Australian Water Management Review Vol 2 2013 | Page 63

Sydney Water awards
$9 million contract in
Sydney’s northern suburbs

S

ydney Water has awarded Water Infrastructure Group Pty Ltd a $9.3 million contract to deliver the latest instalment of a SewerFix™ project on Sydney’s northern beaches.

“We will stabilise the tunnel sections with rock bolting where required and protect them from further acid attack by applying Calcium Aluminate Cement to the tunnel surfaces and maintenance holes,” Stijn explained. To repair the pipeline, crews will use 34 maintenance holes, some up to 33 metres below ground, and build up to four new maintenance holes. The pipe must remain operational during repairs to protect the environment and ensure a reliable wastewater system. Sydney Water will reduce construction impacts on the local community, with repairs mostly done at night when wastewater flows are at their lowest. Fast Facts The $9.3 million rehabilitation of Narrabeen Submain involves repairs to: • 3,937 metres of sewer pipe diameters ranging from 1200 mm to 1800 mm • 330 metres of concrete lined rock tunnel • 404 metres of rock tunnel • 34 maintenance holes, some up to 33 metres deep.

The project involves repairing multiple sections of a large wastewater pipe known as the Narrabeen Submain, which services many thousands of properties in Sydney’s north, across the suburbs of Brookvale, North Manly, Manly Vale, Balgowlah, Collaroy, Cromer and North Curl Curl. The Narrabeen Submain starts in Collaroy and travels through Brookvale to join the Northern Suburbs Ocean Outfall System to finish at the North Head Wastewater Treatment Plant. Narrabeen Submain project manager Glen Nelson said the project will use a mix of technology to maintain the wastewater system and effectively manage dilute wet weather wastewater captured by the Nothern Beaches Storage Project. “Trenchless technology will be used to repair about 3.9 kilometres of pipeline. The work involves establishing ventilation and odour control, removing and disposing silt and debris and installing a structural liner inside the pipe,” he said. Stijn Sampermans, Water Infrastructure Group’s Senior Project Development Engineer, said the work on the submain would start mid-August 2013 and continue until June 2014, weather permitting. “We’ve developed a very efficient and safe access methodology for this type of work on projects like our current rehabilitation of four deep maintenance holes on the Northern Suburbs Ocean Outfall System, said Stijn. “Our proprietary Panel Lok system is the main technology we are using for the relining of this critical sewer. “It is a proven product and we have developed an excellent work methodology and strong track record for rehabilitating sewers.

Sydney Water’s SewerFix™ program aims to improve the wastewater system and protect public health and the environment. From 2012-2016, Sydney Water will spend $400 million on its 24,000 kilometre wastewater network. SewerFix™ is a ‘trademark’ for work on our sewer assets, pipes, maintenance holes, and pumping stations.

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