Tarago reservoir automation improves Melbourne water supply

Located near the small township of Neerim South, the Tarago reservoir is the first of three major Victorian state government infrastructure projects designed to increase Melbourne’s drinking water supplies by 240 billion litres per year by 2011.

The reservoir was constructed in 1969 to supply several nearby townships, the Mornington Peninsula and Westernport regions but supply was stopped in 1994 when the water became unsuitable for drinking purposes. However, water shortages have forced the state government of Victoria to consider all options - Tarago being one.

Central to reconnecting the reservoir (which will supply Melbourne with an additional extra 15 billion litres of water) was the development of a new water treatment plant and several major initiatives to improve water quality in the reservoir.

SEMF, a consulting engineering and environmental solutions company and specialist supplier of new capital works projects to Melbourne Water, was awarded the contract to design and commission software for the $1 million treatment plant control system.

SEMF’s Melbourne-based automation group was responsible for designing and commissioning the PLC and HMI software programs (including various interfaces for SCADA and third-party plant and equipment).

The complex nature of the automation project stems from the quality of the water in the reservoir, which requires several different treatment processes - UV, chlorine, separation and settlement - all of which need to happen simultaneously and in real time. In addition, large volumes of water need to be treated at any given time.

In addition to communicating with the equipment that drives, operates and monitors the treatment plant, the control system is also required to communicate with the SCADA system that manages the entire operation of Melbourne Water’s water systems across Victoria.

The end product is a water treatment control system that is capable of monitoring and controlling the status of more than 50 drives and in excess of 80 valves simultaneously. It also interfaces with a diverse range of vendor packages, such as dosing systems, centrifuges, clarifiers, UV reactors and sampling and analysis systems.

SEMF succeeded in delivering the challenging and complex project in just five months.

“While the complexity and size of the project was a challenge in itself, the biggest single challenge was the incredibly short time frame for delivery. Despite this, we succeeded in completing the project on time and on budget,” said Allan Waitzer, SEMF managing director.

He attributes the rapid turnaround to four factors - throwing sufficient resources at the project, long days, working collaboratively as a team and putting the client first.

“Also critical to the success of the five-month project was working closely with water treatment plant designers GHD and the United Group, which oversaw the construction process, as well as Logica, which developed the plant SCADA system,” he said.

After an extensive commissioning and validation period, the Tarago Water Treatment Plant is now supplying water to customers in Melbourne’s southeast. SEMF is now currently involved in providing automation and control engineering support for the Sugarloaf Pipeline Project in central Victoria.