Pipe bursting

ActewAGL is replacing some of Canberra's old clay sewerage pipes with modern plastic pipes that are tree root resistant as part of a five year plan campaign.

The original clay pipes, laid in some of Canberra's more established suburbs, are susceptible to tree root damage. Tree roots are attracted to the nutrients in the sewage that is transported through the pipes, and when a hair root penetrates a clay pipe the root quickly increases in size, blocking the sewage pipe and causing potential backup and overflow problems.

Pipe bursting replaces the traditional method of digging up the old clay pipes, replacing them and then back filling. Often vegetation had to be removed, and in some cases trees were damaged. In some of Canberra's older suburbs, such as Griffith, Forrest and Red Hill, trees are heritage listed and must be protected. The pipe-bursting process minimises the potential harm to the tree's root system.

The pipe-bursting process involves much less digging. Holes are dug at the access holes and junctions for service branch lines and the vegetation above the ground remains undisturbed. A steel vibrating head is winched through the old clay pipe, bursting the pipe as it proceeds through the pipe. The new plastic pipe is attached to the vibrating head replacing the old clay pipe as the vibrating head is pulled through the pipe. The process causes only slight vibration in the immediate area.

Pipe bursting is 60 per cent faster than conventional methods of replacing pipes. This represents a significant saving to ActewAGL and less disruption to customers.

In some cases customers will not be allowed to dispose of wastewater during the process. Customers will be notified by mail two weeks before pipe-bursting commences.

For further information on the pipe-bursting project contact ActewAGL on 02 6248 3555.