South Australia: the new water gateway
Mary Monro takes a look at water supply and sewage treatment in South Australia where the state-owned SA Water Corp has outsourced the O&M of a number of WTWs and WwTPs, saving state government costs in the process.South Australia has the dubious distinction of being the driest state in the world's driest inhabited continent. And at one time, it also had the reputation of having the worst water in Australia.
The chief sources of potable water are the catchment of the Mount Lofty ranges including the River Torrens system, east of Adelaide, and the Murray river. The Murray-Darling river basin drains one seventh of Australia, and covers five states.
Abstraction is regulated by a Commission on which all the states are represented, and which has to balance the demands of agriculture and water supply along its route. Although SA Water has a guaranteed first call on the Murray water, allocations have recently been limited to 1994 levels.
In a normal year the Murray supplies about 60% of Adelaide's needs, but in a dry year - and the last three years have been dry - SA Water may have to rely on the river for up to 90% of its supplies. Abstraction is also from the lowest section of the river's course, so the water is very heavily silted and contains nitrates. In the last year, around 300 samples taken from various points along the Murray show turbidity has averaged 80 NTU with spikes as high as 450.
New treatment processes are being pioneered to handle turbidity problems. In cooperation with the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and Orica Australia, SA Water is currently running trials with the MIEX magnetic resin system. MIEX is claimed to settle out organics much faster than other methods. Faced with the twin difficulties of a limited supply and poor quality raw water, SA Water has had to take great care managing its resources. It operates an intensive educational campaign to consumers on water conservation and effective use, and is also one of the most active water companies in Australia in R&D on treatment systems, aquifer recharge, recycling and other reuse programmes. An RO plant running without chemicals has just been installed on Kangaroo Island, an environmentally sensitive area off the coast near Adelaide. But as demand increases and supplies are threatened, a greater emphasis is being placed on recycling.
In many instances stormwater is passed through artificial wetlands to recharge aquifers, and significant efforts are being made to reuse the annual 80,000Ml of treated wastewater from the Adelaide area which was formerly discharged to sea.
SA Water recently embarked on a Aus$210M environmental improvement programme involving the upgrade of its four main STPs. The largest scheme, at the Bolivar plant north of Adelaide is currently nearing completion. This incorporates the largest DAFF plant in Australia, designed to produce high quality filtered water for agriculture, viticulture and horticulture. It is piped approximately 100km to market gardens further north to replace the underground supplies on which the area relied, and which are now deteriorating.
The Aus$100M Bolivar upgrade is being carried out on behalf of SA Water as a BOOT project by United Water, a jv of Thames Water, Compagnie Generale des Eaux and Kinhill-Brown and Root, who will operate the plant for the next 15 years.
A concerted effort is also being made to improve water quality. The South Australian Rural Filtration Project, a scheme which involves the setting up of ten filtration plants to provide high quality potable water to rural communities is also a BOOT project, in which North West Water, Bechtel and financial group AMP Asset Management, are linked.
The plants incorporate dosing with activated carbon, flocculation and rapid gravity filtration to treat turbid and contaminated river water to better than WHO standards. The consortium, called Riverland Water, will run the plants for the next 25 years.
One of the unusual elements in both of these large contracts is that they require both consortia (United Water and Riverland Water) to generate exports from South Australia valued at more than Aus$800M during the first ten years. SA Water is in fact leading the development of a successful export focused water industry in the state and to date its drive has resulted in Aus$122.4M in export income.
"While we may be viewed as a small corporation in a global sense, we have the know-how, technical expertise and systems management for major Australian projects," says chief executive Sean Sullivan. "SA Water has crept up on the leaders of the Australian water industry and they now recognise us as major players."
In addition to other water companies in Australia, SA Water is targeting SE Asia and the Pacific Rim as potential markets for its skills. Already the company has been called in by government authorities in Indonesia, the Philippines and China to assist in the management and restructuring of their water utilities.
Using the Digitised Facilities Information System (DFIS) developed originally to capture and store information on its own operations, SA Water has provided a master plan for the co-ordination of water and wastewater systems in West Java which correlates economic development and water availability. SA Water staff are currently working on the overall restructuring of the water industry with the government in Bandung province to enable private companies to contribute more effectively.
High levels of efficiency and a firm commitment to value based management enabled the company to generate a dividend of Aus$198M in 1998. Sullivan is confident of improved profitability this year and in future years mainly due to refocusing and the implementation of long term efficiency strategies.
United Water has operated Adelaide's ten water and wastewater treatment plants since January 1996. In that time, the cost to the South Australian government has fallen by 20%. The company also has one of the first franchise agreements to be awarded in New Zealand - the Papakura contract - which supplies water to parts of Auckland. United Water currently employs 400 people in South Australia.