Orange is a city in the Central West region of New South Wales, 250 kilometres west of Sydney, with a population of approximately 40,000 residents.
The project scope involves upgrading 340 metres of existing 225mm Earthenware (VC) sewer main to a 355mm polyethylene (PE) main – which has an internal diameter of 310mm – as well as the rehabilitation of six manholes. The upsizing of the main is required to enable a larger flow of sewage due to population growth in the area.
Pipe bursting is the optimal technology to use in this situation due to the ability to replace the pipe without the need to excavate three metres deep throughout the entire route. Pipe bursting is a trenchless technology that requires digging a pit at either end of the desired replacement section. A pipe bursting machine is then lowered into one of the pits and rods are inserted through the existing pipeline and through to the second pit. The new pipe is then connected to the rods and when the pipe burster pulls the rods back, the old pipe is cracked and displaced into the surrounding soil and the new pipe is pulled into its place.
UEA anticipates the need to manage several construction difficulties including:
- High flow of the raw sewer flowing through the existing main
- Deep excavations
- Confined spaces
- Sewer by-passing difficulties
- Excavations located within private properties
However, with the use of pipe bursting techniques, UEA is able to avoid trenching to a depth of three metres, reduce the disruption to the community with trenchless methods, and minimise the need for restoration of the excavated areas. Planning, safe working procedures and good communication with the council will ensure all risks are managed and overcome.
Work will take approximately four weeks to complete.