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Partnership turns a problem into a resource

A recent Senate Inquiry has raised concerns over the impacts of stormwater and wastewater discharges on the health of Adelaide's Gulf St Vincent. These pollution streams are equivalent in volume to the city's mains water demand, much of which comes from the Murray River.

Currently a reliable wastewater and stormwater resource is being under-utilised while still impacting on the Gulf. The increasing salinity of the Murray is affecting the competitiveness and long term viability of companies in Salisbury, which is situated in northern Adelaide.

A major employer in a local industry cluster, Michell Australia, is in this situation. Michell operates one of the biggest wool processing facilities in the world. It requires large volumes of good quality water to produce a premium product. As a major individual water user in Adelaide, Michell is adversely affected by the deteriorating quality of the Murray's water.

On Michell's output side, the by-products from the wool processing operation provide a challenge. Up to 20,000 tonnes of biosolids (predominantly wool wax and topsoil) and over 4,000 tonnes of salt are produced each year. Currently, this wastewater load is the largest single input to the Bolivar Wastewater Treatment Plant on Gulf St Vincent. After full treatment at the Bolivar plant, the water is either discharged into the Gulf or piped for reuse to the horticultural district of Virginia.

A partnership has been formed to address the challenge of increasing the environmental and economic sustainability of this operation. The members are the City of Salisbury, Michell Australia, Parafield Airport Ltd, the Northern Adelaide and Barossa Catchment Water Management Board and the South Australian Department for Water Resources.

This consortium is receiving over $1.8 million in Commonwealth Government, Clean Seas funding towards the cost of a project to help turn a problem into a resource.

The project consortium is putting in place a new regional approach to managing polluted stormwater and industrial wastewater. Sustainable methods to protect the coastal environment and create new resources for the Adelaide region will be introduced. The project will supply cleaned stormwater for industrial and irrigation use.

Additionally the separation of saline streams and general rinsewater coming from the woolscour will enhance reuse opportunities within the Adelaide area. Up to 1.5 billion litres per annum of Adelaide mains water, mostly from the Murray River, will be replaced by high quality runoff.

Stormwater from the area will be harvested and then treated in purpose-built, bird proofed reed bed ponds on the Parafield Airport &endash; a world first for an aviation facility. The cleaned stormwater will be supplied direct from the treatment ponds to users during operating periods.

Surplus water will be injected into underground aquifers for storage. It can be recovered during dry periods for use in the wool processing operation and by other users in the Salisbury area.

The project aims at a 90 percent reduction in both the volume and nutrient pollution loads of stormwater from the catchment entering the Barker Inlet in Gulf St Vincent.

It will also reduce by 1.5 billion litres annually, the use of Adelaide's drinking water for industrial and landscape purposes where cleaned stormwater is actually more beneficial.

Members of the consortium are also investigating an exciting prospect of mixing the solid by-products from the wool processing operation with large amounts of Adelaide's green organics, including council tree pruning.

This would produce over 50,000 tonnes of compost each year. This compost is currently undergoing field trials in the Adelaide region's expanding viticulture and horticultural industries.

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