South Australia’s largest wastewater treatment plant is undergoing a series of major upgrades – at a combined investment totalling $121 million - to increase its capacity in preparation for Adelaide’s population growth in the northern suburbs.

The major upgrade of the Bolivar Wastewater Treatment plant has reached a significant milestone with new inlet screens installed to help double the plant’s capacity.  

The Bolivar plant’s inlet – where raw sewage arrives from the wider sewer network – will soon be able to process up to 630 million litres of sewage per day, the equivalent of 252 Olympic-sized swimming pools every day.

Currently, it processes on average 300 million litres of sewage daily.

As greenfield housing developments throughout Adelaide’s north progressively connect to the sewer network, future daily flow volumes to Bolivar are expected to be up to 550 million litres per day.  

All eight of the new inlet’s screens have now been installed, along with two new pump stations within the plant that will supply water to the screens to increase its efficiency and reduce the need for manual cleaning by operators.

The combination of coarse and fine screens serve as the first stage of the treatment process by removing solid inorganic material such as wet wipes, paper and plastic.

Standing more than six metres high, the screens prevent blockages or damage to the plant’s pipes and pumps downstream, and features narrow bars that are as small as six millimetres apart to capture objects that shouldn’t have been flushed.

As part of the upgrade, the plant’s existing 10 inlet pipes are also being replaced to help accommodate increased future flows.

Over the coming months, SA Water will begin testing the inlet’s automated processes and electrical equipment by running clean water through it, while the utility continues to connect the new structure to the plant and existing pump station.

Future upgrades to the Bolivar include optimising the plant’s activated sludge reactor process by utilising capacity in another section of the plant, as well as upgrading its sludge management facility.   

The $121 million investment in the plant includes $64 million funded through SA Water’s 2020-24 capital program and $57 million from its 2024-28 capital program.

The upgrades at Bolivar form an integral part of SA Water’s record $3.3 billion capital works program and underpin its capacity to support Adelaide’s long-term growth.

Announced as a key initiative of the State Government’s Housing Roadmap, the capital program includes an unprecedented $1.5 billion investment to increase the capacity of the water and sewer networks, and treatment facilities, to unlock a potential 40,000 new allotments across the state over the next four years.

View drone vision and time lapse of the inlet installation as well as vision of staff removing wet wipes from the system.