Bolivar high salinity treatment plant from 2004 spares river at Port Adelaide receiving treated sewage inflow

The Bolivar high salinity wastewater plant was needed to keep saline water away from the Virginia pipeline scheme.
Image courtesy SA Water
Bolivar high salinity wastewater treatment plant, north of Adelaide, in 2004 replaced the Port Adelaide wastewater treatment plant that had been discharging treated sewage into the Port River.
South Australia’s Environment protection Authority was concerned about nutrients’ impact on the river water and particularly the increased risk of algal blooms. Most of Port Adelaide drainage area is near the coast and is low lying. Highly saline groundwater is close to the surface with a large amount going \into the sewer network
A plan was developed to pump the more saline raw sewage from Port Adelaide drainage area through a pipeline to an extra new plant at the Bolivar wastewater treatment plant site.
A second wastewater treatment plant at Bolivar – the high salinity plant – was needed to protect the Virginia pipeline scheme from saline treated sewage. The Bolivar high salinity plant was designed primarily to lower nitrogen concentrations in the effluent. Its anoxic tanks provided a stream for treating incoming highly saline sewage.
It is an activated sludge plant and one of the largest in Australia to use sequencing batch reactors.. Immediately downstream of the treated wastewater pumping station, the treated sewage passes through ultra-violet reactors to reduce E. Coli levels.
The comparatively high salinity of the treated sewage made it unsuitable for reuse. Instead, it was mixed with treated sewage discharged from Bolivar lagoons and the flow discharged through mangroves, 11.4km north of the Bolivar site, into coastal waters.
Waste activated sludge was thickened and pumped to the Bolivar wastewater treatment plant dissolved air flotation units where salt was washed out before being rethickened to ensure it was suitable for agriculture use, after anaerobic digestion and dewatering.