option which could help meet the demands of South Australia’s changing climate and population growth predictions.

The Adelaide Desalination Project remains Adelaide’s climate-independent insurance policy against the drought and will be used in conjunction with a range of other water security measures including recycling, storm water reuse and water wise measures.

SA Water requirements for the Adelaide Desalination Project designers are broad ranging and focus on key customer, community and stakeholder requirements including:

• Maintain a health and safety culture as the first priority;
• Providing a sustainable and secure water supply for Adelaide;
• Environmental protection using industry best practices;
• Consistently achieve required quality, durability, performance and production of plant;
• Flexibility to up-scale the desalination plant from 150 ML/d to 300 ML/d (50 to 100 GL per annum);
• Provide energy efficient design and operation and minimize whole of life costs; and
• Achieve a high level of knowledge transfer to SA Water.

The Adelaide Desalination Project is large in scale and covers a variety of building environments and methods. The inlet and outlet works includes both marine and underground construction methods, comprising marine jack up barge and tunnel boring machine tunnel constructions. The process plant involves large scale civil, building, electrical, mechanical and process construction activities and materials.

The building’s major material components include high-grade stainless steel, glass reinforced plastic (GRP), high-strength reinforced concrete, pre-cast concrete panels and building elements and high-grade coatings and lining systems.

The ADP uses various building methods — these include concurrent design activities (designing whilst starting to build); early procurement; and specialized construction processes (including air-freight of large number of overseas components, coordination of building and area disciplines, extensive use of pre-cast concrete building elements and preassembly of some key process components).

 The project is expected to produce its first desalinated water by the end of July 2011 and the overall 100 gigalitre capacity per annum project is on track for completion by the end of 2012.

An important part of the Adelaide Desalination Project is the Transfer Pipeline System to deliver water from Port Stanvac to the Happy Valley water treatment supply. Desalinated water will be pumped through the pipeline to Happy Valley, where it will be combined with water from the water treatment plant before entering the existing water supply network.

In addition to the works by Adelaide Aqua D&C Consortium, SA Water has contracted other parties to undertake associated works. The Transfer Pipeline System (constructed by major contractor McConnell Dowell Built Environs Joint Venture) will transfer desalinated water from Port Stanvac to the Happy Valley drinking water supply system.

Further, a new Lonsdale Substation has been built (by ETSA Utilities) to ensure reliable power supplies to the desalination plant.

A web link to view the most recent fly-through of the ‘completed’ plant is available here:

http://www.sawater.com.au/NR/rdonlyres/CCDAB33F-7455-4EB5-9511-6E71B957891A/0/ADPFlyOver.wmv

Some of the key milestones already achieved on site include:

• Construction completion and commissioning of the Transfer Pump Station and Transfer Pipeline System to Happy Valley;
• Substantial progress with the revegetation completion along Lonsdale Road;
• Completion of significant marine works for the intake and outfall pipelines;
• Tunnel boring machine 2 ‘Cora The Bora’ reaching its final destination 1.1km from the shore; Power supply infrastructure ready to meet needs of the 50 billion litre seawater intake tunnel boring work completed in July 2010;
• Brine outfall cross connection works completed successfully in September 2011;
• Operational transfer of Transfer Pump Station achieved with transfer of water from Port Stanvac to Happy Valley in September 2010;
• An Environmental Protection Agency (EPA) License to operate the Adelaide Desalination Plant was granted in November 2010;
• Feeders 5 & 6 were successfully energized to the Adelaide Aqua high voltage switch room. This provides the 50; • MW N-1 redundancy supply for Stage 1 of the ADP;
• Completion of concrete works in the seawater intake pump station and solid waste building during November 2010;
• Construction completion and flooding of the intake and outfall marine pipelines – now ready for commissioning; and
• Starting installation of the RO and UF membranes.

Environmental outcomes far-reaching for Adelaide desalt plant

The Government, SA Water and Adelaide Aqua D&C Consortium are committed to the highest environmental standards for the Adelaide Desalination Project.

Critical environmental studies have been undertaken and SA Water has environmental performance measures for every step of the project. Detailed information on our environmental studies and monitoring programs, public consultation response document and details of the Independent Technical Review Panel can be found in our Environmental Impact Statement, which is located on our website: http://www.sawater.com.au/SAWater/WhatsNew/Major Projects/EIS.htm. This includes details of the plant and how risks will be managed and mitigated.

