Completed in December 2005, SA Water’s $100 million Bolivar Environment Improvement Program (EIP) was one of the largest capital works projects in the State. It represented a significant investment in the environment for the future benefit of all South Australians.
The first stage of the program involved the construction of a $30 million Dissolved Air Flotation Filtration (DAFF) plant to provide high quality “Class A” reclaimed wastewater for use in irrigation.
The plant was completed in September 1999 and now provides treated wastewater suitable for direct irrigation of market gardens through the Virginia Pipeline Scheme.
Construction of the second stage of the plant - to control odour and reduce nutrient levels - was completed in July 2001 at a cost of approximately $68 million.
This involved replacing the existing biological filters, which were the major cause of odours from the plant, with a new activated sludge treatment process. The process has reduced nitrogen and odour levels significantly.
The final stage was the construction of a new high salinity wastewater treatment plant at Bolivar to replace the Port Adelaide Wastewater Treatment Plant (WWTP). A new pumping station and a 17-kilometre pipeline were constructed to transfer wastewater from the Port Adelaide plant to the Bolivar high salinity plant via the Queensbury Diversion Pumping Main for treatment.
Environmental benefits from the Bolivar EIP have been achieved, including:
Reduced nitrogen concentrations in the treated wastewater
Reduced outflows of treated wastewater to the sea
Reduced demand on the northern Adelaide Plains groundwater basin by providing an alternative source of water for irrigation
SA Water is also exploring options for using more renewable energy by making greater use of methane from biogas produced at Bolivar.
Bolivar now processes almost 70% of metropolitan Adelaide's wastewater.