‘Smart’ automation helping to secure Sydney’s water future

Instrumentation used on desalination plant

The construction of Sydney Water’s new desalination plant at Kurnell, south-east of Sydney, is in full swing and is said to be on track to become operational this summer. The automation and control of this innovative project is based on Profibus technology. Endress+Hauser was selected to be one of three key members of the main automation alliance to engineer and supply all general instrumentation to the plant.

When complete, the plant will provide Sydneysiders with 250 million litres of water a day, satisfying 15% of the city’s daily consumption. Conceived with the future in mind, the plant is designed to have minimal environmental impact and the option to be expanded to a capacity of 500 million litres in the future. The project is a joint venture between Veolia and John Holland called the Bluewater Consortium and has already recorded a number of ‘world firsts’ when it comes to engineering achievements. It has been heralded as one of the largest, ‘smartest’ and most sophisticated desalination plants in the world.

Bluewater’s Electrical, Instruments & Control Manager, Charles Markotter, is responsible for the installation and commissioning of everything electrical within the plant including the facility’s automation and instrumentation systems. A seasoned project manager and engineer with over 30 years of international experience on projects of this size, Charles says: “I have only seen this level of automation on some oil refineries, but never on a water plant. Every single thing around here is monitored, it’s unique.”

Endress+Hauser supplied 1400 instruments to be deployed from the intake of sea water at the start of the process to the final dispatch of fresh water at the end. Critical process measurements include water level, pressure, temperature, pH, ORP, turbidity, conductivity and the concentration of minerals such as nitrates. Ultimately, the instrumentation is there to make sure that the plant is as safe as possible and that it can continually supply safe, high-quality drinking water to the population of Sydney.

Automation and instrumentation plays a vital role in the plant’s day-to-day operations. An important consideration in the selection of suppliers for this critical part of the installation was the interoperability of all of the plant’s 8500 devices with the system’s communication networks. Working closely with Bluewater and the control system supplier, Schneider Electric, Endress+Hauser was able to prove the compatibility of all of its instruments with the Profibus networks during the bidding process. Knowing that the communication would work from the start, Charles said: “That just took a lot of stress off everyone from the beginning, knowing that we weren’t going to have everything connected up only to find incompatible communication protocols and needing to start changing out comms cards and modules and things.” Another vital factor for the plant was the correct installation of the fieldbus networks and the connection of all instrumentation to them. Applying their expertise in this area, Endress+Hauser worked with electrical contracting firm Heyday Electrical to ensure the correct installation of these important system components.

The plant was built and commissioned according to its pipe and instrumentation diagrams that show the necessary process measurement points as numbered ‘tags’. These tags can represent anything from a single instrument to a complex measuring system made up of a number of often small and delicate components. One of the challenges of supplying instrumentation equipment to a large and complex site like this is that if any of these components are lost or broken in storage pending installation, the consequences can be not only costly but can also cause major delays in plant commissioning. In the case of the Sydney desalination plant project, this problem was compounded by the lack of adequate storage facilities available on site. Using the experience that they have gained on similar projects, Endress+Hauser overcome these problems by consolidating the equipment required for every tag at their own storage facility and then delivering each ‘tag’, in either kit form or as preassembled analysis panels, just in time for installation.

Once the plant is operational, it will be run by just eight permanent operators. This will be supported by key service providers who will be able to diagnose problems on site via secure web interfaces. Using real-time data from the instruments and other assets in the plant collected by Endress+Hauser’s asset management software, Fieldcare, Sydney Water’s IBM Maxio ERP system will schedule maintenance and even manage spare part inventories, thus keeping maintenance costs to a minimum. All of this is possible due to the intelligent devices and their ability to communicate seamlessly across the various networks within the plant.