There have been a number of challenges with the design of the plant to meet the stringent environmental and engineering controls sought by Mobil (the previous owner of the land) and statutory authorities. These have been discussed extensively in SA Water’s EIS – which is a public document.

Building on the EIS, some of the key environmental outcomes we have already seen on site are set out as follows:

Tunnelling to avoid environmentally sensitive zones:

During the early environmental investigations the intertidal zone at the base of the cliff at Port Stanvac (and the cliff itself) were identified as being sensitive. A ‘no go’ zone to protect this area was established in consultation with the local community. From an engineering perspective this meant there could be no activities of either a permanent or temporary nature within this zone, which necessitated the development of a tunnelling solution for the intake and outfall. Both tunnels will be driven using tunnel boring machines.

Marine drilling and dredging:

To meet strict water quality and environmental performance criteria for dredging and drilling activities, special settlement tanks were installed on a large barge as part of the management of spoil and water during drilling and dredging operations. Key features of the settlement and treatment system included primary and secondary treatment tanks, baffles to increase flow path and encourage settlement and the installation of progressively finer treatment screens. The process also allowed for flocculent dosing and adjustable discharge points. 

Brine diffuser design:

The use of duckbill valves as part of the final diffuser design for the outfall to assist with initial mixing both due to their ability to maintain relatively high port velocities under low flows as well as the elliptical shape of the duckbill jets enhancing mixing. To support the use of these valves hydraulic performance testing was undertaken and was coupled with dilution performance testing.

Further to this, Adelaide Aqua has an ongoing program to monitor the groundwater as part of its Groundwater Management Plan. Disposal of all material from the site is undertaken in accordance with EPA requirements, including the removal of some materials to an EPA licensed facility for treatment, reuse or disposal. Some other key environmental achievements to come out of the project during construction have been around recycling. Waste recycling has been a key focus for the project. Adelaide Aqua D&C Consortium has an arrangement with Veolia/Resource-co to manage waste disposal. Over 95 per cent of waste produced from site to date has been diverted from landfill and recovered as a raw material/alternate fuel source. This was recently acknowledged by Keep South Australia Beautiful (KESAB) and a certificate was presented to the project for recycling 15,000 tonnes to date. We have also recycled materials for bitumised roads and base material where possible. Together, SA Water and Adelaide Aqua D&C Consortium, have developed a Construction Environmental.

 Management and Monitoring Plan (CEMMP) and a suite of environmental sub-plans to manage on-site environmental management in consultation with the EPA. These plans are regularly reviewed and audited to ensure on-site practices are complying. The ADP has installed an on-site construction water treatment plant facility which has enabled the project to treat construction site water and remove metals, hydrocarbons and sediments prior to discharge into the environment. This is well above the EPA licensing requirements which are set on construction sites to mitigate impacts. In some more locally-based work, the formation of a partnership with the KESAB Clean Site Program and the ADP has supported on-site recycling initiatives, environmental toolbox sessions with on-site construction crews, education materials distributed on site and supporting general environmental initiatives on site. SA Water is also working to put together a proposal for a greenhouse gas inventory and exploring possible options for achieving carbon neutrality. This is part of the greenhouse gas emission reporting under the National greenhouse and Energy Reporting Framework.

Environmental consideration was given to the local of the ADP at Port Stanvac. This area was chosen as the preferred site based on a range of factors – including information from surveys identifying the marine intake and outfall would be located in a mainly bare substrate/ sandy habitat as opposed to significant sea grass meadows present in other parts of the Gulf. The site also has desirable mixing characteristics compared to other sites assessed north of Port Stanvac through the multi-criteria analysis. This has significantly reduced impacts to marine life and habitats and was a key achievement for the site selection. Further, the plant has been constructed in close proximity to the metropolitan water supply, thereby minimizing power consumption and avoiding needed to pump water over large distances.

Another environmental focus of the project has been the natural environment surrounding the plant. Our team has undertaken landscaping with over 200,000 plants using local indigenous species to improve biodiversity. We have also installed rainwater tanks on site to capture water for use around the site. For example, two tanks will capture water from the reverse osmosis buildings, holding a total storage volume of 840 kilolitres for onsite re-use irrigating landscaping. This water is also planned to be used in the plant’s local plumbing features in administration buildings (eg. toilets).

