Sewer pressure surges targeted in pump station upgrades

Adelaide’s Largs North wastewater pump station is now better able to cope with increasing sewage volumes and pressure surges thanks to the completion of a $12 million upgrade to the facility and a new sewer main.

On-site construction works began in April 2018 and involved a refurbishment of SA Water’s Largs North wastewater pump station and the installation of around 4.5km of new sewer main.

SA Water’s General Manager of Asset Operations and Delivery, Mark Gobbie, said the main feature of the upgrade  is two new pressure surge vessels, which are specially-designed to withhold and manage any surges in the local wastewater network.

“The 4.7m high structures, which were fabricated here in South Australia, are made from steel and help to protect both the pump and the connecting pipeline from large fluctuations in pressure caused by any sudden changes in the flow of sewage,” Mr Gobbie said.

“These surge events generally happen during a power outage and can lead to a potential break in the main or a fault in the pump.

“The surge vessels at the pump station absorb the energy produced by any sudden rise in pressure, resulting in a steady, manageable pressure when the sewage re-enters the network.

“These vessels are installed at pump station locations in both our wastewater and water network, and automatically come into play when there’s a surge.

“Another key aim of this upgrade was to ensure our local wastewater network can continue to support growth in the area.

“While the network prior to the upgrade was fit for purpose, it wouldn’t have been able to meet the expected increase in demand brought on by growing urban developments such as Newport Quays and new industry in the northern parts of the Le Fevre Peninsula.

“The installation of new sections of wastewater main increases the network’s capacity and better caters to a higher number of local customer connections.

“The new main connects the Largs North wastewater pump station with its counterpart in nearby Ethelton, allowing the transfer of up to 106L of sewage per second through the local network – an increase of nearly 40 per cent compared to pre-upgrade.”

Together with its contractor Fulton Hogan, SA Water placed a large focus on minimising impacts to the community during construction.

“The majority of works were carried out during the day from Monday to Friday, to limit any disruption to local traffic and property access,” Mr Gobbie said.

“To further reduce the impact to people travelling near the route of our new pipeline, we also used a construction method known as directional boring. This technique requires less excavation than open trenching and means a smaller worksite footprint on the road or footpath.

“We pride ourselves on keeping the community up to date on the progress of our works at all stages and thank them for their patience and support in the lead up to and during the project.”