Potato Point Sewer Rising Main and Water Main Project

ABC Civil group were engaged by FB contracting to complete 5.3 kilometres of HDD conduit installation in rock at the Potato Point Sewage Pump Station, Sewer Rising Main, and Water Main Project in the Eurobodalla Shire located on the south coast of New South Wales.

The pipe sizes installed ranged from 75mm through to 160mm and were installed in bore lengths ranging from road crossings at 20 metres through to 150 metre bores within steep rocky terrain. The project required 4.74 kilometres of pipe to be installed within a national park with HDD being the methodology of choice to minimise the impact on the surrounding landscape and vegetation.

The national park posed significant difficulties with access only via steep terrain and unmaintained tracks through an easement created for existing overhead electrical assets. HDD launch and retrieval pits were excavated at the peaks and valleys of the hills and HDD rigs were located where access could be obtained.

Another complexity of the project was the disposal of approximately 1.5 million litres of drilling muds created through the five-month project duration. Given that the project was located on the far south coast, the nearest EPA approved liquid waste disposal facility is located in Nowra, which is a 7-hour round trip for our vacuum excavation trucks. As this was not a viable option for disposal, a fluid recovery system was setup onsite to recover drilling muds. Processing dirty muds and supplying the drill rigs with clean mud in a closed loop system, resulting in minimal liquid waste requiring disposal.