Another more visually exciting part of the project has been the rehabilitation of the once-degraded creek on site. Whewn we first moved on the Port Stanvac construction site, the creek had severe erosion and weed infestation. Rehabilitation through use of gabion structures, bank stabilization and planting of local indigenous species has significantly improved water quality discharged to the Gulf St Vincent and site habitat.

Wide-ranging challenges have been met by enthusiastic and experienced team

The Adelaide Desalination Project began in February 2008 with the proposal to build a climate-independent source of water supply for Adelaide and an original expectation to produce 50 billion liters per annum for our Adelaide customers by June 2012. Shortly after, following prolonged drought conditions in South Australia and the Murray-Darling Basin, the State and Federal Government changed this to an expanded program which included doubling of the plant size of 100 billion liters per annum by end December 2012. With this bigger program came wide-ranging building disciplines and construction techniques which presented our team with unique aspects to the construction of such a large-scale desalination project. Meeting the construction quality and durability expectations remain key aspects of the project and have a significant impact on the sequence and programming of the works. Apart from the challenges of project delivery there was a strong desire from the Government for a wider community engagement and consultation process and therefore SA Water was required to go through a Major Development approval process and the preparation of a full Environmental Impact Statement.

Some of the challenges faced by the project included:

• Appointment of key leadership roles in the project team with experience on large complex projects – each with unique experience and capability, so the best people were brought on-board to deliver this challenge on the largest infrastructure project in South Australia.
• Staying focussed on the key project objectives in the face of any emerging risks and challenges. This includes major up-front investment in key areas of safety, environment, community interaction and public health.
• Setting up an integrated team – with individuals personally committed to the success of the project. This group was selected for their leadership, expertise and willingness to put-in whatever it takes to deliver the project objectives.
• Retention of key people to support the duration of the project and this required unique employee value proposition and strategy – which ensured committed people were recognised and acknowledged.
• Innovation in an expanded project - which can sometimes get a back-seat. On this project innovative ideas are encouraged to ensure costeffective and long-life solutions are generated, not only in the hardware but also in ongoing operating flexibility and operating costs.
• Senior leadership was established via a senior group of Chief Executives from key agencies which formed the ADP Steering Committee and provided strategic guidance and support to the Project director.
• A unique structure and culture (new norms, policies, procedures). Because of the size, complexity and large risks the project teams were pulled-out and located away from the normal routines of their respective matrix structures. The project team was granted special delegations and procedures considered appropriate for the success of the project. The project team also included specialists and experts to provide independent advice on any critical areas and improve the resilience of the collective team to solve any complex issues or challenges.
• A partnership approach is required for this project to ensure everyone works together towards the common goal.
• From a commercial and contractual sense, a key challenge (high risk) has been to constantly invest effort in ensuring good solid working relationships and timely actions to develop resolution road-maps to any emerging contractual issues. This included developing strategic action plans for any changes or variations.

Some of the other unique aspects to come out of this project are in the marine area. During much of the marine construction period we used helicopter transport to an offshore jack-up barge to facilitate an increased weather window and reduced travel times.

The heavy lift jack-up barge located off shore of the construction site was vital to the marine works. The barge had the capacity to enable large pre-cast segments to be installed in a timelier manner than otherwise and it also housed offshore water treatment facilities to enable all drilling and dredging to be recycled directly into the marine environment.

Construction of the marine tunnels was done in three shaft constructions – intake, outfall and a specific working shaft to support more efficient and safe tunnelling operations. The project has used two purpose-built tunnel boring machines (TBMs) to construct and line the tunnels with pre-cast concrete segments. One a quirky note, these TBM’s were named ‘Cora the Bora’ and ‘Nessie’ by local school kids in a competition we set up for them on arrival.

 One way we overcame a civil issue was to apply an engineered fill solution to all building foundations in lieu of piles.

From a mechanical and electrical perspective we have a dual pass reverse osmosis process which is patented and exclusive to Acciona – one of the companies within the D&C Consortium.

All of the buildings on site have been constructed using high specification concrete, HDP liners in chemical treatment tanks, and aluminium roofs – all to ensure durability and design life.

Efficiency in energy vital to ADP design and operation

Several innovative features have been incorporated into the project. These include the use of energy recovery turbines incorporated into the marine outfall system, advanced ultra filtration seawater pre-treatment system and an innovative high recovery rate two pass reverse osmosis system.

