Palmerson trunk sewer upgrade project completed on time and within budget

Serving a growing population

A new $10 million trunk sewer main in Palmerston East will provide capacity for future growth in the Northern Territory’s fastest growing urban area. The Palmerston Eastern Trunk Sewer Duplication – Stage 2B project by the Power and Water Corporation was delivered on schedule and within budget.

Construction on the sewer main began in May 2017 and was completed in November 2018 ahead of its December 2018 schedule.
The new sewer trunk main became operational in early November and is now servicing the suburbs of Zuccoli, Rosebery and Johnston. The duplication of the existing sewer main will facilitate future developments in the area north of the Stuart Highway.

The 1.5 km main was constructed using a combination of tunnelling and trenching.

Tunnelling technology deployed

The majority of the 1.5 kilometre trunk sewer main was constructed using microtunnel boring machinery (MTBM) with state-of-the-art laser guidance system technology.
The project deployed tunnelling and trenching under and through three Palmerston suburbs, running from Bonson Terrace in Moulden, through park and recreation grounds in Woodroffe to Antonino Drive in Rosebery.

Trenching required in sections

Due to soft soil consistency, open excavation trenching was required for some sections of the project. Trenching was undertaken from Bombax Street to Temple Terrace in Moulden and at the Palmerston Cricket Club oval. The groundwater that was pumped out of those sections was then used to suppress dust during construction.

Trenching was required at various points in the project due to soft soil consistency. 

Innovation to prolong asset life and reduce cost

In an exciting first for the Northern Territory, the project also saw glass-reinforced plastic (GRP) manholes designed, engineered and installed.
The new manholes are corrosion-resistant both internally and externally and will require less maintenance and monitoring.
The use of the GRP product has doubled the estimated  life of both the sewer main and the manholes to around  100 years and provided an additional savings of $200,000 to the overall project.

The use of GRP manholes has doubled the life of the asset while
delivering cost savings.
 An aerial shot of GRP manholes being lowered in a residential area.

Power and Water donated a new $15,000 cubby house to the Scallywags Child Care Centre.

Community collaboration continued

Power and Water engaged some 9,000 stakeholders throughout the duration of the project, including individual households, local community groups and organisations.
As part of the focus in building community partnerships during the project, we also ensured that those affected by the works were not inconvenienced.
A new cubby house was donated to Scallywags Child Care Centre in Moulden in recognition of works undertaken that impacted on the centre.
The soil excavated from the project was transported to and donated for use at the Palmerston Pistol Club and the Top End Moto Cross Club in Catalina Road.