UEA have been awarded the Transfer main installation works via Horizontal Directional Drilling (HDD) as part of the Priority Sewerage Program Appin Wastewater scheme.
In 1997, the NSW Government announced the Priority Sewerage Program (PSP) to address the health and environmental problems caused by un-sewered urban areas within the Sydney Water Corporation area of responsibility. The scheme has been rolled out over several townships with UEA having been previously involved in directional boring works in the Upper Blue Mountains, Freemans Reach, Hawkesbury Heights, Agnes Banks and Londonderry.
The Priority Sewerage Program provides sewerage services to unserviced towns and villages. The Program undertakes investigations, works and activities primarily to provide reticulated sewerage services to properties currently using on-site sewage treatment or collection systems.
The Program identified a need to provide a sewerage treatment scheme for the town of Appin, which is located to the South of Campbelltown. This scheme is known as the “Appin Wastewater Scheme” and involves construction of a new pressure sewerage reticulation and transfer system to service approximately 500 properties.
The scope-of-works under this Subcontract includes the detailed design, directional boring plans and construction of the transfer mains within a known mine subsidence area, inclusive of:
- pipe welding and pipe stringing,
- excavation of entry/exit pits,
- drill and reaming of bore,
- drill fluid capture and disposal,
- pressure testing, and
- restoration of affected areas.
In total over 3200m of transfer main will be installed via HDD through shale and rock. The directional boring process is ideal as the areas to be underbored include sensitive Cumberland Plain Woodland, pockets of heritage and Aboriginal significance and areas where grade requirements restrict traditional construction methods.