Establishment of the renewable energy contract with AGL has been an incredibly significant milestone for the project. This is an investment over a 20-year period, whereby the contract will ensure power consumed from the project will be matched with accredited renewable green energy sources within South Australia through the form of renewable energy infrastructure and purchased renewable energy certificates.

The Adelaide Desalination project will be one of the most energy efficient for any large reverse osmosis desalination plant in Australia. Building on this efficient outcome, the Adelaide Desalination Project team has also designed a range of energy saving and energy recovery systems to ensure the plant will be even more efficient in its use of power wherever possible. For example, the plant has been designed using a gravity hydraulic process. This will ensure the progressive treatment of seawater and turning it into drinking water will not require substantial pumping and assist in further power savings.

Another feature of the plant’s energy recovery systems includes the pumps connected to the reverse-osmosis membranes. These have energy recovery devices to recapture up to 40 per cent of the energy for reuse on site. The turbine generators in the outfall tunnel will also produce renewable electricity and feed this back into the plant to minimise energy consumption. There are two turbine generators, one for each outfall shaft stage and each has a capacity of 720kW.

As far as the plant’s buildings go, they have all been designed to maximise natural light during the day and a selection of high thermal materials (eg solid precast concrete walls and insulation) to improve temperature control properties, thereby minimising energy consumption. More specifically, Solar Photo Voltaic cells have been placed on the reverse osmosis buildings for localised power generation. Each RO building has approximately 100kW cell array with a site capacity of approximately 200kW at peak sun hours.

World renowned desal expert pinpoints environment, safety and durability as stand-outs for ADP Early in 2011, the Adelaide Desalination project hosted Nikolay Voutchkov on our site to gain an expert opinion from a recognised world leader in desalination technology. Mr Voutchkov has more than 25 years of experience in planning, environmental review, permitting and implementation of large seawater desalination, water treatment and water reclamation projects globally and his advice on the project’s progress was incredibly encouraging for those working on site. Some of the key points made by Mr Voutchkov when asked why Adelaide’s desalination project was different to many others around the world, are summarised below:

Outstanding desalination building quality:

The plant is built to last. The quality of materials, work and architecture of the desalination building and other structures is exceptionally high and certainly stands above the rest in the desalination industry. Most desalination plant RO building structures worldwide are pre-fabricated metal buildings which would not last for more than 20 to 25 years before they begin to look like giant rusted thin cans. The Adelaide Desalination Plant is built to last. Building higher quality structures takes more time and expense, but I would consider them an investment into the future. Adelaide’s key plant structures will last twice as long as those of an average desalination plant (25 years).

Deep intake:

Adelaide’s desalination plant marine intake is one of the deepest in the world allowing for improved plant reliability. This deep intake is a great benefit in terms of collecting superior source water quality, which will result in significant reduction of the overall water production costs because it will minimize RO membrane fouling, and RO membrane cleaning frequency and will improve the overall product water quality. The colder the source seawater, the higher the quality of the product water. While building the deeper intake is more costly and takes more time, it certainly is an excellent trade-off for higher capital costs and initial construction time versus reduced long term operation and maintenance costs and plant operational downtime for membrane cleaning and cartridge filter replacement.

Superior noise abatement design:

Usually the noisiest piece of equipment in a desalination building is the energy recovery system. The configuration of your energy recovery system is designed in such a manner that the recovery devices are furthest away from doors as practically possible and located in the centre of the building, rather than on the sites of the RO trains. While this design may make the building a bit wider, it certainly provides superior noise protection at excellent cost.

Exceptionally high quality stainless steel welds:

The Adelaide Desalination Plant’s super duplex stainless steel weld work on the high pressure piping is one of the best I have seen in the industry. Welds of high quality stainless steel include very delicate work which requires superior quality craftsmanship.If this is not done correctly, stainless steel welds are   the first location where pinhole leaks can develop in   6-12 months. Preventing pinhole leaks by applying   more time and paying more for high quality work is an   investment, not an expense. The costs of fixing pinhole   leaks and losing production capacity usually are   significantly higher than taking the time and expense   to complete high quality work the first time around.   My understanding is that it took longer than initially   planned to get this superior quality, but it’s time and   money well spent on investment into preventing future   losses of plant productivity and reliability.