Melbourne Water is set to perform a capacity-boosting upgrade on a Melbourne sewer responsible for carrying more than 30 per cent of the city’s wastewater to the Western Treatment Plant.
Work on the Hobsons Bay Main Sewer is expected to ensure the reliability of the city’s sewerage service for the next century.
The sewer, which was originally built in the 1960s, is integral to the Melbourne sewerage network, running from Westgate Park in Port Melbourne to Spotswood and crossing under the Yarra River.
Melbourne Water’s General Manager Major Project Delivery, Eamonn Kelly, said the 2.1m diameter reinforced pipe, which can handle flows of up to 7,700 litres per second, would be upgraded.
Wastewater flows will be diverted into a new sewer main while works are underway.
“The duplicate sewer main will allow for this upgrade to be completed safely and efficiently,” Mr Kelly said.
“It will ensure the continued smooth operation of the sewer network which caters for Melbourne’s growing CBD and bayside suburbs.”
Two shafts up to 30m deep will be constructed either side of the Yarra – with a Tunnel Boring Machine used to construct the new sewer main.
“The project team is currently working on the design, taking into account the challenging ground conditions on either side of the Yarra River and the existing active sewerage system,” Mr Kelly said.
Mr Kelly said the project will allow South East Water to connect to the system to remove wastewater and turn it into Class A recycled water for use in the Fishermans Bend precinct – in facilities such as toilets and gardens.
Melbourne Water has released an expression of interest for the project, from which a very limited number of contractors will be invited to tender.
The project is due to begin in 2021.