Caloundra City Council, through its commercial arm Calaqua, has embarked on a program to reduce infiltration and so safeguard the regional environment. An important part of this program was the recent awarding of another contract to Interflow Pty Limited for the structural lining and sealing of deteriorated sewers.

Commencing in March this year, the contract requires lining of some 17.5 kilometres of sewer pipelines with diameters from 150mm to 375mm. The pipelines are in the full range of rigid materials commonly used before the advent of flexible pipelines – asbestos cement, concrete, vitrified clay, cast iron. Problems include cracking and leaking joints.

As well as lining, almost 1000 household connections to the lined sewers will be sealed with the Interflow LCR. This is a silicate resin impregnated tee, installed remotely from inside the pipeline, that seals the connection, as well as the first joint up the house service line. It provides a long term water tight barrier against infiltration, exfiltration and roots.

Interflow is installing the Australian developed Rib Loc Expanda Pipe liner in the deteriorated pipelines. This liner is particularly suited to this application as, unlike other types of close-fit structural liners, heating is not used in the installation process. This is an important benefit in pipelines that are being subjected to infiltration.

The work will be done by “trenchless” methods that cause minimal disturbance to the community. Installation of the liners and the LCRs will be from existing manholes, without the need for excavation. Typically 100 metres or more of pipeline can be lined by each crew in a normal working day. As the liners can be installed in live flow conditions, there are no service interruptions to the Council’s customers.

Once installed, it expected that the pipelines will have been effectively renewed rather than repaired, with their life extended by an anticipated minimum of 50 years.

Back to Services Case Studies